The world's most important scientific conference takes place in Cape Town in November?

Never underestimate the importance of the mining industry. I never do, but I know that many people do, including some within our industry.

The world has an insatiable demand for metals and minerals, and the mining industry is the great feeder- without it no other industries could survive. It has become a cliché, but it is a fact that everything we touch is either mined or grown.

The massive demand for minerals has meant that the mining industry has changed enormously from the activities of the late 19th and early 20th centuries. Ores then were fairly easy to treat. In the 19th century Cornwall was the world's largest producer of copper and tin. Copper ores were of very high grade and could be concentrated for the smelter by simple hand sorting, tin ores being treated by crude gravity concentration. The increasing demand after the industrial revolution, however, meant that the 'easy' ores were becoming worked out, and the ores available were becoming more and more difficult to treat. There was an urgent need to develop a new process for concentrating these ores, as simple gravity processes were not up to the job.

The great saviour of the mining industry was froth flotation. Engineers at Broken Hill in Australia had been working on this since 1901 to enable extraction of huge quantities of zinc in the tailings dumps. It was also independently investigated by Guillaume Delprat of BHP, and Charles Potter, a brewer from Melbourne, who each patented processes to recover zinc from gravity tailings by adding acid to hot carbonate mineral slurries to generate carbon dioxide to float the minerals. Delprat's process worked succesfully at Broken Hill for many years, and there were various other attempts to use hydrophobicity, involving film flotation, which had been developed in the late 19th century, but 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 for 6 years.

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 (another cliché), "the rest is history".

Just as it is impossible to overestimate the importance of the mining industry so it is impossible 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?

As the available ores become leaner and more complex, so flotation must continue to adapt to effectively deal with them, so research both into the physical and chemical aspects of flotation (see also posting of 6th March) continues unabated. There will be many very large scientific conferences taking place around the world this year, some with thousands of delegates, but few will be more important to society than the relatively small one which takes place in Cape Town in November- it is Flotation '17.

Flotation '17 will be the 8th in MEI's flotation series, and as always will attract the leading players in this field, researchers, equipment manufacturers, reagent companies and operators. Keynote lectures will be given by distinguished scientists, Prof. Roe-Hoan Yoon from Virginia Tech, USA (posting of 16 June 2016) and Dr. Bill Johnson from Mineralis Consultants, Australia (posting of 15th August 2016).



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Intense discussions at Flotation '15

There is now a final call for abstracts. If you would like to present a paper at the conference, please submit a short abstract no later than the end of May. Papers presented at the conference will be considered for publication, after peer-review, in a special flotation issue of Minerals Engineering.

If you have any interest in flotation, you must be at the beautiful Vineyard Hotel in November! Take a look at the report on Flotation '15.

Delegates relaxing at Flotation '15

Twitter @barrywills    #Flotation17