Method for extracting vanadium from high calcium and high phosphorus vanadium slag

Abstract

FIELD: chemical or physical processes.SUBSTANCE: group of inventions relates to production of vanadium oxide, in particular to a method of extracting vanadium from vanadium slag with high content of calcium and phosphorus. Vanadium slag with high content of calcium and phosphorus containing from 9 to 25 % of V2O5, from 5 to 14 % of CaO and from 0.3 to 1.5 % of P is annealed with formation of clinker. After that, the first stage of clinker leaching is carried out using a mother solution at pH from 3.0 to 3.5. Solid and liquid phases are separated to produce first filtrate and first residue. First step of removing phosphorus is carried out with addition of an agent for removing phosphorus in form of polymer iron sulphate into first filtrate with separation of solid and liquid phases, and production of vanadium-containing liquid. Second leaching step is carried out with the first residue using a mother solution at pH from 1.3 to 2.0. Solid and liquid phases are separated to produce second filtrate and second residue. Second stage of phosphorus removal is performed by bringing pH of the second filtrate to an alkaline agent to 2.5–3.5. Solid and liquid phases are separated to obtain dephosphorized liquid. Third stage of leaching is carried out with the second residue using a mother solution at pH from 0.7 to 1.3. Solid and liquid phases are separated to produce third filtrate and final residue. Stages are repeated until vanadium residue content is reduced to less than 0.6 %.EFFECT: method provides high degree of extraction of vanadium, simple and cheap process of time.7 cl, 1 dwg

Description

technical field [0001] The invention relates to a vanadium extraction method from high-calcium and high-phosphorus vanadium slag, and belongs to the field of vanadium oxide extraction. Background technique [0002] Vanadium titanomagnetite is treated at high temperature in blast furnace or electric furnace to obtain vanadium-containing molten iron, and vanadium slag is selectively oxidized from molten iron. Then it is further blown into qualified molten steel, which is currently the mainstream vanadium extraction-steelmaking method. [0003] In recent years, as users have become more and more strict with steel performance requirements, high-quality steel requires P≤0.015wt%, and low-temperature aviation steel pipes and tinplates require P≤0.01wt%. If vanadium titanomagnetite is used for smelting, the content of P in molten iron is often high, ranging from 0.06wt% to 0.08wt%. After desulfurization and vanadium extraction or vanadium extraction and desulfurization, the S cont...

AI Technical Summary

Problems solved by technology

This method achieves the purpose of deep phosphorus removal from the solution by starting to remove phosphorus 30 minutes before the first acid leaching reaction of the clinker; the first acid leaching residue is dephosphorized by the second acid leaching, and at the same time, the residue is further recovered. vanadium, but there are problems in the process of recovering vanadium from the second acid leaching solution, which are difficult and costly, and it is difficult to realize industrialization

[0007] So far, there is no feasible vanadium extraction method for high calcium and high phosphorus vanadium slag

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