钒渣钠化焙烧熟料浸出液除磷工艺研究

Removal of phosphorus from leaching solution of sodium roasted vanadium slag clinker

以钒渣钠化焙烧熟料浸出后得到的含钒溶液为原料,分析了二水硫酸钙在碱性条件下对含钒溶液中磷的去除机制,研究了二水硫酸钙用量、溶液pH、反应时间、反应温度等因素对磷去除率、钒损失率以及溶液中五氧化二钒与磷质量浓度比的影响。研究结果表明:在弱碱性条件下,二水硫酸钙可有效去除含钒溶液中的磷,磷去除率达到70%以上、钒损失率小于1%、五氧化二钒与磷质量浓度比大于2300,满足后续沉钒的要求。确定的除磷工艺条件:二水硫酸钙与磷物质的量比为5.3,溶液pH为9.0,反应时间为30 min,反应温度为25℃。除磷后的含钒溶液经沉钒、洗涤、煅烧得到五氧化二钒产品,沉钒率大于99%,五氧化二钒产品质量满足YB/T 5304—2011《五氧化二钒》中99级的要求。

Using the vanadium-containing solution,obtained from leaching sodium roasted vanadium slag clinker,as the raw material,the removal mechanisms of CaSO4·2H2O on the phosphorus in vanadium-containing solution under the alkaline condition were analyzed.The effects of CaSO4·2H2O dosage,pH of solution,reaction time and reaction temperature on the removal efficiency of phosphorus,loss rate of vanadium and mass concentration ratio of V2O5 to P were studied.Results showed that phosphorus can be effectively removed from the vanadium-containing solution under weak alkaline condition by using CaSO4 2H2O.The removal efficiency of phosphorus was higher than 70%,the loss rate of vanadium was lower than 1%,and the mass concentration ratio of V2O5 to P was higher than 2300,which satisfied the requirements for the subsequent vanadium-precipitation process.The optimum operation conditions for removing phosphorus were confirmed as follows:n(CaSO4·2H2O)/n(P)=5.3,pH of solution was 9.0,reaction time was 30 min and reaction temperature was 25℃.Vanadium pentoxide was obtained from the phosphorus-removed vanadium-containing solution by vanadium-precipitation,washing and calcinations.The yield of the vanadium-precipitation process achieved as high as 99%,and the product quality satisfied the Level 99 requirements for the standard of Vanadium Pentoxide(YB/T 5304—2011).