Mass Balance Of A Grinding Circuit

CIM Bulletin, Vol. 69, No. 776, 1976

A. L. Mular, Professor of Mineral Engineering, University of British Columbia, Vancouver, R. G. Bradburn, Mill Superintendent, and B. C. Flintoff, Project Metallurgist, Brenda Mines Limited, Peachland, B.C., and C. R. Larsen, Research Assistant, Mineral Engineering, University of British Columbia, Vancouver, B.C.

Following the acquisition of grinding-circuit data at Brenda Mines Limited for simulation purposes, various methods to mass balance the circuit were evaluated. Unfortunately, different answers were obtained for different balancing methods. A data-adjustment procedure was therefore developed. The procedure assumes that all measured data are in error and finds adjusted values which satitsfy a "best-fit" criterion. A search is conducted with the minimum set of water masses and narrow size ranges of solids around the circuit (called search variables), which permit the computation of any of the measured data points. Search variables are used to calculate measured values for an objective function of the form: R = S where Wt is a weighting factor, Mt is a measured value and M( is a corresponding value calculated from search variables. The best values of Mi are those which minimize R. The above method is compared with others that have been utilized for mass balancing circuits.

Keywords: Mineral processing, Grinding circuits, Mass balances, Brenda Mines Ltd., Data processing, Simplex search.