Projects which push the limits of efficient performance concepts of high-pressure grinding rollers

Abstract

The ore pretreatment process evolution is briefly addressed, with some milestones and pioneer projects described. Two advanced projects of concentration mills based on the technology of the pioneer-level high-pressure roll milling are discussed. The operating Canadian Copper Mountain Mill is interesting for using the technology which eliminates bottlenecks of the classical semi autogenous milling circuit, with the resultant increase in the mill capacity more than two times as against the initial project value. This result has been achieved for the first time in the world owing to total rejection of the ore pretreatment circuit and thanks to complete transition to press roller milling. Design and engineering of high-pressure roll mill HRC3000, as well as auxiliary milling and flotation equipment is in progress. The high-capacity Iron Bridge Magnetite Mill under construction in Australia can be assumed as the breakthrough project owing to the world’s first time trial of Enduron high-pressure grinding rolls by Weir Minerals in milling of magnetite quartzite and in dry production of fine products suitable for further processing without ball milling. The power saving in dry milling using high-pressure rolls will make 30 % at the least as compared with the present-day ore pretreatment by wet milling. Ball mills are withdrawn from the processing circuit, water consumption drops, carbon emissions are decreased, and the tailing storage becomes simpler and safer. In dry tailing storage, the capital investment is cut down as the operation of thickening of wet tailings is rejected, dam construction for tailings ponds is eliminated, and the environmental impact related with contamination of surface and ground water bodies, which is intrinsic to operation of conventional tailings storage facilities, is mitigated.