Method for efficiently separating tungsten and tin from tungsten-tin middling through acid process smelting

Abstract

The invention belongs to the technical field of metallurgy, and discloses a method for efficiently separating tungsten and tin in tungsten-tin middling acid process smelting. According to the method, tungsten minerals in the tungsten-tin middlings are decomposed with hydrochloric acid by adopting a smelting method, so that the tungsten minerals are decomposed and converted into solid tungstic acid, meanwhile, most of mineral components containing calcium and iron in the tungsten-tin middlings are dissolved and removed, and tungsten and tin are reserved in a solid phase. And after liquid-solid separation, dissolving tungstic acid in the solid phase into a sodium tungstate solution by using an alkaline leaching solution containing sodium hydroxide, and finally enriching tin in the solid phase after alkali dissolution to be sold as tin concentrate. The sodium tungstate solution is used for preparing a pre-exchange solution, and after ion exchange and molybdenum removal, an ammonium paratungstate product can be obtained through evaporative crystallization. According to the method, tungsten and tin are separated through a smelting method instead of a beneficiation method, the tungsten and tin separation cost of tungsten and tin middlings is reduced, the technological process is short, the manufacturing cost is low, and industrial production can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for efficiently separating tungsten and tin from tungsten-tin ore by acid smelting. Background Art

[0002] China is a country with abundant tungsten resources, of which about 70% is scheelite (mainly composed of CaWO 4 ), about 20% is wolframite (the main component is FeWO 4 、MnWO 4 ), about 10% is a mixed ore of black and white tungsten. Tungsten ore extraction usually adopts gravity separation, flotation or a combination of the two processes. However, it is difficult to separate the associated tungsten in the complex and difficult-to-select tin concentrate by mineral processing. Because tungsten has a high melting point, it will interfere with the smelting process when the tin concentrate enters the metallurgical smelting process, and because tungsten itself has a high value, if it remains in the slag after smelting, it will cause its value to depreciate and cause economic losses. Therefore, it is urgent to develop a new method based on hydrometallurgy to achieve efficient separation of tungsten and tin in tin concentrate. After separation, tin can return to the smelting process, and tungsten can be converted into high value-added ammonium paratungstate products.

[0003] Patent CN201910159646.7 provides a method for preparing ammonium paratungstate products from tungsten minerals by acid-base combination: first, tungsten ore is mixed with hydrochloric acid and hydrogen peroxide to obtain solid tungstic acid and acid decomposition mother liquor; then, solid tungstic acid is dissolved with sodium carbonate and filtered to obtain dissolved slag and sodium tungstate solution; then, the sodium tungstate solution is neutralized with sulfuric acid to a specific pH to prepare a pre-delivery liquid, and tungsten is adsorbed with a macroporous weakly alkaline anion exchange resin to make the pre-delivery liquid into a post-delivery liquid containing sodium sulfate and the resin is washed; finally, the resin adsorbing tungsten is desorbed with ammonia water to obtain an ammonium tungstate desorption liquid, and the ammonium paratungstate product is obtained by removing impurities, evaporating and crystallizing. However, this method has the following problems: 1. Hydrogen peroxide is unstable and easy to decompose. If the decomposition rate is too fast during the reaction, it may lead to incomplete reaction, which will eventually affect the product yield and quality. 2. Ammonia is volatile and produces a pungent odor. If the desorption conditions (such as temperature, ammonia concentration, desorption time, etc.) are not properly controlled, it may lead to incomplete desorption or increase the impurity content in the desorption liquid, affecting the quality of the ammonium paratungstate product.

