Lca Us Steel

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A

PROJECT REPORT

ON

LIFE CYCLE ASSESSMENT OF STEEL INDUSTRY

BY,

SWARUP MUKHOPADHYAY

INST ITUTE OF ENVIRONMENTAL MANAGEMENT & STUDIES

YEAR OF SUBMISSION 2003-04


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LIFE CYCLE ASSESSMENT

OF

STEEL INDUSTRY

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CERTIFICATE FROM THE GUIDE

This is to certify that project work titled Life cycle Assessment of Steel

Industry is a bonafide work carried out by Swarup Mukhopadhyay, a candidate for the

Post graduate Examination of Indian Institute of Ecology and Environment under my

guidance and direction.

SIGNATURE OF GUIDE:

NAME: DESIGNATION: ADDRESS:

DATE: PLACE:

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ENVIRONMENTAL, OCCUPATIONAL HEALTH & SAFETY POLICY

TATA STEEL REAFFIRMS ITS COMMITMENT TO PROVIDE SAFE WORK PLACE

AND CLEAN ENVIRONMENT TO ITS EMPLOYEES AND OTHER STAKEHOLDERS

AS AN INTEGRAL PART OF ITS BUSINESS PHILOSOPHY & VALUES. WE WILL

CONTINUALLY ENHANCE OUR ENVIRONMENTAL, OCCUPATIONAL HEALTH &

SAFETY (EHS) PERFORMANCE IN OUR ACTIVITIES, PRODUCTS AND SERVICES

THROUGH A STRUCTURED EHS MANAGEMENT FRAMEWORK. TOWARDS THIS

COMMITMENT, WE SHALL;

Establish and achieve EHS objectives and targets.

Ensure compliance with applicable EHS legislation and other requirement and go

beyond.

Conserve natural resources and energy by constantly seeking to reduce

consumption and promoting waste avoidance & recycling measures.

Eliminate, minimize and / or control adverse environmental impacts andoccupational health and safety risks through adopting appropriate State-of-the-art technology and best EHS management practices at all levels and functions.

Enhance awareness, skill and competence of our employees & contractors so as

to enable them to demonstrate their involvement, responsibility andaccountability for sound EHS performance.

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Date:31

st

January 2003 (B MUTHURAMAN)MANAGING DIRECTOR

ABSTRACT

The Iron and Steel industry is facing a serious challenge today both in the

developed countries as well as in the newly industrialized parts of the world. In India,

international competition has become sharper with many new players entering the arena

with high quality steel. There has been a simultaneous shift in consumer expectations with

regard to quality of products and services that a steel maker offers. In the present

scenario, the steel industry, as a highly material and energy intensive technology oriented

sector, not only needs to address the obvious questions of profitability, innovation and

adaptation to new technology but also has to refocus its attention on its overall

responsibility to the society in terms of environmental performance.

The pervasive nature of steel industry because of the magnitude of its operations

and its intensive use of energy and raw materials is readily appreciated by all and, so is its

potentially major impact on environment. A major portion of the raw-materials and other

resources used in steel making via the integrated production route get converted into and

discharged as polluted air, water and solid wastes at considerable energy and capital cost.

A material balance of a typical integrated steel plant indicates that the production of one

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tonne of finished steel product generates roughly 420 kg waste stream-mainly slag, dust

and sludges. Compared to its Western counterparts the Indian steel sector is beset with

problems of higher energy consumption (40GJ Vs 18GJ/tonne of crude steel); higher

pollution load (3-6kg of dust Vs 1kg/tonne of crude steel) and; higher raw material

consumption. This is probably so because many of the Indian plants were designed when

the cost of water, energy and raw materials was low and the need for effluent treatment

could be ignored. More importantly, designs were based on discounted cash flow

calculations with long term high running costs. Excessive water, energy and, raw material

usage seemed an acceptable price to pay for short term savings in initial capital investment

to procure rather outmoded technology and machinery.

The emergence of the first energy crisis in mid Seventies and the growing

awareness about the environmental accountability led to the search for new interventions

for improved productivity, profitability and resource optimization through Cleaner

Technologies. Management tools like Impact Assessment, Environment Audit, Life Cycle

Assessment and Natural Resource Accounting became widely accepted. LCA, in particular,

provides a new perspective on products and processes as it examines the industrial

systems and evaluates their performance starting from the extraction of raw materials

through all the varied operations until their final disposal as wastes back into the

ecosystem. By this Cradle to Grave approach LCA provides an objective diagnostic tool to

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take strategic market decisions, material choices, policy initiatives, environmental bench

marking and uncover trade-off.

An LCA study involving three integrated steel plants in collaboration with the

Ministry of Environment & Forests was initiated in 1997 in India. This paper presents the

methodology adopted, relative performance of our steel sector in relation to International

Bench Marks regarding raw material and energy consumption per unit of crude steel,

emissions generated and estimated as per the common basis of measurement suggested in

the global study etc. Requisite interventions emerging from the study are also detailed

with emphasis on integration of the upstream processes, switch over from end-of-the pipe

treatment to cleaner production initiatives, improvements in house-keeping, up gradation

of skills and reorientation of marketing and decision making policy and processes etc.

Special attention is given to handling and management of wastes and, therefore, wastes

minimization initiatives through recycling and reuse for promoting Cleaner Production.

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CONTENTS

I TITLE PAGE

II CERTIFICATE

III, IV, V ABSTRACT

VI, VII, VIII CONTENTS

IX LIST OF TABLES

X LIST OF FIGURES

XI NOMENCLATURE

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CHAPTER TITLE PAGE No.

1.0 INTRODUCTION (1-7)

1.1 LIFE CYLCE ASSESSMENT 1

1.2 STEEL AND SUSTAINABLE DEVELOPMENT 2

1.3 LCA AS AN ENVIRONMENTALTOOL5 5

1.4 BASIC FRAME WORK OF LCA 7

2.0 LITERATURE REVIEW (8-17)

2.1 LCA AND THE STEEL INDUSTRY:INITIATIVE AT IISI 8

2.2 NEED FOR AN LCA STUDY FOR THE INDIAN STEEL SECTOR 9

2.3 OBJECTIVES OF THE INDIAN STEEL SECTOR STUDY 12

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3.0 LIFE CYCLE ASSESSMENT OF THE INDIAN STEEL INDUSTRY (18-26)

3.1 ENERGY USAGE 20

3.2 WATER USAGE TREND 20

3.3 ENVIRONMENTAL PERFORMANCE OF STEEL 20

3.4 MATERIAL RECYCLING AND REUSE 24

3.5 FUTURE CHALLENGES 26

CONTENTS (CON)


4.0 LIFE CYCLE ASSESSMENT OF THE US STEEL INDUSTRY (27-70)

4.1 MACRO ECONOMIC LOOK AT STEEL MAKING 27

4.2 GENERAL 28

4.3 PLANT CATEGORIES 28

4.4 GROWTH TRENDS 29

4.5 INVESTMENT 32

4.6 INDUSTRIAL FINANCIAL PROFILE 32

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4.7 LCA STUDY OF STEEL INDUSTRY 33

4.8 GOAL AND SCOPE 33

4.9 INTEGRATED STEEL PRODUCTION PROCESS 34

4.10 INVENTORY OF INTEGRATED STEEL MAKING 37

4.11 IMPACT ANALYSIS FOR INTEGRATED STEEL MAKING 49

4.12 ALTERNATE WAYS OF STEEL MAKING 50

4.13 INVENTORY OF SEMI-INTEGRATED STEEL MAKING 51

4.14 IMPACT ANALYSIS FOR SEMI-INTEGRATED STEEL MAKING 594.15 INTEGRATED VS SEMI INTEGRATED, COMPARISION 60

4.16 IMPROVEMENT ANALYSIS 67

4.17 ACTIVITIES INCLUDE 70

CONTENTS (CON..)


4.18 CONCLUSION 70

5.0 REFERENCES 71

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LIST OF TABLES

TABLE NO. TITLE PAGE NO.

NATURAL RESOURCE CONSUMPTION PER TON OF STEEL

16

2.1 IMPORTANT INFLOWS AND OUTFLOWS PER TONNE OF 17

STEEL MAKING SYSTEM

4.1 INPUT INVENTORY FOR INTEGRATED STEEL PRODUCTION 42

4.2 TOXIC RELEASE INVENTORY CHEMICALS FOR STEEL (44-47)

MAKING FACILITIES

4.3 INTEGRATED SLAG OUTPUT 48

4.4 BLAST FURNACE AND STEEL MILL AIR POLLUTANT 49

EMISSIONS

4.5 INPUT INVENTORY FOR SEMI-INTEGRATED 53

STEEL PRODUCTION

4.6 TOXIC RELEASE INVENTORY CHEMICALS FOR SEMI- (54 57)

INTEGRATED STEEL

4.7 SEMI-INTEGRATED SLAG OUTPUT 58

4.8 BLAST FURNACE AND STEEL MILL AIR POLLUTANTS 58

EMISSIONS

4.9 INTEGRATED VS SEMI-INTEGRATED INPUT COMPARISION 62

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4.10 TOXIC RELEASE INVENTORY CHEMICALS COMPARISION (63-66)

LIST OF FIGURES

FIGURE No. TITLE PAGE No.

