Rapid Assessment of the Wear Limit of Grinding Balls Used in the Mining Industry

Abstract. The mining industry of the Republic of Azerbaijan is one of the leading sectors of the non-oil economy. Currently, the extraction of non-ferrous metals is carried out by two companies: Azerbaijan International Mining Company (AIMC) and AzerGold. The first company is a joint venture between Azerbaijan and the British company Anglo Asian Mining, while in the second company the production share fully belongs to the Republic.

During the grinding of ores, it is often necessary to determine the residual life of grinding balls. During operation, their mass decreases due to wear, which significantly affects grinding quality and requires additional loading of the mill drum. In this regard, the aim of this study is to establish the relationship between the resource indicator, the physical and mechanical properties of materials, and the operating parameters of the mill, enabling rapid assessment and response to product quality.

As a result of numerous experimental studies and using the MILLTRAJ simulation program, a mathematical relationship was established between the critical wear value, ore hardness, drum rotation speed, impact toughness, and mill loading degree.

During operation, one of the key conditions is to ensure Y ≤ Ykr, where Y and Ykr represent the current and critical wear values of grinding balls, respectively. The value is determined as Ykr = ..., where the diameters of the steel balls after and before use are considered. Ykr is the critical wear limit. The allowable wear limit for SAG mills is taken as Y = 50%.

Based on experimental studies (Y=f(T), Y=f(H), Y=f(V)) and the MILLTRAJ simulation program, a mathematical model was obtained that establishes an empirical relationship between steel ball wear and process parameters:

Y = k·(H+4)V0.2 T2 = (0.012·H + 0.048)V0.2 T2