Benchmarking the energy efficiency of fine grinding in the mining industry

MICHEL BRISSETTE AND JOHN STARKEY (STARKEY & ASSOCIATES) reported on the step change possible in comminution efficiency when comminution is coupled with an innovative technology at Quebec Mines 2013.

"In recent years, the mining industry has shifted toward mining orebodies with decreasing grades in economic minerals and increasing metallurgical complexity, in order to meet the growing demand for certain metals. One of these complexities concerns liberation of these minerals when it is achieved below 45 microns. Conventional technologies consume tremendous amounts of energy to reach the targeted grain size. These projects consequently require higher capital costs due to the larger equipment requirements but mainly due to the higher operating costs resulting from increased energy needs and consumables such as grinding media, thus impacting the profitability of many projects. Successful grinding of these minerals thus requires the development of new technologies.

There are currently five technologies available from four different manufacturers, one of which exists since... 1956! These technologies are used in the mineral industry outside of base and precious metals, in refineries, the chemical industry and the energy sector, namely  for scoria grinding, slaking, and flue gas desulfurization. The nameplate capacity of these types of equipment has increased nearly tenfold from 1998 to 2012.

The efficiency of a conventional technology, long considered inefficient, may be reduced by close to 40% when used with an innovative product. Surprisingly, this combination may be as energy efficient as a new technology! The combination of several technologies may further reduce energy consumption by 60%, and potentially 75% relative to conventional technologies, based on industrial results obtained in the mining sector.

The problem is that these results cannot be predicted through conventional metallurgical testing.

This presentation will focus on the new technologies available and on results obtained in the mining industry. New testing procedures must be developed to reflect industrial performances needed and requested by the mining industry."

View Brissette and Starkey's presentation.