Monday, 5 September 2011

Pyrometallurgy in the 21st Century: Is it still a contender in the race with hydrometallurgy?

This is a question I posed last year on the blog, and it led to some interesting debate. Hopefully it should also lead to much discussion at next year’s Pyrometallurgy ’12 conference in Falmouth, as this is the title of the keynote lecture, which will be given by Prof. Jacques Eksteen, the Consulting Metallurgist on Hydrometallurgy and Pyrometallurgy at Lonmin and Professor (Extraordinary) at the University of Stellenbosch, South Africa.

Dwindling high grade metal resources, significant progress in hydrometallurgical technologies, perceived environmental impacts and high capital costs have all chipped away at the historic pre-eminence of pyrometallurgy. Hydrometallurgy seems to have overtaken pyrometallurgy as the preferred extraction route in the zinc industry, the nickel laterite, copper oxide and low grade sulphide industry, and has an established predominance in primary gold and uranium extraction.

According to Prof. Eksteen, however, pyrometallurgy still has much application potential for the 21st century, but in a modified guise. It is foreseen that the role of hydrogen as a reductant will become more pervasive, that energy recovery from slags associated with whole-ore smelting will offer strong competition to ultrafine grinding during concentrating, and that aspects such as roasting will again receive much attention. In particular, roasting using alkali-metal carbonates, reduction roasting and halide roasting will offer new ways of changing minerals in their solid state for further preparation for either smelting and leaching.

Prof. Eksteen will show that, rather than an either-or competition between hydrometallurgy and pyrometallurgy, these two approaches are often intimately dependent upon another and fulfil complementary roles. Often the choice of ore heap leaching or concentrate pressure leaching to bring metals into solution, versus ore or concentrate roasting, smelting and converting, is more dependent on extraneous factors than on the underlying thermodynamic and kinetic constraints.

In the 21st century, pyrometallurgical extraction routes will always be in a strong position to compete when they are close to river or sea ports, with ready access to non-fossil energy sources (electrical energy via nuclear energy, fuel cells, hydrogen gas, hydro-electric and geothermal sources) and ready access to skilled and educated labour from tertiary institutions. However, the large capital investment associated with most pyrometallurgical facilities will drive many multinational metallurgical companies to consider placing these facilities in socially, politically, financially and geologically stable environments, which limits the number of feasible global locations.

Hydrometallurgical technologies, especially those that are heap leach based will contend strongly where the resource is situated in remote locations, where installed electrical infrastructure is limited and / or where significant political and social risks are present. Due to thermodynamic driving forces, pyrometallurgy will remain competitive in the extraction and smelting of light metals, ferro-alloys, metal carbides, sulphide-rich concentrates, and the making of final metals such as aluminium, as well as in manufacture of silicon for the metallurgical and photovoltaic industry. Pyrometallurgy shows particular promise in the processing of secondary materials such as residues and wastes.

The keynote will re-evaluate pyrometallurgy as the processing option of choice within the macro-economic and technological drivers foreseen for the 21st century and should also be of interest to those attending Biohydrometallurgy ’12 at the same venue.


  1. Vale has the huge Hydromet plant in Long Harbor we all know 2.8 billion set to complete next year. But many do not realize Vale Vale has completed in record time the "Tres Valles project opens in Chile
    In December, Vale inaugurated the Tres Valles copper plant, its first project in Chile. Located in Salamanca, the plant, whose annual production capacity is 18,500 tons of copper cathode (metal plate), is Vale’s first industrial-scale cathode plant using a hydrometallurgical process. Total investment in implementing the project was US$140 million. Let's say a Jr Exploration Company discovered a Zambia style copper deposit 47 miles away from the Long Harbor Plant #1. #2. And let's say Vale signed a JV And initaly surounded this discovery with 300 square miles of lease land and then narrowed that down And then Dr. Hinchey went to the IAGOD symposieun to discuss the Bonavista Copper discovery #1. Hinchey SSC report link... NL Govt Map Fall 2011 with "CU" on Bonavista Peninsula
    Here is another NL pdf that is dated DEC 2011 ! My question is if Vale did discover a Low Grade Large tonnage Zambia style copper deposit there on the Bonavista....would they to save money hauling it 47 miles to the Long Harbor Plant or would they process it on site with a Chile style plant on site and save the money in transportation? Robert D. Nordberg

  2. Just to advise that Pyrometallurgy '12 has been cancelled

    1. Why has Pyrometallurgy '12 been cancelled?

    2. Unfortunately we had insufficient quality papers


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