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Technical reviewGold

Cyanide monitoring continued for AngloGold Ashanti’s

metallurgical plants in southern Africa, Tanzania and

Mali, and this work will be extended to the Ghanaian

operations in the current year. Some preliminary work

was also done for Randgold Resources’ Loulo project

in Mali, which is scheduled to begin production in the

second half of 2005. Together with AngloGold Ashanti,

Mintek began a THRIP-funded project to investigate

various environment-related aspects of cyanide usage,

including the vapour pressure of HCN, the stability

of Prussian Blue-type precipitates in backfill, the

fate of thiocyanate in the environment, and cyanide

destruction by ultraviolet light. Work continued towards

the accreditation of analytical methods for cyanide, and

Mintek plans to apply for

ISO 17025 certification for

cyanide analysis later in

2005.

A programme of testwork was completed as part of the

pre-feasibility study on the Burnstone gold project (South

Rand) for Vancouver-based Great Basin Gold. The work,

which consisted of gravity separation and preg-robbing

tests on a composite sample of borehole cores, showed

that more than 90 per cent of the gold could be recovered

by gravity separation followed by carbon-in-leach. The

metallurgical testwork was carried out in conjunction with

MDM Ferroman, which is responsible for process and

plant design.

In early 2005, Great Basin initiated a feasibility study

on the project with the aim of reaching a development

decision within 12 months. Should the project go ahead,

Burnstone will be the first new gold producer on the

South Rand gold field in over 40 years.

Small-scale batch and continuous testwork, involving

milling and flotation to produce a copper concentrate

and leaching of the tailings for gold recovery, was carried

out for European Minerals’ Varvarinskoye project in

Kazakhstan. A bankable feasibility study was completed

by MDM Ferroman in November 2004, and construction

of the project is under way, with the first gold pour

scheduled for the end of 2006.

Gas-phase sampling

to determine cyanide

volitilisation rates

at a tailings storage

facility

Scale-up work on gold-based catalysts under Project

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RIP testwork using the Minix gold-selective resin was

carried out to recover gold from a copper leach residue

for Cominco Engineering Services Ltd.

Project AuTEK — the collaborative initiative to develop

novel industrial uses for gold and increase local

beneficiation — is now in its fifth year. The work on

catalysts for carbon monoxide oxidation has reached

product development stage. One of the potential

applications is in respirators, where the AuTEK catalyst

has the advantage of retaining its activity for much

longer than the conventional hopcalite catalyst, as well

as the ability to function in humid conditions. Prototype

respirators using the AuTEK gold-based catalyst will

be submitted to the NIOSH (US) for evaluation and

accreditation early in 2006, and the first commercial

production is expected in 2007.

Mintek now has the capacity to produce catalysts, in

batches of up to 20 kg, in a form suitable for a wide range

of industrial applications, and is ready to collaborate with

end-users in the pollution control, chemical processing

and fuel cell industries to design gold-based catalysts for

their specific needs.

Work on nano-monolayer-protected gold clusters for

drug delivery is in progress with the Universities of

Liverpool and Parma (Italy), and an investigation into the

manufacture of nanofibres by electrospinning has begun .

These materials have a very high surface area, and have

potential for use in biosensors as well as catalysts.

An investigation was conducted into the effects of

key growth parameters on the size and shape of gold

nanoparticles produced by biosynthesis. In order for

biosynthesis to compete with existing chemical and

physical methods, techniques need to be developed

that can control the particle size to a very narrow range,

as well as produce uniform shapes. A project was

begun with the University of the Free State to identify

the biomolecules that are responsible for the reduction

reaction and subsequent nanoparticle formation, which

could lead to a more controlled process. Another project,

at Rhodes University, is undertaking an initial screening

of micro-organisms for their potential for synthesising

platinum nanoparticles.

The AuTEK biomedical programme, which originally

focused on anti-tumour drugs, has broadened its

investigations to include anti-HIV and anti-malarial

agents, in collaboration with seven local and six

European universities. Screening work and toxicological

studies are continuing, and in-vivo testing will start

towards the end of 2005. Work has been initiated with

NECSA on radio-labelling to investigate the mode of

action of various compounds.

