Study On Comprehensive Utilization Of Tungsten Tailings From Shizhuyuan Tungsten Molybdenum Bismuth Polymetallic Ore

At present,the efficient and comprehensive utilization of tailings is a worldwide problem in the field of resource development.Tailings are mostly simply stored in dams or used as cheap building materials,currently.Above treatments not only have serious environmental hazard,but make the secondary resources of tailings have not been utilized fully.Due to the low yield of mineral processing,resources after grinding treatment that containing massive valuable elements have not been utilized efficiently.The tailings in Shizhuyuan,Hunan Province,have annual production of millions of tons,in which still contains a large amount of valuable substances such as fluorine,potassium,aluminum,tungsten and so on.In this paper,the efficient and comprehensive utilization of fluorine,potassium,aluminum and rare element tungsten in tailings was studied.Furthermore,a new method for comprehensive utilization of high value components in various non-ferrous metal tailings was proposed.Based on the new technical route proposed in this study,the result shows that the potential value of Shizhuyuan tungsten tailings is estimated to be about 1607.16 yuan/t according to mineralogical analysis.?In the study,two methods was tried to study the pretreatment mineral process of chemical extraction.One way is to remove iron firstly and then remove fluorite.The iron removal test of tailings is carried out by magnetic separation-flotation with CMC-BR as collector.The iron grade in tailings is finally reduced to 0.62%,which indicates that the effect of iron removal is impressive.However,the loss of tungsten tailings is enormous in the process.The other method is to separate fluorite and then remove iron,which adopts a open flotation process including 1 rough concentration and 7 fine-dressing with CMC-FN as collector.The fluorite concentrate with a grade of 90.27%and a recovery of 52.48%could be obtained after flotation.A magnetic separation test under weak magnetic intensity is experimented on the tailings obtained after 1 rough concentration.The result shows that the yield of magnetic separation tailings is high and the iron grade is 0.49%lower than that of coarse tailings.Therefore,the pretreatment route of fluorite separation firstly and iron removal was determined in our study.? In this paper,fluorochemical method was firstly proposed to utilize the K and Al comprehensively and enrich tungsten in the tailings after fluorite separation firstly and iron removal.The results show that the silicate crystal structure of the tailings was destroyed to form stable sulfate after the corrosion of fluorosilicate and sulfuric acid.Moreover,the reaction could take place spontaneously at low temperature.? The optimum reaction conditions were as follows:liquid-to-solid ratio of 7:1,H2SiF6 concentration of 15%,H2SO4 concentration of 15%,reaction temperature of 70?,reaction time of 2h,and stirring speed of 600r/min.The extraction efficiencies of K and Al could reach 84.02%and 93.73%,respectively.?Water-leaching process about the reaction slag after high temperature calcination and defluorination shows that the optimal conditions:liquid-solid ratio 5:1,dissolution temperature 90?,dissolution time 45min,stirring speed 250r/min.The dissolution rates of K and A1 are 80.38%and 90.49%,respectively.The analysis of tungsten in the reaction system shows that tungsten is concentrated in insoluble slag with a enrichment ratio of 3.03.The study on fluorine recycling shows that fluorine existed in insoluble slag is mainly fluorosilicate and fluoroaluminate.And the fluorine content in slag decreases with the increase of temperature,which provides a feasible way for the recovery and utilization of fluorine in the reaction system.In this paper,the new technical route of fluorine chemistry method for comprehensive utilization of various components nearly in tailings is proposed for the first time.Meanwhile,a lot of exploratory research is trialed.The preliminary study shows that the technical route is feasible for the development and utilization of various components in tailings as high value products.Furthermore,the rare elements(e.g.tungsten)in tailings is enriched,which creates conditions for a further development and utilization of these elements.In short,this paper opens up a new pathway for the comprehensive utilization of similar tailings system.