Comparison of the overall circuit performance in the cement industry: High compression milling vs. ball milling technology

In cement production, tube mills having multi-chambers are traditionally used either in open or closed circuit operations. After the introduction of high compression grinding mills (High pressure grinding rolls (HPGR), vertical roller mill (VRM) and Horomill), various circuit configurations have been developed for energy efficient grinding. In this study, in order to evaluate and compare the performances of these cement grinding technologies, industrial scale data were collected from HPGR-ball mill, VRM, Horomill and multi-chamber ball mill closed circuits.The grind abilities of the raw materials of all circuits were varying in a narrow range of 14–20 kWh/t. The specific energy consumptions of the grinding equipment and the standard bond work indexes, used 100 μm screen, of raw materials are given below.CircuitBond work index (kWh/t)Specific energy consumption (kWh/t)HPGR-ball mill14.720.0VRM19.627.5Horomill14.417.5Ball mill14.432.5Full-size tableTable optionsView in workspaceDownload as CSVThe results show that high compression grinding mill circuits are more energy efficient than conventional single stage multi-chamber ball mill circuits. The circulating load ratio around the circuit is much higher compared to conventional ball milling. The reason is less fine and slime production of the high compression technology which prevents the over-grinding.