Molybdenum removal technology for calcium tungstate production process

Abstract

The invention discloses a molybdenum removal technology for calcium tungstate production process. The molybdenum removal technology comprises the following steps of S1, vulcanizing a calcium tungstate solution containing impurity element of molybdenum, so as to convert the impurity element of molybdenum into the corresponding thioic acid radical; S2, adding a precipitant into the vulcanized calcium tungstate solution, stirring for 0.5 to 2.5h at the temperature of 20 to 70 DEG C, and forming an organic compound precipitation together with the thioic acid salt containing the impurity element of molybdenum; S3, finally, adding an adsorbate, filtering and separating, wherein the filtering liquid is the impurity-removed calcium tungstate solution, and the filtering residues are the adsorbate and the organic precipitation; S4, increasing the acidity of the calcium tungstate solution to 140 to 160g / L, and adding tungsten powder into the solution; S5, repeating the steps S1 to S4 once. The molybdenum content of the existing calcium tungstate is 2% to 3.5%. The molybdenum removal technology has the advantages that the existing smelting impurity removal procedure is improved, so that the molybdenum content of the calcium tungstate is less than 0.5%; the impurity removal effect is good, the equipment is simple, the production cost is low, the process flow is short, and the operation is easy.

Description

technical field [0001] The invention relates to a molybdenum removal process in the process of producing calcium tungstate. Background technique [0002] Tungsten and molybdenum are similar elements, and their physical and chemical properties are very similar. Molybdenum is associated with tungsten minerals, but the content is different. With the depletion of high-grade tungsten ore resources, low-grade tungsten ore resources and tungsten secondary resources have become more and more important tungsten metallurgical raw materials, and the concentration of molybdenum ions in the calcium tungstate solution produced from these raw materials is also increasing. higher. In order to prepare pure tungsten compounds, efficient and thorough separation of molybdenum from calcium tungstate solution is an essential link. At present, the industrial process of removing molybdenum from calcium tungstate solution is based on the fact that molybdenum can preferentially generate thiomolybd...

AI Technical Summary

Problems solved by technology

Due to the large co-precipitation loss of tungsten in the molybdenum trisulfide precipitation method and the release of toxic gas H2S in the process, the process defects are quite obvious; although the copper salt precipitation method has strong selectivity and complete removal of molybdenum, when the molybdenum in the calcium tungstate solution When the concentration is higher than 1g / L, the cost of molybdenum removal will be greatly increased due to the expensive and large amount of copper reagent used. For materials with high molybdenum content, it is economically uneconomical; the solvent extraction method has not been applied in industry so far; the existing ion exchange method Both use macroporous strongly basic anion exchange resins. Although the resin has a high working exchange capacity for molybdenum and has a good molybdenum removal effect, it is quite difficult to desorb negative molybdenum resins.

However, the strong oxidation performance of the desorbent and the exothermic reaction in the desorption process will cause damage to the resin, which will significantly reduce the molybdenum exchange capacity and greatly shorten the service life of the resin when the resin is recycled, resulting in an increase in the cost of molybdenum removal