EVALUATING HIGH-PRESSURE MILLING FOR LIBERATION ENHANCEMENT AND ENERGY-SAVING

A programme of laboratory based studies has been undertaken to evaluat e the extent of liberation enhancement and energy saving that might be expected when utilising high pressure rolls comminution, This route h as been compared to that achieved by conventional grinding for the fin al preparation of a base metal ore for feed to a flotation circuit, Bo nd grindability tests were undertaken to estimate expectation of energ y requirements for a close circuit mill and direct interpolation allow ed an estimate of mill energy required for de-agglomeration following high pressure rolls crushing, The energy input to a simulated high pre ssure rolls mill was measured directly from work input to samples of t he ore, The extent of mineral liberation was assessed directly by eval uating the results obtained from flotation release analysis of the gro und samples, The results obtained suggest that a similar degree of lib eration may be obtained by the high pressure route but at a coarser pr oduct size compared to a conventional route, The energy saving as a co nsequence of a coarser product and the use of high pressure rolls may be as high as 30%. Despite the marginally lower overall recovery obtai ned the results from a limited test programme suggest that the high co mpression route may offer significant scope for improved process effic iency. (C) 1997 Elsevier Science Ltd.