Preparation of high-purity vaterite CaCO3 from lead-zinc tailings

This study introduced a green scheme for high value treatment of lead-zinc tailings, which pro-duced high-purity vaterite from lead-zinc tailings. The effects of different experimental parame-ters on the leaching and carbonization of Ca2+ in lead-zinc tailings were discussed. It was found that the optimum leaching ratio of Ca2+ in NH4Cl solution was 74.87% and the optimum car-bonization ratio of Ca2+ in the leaching solution was 96.96%. The spherical CaCO3 with d50 < 10 mu m, 99.41% purity, and 98.70% whiteness was prepared under suitable carbonization conditions. The XRD results showed that the CaCO3 product was high purity vaterite. The pres-ence of NH4+ and Zn2+ in the leaching solution hindered the transformation of vaterite into cal-cite, leading to the formation of high-purity vaterite CaCO3. The SEM results indicated that the dispersants STP or PEG-6000 could improve the dispersion of vaterite, and STP contributed to the formation of fine particle vaterite. This method proposed an approach for the production of va-terite from lead-zinc tailings, broad application prospects.

Automated summary

This study introduced a green scheme for producing high-purity vaterite from lead-zinc tailings, finding that the optimal leaching and carbonization ratios of Ca2+ were 74.87% and 96.96% respectively. Under suitable conditions, spherical CaCO3 with high purity and whiteness was prepared, showing potential for broad application prospects in vaterite production.