4.1 RAW STEEL PRODUCTION BY FURNACE TYPE 31

4.2 TYPICAL FLOW OF INTEGRATED STEEL PRODUCTION 36

NOMENCLATURE

AISI American Iron and Steel Institute

BOF Basic Oxygen Furnace

BSP Bhilai Steel Plant

CDQ Coke Dry Quenching

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DIOS Direct Iron Ore Smelting

EAF Electric Arc Furnace

EIA Environmental Impact Assessment

EPA Environmental Protection Agency

IISI International Iron and Steel Institute

LCA Life Cycle Assessment

LCI Life Cycle inventory

NERI National Environmental Research Institute

NRA Natural Resource Accounting

OHF Open Hearth Furnace

PCI Pulverized Coal Injection

RINL Rashtriya Ispat Nigam Limited

TRI Toxic Release Inventory

JIT Just in time

CHAPTER-1

INTRODUCTION

1.1 LIFE CYCLE ASSESSMENT

Life cycle assessment is a technique used to assess potential environmental,

economic and technical implications associated with a specific product or service. This

type of assessment has become a valuable tool for producers studies in industrial ecology

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and with the rising popularity of practicing product stewardship. Product stewardship

involves designing, building maintaining, and recycling products in such a way that they

pose minimal impact to the wider world. (Graedel, 1995) As defined by the Society of

Environmental Toxicology and Chemistry, an LCA is as follows:

The life-cycle assessment is an objective process to evaluate the

environmental burdens associated with a product, process, or an activity by

identifying and quantifying energy and material usage and environmental releases, to

assess the impact of those energy and material uses and releases on the environment,

and to evaluate and implement opportunities to effect environmental improvements.

The assessment includes the entire life cycle of the product, process or activity,

encompassing extracting and processing raw materials; manufacturing, transportation,

and distribution; use/re-use/maintenance; recycling; and final disposal.

(Graedel, 1995)

This type of analysis is a very large and detailed one, and can typically be defined

into a series of steps. The first very important part of the study is defining the goal and

scope of the project, this gives a detailed overview of the process, product or activity, and

which parts will be focused on in the analysis. Also in defining the goal and scope of the

project, who, where and how the study will be conducted are key points that need to be

defined. After defining the goal and scope, there are three formal steps in the analysis.

These steps include: inventory analysis, compiling an inventory of relevant inputs and

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outputs; impact analysis, evaluating the potential environmental impacts associated with

those inputs and outputs; and improvement analysis, interpreting the results of the

inventory and impact phases in relation to the objectives of the study.

1.2 STEEL AND SUSTAINABLE DEVELOPMENT

Steel is essential for economic development and its versatile range of physical

properties and chemical resistances make it the main structural and engineering material

in different sectors of development. Steel is a strong material and is continuing to provide

benefits to society through safe, environmentally responsible and durable products.

The starting point for the production of steel is the smelting of iron ore in a blast

furnace, which uses coal in the form of coke to reduce iron ore to molten iron. These

process alone uses 70 per cent of the total energy used in steel making. Molten iron is

converted into a range of applications in a Basic Oxygen Furnace (BOF) which uses the

rapid injection of oxygen to remove the excess amount of carbon and silicon in the iron.

Liquid steel at over 16000 C is then cast into different shapes before passing through a

series of finishing mills to give it its final dimensions and mechanical properties. The

recycling of scrap in an electric arc furnace (EAF) also produces steel.

Some 25 years ago, steel making was at its zenith. Steel making was a highly

profitable and vital component of national economies. Integrated steel production was the

norm, while scrap based production using electric arc furnaces was confined to the lowest

grades of steel and played only a marginal role. Today the situation is rather different.

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There is a significant shift in the geography of steel making. In 1900, the USA was

producing 37% of the world steel. With post war industrial development in Asia, this

region accounts for almost 40 % with Europe producing 36% and North America 14.5 %.

There are over 350 steel companies, which have a steel making capacity of half a million

tonne or more per year. Today, on a worldwide basis, over two thirds of the steel is

produced through the blast furnace route. The blast furnace is a very efficient mechanism

for making virgin iron units. However, its role in the developed world will decline, as

environmental pressures will force continued reduction in the use of coal reserves for coke

making. In addition, the capital costs required to refurnish or build new blast furnaces will

mean the gradual reduction in the number of ones which are operating.

On the other hand, the electric arc furnace route of steel making has lower capital

costs per tonne of output, works on a variable cost basis and can be increasingly supported

in the future through supplements to scrap in the form of alternative iron units produced

through direct reduction processes. The size of this industry will be significant in the

years to come.

Over the course of the twentieth century, production of crude steel has risen at an

astounding rate, now fast approaching a production level of 800 million tonnes per year.

Our present time has brought in additional changes and challenges for virtually all-

industrial activities. The steel industry too is facing a challenging time, although the

precise nature of these challenges is different in different parts of the world. Steel use

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strongly reflects major economic forces .Put simplistically, steel use (and hence

production) increases when economies are growing as Governments invest in infrastructure

and transport, building and industry. Economic recession meets with the dip in Steel

production as such investments falter. (IISI, 2001)(1). In India too, international

competition has become sharper with many new players entering the arena with high

quality steel. Concomitant with these developments there has been a simultaneous shift in

consumer expectations with regard to quality of products and services that a steel maker

offers. All the enterprises in the chain from raw material extraction to the consumer are

putting emphasis on cycle time reduction, increased efficiencies in the manufacturing

process, increased emphasis on ''just in time,'' and cleaner production.

In the present scenario, the steel industry, as a highly material and energy

intensive technology oriented sector not only needs to address the obvious questions of

profitability, innovation and adaptation to new technology, but also has to refocus its

attention on its overall responsibility to the society in terms of environmental

performance.

1.3 LIFE CYCLE ASSESSMENT AS AN ENVIRONMENTAL TOOL

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The search for innovation and cost effective ways to improve industry's

performance has led to the development of a wide array of concepts, and management

tools for decision making. Tools such as Impact Assessment, Environmental Audit, Life

Cycle Assessment (LCA) and Natural Resource Accounting (NRA) are, therefore, becoming

increasingly useful for objective analysis related to policy strategies development, product

policy development, business strategies including investment plans and product and process

design etc. These instruments can be used by the industry either to better design and

manage its operations and products; or by the Government to lead the industry towards

resource optimization and Cleaner Production. Environmental Impact Assessment (EIA)

was one of the first such tools developed to predict the impacts of new industrial

facilities on the environment. Today EIA has become mandatory in many countries,

including India. EIAs, however, have their limitations. Since, an environmental impact

assessment considers potential environmental effects during the planning phase before

the operations actually start it essentially projects a scenario, which can hopefully be

achieved. With experience, industry managers and governments have discovered that this

is not enough, and that a wider tool basket is needed to support informed decision making

in response to increased regulatory and public pressure, and demand for a cleaner

environment.

Life Cycle Assessment (LCA) or commonly known "Cradle to Grave" analysis, has

emerged as a powerful analytical tool for material development and product substitution to

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meet the twin objectives of resource optimization and sustainable development. Steel

fraternity world over is engaged in developing rigorous methodologies to appropriately

utilize this tool to uphold the competitive position of steel in the world market. Most

studies have so far been in the Western world where LCA is attracting attention in

response to devising product promotion strategies, meeting customer demands, and

anticipating competitor reaction, Government pressure and process/environmental

benchmarking.

LCA is a new way of looking at products and processes. Also called Ecobalance, it

essentially seeks to determine the impact of a product or a process on the environment

through its entire life cycle from the cradle to the grave. It, however, has its origins in

the premise that the only sensible way to examine industrial systems is to examine their

performance starting with the extraction of raw materials through all the varied

operations until their final disposal as wastes back into the ecosystem (cradle to grave). By

seeking to consider comprehensively the issues associated with the production, use,

disposal and recycling of products including the materials from which they are made and

assessing the burdens assignable to these over their entire life cycle, LCA provides an

objective analysis to make strategic market decisions, material choices, policy initiatives

and uncover trade offs.

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1.4 BASIC FRAMEWORK OF LCA

A review of international practices in the field of LCA indicates that the standardized

framework being promoted as code of practice comprises of a four-step process:

1. Goal definition

2. Inventory analysis or life cycle inventory (LCI)

3. Impact assessment and

4. Improvement analysis

The starting step for any LCA is goal definition and scooping. It involves defining

the scope of the study, the identification of the boundaries, the functional unit of the

study as also the identification of the target group for whom the study is intended. The

next step i.e. the LCI phase (the drawing up of a process tree, filling in the process data

and drawing up an intervention table) is the most crucial step in an LCA exercise. An LCI is

essentially the backbone of any LCA and requires an exhaustive listing and quantification

of energy and raw material requirements, air emissions, effluents and other environmental

releases. A number of advanced models are available which help divide the industrial

system into specific unit operations which can each be studied and linked back together to

form the complete life cycle datasheets for any individual system. The raw output from

the model provides enormous amount of data, which can be overwhelming for the average

user. It is, therefore, necessary to aggregate the data according to known and significant

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impact indicators. These issues are taken care of in the impact assessment and

improvement analysis phases of the study.

