A method for selectively leaching vanadium from stone coal roasting material

Abstract

The invention relates to a method for selectively leaching vanadium from stone coal roasted material. The adopted technical scheme is as follows: mixing the stone coal roasted material entering the first-section pressure leaching section with vanadium-containing sulfuric acid solution with the acidity of 0.4-1.2 mol / L in an autoclave according to the liquid-solid ratio of 1.5-3.0 L / Kg, performing leaching for 1-4 h under the conditions of 0.5-4.5 MPa and 150-300 DEG C, performing solid-liquid separation, and directly sending the first-section leachate into the subsequent process for reduction and extraction treatment; then, mixing the first-section leached residue entering the second-section leaching section with sulfuric acid solution with the acidity of 2.0-4.0 mol / L in the autoclave according to the liquid-solid ratio of 1.0-2.0 L / Kg, performing leaching for 1-4 h under the conditions of 0.5-4.5 MPa and 120-300 DEG C, performing solid-liquid separation, adding K2SO4 accounting for 0.1-1.0 wt% of the stone coal roasted material into the second-section leachate, adding alkali until the concentration of the sulfuric acid solution being 0.4-1.2 mol / L, and returning the obtained vanadium-containing sulfuric acid solution to the first-section pressure leaching section. The method has the advantages of high vanadium leaching rate, better leaching selectivity and lower acid consumption.

Description

technical field [0001] The invention belongs to the technical field of vanadium extraction from stone coal. Specifically relates to a method for selectively leaching vanadium from stone coal roasting material. Background technique [0002] Stone coal is an important vanadium-containing resource in my country, and the extraction of vanadium from stone coal has become the main utilization method of stone coal. However, the traditionally used sodium roasting-water immersion process will produce Cl during the roasting process. 2 , HCl, SO 2 Mixed gas will cause environmental pollution. In order to replace the sodium roasting process, scientific and technological workers have developed many new processes for extracting vanadium from stone coal. The process of acid leaching vanadium extraction from stone coal has less environmental pollution and simple operation process, so it has been paid more and more attention in the field of vanadium extraction from stone coal. However, ...

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Problems solved by technology

This makes it necessary to add impurity removal operations to the acid leaching solution obtained by the ordinary stone coal vanadium extraction process, which makes the stone coal acid leaching vanadium extraction process more complicated.

[0004] The selectivity of the stone coal acid leaching process is poor, and the impurity ions in the acid leaching solution are too high, which will also bring many other problems to the subsequent treatment

Li Wang et al. (Li Wang, Zhang Yimin, Liu Tao, Huang Jing, Wang Yi. The effect of impurity ions on the separation and purification of vanadium from stone coal acid leaching solution by extraction method[J]. Nonferrous Metals (Smelting Section), 2013, 5:27 ~34.) studied the influence of various metal impurity ions on the extraction of acid leaching solution, and found that Al 3+ When the concentration is higher than 10g / L, the extraction rate of single-stage vanadium will be reduced; Fe 3+ When it is greater than 5g / L, V will be significantly reduced 4+ Extraction rate; Fe 2+ Will be co-extracted into the organic phase, causing a decrease in the saturation capacity of the organic phase

Yang He et al. (Yang He, Mao Linqiang, Xue Xiangxin, Liu Dong. The effect of impurity ions on the precipitation of ammonium polyvanadate [J]. Steel Vanadium Titanium, 2013, 34(3):13~18.) found that phosphorus has The acidic ammonium salt has a great influence on the vanadium precipitation, which can significantly reduce the precipitation rate of vanadium, and will form complex complexes with vanadium and precipitate in the product to affect the purity of the product

[0005] To sum up, the existing stone coal acid leaching vanadium extraction technology mainly has the defects of low vanadium leaching rate, high acid consumption, and poor leaching selectivity, resulting in excessively high concentrations of aluminum, iron, and phosphorus in the leaching solution, which will affect the follow-up treatment. many questions

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