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以西北某省高碳石煤为研究对象,通过石煤循环流化床焙烧,灰渣直接酸浸提钒实现碳、钒资源的综合利用。在对石煤中钒的赋存状态进行分析的基础上,考察高碳石煤循环流化床的焙烧特性,同时针对硫酸浓度、酸浸温度、酸浸时间、液固比等因素对钒浸出率的影响,进行了灰渣酸浸提钒的试验研究。研究结果表明:钒主要赋存于钒云母和铁铝氧化物中,分别占总钒含量的73.89%和14.78%;循环流化床焙烧温度为850℃时,燃烧效率可达69.17%,高碳石煤热能得到了有效利用,同时,焙烧脱碳也有利于钒的富集,对灰渣酸浸提钒过程中钒浸出率的提高亦有正面影响作用;赋存于不同矿物中的钒浸取难度不同,游离氧化物中的钒最易浸出,铁铝氧化物中的钒较易浸出,钒云母矿物中的钒最难以浸出;硫酸浓度、酸浸温度、酸浸时间、液固比等对钒的浸出均有影响,而硫酸浓度和酸浸温度的影响更为显著。较适宜的酸浸条件为:硫酸浓度6 mol·L-1,酸浸温度110℃,酸浸时间2 h,液固比2.5∶1.0。在此条件下,钒浸出率可达88.61%。
Taking a high-carbon stone coal in a certain province of Northwest China as the research object, the comprehensive utilization of carbon and vanadium resources was achieved through roasting of stone coal circulating fluidized bed and direct acid leaching of vanadium slag. Based on the analysis of the occurrence state of vanadium in stone coal, the roasting characteristics of circulating fluidized bed of high carbon stone coal were investigated, and the leaching of vanadium was also carried out according to the factors of sulfuric acid concentration, acid leaching temperature, acid leaching time, liquid-solid ratio Rate of the impact of ash acid residue leaching vanadium experimental study. The results show that vanadium mainly occupies 73.89% and 14.78% of the total vanadium content in the vanadium mica and iron-aluminum oxide respectively. When the roasting temperature of the circulating fluidized bed is 850 ℃, the combustion efficiency can reach 69.17% Stone coal thermal energy has been effectively utilized, while decarburization is also conducive to the enrichment of vanadium roasting vanadium leaching process vanadium leaching rate increase also have a positive effect; vanadium leaching in different minerals vanadium With different difficulty, the vanadium in the free oxides is most easily leached, the vanadium in the Fe-Al oxides is more easily leached, and the vanadium in the vanadium mica minerals is the most difficult to leach out; the concentration of sulfuric acid, the acid leaching temperature, the acid leaching time, Vanadium leaching have an impact, and the concentration of sulfuric acid and acid leaching temperature is more significant. The optimum conditions of acid leaching were: sulfuric acid concentration 6 mol·L-1, acid leaching temperature 110 ℃, acid leaching time 2 h, liquid-solid ratio 2.5:1.0. Under this condition, vanadium leaching rate can reach 88.61%.