CHAPTER-2

LITERATURE REVIEW

2.1 LCA AND THE STEEL INDUSTRY: INITIATIVES AT IISI

LCA has been a topic of growing interest to the steel industry. Several steel

companies and associations have already independently carried out LCA studies, each

different in purpose, system boundary and methodology. The International Iron and Steel

Institute (IISI), Brussels, embarked on an ambitious global LCI study on steel industry

products in 1997 with the primary objective of building a data base and developing a

common worldwide methodology for cradle to gate steel product LCIs across member

companies within IISI. An exercise of this magnitude is considered to be the first of its

kind undertaken globally for life cycle assessment of any material. The principal aims of

the project were to

5. Produce worldwide LCI data for steel industry products

6. Assist industry benchmarking and environmental improvement

Programs.

7. Provide a basis for carrying out impact assessments

8. Obtain life cycle information requested by customers

9. Support communication with industry stakeholders

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10. Support response to environmental claims against steel and

11. Train industry in the field of life cycle assessment.

2.2 NEED FOR AN LCA STUDY FOR THE INDIAN STEEL SECTOR

The pervasive nature of the steel industry because of the magnitude of its

operations and its intensive use of energy and raw materials is readily appreciated by all

and, so is its potentially major impact on the environment. A major portion of the raw

materials and other natural resources used in steel making get converted into and

discharged as polluted air, water and solid waste at enormous energy and capital cost.

Steel production involves various processes that result in extensive consumption of

natural resources as shown in Table 2.1

A material balance of a typical integrated steel plant indicates that the production

of one tonne of finished steel product generates roughly 420-kg waste stream-mainly slag,

dust and sludge.

Two and a half decades ago, when steel making was at its peak, and major

expansions were planned every where, energy and environmental considerations were

secondary. However, with the first energy crisis in the mid 70's the situation changed.

Energy considerations became quite important and environmental issues occupied center

stage. The steel processing technology has undergone changes in order to adapt to these

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new requirements. There has been major improvements in energy utilization efficiency,

labor productivity and pollution control, over the last two decades.

Compared to its western counterparts, the Indian steel industry is beset with

problems of higher energy consumption (40 GJ Vs 18 GJ/tonne of crude steel), higher

pollution load (3-6 kg of dust Vs 1 kg/tonne of crude steel) , and higher raw material

consumption. This is probably so, because many of the Indian plants were designed when

the cost of water, energy and raw materials was low and the need for effluent treatment

could be ignored. More importantly, designs were based on discounted cash flow

calculations with long term high running costs. Excessive water, energy and raw material

usage seemed an acceptable price to pay for short term savings in initial capital investment

to procure rather outmoded technology and machinery. The need for technological

intervention in the steel sector can be illustrated using energy inputs in the steel industry

as an example. In India the steel industry accounts for nearly 35% of the total energy

consumed by the industry. Since steel in India has been traditionally produced through

the conventional BF-OHF/BOF route, nearly 67% of the energy in this process is consumed

up to the iron making stage with rolling mills and steel making accounting for another 14%

& 8% respectively. Moreover poor quality input energy especially coal results in higher

specific energy consumption .In fact in the Indian integrated steel plants, 14.3% of the

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steel is still being made through the energy inefficient Open hearth steel making process

with energy consumption ten times more than the BOF process. With over 50% of the

steel still being cast through the ingot casting route, the energy burden gets tremendously

increased. Similar scenarios are available for raw material consumption and pollutant

release from the steel making processes. This is a clear pointer towards the need to

address a number of technology - related issues in the steel sector through integrative

and diagnostic tools such as LCA so that timely interventions can help steel companies to

increase their profitability and improve the quality of their products.

Optimal utilization of natural resources is now imperative for sustainable

development and this is all the more necessary in the case of developing countries where

development operations are still accompanied by avoidable waste of minerals energy, water

and manpower. Considering that the concept of LCA could be gainfully used for drawing up

raw material, energy conservation as well as pollution control and waste recycling plans in

such a key sector such as steel, the first multiinstitutional and multidisciplinary LCA study

for the steel sector was launched by the Ministry of Environment and Forests in India in

1997 with the active participation of three integrated steel plants namely, Bhilai Steel

Plant (BSP) of the Steel Authority of India Ltd. (SAIL), Tata Iron & Steel Co. (TISCO)

and Rashtriya Ispat Nigam Ltd. (RINL) along with leading national consultants in the field

of environmental engineering and steel technologies namely, MECON, Dastur Co and

National Environmental Engineering Research Institute (NEERI). The study also envisaged

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active interaction with the International Iron and Steel Institute (IISI) and Ecobilan,

Paris- leading international LCA consultants.

2.3 OBJECTIVES OF THE INDIAN STEEL SECTOR STUDY

The main objectives of this study are to:

1. Devise protocols for Life Cycle Assessment for steel and to generate

databases and a widely applicable methodology for Life Cycle

Assessment of steel that could

1. Serve as a quantitative baseline for the producers and manufacturers

to assess the environmental consequences of potential process changes

and improvements.

2. Provide ways and means to reduce energy consumption per tonne of

steel manufactured

3. Provide guidance in pollution prevention programs through waste

reduction and resource conservation opportunities

4. Guide product process technology choices compatible with region

specific factors

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2.4 METHODOLOGY

The first multi disciplinary, multi institutional LCA study for the Indian Steel

Sector was evolved through several brainstorming sessions with the top management of

the three steel plants, Ministry officials and the consultants. The jointly funded study

was then launched simultaneously at the three steel plants as per the following schedule

STAGE 1: GOAL DEFINITION AND METHODOLOGY DEVELOPMENT

1. Formation of a Central LCA Core Group within each participating institution

2. Formation of LCI field teams at each participating steel plant site including

mines.

3. Appointment of an LCA Manager (Nodal Officer) at SAIL, TISCO & RINL.

4. Modeling of the steel industry processes at each site, breakdown into

independent, discrete process units (modules), define process unit boundaries

and define input/outputs at the boundaries of each process unit etc.

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5. Application of LCI methodology rules to steel industry

STAGE 2

1. Procurement of software from M/s Ecobilan, Paris

2. Installation and operationalisation of software at participating institutions

STAGE 3: DATA BASE BUILDING (LCI)

1. Questionnaire distribution to LCA field teams drawn from different process

units from the cradle to steel gate

2. Data collection on site by the steel industry personnel & consultants

3. Entering and treatment of data on a computer based LCI/LCA software

(TEAM)

4. Production of LCI spread sheets

STAGE 4: TRAINING SESSIONS

1. Training & Interactive Sessions with Ecobilan Experts for Gap Analysis using

Ecobilan Model

STAGE 5: CREATION OF ECOBALANCES

2. Validation of Results

3. Impact Assessment & Improvement Analysis

4. Report Preparation

The study is a study which covers all the production steps from

raw materials in the earth to the steel gate. Within the scope of the study the system

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function has been defined as the production of crude steel at the factory gate. The

functional unit, which enables the system performance to be quantified, is 1 Kg of crude

steel at the factory gate. The plant have also used the LCA methodology to inventorise

product specific data relating to the production of slabs, billets sections and rails

depending on the plant specific product mix.

The steel product manufacturing system encompasses the activities of the steel

making process and all major upstream and downstream processes for the intermediate

products, including the production and transportation of raw materials, energy sources and

consumables on the steel works.

Terminology has been developed for the various system components as

follows. The 'Route' refers to the full cradle to grave system including upstream supplies,

transport and by-products credits. 'Site ' refers to the steel works boundaries. 'Modules'

are the component unit processes within 'Site' and the 'Route'. Site data were collected

with the custom designed questionnaires available with TEAM. The questionnaires were

organized for all process stages and ancillary units including the power plants, oxygen

plants, etc, each of which contained lists of material and energy inputs, air and water

emissions, waste products and by -products etc. The participating plants have made

important assumptions depending upon the site-specific conditions prevailing at each site.

There are some differences in the process parameters, facilities and capacity of the

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individual process units between the years 1997-98 and 1998-99 which have a marked

impact on the LCI results obtained at the sites.

The external consultants associated with the respective steel plants participating

in this study carried out data validation for the years 1997-98 and 1998-99. Checking the

shop wise log sheets and secondary data was checked using various audits at the steel

plants namely, the Energy Audits, Emission Audits, Performance and Technology Audits did

primary data validation. Data gaps found were clarified and the verified data for the years

1997-98 and 1998-99 was supplied to the steel plants for a final Ecobilan run.