[0004] Patent CN202010767997.9 discloses a two-step acid decomposition method for extracting tungsten, which includes the following steps: (1) using a first acid to control H +The concentration is 0.1-4.0 mol / L to decompose tungsten ore or crude sodium tungstate solution to obtain crude tungstic acid; wherein polyethylene glycol is added during the acid decomposition process; (2) the crude tungstic acid is dissolved in ammonia water or ammonium carbonate solution to obtain a crude ammonium tungstate solution, and then a second acid is added or carbon dioxide is introduced for secondary acid decomposition to separate tungstic acid and ammonium salt solution. Tungstic acid is dissolved in ammonia water again to obtain an ammonium tungstate solution, and ammonium paratungstate is obtained after evaporation and crystallization. This method has many processes, high production costs, and a long time. In addition, due to multiple acid decomposition and dissolution steps, there are many intermediate products, which are easy to affect the purity and quality of the product.

[0005] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0006] The invention aims to solve the problems of difficulty in separating tungsten and tin in the tungsten-tin middling ore dressing method in the prior art and high cost, and provides a method for efficiently separating tungsten and tin by acid smelting of tungsten-tin middling ore.

[0007] The tungsten mineral in the tungsten-tin ore is decomposed with hydrochloric acid by a smelting method, and the tungsten mineral is decomposed and converted into solid tungstic acid. At the same time, most of the mineral components containing calcium and iron in the tungsten-tin ore are dissolved and removed, while tungsten and tin are retained in the solid phase. After liquid-solid separation, the tungstic acid in the solid phase is dissolved into a sodium tungstate solution by an alkaline leaching solution containing sodium hydroxide, and the tin is finally enriched in the solid phase after alkali dissolution, and can be sold as a tin concentrate. The sodium tungstate solution is used to prepare the pre-delivery solution, and then after ion exchange and molybdenum removal, the ammonium paratungstate product can be obtained by evaporation and crystallization. The present invention reduces the cost of separating tungsten and tin from tungsten-tin ore, has a short process flow, low manufacturing cost, and realizes industrial production.

[0008] In order to achieve the above object, the present invention adopts the following technical scheme:

[0009] The method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting of tungsten tin in the present invention comprises the following steps:

[0010] Step 1: After grinding the tungsten-tin ore, add water and stir evenly, then drop hydrochloric acid into it for decomposition, then add water to control the concentration of hydrochloric acid, keep warm and stir until the reaction is complete, and obtain a mixed precipitate of solid tungstic acid and tin;

[0011] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH, and obtain a mixed precipitate of solid tungstic acid and tin slag;

[0012] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 into the sodium hydroxide solution, keep warm and stir until the reaction is completed, and obtain sodium tungstate solution and tin slag;

[0013] Step 4: Separate the sodium tungstate solution and tin residue obtained in step 3 by filtering, and then wash the tin residue with water to adjust the pH;

[0014] Step 5: drying the tin slag obtained in step 4 to obtain a by-product tin concentrate;

[0015] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, the ammonium paratungstate product is obtained by evaporation and crystallization.

[0016] Preferably, the present invention may also have the following technical features:

[0017] Preferably, the WO3 content of the tungsten-tin ore in step 1 is 15%-35%, and the Sn content is 7%-25%.

[0018] Preferably, after the tungsten-tin intermediate ore is ground in step 1, the grinding fineness of the tungsten-tin intermediate ore is -250 mesh ≥ 95%.

[0019] Preferably, in step 1, the hydrochloric acid is industrial hydrochloric acid with a specific gravity of 1.185 g / ml, and the hydrochloric acid consumption is 1.4-2 m 3 / ton of tungsten-tin medium ore, the process is to add water according to the volume of 2 times the weight of the tungsten-tin medium ore, add the tungsten-tin medium ore while stirring, and then slowly add the corresponding amount of hydrochloric acid, add water after adding the hydrochloric acid, control the hydrochloric acid concentration at 15%-20%, heat up, and stir at 75-95℃ for 2-5 hours.

[0020] Preferably, in step 2, the washing is performed with water to adjust the pH to 6-6.5.

[0021] Preferably, in step 3, the sodium hydroxide concentration is 40-50 g / l, the amount of sodium hydroxide solution added is 1.5 times the theoretical alkali consumption of solid tungstic acid, and the mixture is stirred at 50-60° C. for 1-2 hours.

