Salt roasting-leach residue acid leaching process: In order to solve the problem of low conversion rate of salt roasting-leach vanadium extraction, improve the overall recovery rate of V205, simplify the process flow, and reduce the cost low conversion rate of vanadium leaching by salt roasting and water leaching, the total recovery rate of V205 was improved, the process flow was simplified, and the production cost of refined vanadium was reduced. The process of salt roasting and re-acid leaching of water leaching residue was proposed, which improved the recovery rate of V205, reduced resource consumption, and improved the utilization of resources. However, it did not change the pollution problem of vanadium leaching by salt roasting.
The sodium roasting-leach residue acid leaching process was used to recover vanadium from the secondary acid leaching solution of the sodium roasted material from the Xichuan vanadium mine, and the ammonium salt vanadium precipitation method was used on the converted vanadium-containing solution to obtain V205 with a purity of 99.2%, laying the foundation for industrial application.
Salt roasting-acid leaching process: 12%-16% NaCI is added to stone coal, which is then roasted at 780℃-830℃ for 2h-3h. The roasted sand is leached with 4%-8% dilute sulfuric acid, and the leachate is purified, concentrated by heating, the pH adjusted, and vanadium is hydrolyzed and precipitated to obtain crude vanadium, which can be further purified to obtain fine vanadium. The residue after acid leaching has a high acidity and cannot be used as a building material. It takes up a lot of space when piled up, and the wastewater contains a high concentration of harmful metal ions, which need to be treated before being discharged.
In the process of sodium salt roasting to extract vanadium, in addition to the above-mentioned use of salt as a roasting additive, sodium carbonate or sodium sulfate is also used as a roasting additive to extract vanadium, which has also achieved good results and reduced environmental pollution.