One of the major achievements of Project AuTEK has

been the establishment of a pool of skilled researchers

with strong international links. The number of researchers

has grown from five in the year 2000 to more than 50,

and collaborative links have been forged with nine local

universities and more than a dozen overseas in six

countries. Two PhD and eight MSc degrees have already

been completed, and another 30 postgraduate projects

are registered. AuTEK researchers have made 68

contributions in international journals and conferences.

The launch of AuTEK Americas is planned for late 2005.

AuTEK’s budget has grown from R1-million to just over

R14-million in 2005, and the project has been very

A scanning electron microscope image of nanofibres

Gold labelling of neurologically active pentapeptides for

cancer research

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successful in leveraging additional funding, which now

accounts for 40 per cent of the budget. A considerable

contribution has been made by the NRF through THRIP,

for building infrastructure and expertise. During the

period under review, these funds were used to acquire

a RAMAN/Fourier Transform Infrared spectroscope and

an ASAP surface area analyser for studying adsorbed

species on catalyst surfaces. In 2004 the DST approved

a R5-million grant for an atomic force/scanning tunnelling

microscope for the fundamental characterisation of

nanoparticles, and a further R3.7-million in 2005 for a

high-resolution SEM and nuclear magnetic resonance

spectrometer. These facilities make Mintek a leading

centre for nano-research in South Africa.

Platinum Group Metals

Exploration and development work on new platinum

group metals projects in South Africa continued at a high

level during 2004/2005, and Mintek’s testwork facilities

were heavily utilised.

A major piloting campaign was completed on a 500 t

bulk sample from a new project in the eastern Bushveld

Complex, to provide metallurgical data as inputs into the

feasibility study, and to determine the most appropriate

concentrator design and the performance criteria. Two

different MF2 configurations were evaluated, and the

minimum product specifications were attained with both

circuits.

Metallurgical variability testwork, to determine the

factors that influence metal recoveries, was carried out

as input to the pre-feasibility study by Ridge Mining on

the Sheba’s Ridge project. The study was completed

in March 2005, and Mintek will also be involved in work

for the bankable feasibility study on the project, which

is scheduled for completion by the end of 2006. Similar

work was performed for Aquarius Platinum’s Everest

South project - Mintek previously ran piloting campaigns

to determine the design parameters for the Everest South

concentrator, which is due to be commissioned at the end

of 2005.

Bench-scale investigations were done as part of the

pre-feasibility studies for African Platinum’s Leeuwkop

project, and for the Boikgantsho joint venture between

Anooraq Resources and Anglo American Platinum.

A major programme of work on PGM ores from many

different sources, was carried out to evaluate the use of

dense media separation (DMS) for the up-front rejection

of waste material and to compare the flotation recoveries

from DMS concentrate and ROM material.

Mintek has commissioned a dedicated milling and

flotation mini-plant, which is used mainly for reagent

evaluation and comparative testwork. The plant

has a throughput capacity of 100 kg/h, and is easily

configurable and economical to run. It is proving to be

useful for testwork where many different conditions need

to be evaluated, or in cases where there are only limited

quantities of material available, such as from borehole

cores. Examples of the kinds of work undertaken include

an independent evaluation of gangue depressants for

a reagent manufacturer, and continuous rougher rate

tests on UG2 samples containing various amounts

of waste to evaluate the potential benefits of dense

media separation. The infrastructure for the main 1 t/h

milling and flotation pilot plant was also upgraded and

modernised.

Two major collaborative research projects are under

way, supported by industry partners. The first involves

a comparison of preconcentration methods for UG2

(Top and bottom) A pilot plant campaign for a feasibility

study on a new PGM project

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ores, and the second is looking at a number of generic

problems encountered in the PGM smelting industry.

Science Vote-funded research is being undertaken

on the classification of UG2 tailings, optical sorting of

non-UG2 ores, new flotation cell technologies, and the

fundamentals of milling processes.

