Technical and economical appticability study of centrifugal force gravity separator (MGS) to Kef chromite concentration plant

摘要

The results of multigravity separator (MGS) upgrading tests on fine chromite gravity tailings using -100 and -100+150 mu m fractions of the initial sample (-1 mm) with 24.7 percent Cr_2O_3 grade were presented. The metal screen analysis revealed that 20.66 percent of the total Cr_2O_3 content was present in the -106 mu m size fraction. Under optimal operational conditions, a concentrate with 43.7 percent Cr_2O_3 content and 65.0 percent chromite yield for the size fraction of -100 mu m and a concentrate with 30.5 percent Cr_2O_3 and 83.3 percent yield for the size fraction of -100+150 mu m could be produced. Shaking table test results revealed that the coarse fraction of the tailings could not be enriched any further owing to the high concentration of interlocked particles. However, a saleable concentrate could be obtained by MGS when the coarse tailings were ground down to -100 mu m and used as the feed. The results of the study suggested that multigravity separation of the Kef tailings was technically feasible and economically viable. The payback time of two alternatives suggested for the utilisation of MGS in Kef concentrator was calculated to be <7 months.