Drinking water & Sulphur from Acid Mine Drainage
Written by Shaan Oosthuizen   
April 19, 2007
FOR IMMEDIATE RELEASE

Sulphur from Acid Mine Drainage

Pretoria, South Africa, Apr 19, 2007 -- /prbuzz/ -- The CSIR and industrial partner Key Structure Holdings (KSH) have signed a contract with Anglo Coal for the building of a demonstration plant aimed at the recovery of products from waste gypsum, via the patented GypSLiM process.

Anglo Coal and the CSIR have cooperated for more than a decade in the development of water treatment technologies that addresses acid mine water problems. The successful implementation of the CSIR’s limestone-neutralisation technologies at Anglo Coal South Africa’s plants have cut the cost of acid water neutralisation in half, with water treatment plants based on the technology having been built all over Southern Africa and recently in Australia. Anglo Coal is presently constructing the world’s first plant to produce drinking water from acid mine drainage. The plant with a capacity of 20 megaliters per day (Ml/d) will aim to satisfy growing demand for drinking water at the Emalahleni Local Municipality

Peter Gunther, Anglo Coal South Africa’s Section Hydrologist (Senior Project Manager), noted during the contract signing ceremony: "Waste is not only an environmental problem but has measurable economic value as well. Even at the present 99% water recovery at the Emalahleni Water Reclamation Plant, the waste being produced over the next 20 years will cost R300M to manage... Anglo Coal is aiming at zero waste disposal”. As part of this vison the GypSLiM process will demonstrate the feasibility of producing valuable Sulphur, Limestone and Magnesite from the waste gypsum produced during the neutralisation of acid mine water.

Riaan Van Der Merwe, Head: Joint Ventures and New Business Development Anglo Coal South Africa said “Anglo Coal sees this (the GypSLiM process) as an exciting opportunity to solve the waste problem by converting a mining environmental liability into a sustainable asset. With the creation of Anglo Inyosi Coal, a BEE company, we see the future to be one of even greater social responsibility and serving of the community”.

South Africa is a semi-arid country in which large sections of the population have inadequate water supply. The apparent shortage of water is contrasted by the large amounts of waste water generated by mining operations. In the province of Gauteng 320 Ml/d acid mine water is generated by the current and defunct gold mines, and the coal mines of the Mpumalanga province generate 60 Ml/d of neutral and acidic mine water. Acid mine waters may contain high concentrations of dissolved heavy metals and sulphate, and can have pH values as low as 2.5. Unless treated, such waters may not be discharged into public streams. The acid water is formed as a result of bacterial oxidation when pyrites are exposed to oxygen and water after or during the mining process. For this reason, the Council for Scientific and Industrial Research (CSIR), Africa’s largest research and development body, is working in conjunction with industrial partner Key Structure Holdings to utilize the polluted excess water from the mines to alleviate predicted water supply stresses.

Establishing a Sulphur Cycle

Apart from the treatment and utilization of waste water, the CSIR and Key Structure Holdings are also developing technologies to break Africa’s cycle of converting imported sulphur to sulphurous waste, the first of which being the GypSLiM process. The same technologies can be used to capture and convert natural sulphurous pollutants such as sulphur dioxide generated during the burning of sulphur rich coal and the smelting of sulphidic ores, and gypsum precipitated during the production of phosphoric acid from sulphuric acid and rock phosphate.

South Africa imports around 1 Millions tons per annum of sulphur from Canada and the Middle East. The sulphur imported is processed, mainly into sulphuric acid, and utilized. Post-utilization the majority of the sulphur ends up as waste gypsum. There are also several other sources of sulphurous pollution from mining and industry, for example: the planet’s second largest single emitter of sulphur dioxide is Selibe Phikwe, a mining town in Botswana where a copper-nickel smelter emits sulphur dioxide into the air. When sulphur dioxide combines with rain water, sulphuric acid is formed. Sulphuric acid is highly corrosive and as a result kills vegetation and corrodes infrastructure. Instead of venting or releasing these sulphur bearing compounds to the environment, technologies can be developed and implemented to capture and process the pollutants into valuable industrial chemicals.

Drinking water from Acid Mine Drainage

The CSIR and Key Structure Holding are currently developing an integrated chemical process to treat the acid mine water for removal of free acid, metals and sulphate to levels suitable for discharge into public streams or for re-use. It is noted that sulphate can be removed from 4 510 mg/l to less than 250 mg/l, magnesium to less than 2 mg/l and metals to less than 1 mg/l. A portion of the sulphate precipitates as gypsum which is converted to elemental sulphur and calcium carbonate via the GypSLiM process. The produced calcium carbonate is recycled in the process while sulphur can be sold as a by product or us as raw material for manufacturing of sulphuric acid, thus replacing imported sulphur.

With the international success of the limestone neutralisation process, now followed by industry’s support for the GypSLiM process, the hope is that the integrated process will allow that the environmental problems of the past can become an economic mainstay for the future.

Dr. Pat Manders, Acting Executive Director of CSIR Natural Resources and Environment, stated that this project forms a solid bridge between science and industry, and fulfils many of the objects of the CSIR as stipulated in its mandate.

"The objectives of the CSIR are to, through directed and particularly multi-disciplinary research and technological innovation, to foster, in the national interest and in fields which in its opinion should receive preference, industrial and scientific development, either by itself or in co-operation with principals from the private or public sectors, and thereby to contribute to the improvement of the quality of life of the people of the Republic."
Mr Leo Pistorius, director of Key Structure Holdings, stated that “this is yet another instance where Key Structures have managed to tailor a novel technology to the needs of South African industry and the environment, we clearly see a future where e.g. the 1800 tons of gypsum being pumped into the South African ocean on a daily basis is converted into raw materials to fuel the economy.”
About Key Structure Holding (Pty) ltd (KSH):
Key Stucture Holdings offers industry cutting edge technologies and services dedicated to product recovery from industrial wastes and water treatment. KSH’s aim is to add value while resolving the environmental problems faced by mines and industries, this is achieved by using the best technologies presently available or developing new technology. KSH specializes in water treatment technologies, working especially with mine effluents. In addition, there is also focus on the recovery of products such as sulphur, lime and metals from industrial wastes, providing clients with a new range of products to be re-cycled or sold, and dramatically improving the profitability of environmental actions taken. www.keystructures.co.za
About the Council for Scientific and Industrial Research (CSIR):
Established by Parliament in 1945 as the central scientific research and development resource for South Africa, the CSIR remains the country's top technology and innovation agency. Today the CSIR is the largest research and development (R&D) organisation in Africa, accounting for about 10% of the entire African R&D budget. A staff complement of approximately 3,000 include some of the top technical and scientific minds in the country, collaborating in multi-disciplinary teams, to put forward solutions of the highest standard in innovation and excellence. www.csir.co.za
For further information please contact:

Shaan Oosthuizen, Senior Process Engineer, Key Structure Holdings, Tel: 012 841 3172, e-mail: This email address is being protected from spam bots, you need Javascript enabled to view it

Dr Jannie Maree, Principle Researcher, National Resources and the Environment, Tel 012 841 2285, e-mail: This email address is being protected from spam bots, you need Javascript enabled to view it

About the Press Release
South Africa is a semi-arid country in which large sections of the population have inadequate water supply. The apparent shortage of water is contrasted by the large amounts of waste water generated by mining operations. A joint venture between Anglo American, one of the world's leading mining compies and the CSIR, Africa's largest R&D institution promises not only to turn acid mine drainage into drinking water, but also arrest the need for more than 1 Million tons of imported sulphur.


 
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