A new journal and a new generation

On January 1st a new look Minerals Engineering will be launched, as a result of its merger with the International Journal of Mineral Processing (IJMP).  Since the inception of Minerals Engineering in 1988 I have been Editor (see also posting of 8 June 2013), and 3 years ago a dynamic young researcher, Dr. Pablo Brito-Parada, joined me as Associate Editor, to assist with the ever increasing paper flow.

Times are changing and the editorial structure of the hybrid journal will be dominated, quite rightly by a new generation of young minerals engineers. My position now is as Editor-in-Chief. Pablo is promoted to Editor, and is joined by Associate Prof. Kristian Waters, former editor of IJMP.

Pablo Brito-Parada is a Research Fellow in the Department of Earth Science and Engineering at Imperial College London. His research focuses on industrial multiphase flows, particularly in mineral processing, combining experimental techniques and numerical modelling for equipment evaluation and design. A Chemical Engineer by training, he worked in academia and industry in Mexico before moving to the UK, where he completed his PhD in froth flotation at Imperial College London. He has since coordinated industrial flotation optimisation campaigns, led the flotation research at the Rio Tinto Centre for Advanced Mineral Recovery as well as other mineral processing research projects. He is currently Principal Investigator at Imperial College for IMPaCT, a €10m consortium funded by the European Commission with the objective of developing solutions for small scale sustainable mining in Europe.

Kristian Waters is an Associate Professor at McGill University, Canada. He has an M.Eng. in Chemical Engineering with German from UMIST, UK, an MSc in Instrumentation and Analytical Science also from UMIST and PhD in Chemical Engineering from the University of Birmingham, researching into the effect of thermal treatment on the physico-chemical properties of minerals He then spent 2 years as a post-doc at Imperial College London working with Prof. Jan Cilliers on fine particle flotation and PEPT.  In 2009 he moved to McGill as Assistant Professor, and was awarded tenure in 2015. His current research is quite varied, covering the majority of separation techniques and some water treatment, his recent research targeting the beneficiation of rare earth bearing minerals.

Pablo and Kristian will be aided by six Assistant Editors: Grant Ballantyne, University of Queensland, Australia; A. Deniz Bas, Laval University, Canada; Erin Bobicki, University of Toronto, Canada; Zoltan Javor, Aalto University, Finland, Anita Parbhakar-Fox, University of Tasmania, Australia; Martin Rudolph, Helmholtz Institute Freiberg for Resource Technology, Germany.
None of the 8 editors and assistant editors were born when the International Journal of Mineral Processing was founded by eminent sampling statistician Pierre Gy in 1974, the year that I started my 22 years at Camborne School of Mines. Mineral processing itself has seen great changes in those 43 years, and in fact only became a discipline in its own right at the beginning of the 20th century.

Prior to the industrial revolution of the 18th and 19th centuries the demand for metals was not very high. The small county of Cornwall in south-west England was the major producer of copper and tin in the mid 19th century, when world production of copper was about 60,000 tonnes per year, compared with around 20 million tonnes now. The copper ores were of very high grade and needed little upgrading, apart from simple hand sorting by bal maidens, female workers who worked the surface plants. Tin ores did need crushing and grinding, in stamp mills, prior to gravity concentration in crude devices such as buddles and rag frames.

The 'discovery' of electricity had a profound effect on metal demand, particularly for copper, and soon the main source of supply was from the vast deposits discovered in the Americas and Australia. By the beginning of the 20th century the demand for metals and minerals had become so high that the 'easy' ores were becoming scarce and the simple sorting and gravity methods could not adequately treat the ever decreasing grades and complexity of the vast quantities of mineral deposits which were available.

The mining industry was in crisis, and so was the industrialised civilisation, although most people would not have been aware of this. The search was on for an innovative method of upgrading the low grade base metal ores, and the great saviour of the mining industry was froth flotation. The invention of modern flotation is attributed to Francis Elmore, who patented a vacuum flotation process in 1904, which was used in the Zinc Corporation plant in Australia for 6 years, although the first recognisably "modern" flotation technique had been patented in London in 1903 by Sulman and Picard, and this used air bubbles formed by forcing compressed air through holes in the cell, but it would be years before such pneumatic cells would be commercially used. By 1908 flotation was working well for bulk flotation of zinc tailings, but the search was then on for means of treating primary sulphides, which led to the development of xanthate collectors, selective activators and depressants, and, as they say, "the rest is history". Just as it is difficult to overestimate the importance of the mining industry, so it is difficult to overestimate the value of froth flotation to modern society. How would we economically produce the metals and minerals that modern society cries out for without this process, which I have always referred to as the most important technological development since the discovery of smelting? Throughout the century, as the available ores became leaner and more complex, so flotation was adapted to effectively deal with them, and to this day research both into the physical and chemical aspects of flotation continues unabated.

There were also innovations in comminution in the early years of last century, with inefficient and energy consuming stamp mills being replaced by tumbling mills, which could be run in closed circuit with classifiers to control product size, so by the 1930s mineral processing flowsheets typically consisted of comminution in cone crushers and rod mills, and long lines of ball mills running in parallel, followed by banks of small flotation machines also running in parallel. By 1974 there had been innovative new processes, such as high intensity magnetic separation, the first enhanced gravity separators, and the first column flotation cells, and in extractive metallurgy hydrometallurgical techniques such as leaching, solvent extraction and ion-exchange with electrowinning were found to be viable options to traditional smelting. However typical mineral processing plants would have been instantly recognised by pre-war operators, as lines of small mills and flotation cells still dominated.

The biggest impact on minerals engineering was the rapid development, and increase of computer power in the 1980s, which has led to the simulation models that are used today, and the development of DEM, CFD etc. But perhaps more importantly powerful computers led to sophisticated methods of controlling mineral processing operations automatically and this in turn led to designers looking to overcoming the problems associated with replacing many small machines with fewer very large machines which could be more easily instrumented and controlled, and the trend for larger and larger flotation machines and grinding mills continued into the present century. Comminution in particular has seen major changes this century, with the development of high pressure grinding rolls (HPGR) and stirred mills, and it may be that these will replace tumbling mills in circuits in the not too distant future.

Worldwide the mining industry consumes around 2% of all electrical energy, and comminution is the major consumer, so great efforts are now made to reduce energy consumption, as well as water consumption which is also critical. In some respects we have come full circle- in the 19th century hand sorting was an important technique, and now electronic sorters are proving their worth in crushing circuits, thanks to multi-channel sensors made possible by powerful computers. Sorting will be a major feature in future comminution circuits, scalping out coarse barren rock, and hence reducing energy and water consumption.

I have to say that I wish I were 40 years younger, as our young editors now stand on the cusp of a second industrial revolution, the end of the era of the internal combustion engine, and the dawn of the new era of electric cars (see posting of 30 August). There will be a boom in metal demand, particularly copper, nickel and cobalt, and of course lithium for the Li-ion batteries. We are also now in the age of the "Hi-Tech Metals" used in all computers and smart phones (posting of 5th June), and the increasing demand for metals such as germanium, gallium and indium will put huge pressures on the supply of these metals, many of which are the by-products of base metal processing.  As these metals are present in tiny amounts in each individual computer or phone, and often alloyed with other elements, recycling presents enormous problems, but the move to the circular economy means that we have to get smarter at recovering and reusing the vast quantities that we have already extracted from the earth, rather than relying on continued pursuit of new reserves of ever poorer quality and at substantial environmental cost.

There are exciting times ahead, with enormous challenges, and minerals engineers, and Minerals Engineering, will play a critical role in the dawning of this new age.
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