Funding has been approved for a THRIP project, which

will start in the 2005 financial year, to investigate the

limiting factors in the PGM smelting process. All three of

the major platinum producers are supporting the project,

which will include studies such as flow behaviour, the

solid phases, disengagement of the matte from slag,

interactions between the furnace gases and refractory

materials, and matte liquidus temperatures.

A long-term DC furnace campaign was initiated to

recover PGMs from revert tailings and other wastes for

one of the platinum producers. This material is difficult

to process conventionally because of its high chromium

and low base-metal sulphide content. By the end of the

period under review, over 5 000 t of a planned 10 000 t

had been processed. As well as being a major service

work project, this exercise is serving to demonstrate the

smelting stage of the ConRoast process, which involves

the smelting of primary platinum-bearing feed materials

in a DC arc furnace, with the PGMs collected in an

iron alloy. A paper entitled “DC arc smelting of difficult

PGM-containing feed materials” was presented at the

International Platinum Conference in September 2004.

The programme on the development of PGM-based

analogues of the nickel-based superalloys is now in

its fifth year. This work is supported by the three major

platinum producers Anglo Platinum, Impala Platinum and

Lonmin Platinum, with collaborating institutions being

Japan’s National Institute for Materials Science (NIMS)

and the universities of Bayreuth and Leeds. Significant

progress was made in the ThermoCalcTM work, and

investigations of the experimental phase diagrams are

ongoing, with the current focus on resolving anomalies

found in the binary diagrams. A major effort is being

made to identify a niche opportunity for testing prototype

alloys.

Mintek participated in an Innovation Fund project,

managed by the CSIR, on the addition of platinum to

coatings on nickel-based superalloys. The conventional

aluminising process produces a nickel aluminide

coating. Platinum additions result in a mixture of higher-

order phases that strengthen and extend the life of the

coating. This effect has long been known, but is not well

understood. This project will be resumed if an industrial

partner can be found.

Mintek is participating in a second Innovation Fund-

sponsored project at the University of Cape Town on

the development of platinum-based jewellery alloys.

During the year under review, the properties of a range of

compositions based on 95%Pt, were evaluated for their

suitability for use by small-scale jewellers. This work will

continue during 2005/2006.

Mintek has entered into an agreement with Johnson

Matthey Catalysts to act as a test facility for the Smopex®

technology. Smopex is a new metal scavenging system

that uses polyolefin-base ion exchange fibres with high

loading capabilities to recover low levels of precious

metals from process streams. With a local testing facility,

the costs of transporting the test solutions will be lower,

and there will be less chance of the solutions ageing.

Mini-plant work on the evaluation of flotation reagents

DC arc smelting of PGM revert tailings

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Ferrous Metals

Mintek acted as manager, assisted by Bateman Metals,

GBM Minerals Engineering Consultants, and Wardell

Armstrong International (WAI), for the preliminary

feasibility study on Oriel Resources’ Shevchenko

ferronickel project in Kazakhstan. Based on the positive

results, Oriel commissioned a Definitive Feasibility Study

(DFS), with Bateman as lead engineers, partnered by

ThyssenKrupp company Polysius, WAI and Mintek. As

part of the study, about 190 t of calcined lateritic ore was

smelted in Mintek’s DC arc pilot plant at power levels

of up to 1.5 MW, producing 11.5 t of ferronickel alloy at

nickel grades and recoveries in line with targets.

The DFS, which will be completed in the third quarter

of 2005, is based on a smelter plant with an initial

installed capacity of two 80 MW twin-electrode DC arc

furnaces, followed by a third furnace after the third year

of operation. Subject to a positive outcome, construction

could start during the second quarter of 2006, with the

first ferronickel production by early 2008. At full capacity,

the project would produce 140 000 t of ferronickel per

annum.

A “pre-concept” study was completed on the production

of ferrochromium at the Voskhod mine in Kazakhstan.

At the end of the year under review, Oriel commissioned

Mintek to carry out a scoping study to design and cost a

chromite beneficiation flowsheet.

