Quantitative Assessments of Abrasive and Impactive Wear from Ball-Size Distributions in Rotary Mills

摘要

New distribution functions are derived that describe the steady-state size distributions of grinding balls in mills under conditions of combined abrasive and impactive wear. Previously derived and reported size-distribution functions that are applicable under conditions of purely abrasive or purely impactive wear are shown to be special cases of the more general formulae derived in the present work. The new distribution functions are applied to all the data on ball-size distributions found in the literature, and it is shown that quantitative assessments can be made of the abrasive and impactive components in the total rate of ball wear. The correlation between the calculated values and the known conditions that prevailed in the mills is good. This clearly indicates that such assessments can be used in the optimization of the metallurgical and chemical characteristics of grinding balls for any given application. Conversely, this information can provide guidelines for the modification and adjustment of factors of mill operation and liner design to give the most desirable combination of impactive and abrasive conditions in a given mill. The formulae and techniques of analysis developed could also be useful in other applications where particles are consumed at rates proportional to their dimensions.