Method for recovering vanadium and iron from acid liquor containing tetravalent vanadium and ferrous iron

Abstract

The invention relates to a method for recovering vanadium and iron from acid liquor containing tetravalent vanadium and ferrous iron, which comprises the following steps: (1) adding an iron oxyhydroxide seed crystal into the acid liquor containing tetravalent vanadium and ferrous iron, and stirring to obtain a pretreatment solution; (2) carrying out oxidation treatment on the obtained pretreatment solution, and carrying out solid-liquid separation to obtain a ferrovanadium enriched material and a filtrate; (3) mixing the obtained ferrovanadium enriched material with alkali liquor, carrying out conversion treatment, then carrying out water leaching, and carrying out solid-liquid separation to obtain iron oxyhydroxide and a vanadium-containing solution; and (4) sequentially carrying out purification treatment and vanadium precipitation on the obtained vanadium-containing solution, and carrying out solid-liquid separation to obtain ammonium metavanadate. The method realizes enrichment, dissociation and productization of ferrovanadium in the acid liquor, simply and efficiently realizes deep purification of the vanadium-containing solution, synchronously recovers aluminum resources, has the advantages of high resource recovery rate, high product purity, simple operation, low cost and no emission of three wastes, and has a wide application prospect.

Description

technical field [0001] The invention relates to the field of vanadium extraction by wet method, in particular to a method for recovering vanadium and iron from an acid solution containing tetravalent vanadium and ferrous iron. Background technique [0002] Stone coal is a vanadium-containing polymetallic mineral resource and one of the main raw materials for extracting vanadium. In addition to vanadium, stone coal often contains aluminum, potassium, iron, calcium, magnesium, molybdenum, nickel, cobalt, copper, and titanium. , chromium, uranium, silver selenium and other associated elements. At present, the methods for extracting vanadium from stone coal mainly include two categories: roasting method and acid leaching method. Due to the instability of the roasting process, the process of vanadium extraction by roasting is seriously polluted and the recovery rate of vanadium is low. At present, the acid leaching process is mostly used in production, including direct acid lea...

AI Technical Summary

Problems solved by technology

The methods for enriching vanadium mainly include extraction method and ion exchange method, such as CN101289703A, CN106282538A and CN101580902A public extraction methods enrich vanadium usually use P204 extractant, P204 is easier to extract ferric and tetravalent vanadium, so it is necessary to extract Pentavalent vanadium is reduced to tetravalent, and ferric iron is reduced to bivalent. The problem is that the stripping liquid needs to consume oxidant to oxidize tetravalent vanadium to pentavalent vanadium. The extraction agent is easy to emulsify, and the raffinate is difficult to treat organic wastewater.

[0004] CN109706329A, CN104841682A, CN108559843A and CN108754191A disclose that the ion exchange method usually adopts a weakly basic anion exchange resin to absorb pentavalent vanadium anions under the condition of pH=2-3, and long-term operation will produce aluminum and iron hydroxide precipitation to block the resin , to reduce the adsorption capacity of the resin, and at the same time, the ion exchange method also has problems such as a large amount of washing water

[0005] Regardless of whether extraction or ion exchange is used to enrich vanadium in the acid leach solution, the iron in the raffinate and effluent is usually neutralized by adding calcium and enters the slag phase, resulting in no recycling of iron resources in stone coal.

Moreover, there are cationic impurities such as iron, aluminum, magnesium, potassium, and calcium in the extraction and stripping vanadium enrichment solution, and anion impurities such as silicon, phosphorus, arsenic, molybdenum, chromium, and uranium in the ion exchange desorption vanadium enrichment solution, and the types of impurities increase. Reduce the difficulty of impurity removal and reduce the purity of vanadium products

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