INCREASING THE PRODUCTIVITY OF A VERTICAL ROLLER MILL FOR CEMENT GRINDING

A report is given of the experience gained with wear in a vertical rol ler mill used for grinding cement at the Ofunato works of the Chichibu Onoda Cement Corporation (COCC), and also of measures introduced in t he cement works to increase productivity because of their high efficie ncy. The findings in relation to wear protection involved lowering the maintenance costs by hard-facing the wear protection elements on. the grinding table and grinding rollers. The rise in throughput due to in creased gas flow rate through the mill, the reduction in, specific pow er consumption achieved by installing the classifier outside the mill, and the introduction of automatic on-line fineness measurement in the grinding circuit to reduce labour costs and stabilize cement quality are described as further measures to increase productivity.