Update on Finish Grinding with Improved Energy Efficiency

Machinery and equipment suitable for retrofits in existing finish grinding systems and for new installations are described: adjustable diaphragms for ball mills to control the material transfer from the first to the second compartment; static separators for product separation from the mill vent air; dynamic high-efficiency separators for product separation, with and without recirculation of separation air; and high-pressure grinding rolls for pregrinding or for use in a closed circuit. For all equipment, operating results are given with respect to capacity and energy efficiency. These results clearly demonstrate that considerable improvements in existing grinding systems, as well as higher energy efficiencies of new grinding systems, can be accomplished with these features. Capacity increases of existing systems can easily reach 55-68 percent with higher energy efficiency of 25 or 30 percent. For new grinding systems, energy efficiency can be increased by 30 or 35 percent in comparison to the conventional closed-circuit ball milling system. The improved energy efficiency also has a positive influence on the cement quality.