Method for separating and recovering vanadium and chrome from vanadium and chrome-containing waste

Abstract

The invention relates to the field of chemical hydrometallurgy, in particular relates to a method for separating and recovering vanadium and chrome from a vanadium and chrome-containing waste. The method comprises the following steps: (1) alkaline leaching; (2) adsorption of alkaline leaching liquid; (3) acid leaching; (4) ion exchange; (5) desorption and devanadation; and (6) vanadium precipitation. The method has the advantages that: (1) the method has lower cost than a primary and secondary compound amine extraction process; (2) the method has short process flow, convenient operation, easy control, easy mastering and mature production process of recovering vanadium and chrome once the vanadium and chrome are separated; (3) the method has low production cost, and excluding sales revenue from chrome residues and calcium sulphate, the cost of fine vanadium is only 50000-60000 yuan / t; (4) the vanadium and the chrome are completely separated by the method; and (5) the method produces no secondary pollution, all the production processes are performed at normal temperature and has no roasting fume, and industrial water is recycled and subject to zero discharge; produced neutralization residues are of high-quality chrome residues and calcium sulphate and can be sold to chemical plants and cement plants as a raw material.

Description

technical field [0001] The invention relates to the field of hydrochemical metallurgy, in particular to a method for separating and recovering vanadium and chromium from waste materials containing vanadium and chromium. Background technique [0002] Panzhihua is an important resource base of vanadium, titanium and iron in my country. In Panzhihua Iron and Steel's vanadium production process, the vanadium precipitation mother liquor contains a certain amount of hexavalent chromium and vanadium. In order to detoxify hexavalent chromium, a reducing agent must be added to reduce hexavalent chromium to trivalent chromium, while reducing chromium, vanadium is also reduced to low-valence vanadium, and vanadium chromium generates corresponding Cr 2 (V 4 o 9 ) 3 , and then adjust the pH value to 7-8, most of the chromium will generate Cr(OH) 3 Form co-precipitation with vanadium. After filtration, the filter cake contains more than 20% chromium and 4-12% vanadium pentoxide. The ...

AI Technical Summary

Problems solved by technology

This process is difficult to control and operate in the actual production process. The pH value of the given extraction process is 7-8. Vanadium in the solution is tetravalent, and chromium is triple unit valent.

If the vanadium-chromium slag of Panzhihua Iron and Steel is leached with acid to adjust the pH value to 7-8 under acidic conditions, almost all of the vanadium-chromium precipitates, and if it is leached with alkali, Cr 2 (V 4 o 9 ) 3 It is insoluble and difficult to leaching completely, and its leaching recovery rate is only about 20%, so this process has no practical significance for the separation and recovery of vanadium and chromium in the vanadium and chromium slag of Panzhihua Iron and Steel Co., Ltd.

Patent Publication No. CN1073414 discloses a method of chemically reclaiming vanadium-chromium from vanadium-chromium-containing waste water. Its principle is to add ferric chloride to generate Fe(VO 3 ) 3 Precipitate, recover vanadium by filtration, process industrial sulfuric acid and ammonium sulfate in the filtrate, chromium generates basic chromium sulfate, adjust alkali with NaOH to generate chromium hydroxide, this process is only practical for dilute solutions with low chromium and vanadium content, and for A solution with a large amount of chromium has no industrial value, because when the content of vanadium and chromium is large, chromium and vanadium can form co-precipitation, and the separation is not complete

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