钒钛磁铁矿钙化焙烧-酸浸提钒过程中钒铁元素的损失

Loss of vanadium and iron in calcified roasting and acid leaching of vanadium-bearing titanomagnetite

在理论分析的基础上,以钒钛磁铁矿为原料,硫酸钙为钙化剂,系统研究了钙化焙烧和硫酸酸浸过程的钒、铁等有价组元的损失。研究结果表明:钙化焙烧-酸浸提钒工艺在理论上是可行的;焙烧过程中,烧结产物中的钒损失率随温度的升高而升高;尽管焙烧过程损失了部分钒元素,但焙烧后钒元素更易于溶解浸出;钒浸出率随焙烧温度的升高先升高后降低且1450 K时达到最大值;当硫酸浓度增加时,钒浸出率变化不大;当焙烧温度高于1450 K时,浸出渣中铁的损失率快速上升,硫酸浓度增加时,其值随之增大;控制适当条件可强化钒的有效迁移,目前实验室研究条件下,钒的浸出率最大可达79.08%,而此时铁的损失率为3.32%。

Based on the principle of calcified roasting and E-pH diagram of acid leaching, the loss of vanadium and iron in calcified roasting and acid leaching were investigated with vanadium-bearing titanomagnetite as raw material and calcium sulfate as calcification agent. The vanadium extraction process combining calcified roasting and acid leaching was feasible in theory. The loss ratio of vanadium in pellets increased with increasing temperature in the calcified roasting process. Despite some loss of vanadium the calcified roasting process was favorable to the subsequent acid leaching of vanadium. The leaching ratio of vanadium increased with increasing roasting temperature below 1450 K. The leaching ratio reached a maximum at 1450 K, and then it decreased. The leaching ratio of vanadium had no obvious change with increasing sulfuric acid concentration. At the same time, the loss ratio of iron in the leaching process increased rapidly when roasting temperature was higher than 1450 K, and it also increased with increasing concentration of sulfuric acid. By controlling experimental conditions, the leaching ratio of vanadium in vanadium-bearing titanomagnetite could reach 79.08%but the loss ratio of iron was 3.32%.