A method for direct vanadium precipitation from acidic multi-impurity vanadium-containing solution

Abstract

The invention relates to a method used for directly precipitating vanadium from an acid multi-impurity vanadium-containing solution. According to the technical scheme, the method includes the steps that an oxidizing agent is added into the vanadium-containing solution at first, oxidation is performed, and accordingly an oxidized vanadium solution is obtained; the addition amount of the oxidizing agent accounts for 1.0-2.5 times of the theoretical molar weight of an oxidizing agent required when low valent vanadium in the vanadium-containing solution is completely oxidized into pentavalent vanadium; then urea is added into the oxidized vanadium solution to be stirred according to the mass ratio of the urea to vanadium pentoxide in the oxidized vanadium solution being (3-20):1, solid-liquid separation is performed, and accordingly ammonium polyvanadate and vanadium precipitation mother liquor can be obtained; and afterwards, the ammonium polyvanadate is calcined for 0.5-3.0h at the temperature condition of 450-650 DEG C, and accordingly the vanadium pentoxide can be obtained. According to the chemical composition of the vanadium-containing solution, the vanadium concentration is larger than 6g / L, the aluminum concentration is smaller than 20g / L, the ferrum concentration is smaller than 1.0g / L, the sodium concentration is smaller than 30g / L, the potassium concentration is smaller than 2.0g / L, and the calcium concentration is smaller than 1.0g / L. The pH value of the vanadium-containing solution is smaller than 0.5. The method has the advantages that the technological process is short, the vanadium precipitating rate is high and the purity of the vanadium pentoxide product is also high.

Description

technical field [0001] The invention belongs to the technical field of vanadium precipitation from a vanadium-containing solution. Specifically, it relates to a method for directly precipitating vanadium from an acidic multi-impurity vanadium-containing solution. Background technique [0002] Precipitation of vanadium from vanadium-containing solution is a process of separating vanadium and impurity elements by means of precipitation and solid-liquid separation to obtain purer vanadium-containing products. The main chemical precipitation methods of vanadium are hydrolysis of vanadium, iron salt, calcium salt and ammonium salt: ammonium salt is divided into weakly basic ammonium salt, weakly acidic ammonium salt and acidic ammonium. Vanadium precipitation by salt; Vanadium precipitation by hydrolysis is to adjust the pH value of the purified vanadic acid or sodium vanadate solution to 1.5~3.0, and precipitate a mixture of polyvanadic acid and sodium polyvanadate under the co...

AI Technical Summary

Problems solved by technology

After the second stage of vanadium precipitation, it undergoes alkali dissolution-adjustment of pH value with sulfuric acid-ammonium salt precipitation of vanadium, and the purification treatment process is long

[0007] In summary, the existing vanadium-containing solution vanadium precipitation technology mainly has the disadvantages of long process flow, low vanadium deposition rate and low purity of vanadium pentoxide products.