Optimisation of flotation parameters for the low grade flaky graphite oresfrom Orissa by factorial design method.

The samples of low grade flaky graphite ores from Ganbaur area, Bolangir di strict and Daspalla area, Puri District of Orissa, assayed 8.2% and 9.0% fi xed carbon. The original samples were subjected to size reduction operation by a laboratory single toggle blake jaw crusher, followed by a laboratory rolls crusher so as to get a product passing through 12 mesh B.S.S. The pro duct was then fed to laboratory pot mill to study the grinding characterist ics of the samples. The flotation trials were conducted on the ground samples at a pulp density of 14.28% solids in a laboratory Denver flotation cell. The critical flota tion parameteres were observed to be - mesh of grind G, concentration of th e depresesant D, and the concentration of the collector K. These parameters were optimised using the factorial design method to follow the linear equa tions for the grades of the concentrates as follows: G(r) (Ganbaur) = 73.55 + 4.3 G + 0.925 D + 1.625 K and G(r) (Daspalla) = 72.3 + 4.4 G + 1.1 D + 1.75 K.