China Nonferrous Metallurgy

The composition and mineral structure of the Panxi vanadium-titanium magnetite are complex, making it difficult to cost-effectively and efficiently utilize the valuable elements contained within. To address this issue, this paper explores the use of hydrochloric acid leaching at ambient temperature and pressure on the mineral, examining the effects of initial hydrochloric acid concentration, liquid-to-solid ratio, leaching time, and stirring speed on the leaching rates of Fe, TiO₂, and V₂O₅ Additionally, the paper analyzes the mechanism of separation of iron, vanadium, and titanium in the vanadium-titanium magnetite concentrate through mineral structural analysis, reaching the following main conclusions.The optimal process conditions for hydrochloric acid leaching at ambient temperature and pressure are an initial hydrochloric acid concentration of 20.5%, a liquid-to-solid ratio of 12∶1, a leaching time of 3.5 hours, and a stirring speed of 600 rpm. Under these conditions, the leaching rates of Fe, V₂O₅ and TiO₂ are 84.15%, 80.80%, and 10.05%, respectively. The concentrate in the leach residue contains 26.78% Fe, 0.378% V₂O₅ and 32.58% TiO₂, achieving preliminary enrichment of titanium resources. The hydrochloric acid preferentially dissolves the main crystal mineral magnetite in the titanomagnetite mineral, with iron and vanadium preferentially entering the leach solution, while the guest crystal mineral ilmenite and independent ilmenite are minimally disrupted and enriched in the leach residue. This leaching method does not require additional heating or pressurization equipment, offering advantages such as low cost, low energy consumption and equipment investment, simplicity of operation, and environmental friendliness. However, the leaching indicators still need to be improved, and further exploration of the impact of catalysts on the ambient temperature and pressure acid leaching process is needed in the future.