[0022] Preferably, in step 4, the tin slag is washed with water to adjust the pH to 7-8, and the tungsten content in the slag is controlled to be less than 1%.

[0023] Preferably, in step five, the temperature of drying the tin slag is 85-105°C.

[0024] The present invention also provides ammonium paratungstate and tin concentrate prepared by the above-mentioned method for smelting tungsten and tin in the tungsten-tin medium ore acid method with high efficiency.

[0025] The technical principles of the present invention are as follows:

[0026] In the present invention, hydrochloric acid mainly plays the role of decomposing tungsten minerals in tungsten-tin ore and converting them into solid tungstic acid. At the same time, it can dissolve most of the mineral components containing calcium and iron, and achieve preliminary impurity removal. When the parameters such as hydrochloric acid concentration, temperature and reaction time are appropriate, the tungsten minerals can be effectively decomposed into tungstic acid, and at this time most of the tin is retained in the solid phase, thereby preliminarily realizing the separation of tungsten and tin. When the hydrochloric acid concentration is lower than 15%, the tungsten decomposition reaction is difficult to carry out and the reaction time is long; when the hydrochloric acid concentration is higher than 20%, the amount of tin dissolved increases, causing tin loss and reducing the tin yield; when the reaction temperature is lower than 75°C, the tungsten decomposition reaction is slow, the reaction time is long, and the tungsten yield is low; when the reaction temperature is higher than 95°C, the amount of tin dissolved increases, causing tin loss and reducing the tin yield; the reaction time is required to be controlled within 2-5 hours, the tungsten decomposition is more complete, and the tin dissolution loss is minimized.

[0027] Sodium hydroxide solution is used to dissolve tungstic acid in the solid phase after hydrochloric acid decomposition and liquid-solid separation, and convert it into sodium tungstate solution. The appropriate sodium hydroxide concentration and dosage are the key. If the dosage is too little, the solid tungstic acid will not be completely dissolved, affecting the recovery of tungsten; too high a concentration will cause the dissolution loss of tin, because in this process, it is necessary to minimize the dissolution of tin while dissolving tungstic acid, so that tin is further enriched in the solid phase to form tin slag. Temperature also plays a synergistic role. If the temperature is too low, the solid tungstic acid will not be completely dissolved and the dissolution time will be long; and the appropriate temperature, concentration and stirring time can efficiently realize the dissolution of tungstic acid and the further separation of tungsten and tin, so that the obtained sodium tungstate solution has a high purity and the tin slag has a low tungsten content, laying the foundation for the subsequent preparation of ammonium paratungstate and the acquisition of high-quality tin concentrate.

[0028] The grinding fineness of tungsten-tin middlings is -250 mesh ≥95%. If the grinding fineness is too coarse, tungsten is difficult to decompose, because the coarse particles of tungsten minerals have a small contact area with hydrochloric acid, and the reaction is incomplete, resulting in a low tungsten recovery rate; if the grinding fineness is too fine, the mechanical loss of tin increases, and the fine particles are more easily entrained or dissolved during the processing, resulting in a low tin recovery rate.

[0029] In the step 2 of the method for separating tungsten and tin described in the present invention, the pH of the washing precipitate is adjusted to 6-6.5, and in the step 4 of washing the tin slag, the pH is adjusted to 7-8, in order to remove impurities and stabilize the subsequent processing environment. If the pH value is not properly controlled, the residual impurities may react with the sodium tungstate solution or the tin slag in the subsequent steps, affecting the product purity or causing metal loss. For example, excessive acidity may cause the tin in the tin slag to dissolve again, and excessive alkalinity may cause the concentration of impurity ions in the sodium tungstate solution to increase, affecting the ion exchange and molybdenum removal effects, and ultimately affecting the quality of the ammonium paratungstate product.

