Environmental protection type vanadium extraction process through replace of sodium chloride with soda

Abstract

The present invention relates to an environmental protection type vanadium extraction process through replace of sodium chloride with soda. Compared to the vanadium extraction process by a traditional fire baking method, the main characteristic of the process of the present invention is that: an efficient vertical baking furnace is adopted to replace the open hearth furnace in the vanadium extraction process by the traditional fire baking to carry out baking, the formula of the additive is optimized so as to reduce the pollutant discharge, a tank type circulating dump leaching process is adopted to replace the acid leaching extraction or an ion exchange step, at the same time, an aeration evaporator is adopted to treat the vanadium precipitating waste water and the waste gas generated from the furnace by using the baking furnace flue gas waste heat. According to the present invention, the whole mechanical operation is adopted, such that the vanadium recovery rate can be improved by 30%, the labor intensity of the worker is substantially reduced, and the water use amount is saved by 80%; the sodium salt in the waste water can be recovered when the vanadium precipitating waste water is treated, the dust and other harmful components in the waste gas are absorbed, and the recovered sodium salt returns to a material stirring system, such that the assistant material can be reused, and the remaining part can be sold as by-products.

Description

Technical field: [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a process for extracting vanadium pentoxide by an environment-friendly sodiumization method. Background technique: [0002] Vanadium is an important non-ferrous metal. Vanadium and its alloys are widely used in metallurgy, petrochemical industry, national defense industry and other fields. Because of the small investment, simple process and high recovery rate of vanadium, vanadium extraction by sodium chemical method is a vanadium extraction method commonly used by existing domestic vanadium plants. However, because sodium chloride is used as a roasting additive and a flat kiln is used as a roasting furnace for vanadium extraction at present, chlorine gas will be generated due to the decomposition of sodium chloride during the roasting process, and chlorine gas will be discharged into the atmosphere without treatment. It reacts with water vapor in the air to form...

AI Technical Summary

Problems solved by technology

However, because sodium chloride is used as a roasting additive and a flat kiln is used as a roasting furnace for vanadium extraction at present, chlorine gas will be generated due to the decomposition of sodium chloride during the roasting process, and chlorine gas will be discharged into the atmosphere without treatment. It reacts with water vapor in the air to form hydrochloric acid, which is denser than air and will settle to the ground, causing serious pollution, burning nearby vegetation, and causing human and animal damage in severe cases

After the roasting material is leached, most of the existing ion resins exchange vanadium extraction, because the ion resin only absorbs metavanadate ions, and can only absorb the leach solution with a vanadium concentration of about 3 g / L, if the vanadium concentration is high, it must be diluted to an appropriate concentration, so Other components (mainly sodium salts) in the leachate are discharged with the water. Calculated by producing one ton of vanadium pentoxide, 300 tons of clear water, about 10 tons of sodium chloride, and about 3 tons of ammonium chloride are needed. About 300 tons of waste liquid after vanadium extraction was directly discharged because there was no effective treatment method or the treatment cost was too high. The discharged wastewater contained a large amount of salt, ammonium chloride, and various harmful heavy metal ions, so it caused The pollution is quite serious, and the relevant state departments have also issued a document to list vanadium extraction by flat kiln roasting sodium as a prohibited item.