Bayer vanadium sludge (BVS), discharged during the Bayer alumina production, is a promising secondary resource for the supply of vanadium. Previous vanadium extraction process involving Pb5(VO4)3OH precipitation by PbSO4, H2SO4 and (NH4)2SO3 leaching, (NH4)2S2O8 oxidation followed by ammonium vanadate precipitation, suffered from large amounts of reagent consumption and discharge of ammonia-containing waste. In this study, a cleaner and cost-efficient process based on H2SO4 pre-treatment, H2O2 leaching, hydrolytic precipitation, and preparation of V2O5 through oxidative roasting was proposed to reduce reagent consumption and waste. Results show that the maximum vanadium leaching efficiency reached 99.7 % under the most suitable conditions of H2SO4 pre-treatment with H2SO4/Pb5(VO4)3OH molar ratio of 6.5, pulp density of 250 g/L at 90 °C for 4 h followed by H2O2 leaching with H2O2/V molar ratio of 3.0 at 15 °C for 10 min. Furthermore, 96.5 % of vanadium was precipitated in the forms of V5O12∙6H2O and V10O24∙12H2O by heating the leach liquors to 100 °C for 60 min, followed by the oxidative roasting at 400 °C for 2 h to prepare V2O5 product with a purity of 99.2 %, with only H2O as a by-product. This research provides new insights into vanadium extraction in a cleaner, cost-efficient, and sustainable industrial process which saves 147.4 $/t Pb5(VO4)3OH.

中文翻译：

---

利用拜耳钒油泥中回收的Pb5（VO4）3OH制备V2O5，经H2SO4预处理、H2O2浸出、V5O12∙6H2O和V10O24∙12H2O沉淀和400 °C氧化焙烧


拜耳钒污泥 （BVS） 在拜耳氧化铝生产过程中排放，是一种很有前途的钒供应辅助资源。以前的钒提取过程涉及 PbSO4、H2SO4 和 （NH4）2SO3 浸出 Pb5（VO4）3OH，（NH4）2S2O8 氧化后钒酸铵沉淀，遭受了大量的试剂消耗和含氨废物的排放。在这项研究中，提出了一种基于 H2SO4 预处理、H2O2 浸出、水解沉淀和通过氧化焙烧制备 V2O5 的更清洁且具有成本效益的工艺，以减少试剂消耗和浪费。结果表明，在最适宜的条件下，H2SO4/Pb5（VO4）3OH摩尔比为6.5，纸浆密度为250 g/L，90 °C，4 h，然后H2O2/V摩尔比为3.0，H2O2/V摩尔比为3.0，H2O2在15 °C下浸出10 min，钒浸出效率最高。 将浸出液加热至 100 °C 60 min，然后在 400 °C 下氧化焙烧 2 h，制备纯度为 99.5% 的 V5O12∙6H2O 和 V10O24∙12H2O 的钒，仅以 H2O 为副产品。这项研究为在更清洁、经济高效和可持续的工业过程中提取钒提供了新的见解，可节省 147.4 美元/吨的 Pb5（VO4）3OH。