Statistical Analysis of Wear Rate of Phosphate-Grinding Mill

A statistical Box-Behnken design (BBD) of experiments was performed to evaluate effects of individual operating variables and their interactions on the wear rate of grinding ball mills used in the phosphate industry. The wear tests were conducted using a specially designed grinding mill. The variables examined in this study included grinding time, solution pH, rotation speed, mill crop load, and solids percentage. The most significant variables and optimum conditions were identified from a statistical analysis of the experimental results using response surface methodology. Experimental results show that solution pH has the most significant effect on the wear rate for both Type 1018 (UNS G10180) carbon steel (CS) and a high-chromium alloy. The optimum process parameters for minimum wear rate were solution pH at 7.36, rotation speed at 70.31 rpm, a solid percentage at 75.50, and a crop load at 71.94% for Type 1018 CS; for the high-chromium alloys, they include a solution pH at 8.69, rotation speed at 61.13 rpm, a solid percentage at 64.86, and a crop load at 57.63%.