CN101492181B - Method for removing tungsten, vanadium, phosphor and arsenic from molybdate solution by deposition - Google Patents

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

Method for removing tungsten, vanadium, phosphorus and arsenic by precipitation from molybdate solution

Technical field:

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:

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 15ppm. 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.

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 to use the characteristic that the strong basic anion exchange resin has a higher adsorption capacity for MoO ₄ ^2- than PO ₄ ^3- and AsO ₄ ^3- , and remove impurities phosphorus and arsenic in the ion exchange process of sodium molybdate. However, due to the small unit production capacity of the resin and strict requirements on the content of OH ^- , Cl ^- and other anions in the sodium molybdate solution, the process has poor adaptability to raw materials; in order to remove vanadium in the molybdate solution, China Patents CN1792819A and CN101062785A respectively use chelating ion exchange resin and strong basic anion exchange resin to preferentially adsorb and remove metavanadate in molybdate solution at an appropriate pH value. 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 leaching", Lu Ying and Sun put it in "Rare Metals and Cemented Carbide", 2005, 33(3): 1-3 pages reported "Fe(OH) ₃ adsorption method to separate tungsten mother from high molybdenum sodium tungstate solution", the essence of both methods is to use the characteristic of active Fe(OH) ₃ to preferentially adsorb tungsten , selectively adsorb and remove the tungsten in the molybdate solution, but in the process of removing tungsten, the loss of molybdenum is relatively large.

What was invented:

The object of the present invention is to provide a method for removing tungsten, vanadium, phosphorus and arsenic in molybdate solution by one-time precipitation by using a precipitant, which not only has simple process and convenient operation, but also has low cost, no pollution to the environment and can Meet the requirements of molybdenum metallurgy to produce high-quality molybdenum products that meet national standards and end-user requirements.

For achieving the above object, the technical scheme that the present invention takes is:

Adjust the molybdate solution containing one or more of tungsten, vanadium, phosphorus, and arsenic to a pH of 7-11 with acid or alkali, and then add a reagent that can generate manganese dioxide in situ in the solution for reaction , while generating manganese dioxide precipitates, the impurities in the solution are removed by co-precipitation; after the precipitates are filtered, the purified molybdate solution is obtained.

The invention utilizes the reaction of the manganese dioxide generated in situ to selectively remove the above-mentioned impurities by adsorption and precipitation, while the molybdenum remains in the solution. After liquid-solid separation, the purified molybdate solution can be obtained, and the molybdenum, tungsten and manganese dioxide can be recovered after the precipitate is treated with NaOH solution or Na ₂ CO ₃ solution.

The reaction reagent used in the present invention to generate manganese dioxide in situ in the molybdate solution is a high-valent manganese compound and a reducing agent. :

The high-valent manganese compounds used are potassium permanganate, sodium permanganate, ammonium permanganate, permanganic acid, potassium manganate, sodium manganate or a combination of several; the reducing agent is manganese sulfate, manganese chloride , manganese nitrate, manganese carbonate, sodium sulfite, sodium bisulfite or a combination of several.

The reaction reagent can also be a low-valent manganese compound and an oxidizing agent.

The low-valent manganese compound used is one or more combinations of manganese sulfate, manganese chloride, manganese nitrate, and manganese carbonate; the oxidant hydrogen peroxide, persulfuric acid, sodium persulfate, nitric acid, nitrous acid, sodium nitrite, oxygen, Odor, chlorine gas, hypochlorous acid, sodium hypochlorite, potassium chlorate, sodium chlorate, sodium perchlorate, potassium perchlorate, perchloric acid, sodium peroxide, sodium percarbonate, potassium percarbonate, sodium ferrate, potassium ferrate one or a combination of several.

The inorganic acid used in the present invention to adjust the acidity and alkalinity of molybdate solution is hydrochloric acid, sulfuric acid, nitric acid, carbonic acid, and the inorganic base is sodium hydroxide, sodium carbonate, sodium bicarbonate, ammonia water.

The molybdate solution processed by the present invention is sodium molybdate solution or ammonium molybdate solution or ammonium molybdate crystallization mother liquor, and its Mo concentration is 3g/L-300g/L;

The reaction conditions are: adjust the pH of the molybdate solution to 7-11, add the manganese dioxide generated by the reagent and the total molar amount of any one or several impurities in the molybdate solution The ratio is 10-100, the reaction temperature is 5-100°C, and the reaction time is 10 minutes-5 hours;

The addition method of the reagents used is as follows: the gas is directly passed into the solution, and other reagents are added in the form of solutions or solid powders, and then stirred evenly after adding.

