钛白废液浸出赤泥回收钪和钒的实验研究

Experimental Study on Recovery of Scandium and Vanadium from Red Mud by Leaching with Titanium Dioxide Wastewater

利用钛白废液浸出赤泥提取其中的V和Sc,考察了液固比、浸出温度、浸出时间和搅拌速率等对V、Sc浸出率的影响,并采用XRD和ICP-AES分析浸出渣的物相组成和浸出液的化学组成。结果表明:在液固比6 mL/g,搅拌速率400 r/min,浸出温度75℃和浸出时间1 h的条件下,V、Sc浸出率分别为75%和80%。相比于钛白废液,浸出液中氢离子浓度显著降低,V和Sc得到富集,Fe和Al的浓度也有一定提高。相比于赤泥,浸出渣中出现了硬石膏矿物,方解石全部溶解,钙霞石、板钛矿和赤铁矿部分溶解。

The extraction of vanadium and scandium from red mud were carried out by leaching with tita-nium dioxide wastewater.The effects of liquid to solid ratio, leaching temperature, leaching time and stirring rate on the leaching rate of vanadium and scandium were investigated.The phase composition of lea-ching residue and the chemical composition of leaching solution were analyzed by XRD and ICP-AES.The results show that under the conditions of liquid to solid ratio of 6 mL/g, stirring rate of 400 r/min, leaching temperature of 75 ℃ and leaching time of 1 h, the leaching rates of V and Sc are 75% and 80%,respectively.Compared with the titanium dioxide wastewater, the leaching solution contains significantly decreased H+ concentration, vanadium and scandium are enriched and the concentration of iron and aluminum is also increased.Compared with the red mud, anhydrite minerals appears in the leaching residue, while calcite is completely dissolved, cancrinite, brookite and hematite are partially dissolved.