Mintek is in the final phase of a three-year project, funded

by the Innovation Fund/NRF, to develop a low-nickel

austenitic stainless steel for structural applications.

Welding, corrosion, and cold formability tests were

completed, and industrial scale-up trials (approximately

2 t) were carried out in order to validate the properties

achieved in laboratory. Prototype fasteners were

produced from some of the industrial bars by hot forging

and thread cutting, in order to demonstrate the properties

of the alloys. Overseas visits have been made to several

stainless steel manufacturers in order to identify a partner

with which to commercialise the alloy.

Trials of the “smart” rockbolt or SmartboltTM, which

undergoes a phase transformation when strained and

can thus be monitored to provide warning of impending

dangerous rock conditions, continued at a deep-level

gold mine. Mintek is negotiating with a manufacturer of

roof support systems to introduce the bolt in the mining

industry. Further investigations are planned to tailor the

properties to the conditions specific to different mining

operations (eg. gold and platinum). The development

of the Smartbolt was funded by the SIMRAC, which is

continuing to support it through commercialisation.

The Mineral Density Separator (MDS) was used

extensively to characterise iron ore samples for Kumba

Resources’ Sishen Expansion Project. The project,

which will boost Sishen’s production from 28 Mt/a to

38 Mt/a by 2009, is based on a new jigging technology

to upgrade ore that was previously unmarketable. The

MDS separates material into different density fractions

at densities exceeding 4.0, and the results can be used

to evaluate and predict the efficiencies of dense-media

and jigging operations, as well as to design and optimise

processing plants.

Ferronickel product from the Shevchenko laterite

smelting campaign

Graph illustrating the response of Smartbolts under

multiaxial loading

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Non-ferrous Metals

Mintek has been appointed as co-ordinator of the

bioleaching work package in the European Union’s

BioMinE project, part of the EU’s Sixth Framework

Programme (FP6). The project will provide the

opportunity for Mintek and other South African

organisations to interact with the European scientific

community in capacity-building and developing the next

generation of biotechnology techniques for minerals

processing.

BioMinE is an integrated project, involving 35 partners

from 14 different countries, that focuses on innovative

biotechnology-based processes for recovering or

removing metals from primary and secondary materials.

The primary objective of the bioleaching package is

to provide solutions to the technical constraints that

currently limit the broader commercial applications

of bioleaching technologies. R&D activities focus on

improvements in the performance and cost-effectiveness

of bioleaching processes, the wider application

of bioleaching to low-grade, complex and waste

metal resources, and innovations that will minimise

environmental impact and enhance sustainability.

In addition to the EU FP6 funding, Mintek’s contribution

to BioMinE is also being supported by a major strategic

investment by the DST. The ability of Mintek and

other South African organisations to participate in

and to compete for funds under the EU’s Framework

Programmes is facilitated by the SA-EU S&T Co-

operation Agreement signed in 1996.

Large-scale piloting of Mintek’s heap bioleaching

technology for primary copper sulphide ores is scheduled

to begin at the Sarcheshmeh Copper Complex in

southern Iran in the second half of 2005. Mintek has

completed a detailed engineering design of the plant,

and three pilot heaps, each of about 25 000 t, are under

construction with leaching of the first heap scheduled

to start in October. As part of the preparations for the

campaign, two 6 m columns with “intelligent” temperature

profile control, which simulates the temperature regime

within a full-scale heap, were run at Mintek under the

conditions that will be employed on-site.

The process has been designed utilising state-of-the-art

mathematical modelling of the transport phenomena in

heaps, and a control strategy has been developed and

implemented on Mintek’s Star Control System platform

that is designed to steer the operating conditions along

an optimal path throughout the duration of the process.

The heaps will be instrumented to monitor parameters

such as copper dissolution, bacterial activity and acid

consumption, and changes made to the operating regime

to optimise the rate and extent of copper dissolution,

control the heap pH and copper concentration in the

pregnant solution, and satisfy bacterial oxygen demand.

The project is being conducted in terms of a collaborative

agreement between Mintek and the National Iranian

Copper Industries Company (NICICO) that was

announced last year (Annual Report 2004).