NATURAL RESOURCE CONSUMPTION PER TONNE OF STEEL

Iron ore 1.6t

Coking coal 1.3t

Non coking coal 0.4t

Limestone 0.3t

Dolomite 0.1t

Water 10.0 m3

Energy 8.5 G CalAir 1800 m3

Table 2.1:NATURAL RESOURCE CONSUMPTION PER TON OF STEEL PRODUCTION

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Inflows Unit Global Average 1997-98 1998-99

Iron ore T 1.42 1.47 1.48

Coal T 0.599 0.91 0.96

Limestone T 0.0 -0.03 -0.16

Dolomite T 0.025 0.015 0.2

Middling coal T - 0.191 0.246

Scrap T 0.140 0.05 0.049

OutflowsWaste(Total) T 0.021 0.325 0.246

Scrap sold T - 0.09 0.084

Carbon Dioxide Kg 1921 2562 2902

Energy

Feed stock energy MJ - 14410 10900

Fuel energy MJ - 14730 17523

Total primary Energy MJ 22482 29142 28430

Other Emissions

NOX Kg 2.153 2.27 1.82

SOX Kg 2.354 3.16 3.06

Particulates Kg 1.482 2.28 2.08

CHAPTER-3

LIFE CYCLE ASSESSMENT OF THE INDIAN STEEL INDUSTRY

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TABLE 2.2: IMPORTANT INFLOWS AND OUTFLOWS PER TONNE OF STEEL MAKING SYSTEM


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Some of the emerging trends in the Indian steel sector are briefly discussed below

along with the identification of the technological interventions required at the process

stages.

3.1 ENERGY USAGE

Steel is a major user of energy. Steel industry consumes directly and indirectly

(upstream included) 1.80 x10GJ which equates to 5.5 % of global energy consumption. In

the case of Japan for e.g. the steel industry accounts for over 10% of total energy

consumption. As a consequence, the focus on energy efficiency has been very strong and as

a result, savings of nearly 20 % in total specific energy consumption have been achieved

since the 1970's in major steel plants around the world. This is the result of a number of

factors namely:

1. Replacement of obsolete steel making such as open hearths (OH)'s with (BOF)

and EAF.

2. Replacement of ingot casting with the continuous casting of steel (the % of

Continuous cast steel in the Western World has increased from 10% in 1970

to over 80% now).

3. Installation of waste heat recovery units on major production units such as

Sinter strands, blast furnaces, BOF, reheating furnaces and optimization of operating

practices & rationalization of products.

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The results of the Life Cycle inventory calculated for one tonne of product

(slab/billet) at Plant A for the years 1997-98 and 1998-99 have been presented. The

global averages of 26 sites for the year 1994-95 culled out of the IISI study have also

been included in the same table for comparison.

The LCA results for the Indian steel sector study show that the total primary

energy consumption at the steel plants is within the range of world consumption The

average energy consumption is, however, high compared to the regional and world averages.

Results show that despite the increase in the cost of various energy inputs such as coal,

power petro-fuel etc, the energy cost per tonne of saleable steel has dropped by 2.27%

due to reduction in specific energy consumption at TISCO. Some of the contributing

factors for this quantum reduction at the steel plant have been the reduction in the fuel

rates in the blast furnaces, reduction in the specific petro fuel consumption by 35%,

reduction in the specific petro fuel consumption for turbo blowers, higher boiler

efficiencies, use of cleaner & more energy efficient technologies such as concast over

ingot casting resulting in saving of 0.5-0.8Gj/tonne of crude steel, programmed ladle

heating control etc.

Trends indicate that it is possible to further bring down the energy consumption by

nearly 18% up to the hot metal stage and 60% in the rest of the areas through use of both

short term and long term measures.

3.2 WATER USAGE TRENDS

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The iron and steel industry uses water for direct and indirect cooling, for gas

cleaning and for process reagents. As a consequence, there is demand for water

throughout steel production i.e. raw material handling/preparation sintering/palletizing,

coke making, blast furnace iron making, BOF/EAF steel making, continuous casting, hot

rolling, pickling/cold rolling/annealing/tempering, coating and ancillary operations such as

power and steam generation. In terms of pollutant control, a high recycling ratio is

essential. Many companies operate highly integrated recycling systems aimed towards

reducing water consumption and discharge volumes. Trends indicate that it is possible to

achieve water-recycling rates of more than 95 % .At TISCO, a substantial decline in water

consumption from 25.9 m3/tcs in 1990-91 to 10.93m3/tss in 98-99 has been achieved. In

just one year (1998-99) resource conservation interventions at TISCO have brought down

the water consumption by nearly 4 %. At Bhilai steel plant, the interventions identified

have brought down the water consumption to 5.28m3/tcs making it one of the best

internationally.

3.3 ENVIRONMENTAL PERFORMANCE OF STEEL

3.3.1 RAW MATERIALS

Coal, iron ore and recycled Steel (scrap) dolomite/limestone are the basic raw

materials for steel production. Raw Material consumption and conversion in steel making

processes can be measured through estimations of yield. Since, no process can be 100 %

efficient, production of one tonne of steel in an integrated steel plant requires several

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times that quantity of raw materials. Range of yields for some selected steel processes

(BOF steel making (86-95%); continuous casting (76.6-98%); Hot rolling (84.5-98.8%)

pickling, cold rolling, annealing, tempering (82.4 - 93%) and coating (plates - 74.1-94.8%)

reveal areas where significant improvements can be brought about through identification

of factors affecting yield and measures to contain yield loss (Kakkar, 1998)(3).

LCI results indicate general trend of increased resource use as products undergo

further processing from simple to more complex products. In mass terms, the IISI

results indicate that iron ore and coal consumption dominate the resource use via the BF

route. As can be seen in Table 4, the average consumption of coal is high at Plant A for the

years 1997-98 and 1998-99 as compared to the global average. Possible reasons for these

high values are the high coke rate in the blast furnaces and the grid electricity supply

from the thermal power plants.

Emerging trends in the Indian study reveal that the raw material consumption in

the iron and steel industry can benefit significantly through use of cleaner technology

interventions in the coke making and BF stages. Use of technologies such as direct coal

injection using non coking coal into the blast furnace alone is likely to extend the horizon

for coking coal reserves by hundred of years. Advanced technologies such as stamp

charging and PBCC which can use inferior grade coking coals efficiently in place of prime

coking coal reserves can play an equally significant role in resource conservation and

optimization in the steel sector.

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3.3.2 AIR POLLUTION CONTROL - EMERGING TRENDS

The steel industry of the 1950's and the early 1960's was a major source of

pollution, particularly air pollution in the densely populated areas in which steel production

is concentrated in Western Europe, North America and Japan. Addressing the problem of

air pollution has accounted for over 50 % of total expenditure on environmental control by

the steel industry over the last two decades. Initially, in the western steel plants, the

problem was tackled through retrofitting of gas and dust collection systems to existing

plants. Later, there was a perceptible shift towards replacement of obsolete plants with

newer facilities, which incorporate in their design and operation, the best currently

available environmental practice. In Germany, for example, emissions have dropped from

9.3 kg/ton of crude steel or over 300,000 tons of material in 1960 to 2.4 kg/ton by the

late 1970's and below 1 kg/ton today. Investments to remove dust emissions have gone

alongside removal of gases such as nitrogen oxides and sulfur dioxide. It is estimated that

over the last decade, over 10% of the total capital expenditure by the steel industry on

such environmental control have been over $20, 000 million.

In contrast, the situation in the steel industry in the so-called " developing

countries has been very different. The late 50's and the early 60's saw a period of rapid

industrialization in India. The demand for steel (required for "progress") outstripped the

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supply by a large margin. The production of large quantities of steel was the primary

objective; environmental pollution and concerns did not really figure on the agenda.

The IISI study shows escalating emissions with rising product complexity, broad

similarities among BF steel products and greater emissions for BF over EAF production. In

general, the ore based process requires more material and energy inputs to its operations

and gives rise to greater emissions than the scrap-based process. LCI analysis indicates

that it is possible to bring down stack emissions per tonne of product through closure of

polluting units and adoption of cleaner technologies. The suspended particulate matter in

stack emissions at TISCO, for example, has shown a downward trend from 6.75kg/tcs in

1995-96 to 3.0kg/ tcs in 1998-99. At SAIL although older technologies might still be in

use, ecofriendly, energy conserving and cleaner technologies under the modernization

programmes initiated in the recent past are leading to tangible benefits in terms of

reduction in pollution load at the steelworks. At Bhilai steel plant, replacement of the

single conversion single absorption Sulphuric acid plant with a double conversion double

absorption plant has brought down the SO2 emissions from 10-12 kg/ tonne to nearly

1.71kg/ tonne of acid produced. Replacement of OHF's by BOF has brought about twin

benefits of energy conservation and pollution prevention .

