A method for separating vanadium and iron by two-stage selective leaching of stone coal

Abstract

The invention particularly relates to a method for two-section selective leaching and separating of vanadium and iron from stone coal. According to the technical scheme of the method, the stone coal is crushed and roasted for 60-80 min at the inoxidizability atmosphere and under the condition that the temperature ranges from 800 DEG C to 900 DEG C, fine grinding is conducted, and a roasted material is obtained. According to the solid-to-liquid ratio of the roasted material to a sulfuric acid solution I being 1:(1.5-3)t / m<3>, the roasted material is subjected to acid leaching in the sulfuric acid solution I for 10-30 min under the condition that the temperature ranges from 20 DEG C to 40 DEG C, and iron containing pickle liquor and first-section acid leaching residues are obtained. According to the solid-to-liquid ratio of the roasted material to a sulfuric acid solution II being 1:(1.5-3)t / m<3>, the first-section acid leaching residues are subjected to acid leaching for 3-8 h in the sulfuric acid solution II under the condition that the temperature ranges from 90 DEG C to 98 DEG C, and vanadium-containing pickle liquor and second-section acid leaching residues are obtained, wherein the volume concentration of the sulfuric acid solution I ranges from 5% to 7%, the volume concentration of the sulfuric acid solution II ranges from 15% to 20%, and the iron content of iron pyrite in the stone coal accounts for 90% or above of the iron content of the stone coal. The method has the beneficial effects that adaptability is high, the vanadium and iron separating efficiency is high, the technology is simple, and impurity iron control at the source can be achieved.

Description

technical field [0001] The invention belongs to the technical field of vanadium extraction by hydrometallurgy. Specifically, it relates to a method for separating vanadium and iron by two-stage selective leaching of stone coal. Background technique [0002] At present, acid leaching is the main process for extracting vanadium from stone coal, including blank roasting-(leaching aid) acid leaching process, direct (leaching aid) acid leaching process, and oxygen pressure acid leaching process. , Low-valence mica-type vanadium-containing stone coal, the blank roasting-(leaching aid) acid leaching process is more adaptable. In the vanadium extraction process, a large number of impurity ions such as Fe, Al, Mg, etc. will enter the vanadium-containing acid leaching solution together with V, which will affect the subsequent treatment of the acid leaching solution. Fe, as a kind of impurity ion with variable valence, has a particularly prominent impact on the subsequent treatment o...

AI Technical Summary

Problems solved by technology

The solvent extraction method can adapt to the vanadium-containing leaching solution with many impurities and high acidity; however, while the solvent extraction method realizes the efficient purification and enrichment of V, a part of Fe will co-extract with V, which affects the indicators of vanadium products

Under certain conditions, the chemical precipitation method can obtain high-quality vanadium products, but it is often accompanied by high vanadium loss

[0004] To sum up, most of the current separation methods of vanadium and iron are realized in the vanadium-containing leaching solution, which has problems such as poor adaptability, incomplete separation of vanadium and iron, and high loss of vanadium.