Bioleaching columns with “intelligent” temperature

profile control, for simulating conditions in a full-scale

leach heap

Tapping of magnesium metal during the final piloting run

on the Mintek Thermal Magnesium Process

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The programme, which will run for about 18 months, is

aimed at proving the technology at a large scale, and

generating reliable operating information for commercial-

scale operations.

Mintek, in association with an industry partner and

funded by BioPAD, is engaged in a major R&D project

on the tank bioleaching of zinc sulphides. Various

microbiological and engineering strategies have

been examined with the aim of significantly reducing

processing costs, and progress on the engineering

side has led to a patent application for a novel bioleach

process configuration.

A second BioPAD-funded project involves the

development of a novel and effective technique for

innoculating bacteria into leach heaps for rapid start-

up and improved metal recoveries. The principle has

now been proven at the laboratory scale, and testwork

in 6 m columns will be conducted with the objective of

demonstrating the process under conditions applicable

to commercial-sized heaps. Given a successful outcome,

the next stage would involve piloting at a mine site.

R&D work on the Mintek Thermal Magnesium Process

has been completed successfully. During an eight-day

run in November 2004, about 30 t of feed material

were smelted in the DC pilot plant, and the magnesium

extracted as vapour for delivery to the condenser.

Fifteen taps of liquid magnesium, totalling 3 500 kg of

magnesium metal, were carried out from the condenser

during online operation. The crude magnesium was

of a consistently better quality than that produced by

conventional thermal processes, particularly with regard

to calcium.

The new condenser, which was designed to prevent the

build-up of dross that limited previous runs to about 20

hours of continuous operation, performed extremely well,

achieving continuous production with an efficiency of

85 per cent. The robustness of the process was shown

by the ability of the condenser to withstand a furnace

shutdown - for example, to clear a blocked feed port or

to add an electrode section - and immediately re-start

magnesium production and tapping.

This campaign demonstrated, for the first time, the

feasibility of a continuous atmospheric process for

thermal magnesium production. Technically, the process

is now ready for scaling up to a demonstration- and

further to an industrial-size operation.

A major programme of testwork was carried out for

Congo Mineral Developments (Adastra Minerals) in

support of a definitive feasibility study, which is being

undertaken by Murray & Roberts and GRD Minproc, on

the Kolwezi Tailings Project in the DRC. Most of the work

was concerned with manganese removal from the cobalt

electrolyte and the precipitation of cobalt salts, but some

solvent extraction and copper electrowinning work was

also undertaken. The Kolwezi project, which consists of

112.8 Mt of high-grade oxide tailings, has the potential

to be one of the world’s largest and lowest-cost cobalt

producers.

Preliminary comminution and metallurgical testwork was

started on the Kalukundi copper-cobalt deposit in the

DRC. High recoveries were obtained for both copper

and cobalt, and larger-scale testwork is planned for the

current year. This work forms part of the project feasibility

study, managed by MDM Ferroman, for Africo Resources

Ltd.

Leaching testwork was carried out for Casmin SPRL,

which is constructing a cobalt processing plant at

Kambove in the DRC, and sulphate and carbonate salts

produced for testing in the market. Limited leaching

testwork was also conducted for Metorex’s Ruashi-Etoile

copper cobalt project.

Laboratory-scale milling and flotation work was

conducted on samples from the Hunters Road nickel

deposit in Zimbabwe in order to evaluate the variability

of the ore. The results showed that a composite of the

ore zones could be treated to obtain a final concentrate

meeting the grade and recovery specified by the Bindura

Nickel Corporation. Further work was recommended to

optimise the flowsheet and conditions.

Process development work for the Kolwezi Tailings

Project – manganese removal

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Preliminary work was done for Mopani Copper Mines

(Botswana) on the development of a flowsheet for the

purification of cobalt electrolyte, and piloting work is

planned for 2005.

A number of concentration methods, including magnetic

separation, heavy media separation and flotation, were

tested for upgrading samples from Caledonia Mining’s

Nama cobalt project in northern Zambia.

