BENEFICIATION OF SILLIMANITE USING 220 MM DIAMETER FLOTATION COLUMN

Large scale sillimanite beneficiation studies carried out, at the instance of M/s. Indian Rare Earths Ltd, on the largest pilot flotation column set up available in the country are discussed in this paper. Around 2 tonnes of beneficiated sillimanite concentrate containing around 90% sillimanite was produced while treating around 10 tonnes of material from the concentrate upgradation plant (CUP) tailings of OSCOM Chhatrapur, Orissa containing 42% sillimanite. The large scale studies were primarily carried out to substantiate the results obtained on 75 mm diameter Diester flotation column at MRDC, Quilon. It was established that sillimanite concentrate confining 90% sillimanite with around 90% recovery can be obtained by using 0.75 kg/tonne sodium oleate as collector. Effect of feed rate, air rate and collector dosage were also studied while attempting to reproduce the results and the salient findings are presented.