[0030] The beneficial effects of the present invention compared with the prior art include:

[0031] 1. The present invention avoids the problems caused by unstable reagents in the selection of reagents. Hydrochloric acid is mainly used in the decomposition of tungsten-tin ore. Hydrochloric acid is more stable than hydrogen peroxide, and it is not easy to affect the reaction process and product quality due to the decomposition of the reagent itself. And sodium hydroxide is used for alkaline leaching later. Sodium hydroxide is also a common and relatively stable reagent. The prior art uses hydrogen peroxide, which is unstable and easy to decompose. If the decomposition speed is too fast during the reaction, it will lead to incomplete reaction. When ammonia water is used to desorb the resin that adsorbs tungsten, ammonia water is volatile and will produce a pungent odor. In addition, improper control of desorption conditions will lead to incomplete desorption or increased impurity content in the desorption liquid, affecting product quality.

[0032] 2. The present invention is more concise and efficient in process flow, reduces costs, and effectively reduces the impact of impurities and improves product purity through reasonable steps in product quality assurance. The prior art has many processes, high production costs, and takes a long time. In addition, due to multiple acid decomposition and dissolution steps, there are many intermediate products, which easily affect the purity and quality of the product. Compared with the prior art, the present invention has significant progress in terms of convenience of production operation, cost control, and product quality improvement, and is more in line with the needs of industrial production. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below in conjunction with specific embodiments. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope of the present invention and its application.

[0034] Example 1

[0035] The composition of tungsten-tin ore contains WO 3 :32.91%, Sn: 17.46%.

[0036] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -250 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 400mL, control the hydrochloric acid concentration to 18%, heat to 90℃, control the temperature in the range of 90±4℃, keep warm and stir for 3h to obtain a mixed precipitate of solid tungstic acid and tin;

[0037] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6.5, to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0038] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 340 ml of sodium hydroxide solution with a concentration of 50 g / L, heat to 55°C, control the temperature within the range of 55±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0039] Step 4: Separate the sodium tungstate solution and tin residue obtained in step 3 by filtering, and then wash the tin residue with water to adjust the pH to 7.5;

[0040] Step 5: Dry the tin slag obtained in step 4 at 85°C to obtain 58.9g of tin concentrate. The composition of the tin slag was determined to contain WO 3 :0.527%, Sn: 29.05%;

[0041] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 35.94g of ammonium paratungstate product.

[0042] Example 2

[0043] The composition of tungsten-tin ore contains WO 3 : 26.8%, Sn: 7.61%.

[0044] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -250 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 400mL, control the hydrochloric acid concentration to 18%, heat to 85℃, control the temperature in the range of 85±5℃, keep warm and stir for 4h to obtain a mixed precipitate of solid tungstic acid and tin;

[0045] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6.2 to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0046] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 280 ml of sodium hydroxide solution with a concentration of 50 g / L, heat to 58°C, control the temperature within the range of 58±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0047] Step 4: The sodium tungstate solution and tin residue obtained in step 3 are separated by filtration, and then the tin residue is washed with water to adjust the pH to 7.0;

[0048] Step 5: Dry the tin slag obtained in step 4 at 95°C to obtain 52g of tin concentrate. The composition of the tin slag is tested to contain WO 3 : 0.32%, Sn: 14.34%;

[0049] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 29.36g of ammonium paratungstate product.

[0050] Example 3

[0051] The composition of tungsten-tin ore contains WO 3 : 18.5%, Sn: 23.4%.

[0052] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -250 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 400mL, control the hydrochloric acid concentration to 18%, heat to 85℃, control the temperature in the range of 85±5℃, keep warm and stir for 4h to obtain a mixed precipitate of solid tungstic acid and tin;

[0053] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6, to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0054] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 210 ml of sodium hydroxide solution with a concentration of 45 g / L, heat to 60°C, control the temperature within the range of 60±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0055] Step 4: Separate the sodium tungstate solution and tin residue obtained in step 3 by filtering, and then wash the tin residue with water to adjust the pH to 7.5;

[0056] Step 5: Dry the tin slag obtained in step 4 at 105°C to obtain 50.58g of tin concentrate. The composition of the tin slag was determined to contain WO 3 :0.428%, Sn: 45.64%;

[0057] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 20.76g of ammonium paratungstate product.

