BFK98 as Additive to Enhance the Performance of Classified Tailings in a Deep Level Gold Mine

摘要

Savuka Mine, a seismically active deep level gold mine, which is part of the Anglogold South African operations, places backfill as part of the regional support strategy in their narrow tabular workings. Since introducing backfill as regional support to reduce seismic related damage in the late nineteen eighties, the percentage backfill placed has been gradually increasing. Being an old mine, initially designed to mine without backfill, the increased placement percentage and pumping distances in excess of 4000 meters, stretched the backfill infrastructure to its limits. The increased tonnage's required to be placed and the constant drive to increase productivity, required an in depth study to increase flow rates, reduce pipe wear and associated maintenance, increase placement density, reduce fill time and ensure consistent good quality backfill. Due to the layout of the mine the addition of flocculent would have been extremely labour intensive and was thus not considered viable. The addition of super plastisicer enriched gypsum, BFK 98, was assessed and found to enhance the performance of the backfill and infrastructure satisfactory. The function of the gypsum was to increase the density of the backfill to close to 1,8 grams per ton, and reduce water and fines loss. The super plastisiser ensures increased flow rates at the higher density, and reduce, in conjunction with the gypsum, pipe wear and maintenance. This paper addresses the research and tests done from the initial stages to full implementation of the addition of the gypsum in pulp form.