A Mechanistic Approach to Modelling Slurry Transport in AG/SAG Mills-transport through the Charge
In spite of the importance of the slurry transport and discharge in autogenous and semiautogenous (AG/SAG) mills, it is evident that a more comprehensive and useful model is still required.Semi-empirical models used up to now have many limitations and cannot be used beyond the ranges in which they were developed. The breakage of particles as they are transported along a mill complicates the experimental analysis and the modelling of the transport process within the mill. The interaction of the grate discharge and the pulp lifters, with the added issue of backflow from the pulp chamber into the mill, makes the discharge modelling process difficult. In order to overcome these difficulties, a mechanistic approach has been applied. The general transport and discharge model was subdivided into four independent models: Flow through the charge, flow through the grate,flow in the pulp lifter, and flow-back.This paper gives an overall description of the modelling approach and discusses in particular the modelling of transport of fluids through the charge. In order to evaluate and calibrate the model,experimental work was carded out. To evaluate the gradient pressure under different conditions of charge packing and flow rate, a specialised experimental rig with a highly sensitive pressure gauge was used. Preliminary results identify the differences of the charge and grate on the restriction of flow. The existence of a dynamic voidage in our particular system was more evident and as a result,a semi-empirical correlation for the voidage was developed. In general, results show that the mechanistic model derived from Erguns equation for flow through a packed bed can be satisfactorily adapted.
SAG mills Slurry transport Mill modelling
P. Condori A. Mainza I. Govender M. Powell
Centre for Minerals Research, University of Cape Town, Cape Town, South Africa
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
384-391
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）