[0058] Comparative Example 1

[0059] The composition of tungsten-tin ore contains WO 3 :32.91%, Sn: 17.46%.

[0060] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -200 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 400mL, control the hydrochloric acid concentration to 18%, heat to 90℃, control the temperature in the range of 90±4℃, keep warm and stir for 3h to obtain a mixed precipitate of solid tungstic acid and tin;

[0061] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6.5, to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0062] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 340 ml of sodium hydroxide solution with a concentration of 50 g / L, heat to 55°C, control the temperature within the range of 55±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0063] Step 4: Separate the sodium tungstate solution and tin residue obtained in step 3 by filtering, and then wash the tin residue with water to adjust the pH to 7.5;

[0064] Step 5: Dry the tin slag obtained in step 4 at 85°C to obtain 64.2g of tin concentrate. The composition of the tin slag is analyzed to contain WO 3 : 5.28%, Sn: 26.64%;

[0065] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 32.87g of ammonium paratungstate product.

[0066] Comparative Example 2

[0067] The composition of tungsten-tin ore contains WO3: 32.91%, Sn: 17.46%.

[0068] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -325 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 400mL, control the hydrochloric acid concentration to 18%, heat to 90℃, control the temperature in the range of 90±4℃, keep warm and stir for 3h to obtain a mixed precipitate of solid tungstic acid and tin;

[0069] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6.5, to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0070] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 340 ml of sodium hydroxide solution with a concentration of 50 g / L, heat to 55°C, control the temperature within the range of 55±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0071] Step 4: Separate the sodium tungstate solution and tin residue obtained in step 3 by filtering, and then wash the tin residue with water to adjust the pH to 7.5;

[0072] Step 5: Dry the tin slag obtained in step 4 at 85°C to obtain 57.6g of tin concentrate. The components of the tin slag are analyzed to contain WO 3 : 0.43%, Sn: 28.74%;

[0073] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 36.13g of ammonium paratungstate product.

[0074] Comparative Example 3

[0075] The composition of tungsten-tin ore contains WO 3 : 26.8%, Sn: 7.61%.

[0076] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -250 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 600mL, control the hydrochloric acid concentration to 12%, heat to 85℃, control the temperature in the range of 85±5℃, keep warm and stir for 4h to obtain a mixed precipitate of solid tungstic acid and tin;

[0077] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6.2 to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0078] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 280 ml of sodium hydroxide solution with a concentration of 50 g / L, heat to 58°C, control the temperature within the range of 58±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0079] Step 4: The sodium tungstate solution and tin residue obtained in step 3 are separated by filtration, and then the tin residue is washed with water to adjust the pH to 7.0;

[0080] Step 5: Dry the tin slag obtained in step 4 at 95°C to obtain 59.5g of tin concentrate. The composition of the tin slag was tested to contain WO 3 : 4.58%, Sn: 12.53%;

[0081] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 26.48g of ammonium paratungstate product.

[0082] Comparative Example 4

[0083] The composition of tungsten-tin ore contains WO 3 : 26.8%, Sn: 7.61%.

[0084] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -250 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 300mL, control the hydrochloric acid concentration to 24%, heat to 85℃, control the temperature in the range of 85±5℃, keep warm and stir for 4h to obtain a mixed precipitate of solid tungstic acid and tin;

[0085] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6.2 to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0086] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 240 ml of sodium hydroxide solution with a concentration of 50 g / L, heat to 58°C, control the temperature within the range of 58±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0087] Step 4: The sodium tungstate solution and tin residue obtained in step 3 are separated by filtration, and then the tin residue is washed with water to adjust the pH to 7.0;

[0088] Step 5: Dry the tin slag obtained in step 4 at 95°C to obtain 51.6g of tin concentrate. The components of the tin slag are analyzed to contain WO 3 :0.661%, Sn: 13.72%;

[0089] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 29.18g of ammonium paratungstate product.

