Recovery of ZrO₂ from zirconium-containing waste salt based on response surface methodology

Zirconium-containing waste salt is the main solid waste in the purification process of crude zirconium tetrachloride, which contains a large amount of zirconia and soluble chloride, and zirconia can be recovered by water leaching and roasting. Response surface methodology is used to optimize the water leaching process. When the liquid-solid ratio is 8:1 mL/g, the stirring time is 60 min, and the leaching times are 3 times, the predicted value of zirconia content in the leaching residue is 95.2%. At the same time, the leaching residue is roasted. When the roasting temperature was 600 ℃ and the time is 60 min, in this connection, the content of zirconia is 96.23%. The micro morphology and composition of leaching residue and roasting product are characterized and analyzed by SEM, XRD and XRF. The results show that the main component of the leaching and roasting products is zirconia, and the content of zirconia in the roasting products is increased by 1% compared with that of the leaching products, and the grain size is better than that of the leaching residue.