Comminution is the oldest process technology and it is also one of the largest, most extensive and most complex. It is very large because of the huge amounts of rocks and particles which are broken annually to support the world’s population, it is extensive because of the wide range of processes for which comminution must be used, and it is complex because of the many variables which affect its performance. There is an old dictum – get the comminution right and concentration looks after itself. This may be an overstatement, but the sentiment is correct. Comminution is very important in Peru because of the wealth of ores which contain fine grained valuable minerals.
Regular meetings to review current comminution practice and look towards the future may be wide ranging as far as the topics discussed are concerned but to make a significant contribution to process technology the papers presented will have some focus on the practice of comminution technology.
Comminution 2019, which is an early meeting in what is planned to become a series, will necessarily be restricted to a limited range of topics, suffice it to write that it will be concerned with the breakage of coarse rocks and their progeny in SAG mills, of smaller pebbles in HPGRs, and of finer particles in vibrating and tumbling ball mills of various types.
Classification is regarded in Comminution 2019 as an extremely important part of fine grinding processes. It has been handled better by dry grinding engineers than by those concerned with wet grinding because circulating load can build quickly in dry grinding and can reduce productivity. .For example cement production engineers have built three generations of classifiers for cement circuits and the circulating loads have been reduced from a high to a low multiple. By contrast wet classification has progressed slowly, the main developments being the rake classifier more than 100 years ago and the hydrocyclone more than 50 years ago.
Comminution 2019 will be a forum for new ideas and debate. It was the debate generated by Ritter von Rittinger’s new ideas about the energy-size reduction relationship in the mid 19th century which started our process of understanding comminution, may this meeting help the debate to flourish. We welcome technical contributions from the global metallurgical industry to the Comminution Conference in Lima.