废钒催化剂综合利用的实验研究

Study on comprehensive utilization of waste vanadium catalyst

研究了以废钒催化剂为原料,经水浸-还原酸浸-萃取-沉钒等环节制取五氧化二钒、硫酸钾、液体硅酸钠的方法。考察了以三正辛胺(TOA)-仲辛醇-煤油溶液为萃取液提钒的最佳工艺条件:将废钒催化剂磨碎至375μm左右,经过水浸、还原酸浸后,合并其浸出液进行氧化,在水相pH为2.3时,用9%的TOA-3%的仲辛醇-88%(均为质量分数)的煤油溶液萃取,在浸取时间为2.5 min条件下,经三级萃取,钒的萃取率达99%以上;在pH>8、反萃取剂为0.25 mol NaOH+0.25 mol NaCl、反萃时间为3 min条件下,经三级反萃,钒的反萃取率达99.4%。在此工艺条件下,钒、钾的回收率分别达到91.5%和93.8%,产品五氧化二钒、硫酸钾、液体硅酸钠的主要成分含量均达到相应国家标准要求。

The method of preparation of vanadium pentoxide, potassium sulfate, and sodium metasilicate liquid with the waste catalyst containing vanadium as raw material was researched.The processes of the method included water extraction, acid reductive leaching, extraction, and vanadium precipitation etc..The optimal process conditions of the recovery of vanadium with the solution of TOA-2-octanol-kerosene as extraction liquid have been investigated：the waste vanadium catalyst was grinded down to about 375 Ixm,then it was soaked by water and reduetive leached by acid;the combined lixivium was oxidized, and when the pH was 2.3 in the phase of water, it was extracted by the solution of 9% TOA-3% 2-oetanol-88% （all mass fraction） kerosene;the extraction rate of vanadium was above 99% by three steps of the extraction and the time of 2.5 min.Under the conditions of pH 〉8, back-extraction agent of 0.25 mol/L NaOH ＋0.25 mol/L NaC1, and back-extraction time of 3 min ,the back-extraction rate of vanadium reached 99.4% by three steps of back-extraction.Under such conditions, the recovery rate of vanadium and potassium reached 91.5% and 93.8% respectively.The contents of products of vanadium pentoxide, potassium sulfate, and sodium metasilieate liquid were all in line with the corresponding national standards.