Grindability and Dissociation of Minerals in Rod and Ball Milling of Ferruginous Quartzites
S. A. Alekseeva
Mining Institute, Kola Science Center, Russian Academy of Sciences, Apatity, Russia
s.alekseeva@ksc.ru
Keywords: Rod milling, ball milling, milling rate, dissociation degree, magnetite, silicates, pay size, magnetic separation
Abstract
In terms of ferruginous quartzites, a set of studies is carried out, including the comparative analysis of the rod and ball milling performance, as well as the analysis of dissociation of base minerals and magnetic treatment of products. It is shown that in milling to the size of the first milling stage, conformable with the size of the upper impregnation of magnetite, both mill types operate in the energy-efficient mode. Owing to the uniform grain-size composition, the rod milling produces higher dissociation of magnetite and better magnetic separation in open operation cycle. The presence of large sizes in the ball mill discharge predetermines recleaner flotation of the mill tailings. From the obtained relationships of the specific output and specific energy consumption of the pay size of - 0.63 mm with the rod and ball milling fragmentation size, it is found that in transition to processing lower grade and refractory ore, with the required decrease in the milling size to 20% and more of the size of - 0.071 mm, it is economically expedient to replace rod mills by ball mills.
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