Technology of the present invention owing to what adopt is to add reagent in molybdate solution and make it generate precipitating agent in solution, tungsten, vanadium, phosphorus, arsenic impurity in solution are removed; This method can not only remove multiple impurity simultaneously, remove The impurity depth is high, and the loss of molybdenum is small; the method has short flow, simple equipment, easy implementation, low cost and no pollution to the environment.

Detailed ways:

The following examples are intended to illustrate the implementation of the present invention, rather than further limiting the present invention.

Example 1. 1 L of sodium molybdate solution, containing Mo 100 g/L, WO ₃ 1.0 g/L, pH=9.6. Under the conditions of room temperature and a stirring speed of 150rpm, the in-situ generated _MnO2 is 50 times the theoretical amount (the molar ratio of _MnO2 to _WO3 is equal to 1 as the theoretical amount), and the required reagent is added, that is, potassium permanganate is added. 13.6g, after it dissolves, slowly add manganese sulfate 29.24g (prepared to 200-300g/L manganese sulfate solution to add), and finally slowly add NaOH6.88g. Continue to stir for 1 hour and then filter. The filtrate contains 0.05 g/L WO ₃ and 97.5 g/L Mo.

Example 2. 1 L of sodium molybdate solution, containing Mo 80 g/L, WO ₃ 1.0 g/L, V ₂ O ₅ 1.0 g/L, P 0.1 g/L, As 0.5 g/L, pH=11. Under the conditions of room temperature and a stirring speed of 150rpm, the in-situ generated _MnO2 is 80 times the theoretical amount (the molar ratio of _MnO2 to _WO3 is equal to 1 as the theoretical amount), and the required reagent is added, that is, potassium permanganate is added. 21.76g, after it dissolves, slowly add 46.78g of manganese sulfate (prepared to add 200-300g/L manganese sulfate solution), and finally slowly add NaOH11.0g. Continue stirring for 2 hours and then filter. The filtrate contains 0.03g/L WO ₃ , 0.02g/L V ₂ O ₅ , 0.01g/L P, 0.045g/L As, and 75g/L Mo.

Example 3. 1 L of sodium molybdate solution, containing Mo 100 g/L, V ₂ O ₅ 1.0 g/L, pH=10. Under the conditions of room temperature and a stirring speed of 150rpm, the in-situ generated MnO ₂ is 40 times the theoretical amount (the molar ratio of MnO ₂ to V ₂ O ₅ is equal to 1 as the theoretical amount), and the required reagent is added, that is, high manganese is added. Potassium acid potassium 13.88g, after it dissolves, then slowly add manganese sulfate 29.84g (prepared to add 200-300g/L manganese sulfate solution), and finally slowly add NaOH 7.02g. Continue stirring for 1 hour and then filter. The filtrate contains 0.06 g/L of V ₂ O ₅ and 98 g/L of Mo.

Example 4. 1 L of ammonium molybdate solution, containing Mo 150 g/L, WO ₃ 1.2 g/L, pH=8.5. Under the conditions of room temperature and a stirring speed of 150rpm, the in-situ generated _MnO2 is 50 times the theoretical amount (the molar ratio of _MnO2 to _WO3 is equal to 1 as the theoretical amount), and the required reagent is added, that is, ammonium permanganate is added. 14.16g, after it dissolves, slowly add 35.11g of manganese sulfate (prepared into 200-300g/L manganese sulfate solution), and finally slowly add 32ml of NH ₄ OH with a concentration of 25%. Continue to stir for 1 hour and then filter. The filtrate contains 0.06 g/L WO ₃ and 145 g/L Mo.

Example 5. Ammonium molybdate acid precipitation mother liquor 2L, containing Mo3g/L, WO ₃ 0.1g/L, pH=1.5. The pH of ammonium molybdate acid precipitation mother liquor is adjusted to 7.0 with ammoniacal liquor, under the condition of 150rpm at room temperature, stirring speed, generate _MnO in situ Be 60 times of theoretical amount (assuming _MnO with WO _The mol ratio equals 1 is the theoretical amount) to add the required reagent, that is, add 3.0g of ammonium permanganate, and after it dissolves, slowly add 7.44g of manganese sulfate (mixed with 200-300g/L manganese sulfate solution to add), and finally slowly add the concentration of 25% NH ₄ OH 6.8ml. Continue stirring for 1 hour and then filter. The filtrate contains 0.008 g/L WO ₃ and 2.8 g/L Mo.

