Experimental Study On New Mineral Processing Of A Mixed Ore Of Scheelite And Wolframit In Jiangxi

Domestic consumption of tungsten resources called for a huge growth of tungsten exploitation. In the meantime, tungsten with low valuable mineral grade, fine disseminated extent and complex components are more and more processed than before, leading to more difficulties in industrial operation.This thesis targets a polymetallic deposit in Jiangxi province, the raw material contains low amount of tungsten and the fine disseminated extend. On an industrial scale, the full flotation process are adopted and the flotation recovery is unsatisfactory. Based on the original operation parameters, this thesis endeavors to develop a new flotation process that allows more effective recovery of the valuable minerals.Mineral analysis shows the raw minerals contains mainly scheelite, additionally, wolframite accounts for 18.69%. Previous studies have shown that disseminated extend of scheelite are likely to result in poor mineral liberation. Further, the large composition of black mica and common mica in the raw material are apt to worsen the flotation process, thus, a loss of wolframite during the process.The full flotation process is studied in depth, specifically, three collectors are chosen for the flotation process, namely, sodium oleate, 733 and laboratory synthetic fatty acid collector PZ–2. Experimental results show PZ-2 possesses better selectivity over the other two surfactants. Full-flotation-circuit is employed, the concentrate grade of WO3 has reached 58.35% and the flotation recovery sores to 72.31%, as for gangue minerals, the raw tailing and concentrate tailing contains only 0.039% and 0.62% valuable minerals respectively. Based on our results, the low recovery of industrial operation is analyzed. The analysis of tungsten phase shows only a small part of wolframite was recovered and the full-flotation method caused a loss of most wolframite. On the other hand, the gridding and heating processes are accompanied by high economy costs. Therefore, we draw the conclusion that the operation parameters need improvement to create more feasible benefits.Gravity separation process has the advantages of low cost, so the new process uses spiral concentrator to discard tailings by gravity separation. The particle distribution and feeding concentration are studied. Results show discarding tailings reaches 37.28% and the loss of tungsten is reduced to 6.12%. Two sets of experiments are carried out on the gravity separation products, mixed tungsten flotation and magnetic separation and results give no improvements in mixed flotation whereas magnetic separation and shaking table are able to concentrate wolframite. According to the above discussion, a new tungsten process is proposed, in short, joint process of discarding tailing via gravity separation-black tungsten strong magnetic separation – flotation. This novel method is able to raise concentrate grade to 57.08% and recovery to 77.11%. A 4.80% increase can be observed compared with the full-flotation recovery, in addition, the wolframite recovery has imporved. The advantage of the new process is that it not only can reduce the cost of grinding by discarding tailings, but more importantly, the floating mineral feed is only 62% of raw materials. Compared with full flotation process, the agent consumption is reduced, thus, highly applicable in industrial scale.Study on the Zeta potential of scheelite and fluorite surface indicates that, after the addition of water glass, Zeta potential of two minerals have obvious decreased, showing that water glass can be absorbed on the mineral surface, and if continue to join collector PZ-2 into the solution, potential of mineral surface enlarged. It is probably that the collector competes with water glass in the mineral surface adsorption. In the determination of adsorption at the surface of scheelite and fluorite, fluorite is inhibited by low concentration of water glass, but scheelite was inhibited only at higher concentration. Infrared spectroscopic studies prove that collector PZ-2 can occur chemical adsorption stability on the surface of scheelite.