摘要:
以含钒钢渣为原料,进行新硫酸和钛白废酸直接酸浸提钒研究。首先对试验用含钒钢渣进行成分、结构分析,结果表明:含钒钢渣主要由Ca2SiO4,(MgO)0.593(FeO)0.407,Ca3Fe2(SiO4)3,Ca3(V,Ti)2O7等相结构组成。钒在含钒钢渣中弥散分布在多种矿物中,以V4+价态与元素Ti、Fe、Ca、O元素形成的较为致密的大颗粒的钒钛钙氧化物(Ca3(V,Ti)2O7),是主要的钒富集相。直接酸浸难以破坏其结构,要提高钒的浸出率需要对含钒钢渣进行球磨。元素Ca、Si、V、O等元素形成了硅酸二钙等矿相,这些矿相中钒含量较低且较为分散,但其中V容易被酸直接浸出。含钒钢渣新酸直接浸出表明:常温,搅拌速度200 r/min,硫酸浓度30%,含钒钢渣粒度为-120目(124μm)粒级占比65%,液固比7∶1,酸浸时间1 h时,为较好的酸浸条件,钒的浸出率可以达到79%。上述工艺条件下液固比为5∶1时,以钛白废酸进行浸出时,钒的浸出率达到74%,新硫酸和废酸的钒浸出率相差不大。由于含钒钢渣CaO、FeO含量较高,耗酸量大,以新硫酸浸出,成本太高,而钛白废酸是废弃物,不能直接排放,传统处理工艺是采用碳酸钙中和,采用含钒钢渣中和钛白废酸可以大大消耗钛白废酸用量,降低单独中和废酸的碳酸钙用量,同时将含钒钢渣中的钒提取出来,实现了含钒钢渣的高值化利用。
关键词:
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含钒钢渣 /
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钛白废酸 /
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酸浸 /
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浸出率
Abstract:
Direct acid leaching of vanadium-containing steel slag with new sulfuric acid and titanium white waste acid was carried out.The compositions and structure of the vanadium-containing steel slag were analyzed firstly.The results show that the vanadium-containing steel slag is mainly composed of Ca2SiO4,（MgO）0.593（FeO）0.407,Ca3Fe2（SiO4）3,Ca3（V,Ti）2O7.Vanadium is dispersed in a variety of minerals in vanadium-containing steel slag.Relatively dense and large particle of vanadium titanium calcium oxide（Ca3（V,Ti）2O7） is the main vanadium-enriched phase.It is hard to damage the structure of Ca3（V,Ti）2O7 by direct acid leaching.To improve the leaching rate of vanadium,ball milling of the vanadium-containing steel slag is required.A lower content of vanadium is dispersed in dicalcium silicate,while V in the phase can be easily leached directly by the acid.79% of V is extracted by new acid direct leaching at optimum conditions of 200 r/min of stirring speed,30% of sulfuric acid concentration,65% of particles smaller than 124 μm,7∶1 of liquid-solid ratio and 1 h of leaching time.At the same conditions mentioned above,74% of V can be leached at 5∶1 of liquid-solid ratio using titanium white waste acid.Due to the high content of CaO and FeO,new sulfuric acid leaching of the slag will lead to a high cost.Titanium dioxide waste acid is a waste and cannot be directly discharged.Neutralizing the titanium white waste acid by vanadium-containing steel slag can greatly reduce the consumption of calcium carbonate for treating the waste acid.Simultaneously,vanadium can be extracted from the slag,realizing the high value utilization of the vanadium-containing steel slag.
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