铬盐无钙焙烧工艺铬酸钠中性液铁盐除钒

摘要

According to the current existing problem in the vanadium precipitating process in calcium salt by non­calcium roasting technology with chromium salt, such problems as large amount of calcium salt, repeatedly adjusting the pH value, slag containing calcium chromate and other issues, iron salts were used as precipitating agent to remove vanadium. The amount of iron salt added, pH value, temperature and other major factors on the impact of vanadium removal were investigated, the optimum conditions are that the vanadium concentration in final liquid is less than 0.08 g/L, which satisfies the follow­up process requirements. Utilizing iron salt to remove vanadium can be operated in wide pH range, without repeatedly adjusting the pH value. By analyzing, the slag phase is ferric hydroxide, which adsorbs vanadium, containing no chromium. And by further exploring against adsorption mechanism, vanadium is adsorbed on the surface of the iron hydroxide by inner layer complexation.%针对铬盐无钙焙烧工艺浸出液除钒现行钙盐沉钒法钙盐加入量大、需反复调节pH值、脱钒渣含铬酸钙等问题，提出采用铁盐作为沉钒剂进行除钒。考察铁盐加入量、pH 值和温度等主要因素对钒脱除的影响，得到了最佳工艺条件，且终液钒浓度低于0.08 g/L，满足后续工艺要求。铁盐除钒可在较宽的pH值范围内操作，不需反复调节溶液pH值。渣相分析表明：脱钒渣为吸附钒酸根的氢氧化铁，其中不含铬，进一步探讨氢氧化铁对钒的吸附机理，确定钒酸根通过内层络合方式吸附在氢氧化铁表面。