Process Design study for the beneficiation of Kaluwe Phosphate Ore

Abstract

Kaluwe phosphate ore constitutes calcite(74.4 wt %)as the major mineral with minor amounts of apatite(5.9 wt %),opaques(13.5 wt%),which are predominantly iron minerals,quart/feldspar(5.7) and traces of biotite(o.5 wt %).The chemical composition of the ore averaged 2.2% p2o5,47.7% Cao,1.6%mgo,1.2% Al2o3,3.3% Fe2o3 and 4.7% Sio2.Beneficiation studies were performed to investigate methods of concertrating the phosphate values.Preliminary studies involved detailed identification of mineralogical and chemical properties of the constituent minerals which could form the basis of selective seperation of apatite from the gangue.The results of these studies showed that liberation of apatite ocurred below 425um.On the basis of the identified mineralogical and chemical properties of the minerals,tabling,magnetic concertration and flotation techniques were applied in the beneficiation tests.The results indicated that these techniques could not be individually applied to produce a final phosphate concertrate because of the poor grade of ore.Encouraging concertrate grades were obtained after combining these techniques.A treatment flowsheet has been proposed on the obtained results.The multiplicity of processing steps in the flowsheet implies increased capital and operating costs.This is unavoidable due to low grade nature of the ore.