3.3.3 CO2 EMISSION

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A number of countries are considering programmes to control the emissions of the

'greenhouse gas ' carbon dioxide despite the scientific uncertainty over the magnitude of

the, causes and consequences of global warming. With regard to the steel industry it has

been long recognized that carbon inputs (& therefore CO2 outputs) are required as

chemical feedstock (reductants) and for energy units. Trends indicate that the carbon

consumed (& CO2 released) by the EAF route is substantially less than that for the BF

route .The data presented in Table 4 indicates that the CO2 emissions in case of Plant A

are much higher than the world average. Possible reasons include higher coke rates,

associated with the use of high ash coking coal blends supply of grid electricity from the

thermal power plants etc. For the BF steelmaker the most significant improvements are

likely to come from the cleaner technologies such as pulverized coal injection (PCI), dry

quenching of coke (CDQ) and coke moisture control. These are likely to lead to carbon

equivalent savings of 6%, 5% and 1.5% respectively. The Indian steel plants are integrating

these emission reduction strategies into their modernization packages so that the twin

objectives of resource optimization and pollution containment can be simultaneously met.

3.4 MATERIAL RECYCLING AND REUSE

Steel is 100% recyclable, and is the world's foremost recycling industry. It can be

repeatedly used without downgrading to a lower quality product. On a world basis, the

recycling ratio of steel (defined as the ratio between the total quantity of scrap arising

and the actual quantity of scrap recycled) is estimated to be about 80%. Steel is recycled

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in both electric arc and basic oxygen steel making and in the former it represents between

90% and 100% of the raw materials charged while in the latter it constitutes up to 30%.

By recycling nearly 300mt of scrap each year, the steel industry does not have to extract

475mt of iron bearing ores, saves energy equivalent to 160mt of hard coal and avoids CO2

emissions of 470mt. The IISI study confirms that the energy required to produce scrap

based (EAF) steel is less than to produce ore based (BF) steel. However, the recycling of

scrap as an integral part of the BOF route must not be overlooked or underrated. The

scrap recycled via the BOF plant is effectively replacing the energy and emissions

associated with the hot metal produced via the blast furnace route. Multiple recycling

scenarios in the context of the Indian steel sector study are being worked out. An

integrated steel plant can produce up to 500-700 kg of byproducts and sludge for every

tonne of steel. The largest volume of by-products is slag, followed by other solid residues,

gases and chemicals. On an average 90% of the BF and 70% of the steel melting slags can

be put to use. It is estimated that replacing every tonne of Portland cement with blast

furnace cement brings about a reduction of 96kg of CO2 emissions. The utilization of the

steel plant wastes at the Indian plants has tremendous scope for improvement The waste

generation figures have improved in the years 1998-99 due to an increase in the amount of

BF slag used for steel making and cent percent utilization of BOF sludge in sinter making

and increase in the amount of flue dust being sold off to outside parties.

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At SAIL, efforts towards byproduct management have been intensified in the

recent past. Principals among these are, setting up of cast house slag granulation facilities,

use of LD slag as railway track ballast and use of wastes such as iron fumes, coke breeze,

mill scale as recycled inputs in the blast furnace. Around 70-75% sinter is used in the

blast furnace cutting down on precious coke consumption. As a result of these measures,

the solid waste utilization at Bhilai steel plant has shown an upward trend with nearly 59%

of the wastes being put to constructive use.

3.5 FUTURE CHALLENGES

The challenges posed by a competitive market are forcing steel makers to switch

over to cleaner production by adopting the best practices at each stage in the life cycle of

steel making. This shift may be gradual but is unmistakable. Heavy investment

programmes, top management support, employee education and training are all contributing

towards enhanced environmental performance. It is hoped that in the coming years, the

use of new and innovative management tools such as LCA will increase. The Indian Steel

sector study will surely emerge as a path-breaking endeavor in this direction.

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CHAPTER-4

LIFE CYCLE ASSESSMENT OF THE U.S. STEEL INDUSTRY

Thanks to natures abundance supply of iron ore, bituminous coal and limestone,

steel has become mans most useful servant. Steel is the most adaptable material at the

command of man; it can be made hard enough to cut glass or as pliable as the steel wire in

a paper clip. It can be made springy as the steel in springs or strong enough to withstand a

pull from extremely high weights. It can be welded into pipe over twelve feet in diameter

or as small as one-fiftieth of an inch in diameter for hypodermic needles. Steel can be

made resistant to heat, rust and chemical breakdown. So important is this basic metal to

modern American life approximately one out of every four persons lives in a community

where there is a plant of the iron and steel industry. What may be most impressive is its

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ability to be recycled. This paper will provide a background of the steel industry by giving

a macroeconomic snapshot of the industry, followed by a detailed life cycle assessment,

and finally a comparison between integrated and mini-mill technology in regard to total

environmental impacts.

4.1 MACRO ECONOMIC LOOK AT STEEL MAKING

To provide background for completing a life cycle assessment for the steel

industry, we should first look at macroeconomic trends in the industry. This will be helpful

in understanding how the steel mill fits in with the rest of the economy, by illustrating how

the industry interacts in the world economy. This section will be broken down into five

subtopics. First will be the introduction or general background, second will be plant

categories, third will be growth trends, fourth will be investments, and lastly we will talk

about the industry financial profile.

4.2 GENERAL

The United States has consistently ranked in the top two among world producers of

steel, and this trend doesnt look to be changing any time soon. Although the United

States is among the top two producers of steel there production has diminished over the

years. In 1950 the United States produced nearly 50% of the worlds steel, but by 1973

that number dropped to only 20%. (Little, 1975) About 130 steel-making plants account

for the production of raw steel in the United States. Grouped together with associated

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steel rerolling and steel finishing plants, the U.S. industry is composed of some 400 plants

employing approximately 500,000 people in 37 states. (Little, 1975)

4.3 PLANT CATEGORIES

Raw steel making plants can be categorized into three main groups, but for the

purpose of this paper we will discuss only two of them, integrated and semi-integrated

steel mills. Both iron and steel-making operations are dealt with in the integrated process.

Integrated plants normally start with iron ore and coking coal, these are then heated in a

blast furnace to produce molten pig iron (or hot metal). Along with any scrap, the molten

pig iron is then charged into steel-making furnaces, which as a result molten raw steel is

produced. This raw steel is then fabricated to finished steel products.

Because of the economic advantages and flexibility of operation, most semi-

integrated plants in the United States use electric arc furnaces. Unlike the integrated

plants, the semi-integrated plants charge cold metal raw materials. These materials

include scrap, pig iron and sponge iron made by direct reduction. The materials are then

melted down and refined in the steel-making furnaces. Small semi-integrated plants also

known as mini-mills are included in this category as well. These mills limit their production

to bar mill products, rebars and merchant bars. Because of there size, mini- mills have

annual capacities of less than 200,000 tons. (Little, 1975)

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4.4 GROWTH TRENDS

Assuming that U.S. steel requirements continue to grow, and as long as the U.S. iron

and steel industry continues to supply the domestic demand, raw steel production will

continue to grow as well. Analyzing some statistics from the American Iron and Steel

Institute annual statistical reports can easily show this. We have focused our study on

shipments by market classification and U.S. raw steel production. We would like to

specifically analyze the total raw steel production of integrated plants vs. mini-mills, and

how shipment to market classification has evolved, showing these statistics over time

(1950-present).

We first looked at U.S. raw steel production statistics provided by the AISI. We

chose the time period to look at to be 1950- present. This time period was chosen because

the middle of the century was when the EAF started becoming popular among U.S. steel

producers and this was around the time the mini-mill was born. We collected and plotted

data points for approximately every ten-year interval. This interval was chosen because

there were enough data points to show the general growth trend while keeping the data to

a minimum. When looking at Fig. 1, you can see total raw steel production rise over time as

well as the production from both the EAF and BOF. Mid-century, most integrated steel

production processes used open-hearth (OH) furnaces. The integrated producers strayed

away from using OH furnace because molten iron could be charged in a BOF, and the BOF

had a substantially faster heat time.

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FIG.4. 1: RAW STEEL PRODUCTION BY FURNACE TYPE: SOURCE: (AISE)

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U.S. Raw Steel Production By Furnace Type

(thousands of net tons)

Year Total Raw Integrated Steel Making % Mini-mills %

Steel Production (U.S) (B.O.F) Integrated (E.A.F) Mini-mill

1995 104,930 62,523 59.6 42,407 40.4

1990 98,906 58,471 59.1 36,939 37.4

1982 74,577 45,309 60.7 23,158 31.1

1970 131,514 63,330 48.2 20,162 15.3

1960 99,282 3,346 3.4 8,379 8.4

1956 115,216 506 0.44 8,641 7.5

Raw Steel Production by Furnace Type

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

199519901982197019601956

Year

Thousand

s

ofnettons

Total Raw Steel

Production (U.S)

Integrated Steel

Making (B.O.F)Mini-mills (E.A.F)


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Another method we used to show general growth of the industry in the second half

of the 20th century was to collect and plot total shipments and shipment categories over

the same time span.

4.5 INVESTMENT

Like any thing else steel producers are required to have capital expenditures to

replace obsolescent facilities, for additions to plant and equipment as well as disposals of

plant and equipment. Primarily over the years this has been done to reduce costs, and to

improve product quality. In 1986 additions to plant and equipment cost the steel segments

862.0 million dollars, this figure had grown to 2.4 billion dollars in 1995. (AISI, 1995)

Disposals of plant and Equipment cost the steel segments in 1986 505.5 million dollars and

in 1995 it had diminished to 207.2 million dollars. (AISI, 1995) Pollution control costs, and

other capital expenditures would be important to look at as well when figuring out total

plant expenditures.

