Optimization of grinding process in ball mill drum mill

Ball drum mills have found wide application in many industries, where high hourly productivity of one unit is required, reaching several hundred tons of finished product - mining, energy, chemical and building materials industries. To date, the overall dimensions of mills have reached their limits, the world's largest mill has a diameter of 12 meters and a drum length of 36 meters, and its capacity is 3000 tons per hour. One of the main directions of improvement of mills is the development of such designs of inner-mill devices, which would increase the efficiency of the grinding process as a whole. A brief analysis of the design of ball drum mills, the efficiency of the grinding process is given. The authors describe the design of the lining proposed by the authors, which consists of standard plates, in which made transverse chutes diameter of chutes corresponds to the diameter of the grinding bodies, which are in this section of the drum of the mill. The diameter of the chutes decreases from loading to unloading. The interaction of lining with grinding bodies and its ability to prevent transverse and longitudinal segregation of grinding bodies is shown. In the course of search experiments the main factors influencing the classification of grinding bodies were revealed. These factors include: the coefficient of loading of the mill drum with grinding bodies; the rotation speed of the mill drum; the depth of the grooves of the lining; the number of projections in the grooves of the lining. As optimization parameters were chosen: mill productivity; power consumption of the drive; specific energy consumption; residue on sieve 008; specific surface of the finished product. The results of experimental studies in the form of regression equations and graphs are given. A comprehensive analysis of the influence of the studied factors and interaction effects on the formation of response function values and the efficiency of the grinding process as a whole has been carried out. For revealing of rational design and technological parameters of the ball drum mill and modes of its operation the dependences of mill productivity and specific energy consumption on its main factors have been jointly considered. Rational modes of operation of the ball drum mill equipped with a new design of lining have been established.