Abstract

Research was performed to make an objective comparison of Bond Ball Mill Grindability Work Index results derived from using two commercial testing apparatus, from BICO and Sepor respectively, each with a different mill shell design. Six tests were carefully performed with both mills using the same aggregate rock sample and with the same method of grindability testing based on Fred Bond’s Ball Mill Grindability Work Index (BWi) testing methods. After the tests were completed, statistical analysis using the Q test, p values, the F test and the student t test were used to confirm and compare the data sets derived from both commercially available testing equipment. The result of this testing indicates that the design of the Sepor ball mill delivers less variable BWi results than the BICO ball mill. As well, the Sepor mill returned a significantly higher and more reproducible mean BWi value of 12.238kWhr/t versus the BICO BWi mean value of 10.786kWhr/t in testing of the same material. It is postulated that the differing shell design on the BICO mill is the root cause of these differences.

Keywords:Grindability; Material; Energy; Bond ball; Crushing