In mint condition
Mintek, a South African mineral research and mining technology organisation, may be celebrating its 75th anniversary this June, but Dr Roger Paul explains to Gay Sutton how the company is addressing the problems of the futureÔÇödwindling earth resources, global warming and AfricaÔÇÖs archenemies, malaria and HIV.
During the first week in June, South African mining technology and services company Mintek will be celebrating its 75th anniversary, commemorating a lifetime of significant achievements. A five-day programme of events will culminate in a high-level international two-day conference and a glittering gala dinner attended by the industryÔÇÖs most influential people.
Mintek has much to celebrate. Since its inauguration in 1934, it has played a leading role in the development and use of new metallurgical technologies and techniques, and it continues to lead the way today, tackling some of the worldÔÇÖs more intractable issues.
Originally known as the Government Metallurgical Laboratories, the company was set up by the South African government to improve the recovery of uranium, which was in great demand throughout the Second World War and the Cold War that followed. Within a short space of time, Mintek had become the world leader in the field, but its remit expanded and diversified considerably, and its achievement grew in number and significance. During the 1970s, for example, the company played a major role in developing and commercialising the highly effective carbon-in-pulp process that dramatically improved the rate of gold recovery.  
Later, it developed new techniques for recovering and smelting platinum concentrate, in response to specific metallurgical difficulties experienced on the South African UG2 platinum reef. The reef itself lies under the highly productive Merensky Reef, and the two combined account for a staggering 80 per cent of the worldÔÇÖs annual platinum production.
Today, Mintek employs 750 staff, the majority of whom are scientists, engineers and R&D specialists. ÔÇ£We operate in three broad categories,ÔÇØ explains Dr Roger Paul, general manager for technology. ÔÇ£Metallurgical services, which account for around 70 per cent of our revenue; the manufacture of new technologies which are sold worldwide; and the licensing of technologies.ÔÇØ
Samples of ore from around the world are sent to MintekÔÇÖs facility at Randburg on the outskirts of Johannesburg for analysis. Many of these samples are highly complex, and the company is asked to develop a special-purpose process flow sheet which it then tests and proves in its extensive pilot plant. ÔÇ£And itÔÇÖs here, where weÔÇÖre running the complete process, that we can generate the data that financial institutions require from our clients before raising the financing to exploit the mineral reserve,ÔÇØ Paul says.
It is an indication of the achievements of the company that at its first inauguration it was totally government-funded. Today, 80 per cent of its finance is generated from revenue, and only 20 per cent is provided by the South African Government.
ÔÇ£That government funding is where we do the more avant garde blue-sky researchÔÇöwhere we are looking to develop completely new technologies that will benefit South Africa and the world,ÔÇØ Paul explains. When it comes to investing the taxpayersÔÇÖ money, however, Mintek has a rigorous internal process for selecting projects, which is based on the best return on investment and the best benefit to South Africa. ÔÇ£These projects are then kept strictly within their objectives, their budget and their time frameÔÇöas one would with a commercial project.ÔÇØ
Finding ways to reduce the energy and water consumption by the mining industry and decreasing the impact on the natural environment are strong areas of focus for Mintek at the moment. In most mining operations, all the ore coming from the mine is processedÔÇöcrushed and milledÔÇöregardless of the mineral content. ÔÇ£WeÔÇÖre looking at pre-sorting the ore, separating out the rock that is largely barren, so that energy and water are not wasted on non-productive work. So far weÔÇÖve made strides in what we call dense media separation, optical sorting and X-ray sorting, and the first platinum plants using these technologies are now up and running,ÔÇØ he says.
The company has also been working on a technique known as DC arc smelting, which provides much tighter metallurgical control over the smelting process. ÔÇ£WeÔÇÖre now extending the technology into platinum smelting,ÔÇØ Paul says. ÔÇ£Until now, the concentrate from the UG2 reef has been blended with Merensky ore and smelted in AC furnaces. But itÔÇÖs becoming less and less easy to blend it, while more and more production is coming from UG2. So weÔÇÖve developed what we call the Conroast process, and licensed it to Braemore Resources. We have a 3MW demo plant running on the Mintek site, smelting close to 2,000 tons of material a month, demonstrating the technology works on a reasonable scale. We hope the first commercial furnace will be operating next year.ÔÇØ
Another area Mintek is looking at with considerable interest is new industrial uses for gold. The precious metal has had medicinal applications for over 2,000 years, and Mintek is exploring this area further. Gold is already used in the treatment of arthritis. ÔÇ£But we have developed a whole range of gold compounds which we believe will have an application for combating malaria, cancer and HIV,ÔÇØ Paul explains.
MintekÔÇÖs business model is to develop the products to the stage where they can be patented, and then to take them to the pharmaceutical companies for detailed in vivo testing. The most advanced of these compounds is a cancer treatment which is at the in vitro testing stage. ÔÇ£And weÔÇÖre currently in advanced negotiations with the pharmaceutical companies for in vivo testing,ÔÇØ says Paul.
Meanwhile, malaria and HIV are very specific problems in South Africa, and research in this area has attracted some interesting additional investment. ÔÇ£We are not at the stage where we can approach the pharmaceutical companies yet,ÔÇØ Paul says. ÔÇ£But we are getting encouraging results, to the extent that the research is being partly funded by some of the gold mining companies in South Africa who are keen to have a hand in the initial research.ÔÇØ
Mintek has also been doing some considerable work developing gold as a catalyst. ÔÇ£For example, we have developed a catalyst that oxidises CO to CO2, and we are currently providing industrial-sized samples to a number of clients around the world who have applications for it.ÔÇØ And those applications can be quite diverse, ranging from lightweight inexpensive minersÔÇÖ respiration masks to cleaning the air in submarines.
The mineral and mining industry fully recognises that the worldÔÇÖs resources are finite and precious, and Mintek is playing a key role in developing technologies that increase the amount of minerals that can be extracted from ore. Bioleaching of refractory gold ores has been used for many years, but Mintek is applying the concept to extracting copper more efficiently from ore. ÔÇ£Most of the high-grade copper deposits around the world are either being exploited or have been completely exploited. WhatÔÇÖs left is a much lower-grade resource which is not economically viable to mine, recover and smelt in the conventional way.ÔÇØ
The new method involves crushing it to a coarse 20mm size, then applying bacteria and dilute sulphuric acid to dissolve the copper minerals; these are then collected from the bottom of the heap. ÔÇ£We believe this will allow lower-grade copper ores to be treated at much lower energy costs,ÔÇØ Paul says. The process has already been piloted on small copper operations and is now undergoing trial at a major copper plant.
ÔÇ£Eventually we will take the technology into nickel and various other metallic compounds. Ultimately we want to be able to extract as close as possible to 100 per cent of the mineral content of the ore. We will never actually reach 100 per cent, but husbanding these precious natural resources and looking after them wisely is now a global imperative and a driving force for all that we do.ÔÇØ
