Optimization Research On The Working Parameters Of Half Autogenous Tumbling Mill

ABSTRACT:This thesis makes an introduction to Dongguashan copper mineral separation plant and φ28ft×13ft half autogenous tumbling mill imported from America in2003.Since the trial production from Octorber,2004, it is rather high-energy-consumption and can not meet the intended requirements for a long time. Based on investigation, we find out problems according to the theory of kinematics and dynamics attached to free-fall motion of steel balls in mill. Therefore,we advance some reformation measures to increase production and to save energy by a large margin.Before May,2010, the motion trace of steel balls is regular. Casted too high, steel balls impact on lining board instead of ore. The result is that the grinding efficiency is low and the lining board is severely damaged. So the back part of this thesis will have an analysis of the motion medium in mill and seek out the law of motion. The height and setting point will be strongly controlled to make full use of kinetic energy of steel balls to smash ore. Theoretical explanation accounted for full production of half autogenous tumbling mill will be provided.The seize of steel balls is small at the begining of production. The process of grinding is a process of energy transformation. The research of falling kinetic energy of steel balls is very important as for grinding is done by steel balls. The impacting energy of steel balls is the kinetic energy when fall to destination which decide the quality of steel balls and the eight to fall. So as for the same mill, proper largement of the diameter of steel ball can enhance the impacting energy to increase the working efficiency of mill. If the diameter is enlarged from φ130mm to φ200mm, working rate will be enhanced from200t/h to542t/h and reach the standtard and production requirements.In addition,this essay also analyzed the impact of lifting strip’s amount and structure to semi-autogenous mill.What’s more, the result of the research on discrete element simulation revealed the impact of the media fill rate and rotation rate to the semi-autogenous mill’s efficiency.As a result, the article put forward the improvement measures of improving semi-autogenous mill’s productivity in theory and provides a reference for engineering application of semi-autogenous grinding mill.