MODELLING THE EFFECTS OF SOIL AND OTHER FACTORS ON MUD FILTRATION

THIS PAPER reviews and discusses the problems at the filter station caused by high soil levels in cane, particularly with milling factories. It assembles known information on soil retention in milling trains and diffusers, clarifier underflow mud solids concentration, and then presents a spreadsheet model of the effect of soil on the filter station, pointing out areas where it can be improved with more information. It also discusses the effect of mud retention on the loading of underflow and filtrate, and presents a spreadsheet for the calculation of the effect of mud solids retention on filter flows, as well as the factors which influence filter mud cake production. Spreadsheet models have been derived and presented in an attempt to quantify the effect of soil on the filter station, to determine the effect of mud retention on the loading of underflow and filtrate, and to facilitate the estimation of filter cake removal capacity (based on results from a small test filter applied to the actual filter feed). The study is intended to assist technical staff in their understanding of the behaviour of the filter station under changing conditions.