Concentration of phosphate ore by flotation with/without desliming

A 3000 TPD dolomitic rock phosphate beneficiation plant in Western India recovers a fertiliser grade concentrate assaying 32 per cent P2O5 from a ROM feed assaying 20 per cent P2O5 with 80 per cent P2O5 recovery and generates dolomite tailings containing around 8 - 10 per cent P2O5. Huge quantities of P2O5 values are locked up with these tailings in addition to posing disposal problem in Tailing Pond. Indian Bureau of Mines (IBM) is a premier organisation catering to the need of conservation of minerals and protection of environment in mining areas in India. IBM has successfully addressed this problem by systematic characterisation of this dolomitic rock phosphate deposit (assaying 20.7 per cent P2O5, 9.87 per cent MgO) followed by process development. The beneficiation process evolved in the Ore Dressing Laboratory of IBM at Nagpur is flotation which has generated three useful products viz (i) High grade phosphate concentrate 36.8 per cent P2O5, 1.32 per cent MgO with 90 per cent P2O5 recovery, (ii) a blendable refractory grade dolomite concentrate (MgO 19.32 per cent) with 84 per cent dolomite recovery and (iii) a middling product (P2O5 > 16 per cent) suitable for direct application as fertiliser in the soil. This process is thus capable of converting the ROM ore into three usable products which find industrial application, establishing the process developed as a Zero-waste Beneficiation Technology. High pulp density conditioning of the ground pulp with anionic collector, use of starvation quantities of reagents and short conditioning time are some of the key features of the process developed. The Industrial application of the above process, it is hoped could dispense with the problem of disposal of waste and help in conservation of valuable phosphate mineral.