4.6 INDUSTRY FINANCIAL PROFILE

The U.S. iron and steel industry had total revenues of 24.9 billion dollars in 1986;

this figure had increased 31% by 1995 to 35.9 billion dollars. (AISI, 1995) However,

industry after-tax profits as a percentage of revenues generally reflect the cyclic nature

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of the steel industry. After-tax profits have fluctuated over time, from 4.2 billion dollars

in 1986 to 1.6 billion dollars in 1995. (AISI, 1995)

4.7 LCA STUDY OF THE STEEL INDUSTRY

Following the model given above, we have prepared a life cycle assessment for the

steel industry. Similar to all LCA studies, the goal and scope of the study was defined

first. After the goal and scope of our study are clearly defined, we compiled an inventory

containing a detailed list of the major inputs and outputs of relevant processes. We then

evaluated these inputs and outputs based upon environmental risks and hazards associated

with then. Upon completion of our impact analysis study, we interpreted the inventory and

impacts and suggested possible alternatives.

4.8 GOAL AND SCOPE

In our LCA of the steel industry, we have analyzed the environmental aspects of

producing steel in the United States. Using integrated steel production as a base case,

and several sources for LCA data, we have compiled a relatively detailed inventory of

inputs and outputs. From our inventory we were able to identify potentially harmful

emissions, and analyze sources, toxicity and carcinogenicity. After reviewing emissions

produced by a typical integrated mill, we then focused our study on describing actions

taken by the industry to lower these emissions. Specifically, we have emphasized on steel

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making using the electric arc furnace (EAF), and intern, created a second inventory and

impact analysis for mini-mill steel making technology. Based on our findings, we have been

able to hypothesize on which steel production technology (integrated vs. mini-mill

technology) is more environmentally friendly.

Our LCA will first focus on integrated steel making. Originally our plan was to

create an inventory using the cradle to gate concept. This concept involves compiling an

inventory that includes inputs and outputs from mining of ores and coal, until the finished

product is shipped from the steel mill. After finishing our preliminary research we found

that data for such an inventory would be too detailed and costly for this study. As an

alternative we chose to use a similar scope, we decided to use the gate to gate concept.

This concept involves tallying an inventory that only contains processes that occur inside

the steel mill gates. This approach excludes primarily the mining of ores, and coal.

We have compiled an inventory that contains data from several sources. Our

consumption data is from the AISI 1995 Annual Statistical Report. Our TRI data was

calculated using data from the EPAs TRI Comparative Spreadsheet that corresponds to

the 1997 calendar year. From the EPA Office of Air Quality and Planning Standards

Source SIC Report made available January 28 2000, we compiled our air emissions data.

Slag output data was found in the AISIs "Steel Industry Technology Roadmap", that was

published in 1998. Several other sources were also used to complete our LCA of the steel

industry.

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4.9 INTEGRATED STEEL PRODUCTION PROCESS

To better understand the gate to gate concept for integrated steel making, we

must define process being analyzed. The first step in the integrated steel production is

the collection of raw materials. This includes the mining of coal, limestone, and ore (most

commonly taconite). Also included in this step is the preparation of these materials is the

crushing of limestone, and separating and sintering of ore. These processes will not be

analyzed in our LCA because we are only looking at processes that occur in the mill, and

these processes usually occur near the mines because of high transportation costs. We

will be analyzing the coking of coal, because it usually takes place near the mill, and is a

large polluting body. The second step in steel production is the combining the raw

materials in a blast furnace to produce pig iron. The blast furnace melts the ore and

removes the impurities in the form of slag. The resulting iron is contains around 4-5%

carbon. This iron is still too brittle to be mechanically forged so it is refined further to

produce steel. Next, pig iron is charged with scrap into a basic oxygen furnace (BOF).

This furnace will lower the carbon content enough that it can be mechanically forged. The

basic oxygen furnace is charged with liquid pig iron plus scrap onto which oxygen is blown

creating carbon dioxide, removing carbon from the iron forming steel. The last step in the

production of steel is forming finished product. In can be directly poured into molds to

form ingots or continuously cast. Traditionally, ingots where cast then transported to a

rolling mill. In continuous casting, liquid metal is poured into a tundish, which supplies a

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steady amount of liquid to the caster. As the metal flows it solidifies while passing

through rolls, then is cut into slabs. These slabs are then transported to the rolling mill.

At the rolling mill the ingots or slabs are rolled to form a variety of finished steel

products. Some of these products are sheet steel, pipe, beams, bars, rods and rails. The

following flow chart (fig 4.2) gives a step by step depiction of the production process.

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Fig. 4.2: TYPICAL FLOW OF INTEGRATED STEEL PRODUCTION

Iron ore, limestone, are mined, and coal is mined and coked. Iron ore, coke,

and limestone are then charged in a blast furnace. Molten iron is produced and charged in

a BOF, to be injected with oxygen. Molten steel is produced and formed in a continuous

caster.

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4.10 INVENTORY OF INTEGRATED STEEL MAKING

4.10.1 QUALITATIVE INVENTORY

The first step in compiling an inventory for integrated steel making was to outline

the major processes and the inputs and outputs associated with each. Outlined here are

the main polluting processes that are encountered while producing steel in an integrated

mill, and the inputs and outputs that are encountered each process:

COKEMAKING

INPUTS

Coal

Heat

Quench water

OUTPUTS

Process residues from coke by-product recovery

Coke oven gas by-product such as coal tar, light oil, ammonia liquor, and

the remainder of the gas stream is used as fuel. Coal tar is typically

refined to produce commercial and industrial products including pitch,

creosote oil, refined tar, naphthalene, and bitumen.

Charging emissions (fine particles of coke generated during oven pushing,

conveyor transport, loading and unloading of coke that are captured by

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pollution control equipment. Approximately one pound per ton of coke

produced are captured and generally land disposed.

Ammonia, phenol, cyanide, and hydrogen sulfide

Oil

Lime sludge, generated from the ammonia still

Decanter tank tar sludge

Benzene releases in coke by-product recovery operations

Naphthalene residues, generated in the final cooling tower

Tar residues

Sulfur compounds, emitted from stacks of coke ovens

Wastewater from cleaning and cooling, (contains zinc, ammonia still lime,

or decanter tank tar, tar distillation residues)

Coke oven gas condensate from piping and distribution system

IRONMAKING

INPUTS

Iron ore (primarily in the form of taconite pellets)

Coke

Sinter

Coal

Limestone

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Slag

Carbon monoxide

Nitrogen oxides and ozone, which are generated during the melting

process

This preliminary inventory of the integrated steel industry covers

three of the highest polluting sectors of production. As seen above there are a large

number of outputs coming from coke production. Intern, in coke production there are also

a large number of pollutants being emitted. Some outputs, such as certain off gases are

collected and reused in other production processes. These processes include firing of

blast and steel making furnaces. During iron making there also are several outputs that

are emitted. Slag, the largest output being produced, is tapped off the steel and used as

aggregate or deposited in a landfill. Off gases from the blast furnace are also collected

and used in other steel making processes. The last area of concern in integrated steel

making is the BOF. The BOF also produces a large amount of slag and off gas. The slag is

generally dealt with in a similar manner as blast furnace slag. But the off gas is comprised

mostly of carbon monoxide and nitrogen oxides, and is useless for the steel production

process. Our data from the EPA and our other sources found in our secondary resources

will allow us to compile a detailed list of inputs and amounts based on industry averages.

From our compiled inventory data we can start our impact analysis.

4.10.2 QUANTITATIVE INVENTORY

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Using several sources we were able to compile a relatively detailed quantitative

inventory for the integrated steel industry. Our main focus was on the inputs, as well as

the outputs, for integrated steel production. We started by producing a table containing

the largest and most important inputs. These included coke consumption, flux consumption,

ore consumption, oxygen consumption, and fuel consumption. The data in fig. 3 is from the

AISI 1995 Annual Statistical Report. The left-hand column displays the total yearly

output, the right column contains the amount of input consumed per pound of steel

produced. This number was found by dividing the total yearly consumption of input by the

total steel production from integrated firms.

The second inventory that we compiled was toxic release inventory (TRI) chemical

data. This data was calculated from raw data provided by the EPAs TRI Comparative

Spreadsheet that corresponds to the 1997 calendar year. This spreadsheet gave the

amount of TRI chemical produced at every integrated steel firm in the United States. In

all the spreadsheet gave data for 70 different TRI chemicals. It also gave the production

capacity of each integrated mill.