At the end of the period under review, Vancouver-based

Formation Capital Corp. commissioned Mintek to develop

a hydrometallurgical flowsheet for its Idaho Cobalt Project

(ICP). The ICP, a high-grade primary cobalt deposit

unique to North America, is currently in the bankable

feasibility and advanced permitting stage of development.

A pilot Bateman Pulsed Column (BPC) was installed

and operated at Anglo American Research Laboratories

to compare the performance with conventional mixer-

settlers for extracting zinc from pregnant leach solution

generated by leaching Zincor tailings. The chemical

performance of the extraction and stripping circuits in

both equipment configurations was identical, and it

was demonstrated that the BPC is a viable alternative

contactor to mixer-settlers in terms of recoveries.

Removal of manganese from zinc electrolyte using

air/SO2 on a large batch scale was tested successfully

for Kumba Resources. This technology, which will allow

the company to process zinc concentrates with a higher

manganese content than it is able to at present, will

probably be implemented in 2005.

Comminution, heavy liquid separation and leaching

testwork were carried out as part of a feasibility

study, managed by Green Team International (GTI) of

Johannesburg, on the oxide zinc mineralisation at Sierra

Mojada, Mexico, for Metalline Mining Co.

A project on ion exchange fibres for metal recovery

was initiated under the technology bilateral agreement

with Belarus, and funded by the Innovation Fund. The

initial focus was on the removal of copper from cobalt

electrolyte. The fibres were prepared by the Institute

of Physical Organic Chemistry (IPOC) of the National

Academy of Sciences of Belarus, and evaluated at

Mintek with encouraging results. Follow-up work will be

done with Bateman to compare the costs of fibres versus

conventional resins. Ion exchange fibres have a great

kinetic advantage over granular ion exchangers, due to

a short diffusion track of the absorbable ion in the fibre,

and could potentially minimise the very large volumes of

solutions on ion exchange plants. An investigation into

the use of the fibres for gold recovery, which involves

grafting the Minix gold-selective active group onto the

fibre, was also started.

An industrial-scale melting trial was performed to

manufacture an Al-10%Ti master alloy using Al-Ti

concentrate produced in the 200 kVA DC arc furnace.

This work forms part of a three-year project sponsored

by the Innovation Fund to research the production of

additives (grain refiners and hardeners) for aluminium

and titanium alloys by aluminothermic reduction of

oxides in a DC arc furnace. The properties of the alloy

(grain refining efficiency and the dissolution rates) were

found to be comparable to those of a commercial master

alloy. However, the viability of the new process will be

determined by whether it is more cost effective to use the

Al-Ti concentrate as a source of titanium units compared

to using titanium scrap.

Recovery of uranium by ion exchange (top), and

precipitation of uranium peroxide (U3O8)

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Industrial Minerals

Metallurgical testwork was carried out on about 6 t of

ore from the Langer Heinrich uranium project in Namibia

in support of the bankable feasibility study, conducted

by GRD Minproc, for Australian company Paladin

Resources. The work included feed preparation by

scrubbing and attritioning, alkaline (carbonate) leaching

at atmospheric pressure and elevated temperature, ion

exchange and precipitation of uranium peroxide. The

calcined products generally contained about 90 per cent

U3O

8, and complied with published specifications for

uranium concentrates. At the beginning of May 2005,

Paladin approved the development of the project, which

will be the first conventional uranium mining operation to

be developed outside of Canada in the past twenty years.

Uranium production is scheduled to begin in September

2006.

Bench-scale leaching and recovery work was begun on

process development for Aflease Gold and Uranium’s

Dominion uranium project.

Laboratory-scale work was undertaken for AngloGold

Ashanti to assist with upgrading the uranium circuit

at Vaal River Operations. AngloGold Ashanti plans to

upgrade the South Uranium Plant to maintain uranium

production for at least an additional 11 years by exploiting

the by-product uranium reserves associated with its new

Moab Khotsong Shaft.

The movement and handling of radioactive material in

South Africa is subject to the Nuclear Energy Act (NEA).

