Method for removing tungsten, vanadium, phosphor and arsenic from molybdate solution by deposition

Abstract

The invention provides a method for removing tungsten, vanadium, phosphorus and arsenic from a molybdenate solution by deposition. The method comprises that: a reagent is added into the molybdenate solution to generate a precipitator in the solution, and by the precipitator, the impurities of tungsten, vanadium, phosphorus and arsenic in the solution are removed. The method has the advantages of removing various impurities at the same time and having high impurity removing degree, along with little loss of molybdenum, short flow, simple equipment, easy implementation, low cost and no environmental pollution.

Description

Technical field: [0001] The invention belongs to the purification of metal solutions in the extraction of nonferrous metals, in particular for the purification of tungsten, vanadium, phosphorus and arsenic in molybdate solutions for preparing ammonium molybdate, sodium molybdate and molybdenum oxide. Background technique: [0002] With the development of science and technology, the requirements for the content of impurity elements tungsten, vanadium, phosphorus and arsenic in molybdenum metallurgical products are becoming more and more stringent. my country's national standard GB / T3480-2007 stipulates that MSA-0 grade molybdenum acid is based on the content of tungsten and phosphorus in the product. , arsenic are not more than 150ppm, 5ppm, 5ppm respectively, and although the national standard for vanadium does not clearly stipulate its content requirements, but in the molybdenum smelting industry, the vanadium content in ammonium molybdate is required to be not more than 15pp...

AI Technical Summary

Problems solved by technology

However, the current molybdenum mineral raw materials are becoming more and more complicated, especially when dealing with high-tungsten molybdenite, nickel-molybdenum ore, spent catalysts and other raw materials, removing tungsten, vanadium, phosphorus, and arsenic from molybdate solution has become a major step in molybdenum metallurgy. An important task and problem of

[0003] In order to remove phosphorus and arsenic impurities in molybdate, the classic ammonium-magnesium salt precipitation method is widely used in industry at present. Its disadvantages are complicated operation, difficult filtration of precipitated slag, and large loss of molybdenum; a company uses ion exchange process in tungsten metallurgy for reference , that is, the use of strongly basic anion exchange resins for MoO 4 2- The adsorption capacity is greater than that of PO 4 3- , AsO 4 3- The characteristics of the sodium molybdate ion exchange process to remove impurities phosphorus and arsenic

However, due to the small unit production capacity of the resin, the OH in the sodium molybdate solution - , Cl - The strict requirements on the content of such anions make the process poorly adaptable to raw materials; in order to remove vanadium in the molybdate solution, Chinese patents CN1792819A and CN101062785A respectively use chelating ion exchange resins and strong basic anion exchange resins. The metavanadate in the molybdate solution is preferentially adsorbed and removed at a pH value of

However, the above method can only remove vanadium as an impurity, and the process operation is complicated; in order to remove tungsten in the molybdate solution, the classic method commonly used in molybdenum metallurgy is to control the precipitation of ammonium molybdate crystals by adding acid from ammonium molybdate solution The end point pH value, using the characteristics of ammonium molybdate crystallization preferentially when pH>2.0, but tungsten is difficult to crystallize, to achieve the purpose of tungsten removal

However, the depth of tungsten removal by this method is limited, and the crystallization rate of ammonium molybdate is low at a higher pH value, so it can only play an auxiliary role in removing tungsten; Fan Wei, Huang Puxuan, Yao Li, etc. in "Inorganic Salt Industry" 2001, 33(5): 3-4 pages reported the method of "separation of tungsten in the production of ammonium molybdate by ammonia immersion method", Lu Ying and Sun put it in "Rare Metals and Cemented Carbide", 2005, 33(3): Pages 1-3 reported "Fe(OH) 3 Study on separation of tungsten mother from high molybdenum sodium tungstate solution by adsorption method", the essence of both methods is to use active Fe(OH) 3 With the characteristic of preferential adsorption of tungsten, the tungsten in the molybdate solution is selectively adsorbed and removed, but in the process of removing tungsten, the loss of molybdenum is relatively large