Example 6. 20L of sodium molybdate solution, containing Mo300g/L, _WO30.5g /L, pH=9.6. Under the conditions of room temperature and a stirring speed of 150rpm, the in-situ generated _MnO2 is 10 times the theoretical amount (the molar ratio of _MnO2 to _WO3 is equal to 1 as the theoretical amount), and the required reagent is added, that is, potassium permanganate is added. 27g, after it dissolves, slowly add 58g of manganese sulfate (prepared to 200-300g/L manganese sulfate solution to add), and finally slowly add NaOH13.7g. Continue to stir for 1 hour and then filter. The filtrate contains 0.04 g/L WO ₃ and 99 g/L Mo.

Example 7. 5 L of sodium molybdate solution, containing Mo 100 g/L, WO ₃ 2.0 g/L, pH=9.5. Under the conditions of room temperature and a stirring speed of 150rpm, the in-situ generated _MnO2 is 100 times the theoretical amount (the molar ratio of _MnO2 to _WO3 is equal to 1 as the theoretical amount) and the required reagent is added, that is, potassium permanganate is added. 272g, after it dissolves, slowly add 584.8g of manganese sulfate (prepared to add 200-300g/L manganese sulfate solution), and finally slowly add NaOH137.6g. Continue to stir for 1 hour and then filter. The filtrate contains 0.12 g/L WO ₃ and 95 g/L Mo. Add the precipitate obtained after filtration to 400ml of water for slurrying, then add 30g of NaOH, heat to 150°C in an autoclave and keep it warm for 2 hours, and obtain a mixed solution of _MnO2 solid, sodium molybdate and sodium tungstate after filtration.

Claims (7)

1. one kind precipitates the method for removing tungsten, vanadium, phosphorus, arsenic from molybdate solution, it is characterized in that: for the molybdate solution of any one or a few impurity in tungstenic, vanadium, phosphorus, the arsenic, with mineral acid or mineral alkali or adjusting to pH with yellow soda ash or sodium bicarbonate is 7-11, add then and can in solution, react by the reaction reagent of original position generation Manganse Dioxide, when generating manganese dioxide precipitate, the impurity in the solution is removed in the mode of co-precipitation; After the throw out filtration, the molybdate solution after must purifying.

2. a kind of method of removing tungsten, vanadium, phosphorus, arsenic that from molybdate solution, precipitates according to claim 1, it is characterized in that: described reaction reagent is high price manganic compound and reductive agent;

Used high price manganic compound is the one or more combination in potassium permanganate, sodium permanganate, ammonium permanganate, permanganic acid, potassium manganate, the sodium manganate; Used reductive agent is an one or more combination in manganous sulfate, Manganous chloride tetrahydrate, manganous nitrate, manganous carbonate, S-WAT, the sodium bisulfite.

3. a kind of method of removing tungsten, vanadium, phosphorus, arsenic that from molybdate solution, precipitates according to claim 1, it is characterized in that: described reaction reagent is low price manganic compound and oxygenant;

Described low price manganic compound is the one or more combination in manganous sulfate, Manganous chloride tetrahydrate, manganous nitrate, the manganous carbonate; Described oxygenant is the one or more combination in hydrogen peroxide, persulfuric acid, Sodium persulfate, nitric acid, nitrous acid, Sodium Nitrite, oxygen, chlorine, hypochlorous acid, clorox, Potcrate, sodium chlorate, sodium perchlorate, potassium perchlorate, perchloric acid, sodium peroxide, SPC-D, antihypo, Na2Fe04, the potassium ferrate.

4. according to each described a kind of method of removing tungsten, vanadium, phosphorus, arsenic that from molybdate solution, precipitates of claim 1-3, it is characterized in that: the mineral acid of used adjustment molybdate solution acid-basicity is hydrochloric acid, sulfuric acid, nitric acid or carbonic acid, and mineral alkali is sodium hydroxide or ammoniacal liquor.

5. according to each described a kind of method of removing tungsten, vanadium, phosphorus, arsenic that from molybdate solution, precipitates of claim 1-3, it is characterized in that: handled molybdate solution is sodium molybdate solution or ammonium molybdate solution or ammonium molybdate crystalline mother solution, and its Mo concentration is 3g/L-300g/L.

6. according to each described a kind of method of removing tungsten, vanadium, phosphorus, arsenic that from molybdate solution, precipitates of claim 1-3, it is characterized in that: reaction conditions is: in the Manganse Dioxide of generation and the molybdate solution in tungsten, vanadium, phosphorus, the arsenic ratio of the integral molar quantity of any one or a few impurity be 5-100 ℃ for the 10-100 temperature of reaction, the reaction times is 10 minutes-5 hours.

7. according to the method for claim 1, it is characterized in that: after liquid-solid separation, the molybdate solution after being purified, and throw out is through NaOH solution or Na ₂CO ₃Recyclable molybdenum, tungsten and Manganse Dioxide wherein after the solution-treated.