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TABLE 4.1: INPUT INVENTORY FOR INTEGRATED STEEL PRODUCTION

SOURCE: (AISI, 1995)

- 58 -

Input Inventory for Integrated Steel Production

Integrated Stee l Production Net tons of input

Blast Furnace/BOF Per ton of steel produced

Raw Steel Production 62,523 N/A


Coke Consumption 24,568 0.393


Flux Consumption 4,313 0.069


Fluorspar 20 0.000312

Limestone 1,108 0.0177

Lime 2,905 0.0465

Other Fluxes 280 0.00448

Ore Consumption 89,796 1.436


Natural Ore 1,326 0.0212

Pellets 74,515 1.192

Sinter and Others 13,654 0.218

Oxygen Consumption 215,187 3.442

(millions of gaseos cubic feet)

Blast Furnace 90,698 1.451

Steel Furnace 124,489 1.997

Fuel Consumption

Fuel Oil 108,196 1.73

(thousands of gallons)

Natural Gas 106,698 1.707

(millions of cubic feet) *

Coke Oven Gas 121,061 1.936

(millions of cubic feet) **

Blast Furnace Gas 810,252 12.959

(millions of cubic feet) ***

* Millions of cubic feet based on 1,000 B.T.U. per cubic foot

** Millions of cubic feet based on 500 B.T.U. per cubic foot

*** Millions of cubic feet based on 95 B.T.U. per cubic foot


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Since the focus of our study was to analyze a typical U.S. integrated mill we wanted to

find an average of TRI releases for each chemical. We did this by using the following

formula:

Average TRI R C = (RCF1 + RCF2 ++ RCFi)/ (PF1 + PF2 ++ PFi)

This equation takes the sum of the total release (R) from each firm for a chemical

(C) and divides them by the sum of total production capacity (P) of each corresponding

firm to get the Average TRI release for a certain chemical (C).

This raw data, though, was incomplete in some instances. Not all of the mills

reported their emissions to the EPA, leaving blanks in the spreadsheet. To correct for

this, we created an algorithm in Microsoft Excel that would show all production capacities

and chemical releases for each firm in columns. Before making a calculation we had to

manually delete production capacities for firms which we did not have chemical release

data for. We then could calculate the average using an algorithm set up to automatically

calculate each sum of production capacities and chemical releases, and divide them to get

the average. This average is reported in lbs. /short tons of steel produced, and each

average TRI chemical release was calculated from all the firms that data was available for.

Fig. 4 shows the averages TRI chemical releases for integrated steel production, found by

using the method above.

The third inventory we calculated for integrated steel production was the slag

output. We obtained this data from AISIs "Steel Industry Technology Roadmap" which

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uses 1997 slag output data. Instead of giving industry averages AISI reported this

information in intervals. Table 4.2 shows slag output from integrated steel production in

lbs./short tons of steel produced.

Toxic Release Inventory Chemicals for Integrated Steel Making

Facilities

Chemical TRI Releases and

Transfers(lbs./short ton)

MANGANESE COMPOUNDS 3.79CHROMIUM COMPOUNDS 0.022ZINC COMPOUNDS 0.973NICKEL COMPOUNDS 0.021AMMONIA 0.125PHOSPHORIC ACID 0.000715ETHYLENE 0.0447BENZENE 0.00829

HYDROCHLORIC ACID (>=1995 "ACID AEROSOLS" ONLY) 0.0486LEAD COMPOUNDS 0.0441NAPHTHALENE 0.0227ETHYLENE GLYCOL 0.00366PHENOL 0.0336CYANIDE COMPOUNDS 0.00816METHANOL 0.0131

ANTHRACENE 0.00229

TOLUENE 0.00172

XYLENE (MIXED ISOMERS) 0.00164ANTIMONY COMPOUNDS 0.00218POLYCYCLIC AROMATIC COMPOUNDS 0.000869STYRENE 0.000417ALUMINUM (FUME OR DUST) 0.0746COPPER COMPOUNDS 0.00811MOLYBDENUM TRIOXIDE 0.00301

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PHENANTHRENE 0.00776BARIUM COMPOUNDS 0.00183CHLORINE 0.0000651CRESOL (MIXED ISOMERS) 0.0000527ETHYLBENZENE 0.000627SODIUM NITRITE 0.00789COPPER 0.00527MANGANESE 0.157PROPYLENE 0.002291,2,4-TRIMETHYLBENZENE 0.0217BIPHENYL 4.05E-07CARBON DISULFIDE 0.00305CHROMIUM 0.004LEAD 0.00792NICKEL 0.00122ANTIMONY 0.00162CADMIUM 0.000547CALCIUM CYANAMIDE N/ACOBALT COMPOUNDS 0.000802CUMENE 0.00936DIETHANOLAMINE 0.00222HYDROGEN CYANIDE 0.0000241

Toxic Release Inventory Chemicals for Integrated Steel Making

Facilities (cont.)

Chemical TRI Releases and

Transfers

(lbs/short ton)

PYRIDINE 0.00204SULFURIC ACID (1994 AND AFTER "ACID AEROSOLS" ONLY) 0.0000607

ZINC (FUME OR DUST) 0.00418

1,3-BUTADIENE 0.00002592,4-DIMETHYLPHENOL 0.00002592-MERCAPTOBENZOTHIAZOLE N/AARSENIC COMPOUNDS 0.000827BERYLLIUM 9.4E-08CARBONYL SULFIDE 5.19E-07

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CERTAIN GLYCOL ETHERS N/ACOBALT 8.46E-07

DI(2-ETHYLHEXYL) PHTHALATE N/AHYDROGEN FLUORIDE N/AMERCURY COMPOUNDS 0.0000292NITRATE COMPOUNDS 0.113O-XYLENE 0.00216QUINOLINE 0.0000259

THIOUREA 0.0000451VANADIUM (FUME OR DUST) 0.000114

Total TRI Releases 5.611468464

TABLE 4.3: INTEGRATED SLAG OUTPUT: SOURCE (AISI, 1998)

- 62 -

Integrated vs. Mini-mill Slag Output Comparison

Integrated Steel Production Mini-mil l Steel Production Total

Blast Furnace/BOF EAF

Total Slag Produced 400-1,340 110-420 550-1,760

(lbs/short ton)

Slag Produced by 300-700 N/A

Blast Furnace


BOF

Slag Produced by N/A 110-420

EAF

TABLE 4.2:TOXIC RELEASE INVENTORY CHEMICALS FOR STEEL MAKING FACILITIES

These averages were calculated by using the formula Average TRI R C = (RCF1 + RCF2 ++ RCFi)/

(PF1 + PF2 ++ PFi)


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The final inventory we compiled for integrated steel making was air pollution emissions

data. This data was collected from the EPAs Office of Air Quality and Planning

Standards Source SIC Report, that was made available January 28, 2000. This data,

though, is an industry total for both integrated and mini-mill steel operations. Even

though it does not focus on integrated production alone it should still be examined in

this inventory. Table 4.4 shows air pollutant emissions from blast furnace and steel

mill operation.

TABLE 4.4: BLAST FURNACE AND STEEL MILL AIR POLLUTANT EMISSIONS

SOURCE: (EPA, 2000)

4.11 IMPACT ANALYSIS FOR INTEGRATED STEEL MAKING

Like its counterpart (EAF), there is typically one large polluting body and thats the

steel-making process itself, when using the basic oxygen furnace (BOF). Like the electric

- 63 -

Blast Furnace And Steel Mill Air Pollutant Emissions

Industry Total

Number of Facilities 116

Air Pollutant Emissions

(in tons per year)CO Emissions 940055

NO2 Emissions 105880

PB Emissions 290.5

PM10 Emissions 29267

PT Emissions 59412

SO2 Emissions 215582

VOC Emissions 43987


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4.11.3 SOLID WASTES

The Solid wastes include lime sludge, generated from the ammonia still, decanter

tank tar sludge, slag, and dust and sludges from air and water pollution control systems.

Like the mini-mill many of these solids may be reused by the manufacturing operations and

may be resold as by-products for use in other industries.

4.12 ALTERNATIVE WAYS OF STEEL MAKING

For complexity reasons, we have decided to narrow our study down to Electric Arc

Furnaces. The inputs of the steel-making process that uses electric arc furnaces (EAF)

include scrap, electric energy and graphite electrodes. Fluxes and alloys are also added,

and may include fluorspar, dolomite, and alloying agents such as aluminum, manganese, and

others. (EPA, 1995) Electric Arc furnace emission control dust and sludge; 20 pounds of

dust per ton of steel is expected, this number may be as high as 40 pounds depending on

the scrap that is used. (EPA, 1995) Similarly to the inventory done with the integrated

base case, we plan to compile an inventory for semi-integrated steel making (mini-mills).

With this second inventory we will be able to complete an impact analysis and compare it

with the integrated base case.

4.13 INVENTORY OF SEMI-INTEGRATED STEEL MAKING

4.13.1 QUALITATIVE INVENTORY

Similar to inventorying the integrated firm, the first step in compiling an inventory

for semi-integrated steel making was to outline the major processes and the inputs and

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outputs associated with each. Outlined here are the main polluting processes that are

encountered while producing steel in an semi-integrated mill, an the inputs and outputs

that are encountered each process:

STEELMAKING

INPUTS

Scrap metal

Electric energy

Graphite Electrodes

OUTPUTS

Electric Arc Furnace emission control dust and sludge

Slag

Carbon monoxide

Nitrogen oxides and ozone, which are generated during melting process.

