Method for producing low-chromium ammonium polyvanadate

Abstract

According to a method for producing low-chromium ammonium polyvanadate, ammonium polyvanadate produced from vanadium slag with an acidic ammonium salt precipitation method is used as a raw material and is added to a sodium carbonate solution, after a solution is produced through heating and reaction, polyacrylamide is added, the solution is left to stand for clarification, and a vanadium solution is obtained through filtration; the vanadium solution is diluted with water, sulfuric acid is added for adjustment of the pH value, ammonium sulfate is added, after the solution is heated to be boiling and the ammonium polyvanadate reacts, ammonium polyvanadate solids are obtained through filtration and then are washed with a mixed solution of sulfuric acid and ammonium sulfate, the ammonium polyvanadate is rinsed with water, and a low-chromium ammonium polyvanadate product with the chromium mass content being smaller than or equal to 0.03% is obtained. The method has the advantages as follows: the technology is simple, the prepared ammonium polyvanadate has the relatively high purity (V2O5% is larger than or equal to 99.6%), the content of potassium and sodium is low (the sum of the content of K2O and the content of Na2O is smaller than or equal to 0.05%), the chromium content is low, and the defect that ammonium polyvanadate prepared from the vanadium slag used as the raw material has the high chromium content is effectively overcome.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy for extracting vanadium from vanadium slag, and particularly relates to a process for producing low-chromium ammonium polyvanadate in the process of extracting vanadium from vanadium slag. The method can reduce the chromium content in ammonium polyvanadate to 0.03%. the following. Background technique [0002] Low-chromium ammonium polyvanadate is the main raw material for the production of low-chromium flake vanadium pentoxide. It is expensive, has high added value, and has wide application prospects. It is often used to prepare high-end vanadium-aluminum alloys, titanium alloys, and metal vanadium products. [0003] Vanadium-titanium magnetite is the main mineral resource of vanadium. Vanadium-titanium magnetite is smelted into vanadium-containing molten iron by blast furnace, then oxidized and blown by converter. After enrichment, vanadium enters the slag phase to obtain vanadium slag. The vanad...

AI Technical Summary

Problems solved by technology

However, because the vanadium solution prepared by roasting vanadium slag with sodium method contains vanadium and chromium (containing 15-35g / L of vanadium and 0.3-2.5g / L of chromium), the properties of vanadium and chromium are similar, and the vanadium solution is more likely to be precipitated by sulfuric acid and ammonium sulfate. During the process of ammonium vanadate, a small amount of chromium will be entrained into ammonium polyvanadate along with the vanadium precipitation reaction. The impurity chromium cannot be removed by water washing. The chromium content of ammonium polyvanadate is usually 0.08-0.40%, which cannot meet the needs of high-end users for low chromium. Special requirements for ammonium polyvanadate (usually chromium ≤ 0.05%)

Images