湿法炼锌过程中纳米级二氧化硅除氟技术工艺研究

以工业水玻璃为原料,采用液相沉淀法制备了纳米级二氧化硅,并将其应用于锌电积液除氟。实验结果表明,未经焙烧处理的纳米级二氧化硅无除氟能力; 纳米级二氧化硅经400 ℃、4 h焙烧后,在加入量为锌电积液中F-质量的60倍、锌电积液硫酸浓度145 g/L、除氟温度40 ℃、除氟时间3 h条件下,纳米级二氧化硅吸附氟容量为13 mg/g,对锌电积液中氟脱除率达到78.05%,除氟后溶液含氟0.09 g/L,满足锌电积工序要求。

Investigation of Fluorine Removal with Nanosilica During Zinc Hydrometallurgy Process

Nanosilica was prepared by liquid phase precipitation process with industrial water glass as raw material, and then applied for fluorine removal from electrolyte of zinc electrowinning. Results show that the uncalcined nanosilica is not capable to remove the fluorine. However, after the nanosilca was subjected to a 4 h-calcination at 400 ℃, it was added into the electrolyte for fluorine removal with an amount of 60 times the mass of fluorine in the solution. After 3 h defluorination reaction at 40 ℃ with the sulfuric acid concentration of the solution at 145 g/L, the fluoride removal rate of the electrolyte was up to 78.05%, showing the fluoride adsorption capacity of nanosilica was 13 mg/g. The solution after fluorine removal only contained 0.09 g/L fluorine, meeting the requirements for zinc electrowinning process.