Alternative Approaches for Determination of Bond Work Index on Soft and Friable Partially Laterised Khondalite Rocks of Bauxite Mine Waste Materials

摘要

PLK (Partially Laterised Khondalite) rock is a general terminology used in this paper for those rocks which are in general associated in bauxite mining such as Partially Altered Khondalite (PAK) rocks, Partially Kaolinised Khondalite (PKK) rocks and Lithomerge. This paper deals with the Bond’s work index, Hardgrove index and Brittleness tests on six typical rock samples and its correlation. As a fast method, the determination of the Bond index from the Hardgrove index (by calculation) is almost matching with measured Bond’s work index. The Bond’s work index of the above rock samples calculated from the Hardgrove index value has shown a variation from 7.7 to 10.3 kWh/sh.t. A correlation is found between the friability value and work index. The correlation coefficient of 0.93 between the friability value (S1) and Bond’s work index, Wi = -18.193 Ln (S1) + 66.747 has been found. The brittleness test results may not be very close to the work index values, as in brittleness tests relatively large grains are ground, whereas the HGI values, grinding of fine –grain samples involved. Thus the grindability of PLK rocks or bauxite can be determined by the simple test performance, HGI.