Deironing method for vanadium-bearing stone coal lixivium

Abstract

The invention relates to a deironing method for vanadium-bearing stone coal lixivium. According to the technical scheme, the deironing method comprises the steps that vanadium-bearing stone coal is firstly subjected to crushing, roasting and ore grinding to obtain vanadium-bearing stone coal roasted ore, the vanadium-bearing stone coal roasted ore and water are stirred to obtain vanadium-bearing stone coal ore pulp, then a leaching agent is added, heating and stirring are carried out, and solid-liquid separation is carried out to obtain the vanadium-bearing stone coal lixivium and leaching residues; reduced iron powder is added into the vanadium-bearing stone coal lixivium, and the adding amount of the reduced iron power is 2-4 times the stoichiometric number of the chemical reaction for reducing Fe3+ in the vanadium-bearing stone coal lixivium into Fe2+; heating and stirring are carried out, the pH value is adjusted to range from 1.5 to 5, heating and stirring are carried out, solid-liquid separation is carried out, and deironed lixivium and a filter cake are obtained; and the deironed lixivium is used for the vanadium enrichment technology, and a ferrous oxalate dehydrate byproduct is obtained after the filter cake is dried. Vanadium and iron in the vanadium-bearing stone coal lixivium can be effectively separated, the iron in the vanadium-bearing stone coal lixivium can be recycled, the vanadium loss rate in the deironing process is low, the iron content of the deironed lixivium is low, and the influence of the iron on the subsequent vanadium enrichment technology is reduced.

Description

technical field [0001] The invention belongs to the technical field of vanadium extraction from vanadium-containing stone coal. In particular, the invention relates to a method for removing iron from a vanadium-containing stone coal leaching solution. Background technique [0002] At present, vanadium-containing stone coal is usually leached with sulfuric acid and leaching aids to obtain a vanadium-containing leach solution. During the leaching process, a large amount of iron enters the leach solution with vanadium, which reduces the ability of subsequent extraction or ion exchange processes to enrich vanadium, and at the same time increases the consumption of subsequent reagents. amount; the waste liquid after the leach liquid is enriched with vanadium by extraction or ion exchange process is usually used to prepare the acid solution required for leaching, and the valuable iron element in the waste liquid is not recycled, resulting in a waste of iron resources. [0003] Zh...

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Problems solved by technology

[0002] At present, vanadium-containing stone coal is usually leached with sulfuric acid and leaching aids to obtain a vanadium-containing leach solution. During the leaching process, a large amount of iron enters the leach solution with vanadium, which reduces the ability of subsequent extraction or ion exchange processes to enrich vanadium, and at the same time increases the consumption of subsequent reagents. amount; the waste liquid after the leaching liquid is enriched with vanadium by extraction or ion exchange process is usually used to prepare the acid solution required for leaching, and the valuable iron element in the waste liquid is not recycled, resulting in a waste of iron resources

[0003] Zhao Jie et al. (Zhao Jie, Zhang Yimin, Huang Jing, Liu Tao, Wang Fei, Liu Juan. Thermodynamic analysis of acid leaching process for roasted stone coal samples[J]. Nonferrous Metals (Smelting Section), 2013, (10): 27- 31.) The stone coal raw ore is crushed to less than 3mm, roasted at 700°C for 1 hour, and then ground to a particle size of less than 0.074mm, accounting for 80wt% of the roasted cooked sample. The roasted cooked sample has a sulfuric acid concentration of 4mol / L and a liquid-solid ratio 1.5︰1, 5wt% fluorine-containing leaching agent, and 98°C for 4 hours of stirring and leaching, the vanadium concentration in the obtained acid leaching solution is 1.01g / L and the iron concentration is 2.05g / L, and the iron concentration is the vanadium concentration 2.03 times of that, too high iron concentration will not only increase the consumption of chemicals in the subsequent process, but also affect the subsequent vanadium-enriched liquid and product purity

[0004] Li Changlin (Li Changlin. Refractory stone coal vanadium extraction process and related theoretical research [D]. Changsha: Central South University, 2010.) used two-stage countercurrent leaching, the total acid consumption during leaching was 55wt%, and the amount of calcium fluoride additive 1.9wt%, the temperature is 95°C, the liquid-solid ratio is 1:1, the leaching time of each stage is 4h, the leaching rate of vanadium can reach 83.27%, the concentration of vanadium in the leaching solution is 4~5g / L and the concentration of iron is 30g / L About L, the iron concentration is 6~7.5 times of the vanadium concentration, and the iron content in the leaching solution is too high, which increases the difficulty of subsequent processing

[0005] Huang Yunsheng et al. (Huang Yunsheng, Wu Haiying, Dai Zilin, Wei Qing, Li Guiying. Study on the separation of vanadium and iron in the acid leaching solution of a stone coal vanadium mine in Shaanxi [J]. Mining and Metallurgy Engineering, 2013, 33(4): 104-107.) The supernatant of the No. 1 dense pool that was leached by sulfuric acid in a certain place in Shaanxi and washed by 6-stage countercurrent thickening was separated from vanadium and iron by extraction, wherein the concentration of vanadium in the supernatant was 1.34g / L and the concentration of iron was 4.12g / L, the iron concentration is 3.1 times of the vanadium concentration, and the iron concentration in the supernatant is high, which affects the subsequent enrichment process of vanadium. At the same time, the test did not recover and utilize the iron element in the raffinate with an iron concentration of 2.19g / L , resulting in a waste of iron resources

[0006] "A Method for Recycling the Raffinate of Vanadium Extraction from Stone Coal" (CN102787238A) patent technology provides a method for recycling the raffinate. The iron concentration in the raffinate is greater than 2g / L and the iron element has not been recycled, resulting in waste of resources

[0007] To sum up, the leach solution obtained by sulfuric acid leaching for extracting vanadium from stone coal has the disadvantage of high content of iron ions, which increases the consumption of reagents in the subsequent process. Iron element has not been recycled, resulting in waste of iron resources