John Kline – Kline Consulting

Charles Kline – Kline Consulting February 2014

The Future of Flyash

Globally there is not enough flyash

Locally there is too much flyash

CO2 reduction will increase the value of “clean” Flyash

Utilities that market flyash will need to consider their path forward carefully

Mercury

Carbon / sorbents

Trona / sodium bicarbonate

The use of flyash in concrete

Pros

Improve concrete

Reduce costs

Reduce carbon footprint

Cons

Reduce strength

Reduce air entraining

CO2 from Cement

Depending on how you count …

Global cement production accounts for

some 4 – 7% of anthropogenic CO2

emissions

Main levers to reduce CO2 emissions

Clinker Reformulation

Energy Efficiency

Biogenic Fuels

Clinker Substitution

The Cement Technology Roadmap (CSI+IEA) B

t o

f C

O2

Supplemental Cementing

Materials (SCMs)

Portland cement is made up primarily of

calcium silicates

These react with water

Other Produced and Natural Materials

also contain calcium and silica oxides

Blast furnace slag

Flyash

Pozzolans (Natural and Artificial)

78%

4%

18%

11%

41%

26%

16%

6%

Water

Sand

Gravel

Cement

Air

Clinker

Gypsum

SCMs

Cement In

Concrete

Clinker In

Cement

Limestone in

Clinker

80%

20%

Limestone

Other Raw

Materials

CaO

SiO2

Flyash

Flyash

How Cement Works (The Simplified Version)

CaO SiO2 H2O

Calcium Silicate Hydrate

Both the Calcium and Silica Oxides

need to be in a reactive form

Clinker Substitution

2006 data, CSI

0%

5%

10%

15%

20%

25%

30% 26% 26%

24% 22%

21% 20%

17% 16% 16%

Avera

ge A

dd

itio

n c

on

ten

t in

cem

en

t

Most Important Binder Materials

C-Ash

SiO2

CaO Al2O3

PC

Slag

SF

F-Ash

MK

L

LegendC-Ash – ASTM Type C FlyashF-Ash – ASTM Type F FlyashL – Lime (Limestone - CaCO3)MK – MetakaolinPC – Portland CementSF – Silica FumeSlag – Ground Blast Furnace

PozzolanicReactions

Hydraulic Reactions

SlowerLater Strength

FasterEarly Strength

Keys to SCM Use

Chemistry and purity of the SCM

Reactivity of the SCM

Calcium in CaO form

Amorphous silica

Small particles (high surface to weight)

Availability of the SCM

Local specifications and norms

Most locations opening up to more SCMs

Iron and Steel Producing Countries

<

Where the Slag is

Where the Pozzolans Are

Coal Consumption

All Uses by Country

Where the Fly Ash is

0%

20%

40%

60%

80%

100%

120%

140%

160%

180%

200%

-

500

1,000

1,500

2,000

2,500

3,000

3,500

China Europe US India Russia Rest of World

Mill

ion

Me

tric

To

ns

Cement

Coal

Coal Ash

Saturation

Normal SaturationWorld Average 27%

Coal Ash to Cement Balance

Assumes 12% Ash

23%

4%

6%

4%

4%3%

56%

Use of Fly Ash in US

Concrete / Grout

Blends / Clinker Feed

Structural Fill

Mining Applications

Waste Stabilization

All Other Uses

Discarded

ACAA 2012 Data

Potential to Increase Flyash

Today Potential

Clinker 2780 77.2% 2780 68.6%

Gypsum 120 3.3% 120 3.0%

Flyash 250 6.9% 500 12.3%

Slag 150 4.2% 200 4.9%

Pozzolan 150 4.2% 300 7.4%

0 0.0% 0 0.0%

Limestone 150 4.2% 150 3.7%

Total Binder 3600 100.0% 4050 100.0%

$-

$2.00

$4.00

$6.00

$8.00

$10.00

$12.00

$14.00

$16.00

$18.00

$20.00

CO SC NC

MI

WY

MI

MD

OH

NE

MS

MI

OH FL FL TN IA LA WY

NE

LA WV

NV

MO TX LA WV

OH FL

MO

ND IN TX AL

TX CO IA

NM NH TX IA IA MI

WI

SC KS

PA

WI

OK

Fly Ash Revenue

Mean - $6.60

Data from EIA

Impact of Additives on Use

Material Raw

Materials

Cement Concrete

Lime Good Limited Limited

Limestone Good Limited Limited

CaBr2 OK OK OK

Mercury Very Limited OK OK

Activated Carbon Good Very Limited Very Limited

Trona Limited Very Limited Very Limited

Sodium Bicarbonate Limited Very Limited Very Limited

The Future of Flyash in Concrete

There is a need in most of the world

Flyash value will increase with CO2 constraints

Substitutes may be limited

Finite amount of slag available

Natural pozzolans not available globally

Artificial pozzolans require processing

Cost of disposal is increasing

Careful planning is therefore required