Purification of Vermiculite from Ranchi District, Bihar

Abstract

Studies were undertaken to purify and evaluate a vermiculite sample from Ranchi District, Bihar. The sample contained about 20% gangue consisting mostly of biotite, chlorite, lateritic clay, tremolite and actinolite. Drying and crushing the sample in a hammer mill to -1”, followed by rejection of -65 mesh fines, yielded a vermiculite concentrate. Screen fraction of this concentrate i.e., +1/2”, -1/2” +3 mesh, -3+20 mesh and -20+65 mesh, when exfoliated had bulk densities of 5.8, 7.6 and 17.0lbs/cu.ft. respectively. The ese values were comparable to those of similar produces obtained from abroad and marketed in India.