4.13.2 QUANTITATIVE INVENTORY

Similar to integrated steel making, we were able to compile a relatively detailed

quantitative inventory for the semi-integrated steel industry. Our focus was the same as

the integrated sector, looking closely at the inputs, as well as the outputs, for semi-

integrated steel production. We started again by producing a table containing the largest

and most important inputs. These included flux consumption, scrap consumption and oxygen

consumption, and fuel consumption. The data is also from the AISI 1995 Annual

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Statistical Report. The left-hand column again displays the total yearly output, along with

the right column containing the amount of input consumed per pound of steel produced.

This number was found by dividing the total yearly consumption of input by the total steel

production from integrated firms.

The second inventory for the semi-integrated sector that we compiled was toxic

release inventory (TRI) chemical data. This data was calculated from raw data provided

by the EPAs TRI Comparative Spreadsheet that corresponds to the 1997 calendar year.

This spreadsheet gave the amount of TRI chemical produced at every semi-integrated

steel firm in the United States. In all the spreadsheet gave data for 70 different TRI

chemicals. It also gave the production capacity of each semi-integrated mill. We found

again, that all mills did not report each chemical release so we had only divide each total

TRI release by the sum of all the reporting mills production capacities. This gave us the

average TRI release for each chemical using as much raw data as possible.

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TABLE 4.5: INPUT INVENTORY FOR SEMI-INTEGRATED STEEL PRODUCTION

The third inventory we calculated for semi-integrated steel production was the slag

output. We obtained this data from AISIs "Steel Industry Technology Roadmap" which

uses 1997 slag output data. Instead of giving industry averages AISI reported this

information in intervals. Fig. 9 shows slag output from semi-integrated steel production in

lbs./short tons of steel produced, as well as integrated steel production.

- 68 -

Input Inventory for Mini-mill Steel Production

Mini-mill Steel Production net tons of input

EAF per ton of steel produced

Raw Steel Production 42,407 N.A


Flux Consumption 1,319 0.0311(thousands of net tons)

Fluorspar 32 0.000755

Limestone 133 0.00314

Lime 993 0.0234

Other Fluxes 161 0.00379

Scrap Consumption 61,700 1.455


Carbon Steel 57,200 1.349

Stainless Steel 1,200 0.0283

Alloy Steel 870 0.0205

Iron Scrap 880 0.0208Other Grades 1,600 0.0377

Oxygen Consumption 55,398 1.306

(millions of gaseos cubic feet)

Blast Furnace 0 0

Steel Furnace 55,398 1.306


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Toxic Release Inventory Chemicals for Mini-mill Steel

Making Facilities

Chemical TRI Releases

and Transfers(lbs./short ton)

MANGANESE COMPOUNDS 0.931CHROMIUM COMPOUNDS 0.207ZINC COMPOUNDS 4.765

NICKEL COMPOUNDS 0.0812AMMONIA 0.245PHOSPHORIC ACID 0.00938ETHYLENE 0BENZENE 0HYDROCHLORIC ACID (>=1995 "ACID AEROSOLS" ONLY) 0.0256LEAD COMPOUNDS 0NAPHTHALENE 0ETHYLENE GLYCOL 0.0109PHENOL 0

CYANIDE COMPOUNDS 0.00265METHANOL 0.0189ANTHRACENE 0TOLUENE 0.0173XYLENE (MIXED ISOMERS) 0.044ANTIMONY COMPOUNDS 0POLYCYCLIC AROMATIC COMPOUNDS 0STYRENE 0ALUMINUM (FUME OR DUST) 0.118COPPER COMPOUNDS 0.0934

DIBENZOFURAN 0MOLYBDENUM TRIOXIDE 0.0205PHENANTHRENE 0BARIUM COMPOUNDS 0.0728CHLORINE 4.0712CRESOL (MIXED ISOMERS) 0ETHYLBENZENE 0SODIUM NITRITE 0

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COPPER 0.0619MANGANESE 0.424

PROPYLENE 0

1,2,4-TRIMETHYLBENZENE 0BIPHENYL 0

CARBON DISULFIDE 0CHROMIUM 0.34LEAD 0.353NICKEL 0.0801ANTIMONY 0.00222CADMIUM 0.0303CALCIUM CYANAMIDE 0COBALT COMPOUNDS 0CUMENE 0DIETHANOLAMINE 0

HYDROGEN CYANIDE 0PYRIDINE 0SULFURIC ACID (1994 AND AFTER "ACID AEROSOLS" ONLY) 0ZINC (FUME OR DUST) 4.8162,4-DIMETHYLPHENOL 02-MERCAPTOBENZOTHIAZOLE 0ACETONITRILE 0ARSENIC COMPOUNDS 0BERYLLIUM 0.00129BROMOTRIFLUOROMETHANE 0

CERTAIN GLYCOL ETHERS 0.101COBALT 0.0111DI(2-ETHYLHEXYL) PHTHALATE 0HYDROGEN FLUORIDE 0.095LITHIUM CARBONATE 0MERCURY COMPOUNDS 0NITRATE COMPOUNDS 5.811O-XYLENE 0

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QUINOLINE 0VANADIUM (FUME OR DUST) 0

Total TRI Releases 22.86074

TABLE 4.7:SEMI-INTEGRATED SLAG OUTPUT: SOURCE (AISI, 1998)

The final inventory we compiled for semi-integrated steel making was air pollutionemissions data, following the same inventory for integrated steel production. This data

was collected from the EPAs Office of Air Quality and Planning Standards Source SIC

Report, that was made available January 28, 2000. This data, is the same as Table 4.7,

but it is important to also look at when assessing semi-integrated production.

- 71 -

Integrated vs. Mini-mill Slag Output Comparison

Integrated Steel Production Mini-mill Steel Production Total

Blast Furnace/BOF EAF

Total Slag Produced 400-1,340 110-420 550-1,760

(lbs/short ton)


Blast Furnace


BOF

Slag Produced by N/A 110-420

EAF

TABLE 4.6: TOXIC RELEASE INVENTORY CHEMICALS FOR SEMI-INTEGRATED STEEL

These averages were calculated by using the formula Average TRI R C = (RCF1 + RCF2 ++ RCFi)/ (PF1 +

PF2 ++ PFi)


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TABLE 4.8: BLAST FURNACE AND STEEL MILL AIR POLLUTANT EMISSIONS

4.14 IMPACT ANALYSIS FOR SEMI-INTEGRATED STEEL MAKING

Due to the process of steel making used by mini-mills, there is typically one large

polluting body, steel-making itself, using the electric arc furnace (EAF). This process has

several types of pollution, with several controls to compliment each type. Types of

pollution control can be broken down into three groups, air pollution control, water pollution

control, and solid wastes.

4.14.1 AIR POLLUTION

Arc furnaces emit gaseous and particulate pollutants, principally during charging,

melt down, refining, and tapping. Metal transfer and teeming may also give off emissions.

The furnace size, power, and melt rate all play a factor in the quantity and type of

emissions. Treatments include fabric filters and high-energy scrubbers.

4.14.2 WATER POLLUTION

The major water pollutants include suspended solids, fluorides, and zinc from air

pollution control equipment. Because industrial water can often be recycled many times,

- 72 -Blast Furnace And Steel Mill Air Pollutant Emissions

Industry Total

Number of Facilities 116

Air Pollutant Emissions

(in tons per year)

CO Emissions 940055

NO2 Emissions 105880

PB Emissions 290.5

PM10 Emissions 29267

PT Emissions 59412

SO2 Emissions 215582

VOC Emissions 43987


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the possible combinations of individual technologies into a wastewater treatment system

are exceptionally large.

4.14.3 SOLID WASTES

The Solid wastes include dust and sludges from the air and water pollution control

systems. Most of these solids are reused by the manufacturing operations and may be

sold as by-products for use in other industries.

An effective arc furnace emission control system consists of the following phases:

Emissions gathering by hoods and/ or direct evacuation

Pretreatment (usually for temperature control)

Ducting to collection unit

Disposal (Little, 1975)

A malfunction in any of the above phases is likely to cause the whole system to be

ineffective. Our final assessment will also include upstream and downstream inputs and

outputs, such as transportation and rolling operations. It will encompass the entire semi-

integrated industry, not just pollution associated with the EAF.

4.15 INTEGRATED VS. SEMI-INTEGRATED COMPARISON

After completing each inventory for each sector of steel production, we analyzed

the data we found and tried to find out which sector produced more environmental steel.

After looking at the impact analysis for each sector we could see which harmed the

environment more. First we looked at a comparison of the inputs. We found that per ton

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of steel produced integrated production used more input. This is due to, integrated

production needs more oxygen, and needs ore and coke, where semi-integrated production

only needs scrap.

Next we compared the TRI outputs for each sector of production. We found that

on average semi-integrated production produced about 4 times more TRI chemical output

than integrated firms. We found this number to be high. This could have been due to the

calculation we used to find the industry average, or it could have been true due to the

smaller amount of total production from

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