Monday 29 July 2019

The Evolution of Mineral Processing- thoughts from 40 years ago

Way back in 1979 I was a young lecturer at the Camborne School of Mines (CSM) and in that year we had a very eminent Visiting Fellow from Australia, Prof. Alban Lynch, the founding Director of the JKMRC.
Prof. Alban Lynch in the early 1970s
I was involved with the production of the CSM Annual Journal, and persuaded Alban to contribute an article, and the subject that he chose was The Evolution of Mineral Processing, a subject that I have presented a couple of times in China over the past two years, and have been invited to present at the Helmholtz Institute Freiberg in Germany in October.
It is fascinating to look back and read what Alban had to say about the developments that had taken place in the first 80 years of the 20th century, and what his thoughts were for the future.
He began by comparing mineral processing advances with other technologies, such as jet aircraft, nuclear power, space flights, lasers and computers and felt that it was depressing to realise that there had been only three major advances in mineral processing during the century, one occurring in each quarter of the century.
However he stressed that "our reputation as engineers" was somewhat restored by the fact that the first of these developments was froth flotation, "one of the greatest technological advances of our age and this will be realised if an attempt is made to conceive of a world without ample and cheap supplies of copper, lead, zinc and nickel".
The other two major developments were, Prof. Lynch suggested, the industrial processing and pelletising of taconites, and the development of on-stream analysis. The moral from these developments, he said, is that important advances in mineral processing, advances which solve serious problems, are slow and require a large investment of money and effort. With this in mind, he asked what we can say about the problems of the present and the future? He predicted that the solution of the problem of concentrating fine particles less than about 10 microns in size could be the fourth achievement of the 20th century.
Little did Alban know that in 1979 we were at the cusp of the 3rd Industrial Revolution, and the explosion in computing power that would take place in the 1980s, leading to rapid developments in automatic control, simulation and process design, and that he would be one of the pioneers in the relatively new field of modelling and simulation, which would aid design of ever larger equipment and innovative new processes. He did identify one of the most important problems, and an area in which the JKMRC would become a leader, 'mine-to-metal' relating to rock breakage by explosives and the ability to tailor these processes such that "we finish up with a product which is the best that we can get for future use".
He said that he could not emphasise too strongly the importance of further advances in mineral processing technology because of the major influence which minerals have always had on the welfare of society. He quoted Sir Paul Hasluck, a politician, historian and former Governor-General of Australia who said that "engineers are the shapers of contemporary civilisation and to no group does this apply more than the minerals engineers".
Prof. Lynch concluded by saying that the achievements of the final quarter of the 20th century would be in the hands of the new generation of metallurgists. I was fortunate to be involved in the teaching of this new generation, many of whom I have kept in contact with and have been proud to follow their achievements in this crucial industry. They in turn have produced a new generation and some of these are also now a part of the minerals world, and I would like to ask the young (and not so young) metallurgists of today- what do you feel are the main problems of the present and the future?
Twitter @barrywills

5 comments:

  1. Great, Barry!
    Today, I think, there are three processes: SAG milling, heap leaching and bacterial oxidation. Tomorrow will be: bacterial leaching, water & reagents cycling, dry tailing.
    Thanks.

    Khvan Alexander, Uzbekistan

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  2. Really GREAT to read your article, that too on what Dr.Lynch predicted--I am fortunate to be his first international Ph.D. student.
    Thank you very much Barry. Another aspect of the foresight and implementation of Dr.Lynch was interaction with industry which led to many developments on "how to look at practice and apply knowledge".
    You covered many on many occasions. For me and as Dr.Lynch foresaw --"mine to metal" has to be a single package" which is cost effective and environmentally acceptable.
    Dr.Lynch brought a paradigm shift in the thinking of mineral engineers and we need another push.


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  3. Dear Dr. Wills,
    This blog instantly took me back to the year 1979 when I joined M/s Hindusthan Zinc Ltd at Zawar mines, near Udaipur. I still remember your article on hydro-cyclones that appeared in World Mining during those days. It is in that period Mr.BN Chaterji invited Prof. TC Rao to organize a work shop on Hydro Cyclones at Zawar mines.

    Thanks,
    Sekhar

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  4. Dear Dr. Wills,

    I liked your article on Prof. Lynch, I have great personal regards for him. I am his second generation indirect disciple, Dr. T.C.Rao being in the first.

    I agree with him that Floatation was a breakthrough technology, essentially in the thirties of the last century.

    But since then if you talk of any technology of similar impact I would say it is AG/SAG mills as these have made large tonnage plants possible which a 3 stage crushing was a physical limitation.

    More revolutionary is Roller Press technology though somehow it has not yet been endeared enough by the industry.

    I have great doubts if we should consider onstream or in stream analysers or process control systems as mineral engineering achievements. These are entirely different technologies which we have adopted successfully. There is nothing “mineral engineering” about them. I would welcome your opinion.

    As regards treatment of fines as low as 10 micron is still a distant dream. In India we are struggling to beneficiate 45 micron iron ore slimes, a vast disposal problem, effectively.

    I enjoy reading the articles in the blog enormously. These are very educative. Your recent one on zero carbon by 2050 is very informative.

    Regards,
    Dr. Arabinda Bandyopadhyay
    Chief Technologist
    CDE Asia Limited, India

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  5. Dear Sir,

    Ball Mill -SAG mill circuit consumes more energy compared to Rod Mill РBall Mill circuit. This is what an Indian Case study tells. See the article in the attachment at the bottom of the page in this link http://mineralengineer.wikifoundry.com/page/Size+Reduction The invention of HPGR by Klaus Sch̦nert is a land mark.
    Thanks,
    Sekhar

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