Avaliação dos mecanismos de desgaste de corpos moedores em moinhos de bolas

Abstract

The grinding of ores is an important cost item in the production of metals. Metal wear is a major part of it. This paper reviews the most accepted models for wear during grinding. This process, in fact, is not just a mechanical one as most of the models induce, but also electrochemical as in the slurry inside the mill there are ionic species able to carry out metal corrosion. The joint action of abrasion and corrosion has a synergetic effect and the rate of the joint process is greater than the sum of the rates of the two individual processes. A series of bench tests with two iron ore concentrates of different silica grades, using marked balls, varying metal composition and slurry pH was performed. Wear rates were calculated from diameter reduction as a function of time. Results make able to identify and measure the abrasion and corrosion components on the final result.