Pre-concentration: a necessary step for upgrading tungsten ore

In upgrading lean tungsten ore, gravity concentration by jigging of vein quartz produced a pre-concentrate containing 4.5% WO3. For further upgrading the pre-concentrate, beneficiation studies were conducted with an objective of obtaining a product analysing >65% WO3 with less than 1% impurities of SiO2 and S each. The sample contained quartz, topaz and iron sulphides as gangue. The study presented in this paper has shown that a further pre-concentration to remove topaz is necessary for improving efficiency of downstream separation process and to achieve desired product. Results of enrichment studies using −200# ground sample have also been discussed. Desired product could be obtained by pre-concentration of the jig pre-concentrate by tabling followed by flotation at −200# and vanning of flotation tailing.