摘要:
采用水解沉钒技术分离溶液中的钒和铬,考察了沉钒pH值、温度、时间对钒铬分离率的影响,确定了最佳工艺参数:pH为2.0,沉钒温度为90℃,沉钒时间为60 min,在此条件下98%以上的钒进入滤饼(红饼),且滤饼洗涤后铬<0.3%;铬留存于溶液中,实现了钒铬简便高效分离。含钒滤饼经碱溶、铵盐沉钒、煅烧,获得了达到99级粉钒要求的V2O5产品。沉钒后的铬溶液采用Fe2(SO4)3除钒、Na2SO3还原、NaOH沉淀、Cr (OH)3洗涤煅烧,获得了达到颜料用优等品要求的Cr2O3产品。实现了溶液中钒铬的低成本高效分离及高品质钒铬产品制备,全流程钒收率为97.0%、铬收率为86.4%。
Abstract:
This paper focused on vanadium and chromium separation in solution using hydrolysis technology.The factors of p H value,temperature and time for vanadium precipitation have been investigated to study their effect on the precipitation rate of vanadium,and the optimum parameters have been determined as follows: p H of 2,temperature of 90 ℃ and time of 60 min,at which the precipitation ratio of vanadium exceeds 98% with less than 0.3% of chromium residual in the filtration cake after washing.Chromium mainly remains in solution through precipitation,which realizes simple and efficient separation of vanadium and chromium in solution.V2O5 products with purity more than 99% can be obtained stepwise via alkali dissolution of the vanadium cake,vanadium precipitation by（NH4）2SO4 and calcination.Using Fe2（SO4）3 to remove vanadium in chromium solution,Na2SO3 for reduction and Na OH for precipitation,pigment grade Cr2O3 can be acquired by roasting the washed Cr（OH）3.This work has realized low cost and high efficiency separation of vanadium and chromium in solution as well as preparation of high quality vanadium and chromium products,with 97% and 86.4% of total yield rate for vanadium and chromium,respectively.
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