Mintek is registered with the National Nuclear Regulator

(NNR), and is authorised by the DME to possess and

process source material (natural uranium ore or U3O

8)

with a uranium content not exceeding 50 kg at any one

time. Separate transport and (in the case of material

from outside South Africa) import permits are obtained

from the DME for each sample brought to Mintek. Before

the permits are granted, the NNR ascertains the level of

radioactivity of the sample, and that the exporting country

will accept the processed material back at the end of the

project. The transport company must also be registered

with the NNR. Mintek’s environmental officer has passed

the examinations set by the NNR to be registered as an

official Radiation Protection Officer.

A major programme of testwork was begun to evaluate

ore samples from CVRD’s manganese exploration

projects in Gabon. The work, which consists of scrubbing,

screening, gravity concentration, and density separation

tests on about fifty 500 kg samples each month, is

expected to continue until the end of 2005. CVRD,

which is also developing the Moatize coal project in

Mozambique and exploring for diamonds and various

metals in Angola, has entered into an MOU with Mintek,

whereby Mintek will act as the “preferred supplier” of

testwork for the company’s projects in Africa.

Pilot-scale gravity and magnetic separation testwork was

done on an alluvial chromite sample from Zimbabwe, and

the sample was successfully upgraded to foundry sand

specifications.

Milling, thickening and pressure filtration tests on

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Attritioning, magnetic separation, and two pilot-scale

DMS runs were conducted to develop a flowsheet for an

andalusite deposit in Spain.

Routine sample characterisation, using sizing and heavy

liquid separation, was carried out on various kimberlitic

ores for De Beers. An 800 t sample from Jwaneng in

Botswana was upgraded in the dense media separation

plant after milling to various size fractions at Anglo

American Research Laboratories. A bulk sample of

kimberlite from an arid area was milled, and thickening

and pressure filtration tests carried out in conjunction with

an equipment vendor, to test the feasibility of recycling

water from the tailings back to the processing plant.

An audit was performed on the milling circuit at Foskor,

and recommendations made for improving the liberation.

A computer simulation study, using JKSimMet, was used

to evaluate proposed modifications to the comminution

circuit at Vergenoeg fluorspar mine, and a mass-balance

reconciliation carried out for Samquartz.

Quality, environment and safety

Mintek holds certification for the ISO 9001 (Quality),

ISO 14001 (environment), and OHSAS 18001

(Safety and Health) standards,

confirming its commitment to

deliver high-quality products and

services that meet international

standards in these areas. In

addition, the Analytical Services

Division is certified to ISO

17025 (Testing Laboratories).

Mintek’s integrated programme

of continual improvement in

quality, environment, safety and

health is officially driven by these

standards, and its performance

is monitored by international

auditors.

Mintek’s Environmental

Management System underwent

surveillance audits in August

2004 and February 2005.

Integrated QES internal audits

were also held to ensure that

all the environmental aspects of Mintek’s activities

are addressed and managed by means of Standard

Operating Procedures, and that the requisite

emergency procedures are in place.

In August 2004, SGS (SA) Ltd audited the safety

system and programme and certified Mintek to

the international standard OHSAS 18001. A safety

surveillance audit was carried out in February 2005.

A Lost Time Injury Frequency Rate of 1.1 was

achieved in April 2005, and the current target is less

than 1.0. Two of the eight injuries in the past twelve

months were reportable injuries. A behavioural safety

programme was introduced in 2004, and further

reductions in the accident rate are anticipated.

The CDFR target was reduced from 15 per cent

to 10 per cent in September 2004. The new target

was consistently achieved until January 2005, when

some issues regarding deliveries and invoicing

increased the CDFR. These issues were identified

and corrective action taken, and Mintek’s Corporate

Quality team continues to closely monitor these areas

to ensure that services to clients remain at a high

standard.

Checking the level of radioactivity in a uranium ore

sample

SGS

SYSTEM CERTIFICATION

ISO

14001

SGS

SYSTEM CERTIFICATION

ISO

18001

SGS

SYSTEM CERTIFICATION

ISO9001:2000

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