Operational experience from the United States´ first vertical roller mill for cement grinding

For several decades the cement industry has successfully utilized vertical roller mills (VRM) for grinding of raw materials and solid fuels. Most recently, this technology has been employed for the combination of Portland cement, blended cements and slag cements. The VRM offers several benefits compared to the ball mill in regards to operating costs and flexibility. However, the quality of the cement produced is extremely important in cement grinding and there is little experience with cement produced from a VRM in the US market. This paper relates the operational experiences from the first VRM for clinker grinding put into operation in the United States in 2002. Included in the discussion are operational data, maintenance discussion and laboratory data focused on product quality. All of the discussion is based on comparison to ball mill operation at the same plant.