[0090] Comparative Example 5

[0091] The composition of tungsten-tin ore contains WO 3 : 18.5%, Sn: 23.4%.

[0092] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -250 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 400mL, control the hydrochloric acid concentration to 18%, heat to 60℃, control the temperature in the range of 60±5℃, keep warm and stir for 4h to obtain a mixed precipitate of solid tungstic acid and tin;

[0093] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6.0, to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0094] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 210 ml of sodium hydroxide solution with a concentration of 45 g / L, heat to 60°C, control the temperature within the range of 60±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0095] Step 4: Separate the sodium tungstate solution and tin residue obtained in step 3 by filtering, and then wash the tin residue with water to adjust the pH to 7.5;

[0096] Step 5: Dry the tin slag obtained in step 4 at 105°C to obtain 51.02g of tin concentrate. The components of the tin slag are analyzed to contain WO 3 : 3.39%, Sn: 44.98%;

[0097] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 18.56 g of ammonium paratungstate product.

[0098] Comparative Example 6

[0099] The composition of tungsten-tin ore contains WO 3 : 18.5%Sn: 23.4%.

[0100] Step 1: Weigh 100g of tungsten-tin medium ore with a grinding fineness of -250 mesh ≥95% after grinding, add 100ml of water and stir evenly, drop 200ml of industrial hydrochloric acid with a concentration of 36% to decompose, after dropping the industrial hydrochloric acid, add water to 400mL, control the hydrochloric acid concentration to 18%, heat to 102℃, control the temperature in the range of 102±3℃, keep warm and stir for 4h to obtain a mixed precipitate of solid tungstic acid and tin;

[0101] Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH to 6.0, to obtain a mixed precipitate of solid tungstic acid and tin slag;

[0102] Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 to 210 ml of sodium hydroxide solution with a concentration of 45 g / L, heat to 60°C, control the temperature within the range of 60±5°C, keep warm and stir for 1 hour until the reaction is complete, and obtain sodium tungstate solution and tin slag;

[0103] Step 4: Separate the sodium tungstate solution and tin residue obtained in step 3 by filtering, and then wash the tin residue with water to adjust the pH to 7.5;

[0104] Step 5: Dry the tin slag obtained in step 4 at 105°C to obtain 55.28g of tin concentrate. The components of the tin slag are analyzed to contain WO 3 :0.553%, Sn: 40.21%;

[0105] Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, evaporation and crystallization are performed to obtain 20.78g of ammonium paratungstate product.

[0106] The tungsten-tin ore and tin slag were detected, tungsten trioxide was determined by ignition weight method, and tin was determined by iodine titration method. The tungsten-tin content in the tungsten-tin ore and the prepared tin slag of Examples 1-3 and Comparative Examples 1-6 was detected respectively, and the results are shown in the following table:

[0107]

[0108]

[0109] Note: The recovery rate is above 97%.

[0110] (1) As can be seen from the above table, the ammonium paratungstate product and tin slag prepared by the method for efficiently separating tungsten and tin by acid smelting of tungsten and tin in Examples 1-3 of the present invention have a tungsten and tin recovery rate of more than 97%.

[0111] (2) In comparative example 1, on the basis of Example 1, the grinding fineness in step 1 was controlled at -200 mesh ≥ 95%, and the other parameters remained unchanged. After tungsten-tin separation, the recovery rate of tungsten was less than 97%, which was unqualified; in comparative example 2, on the basis of Example 1, the grinding fineness in step 1 was controlled at -325 mesh ≥ 95%, and the other parameters remained unchanged. After tungsten-tin separation, the recovery rate of tin was less than 97%, which was unqualified.

[0112] (3) In Comparative Example 3, based on Example 2, step 1 is changed to control the hydrochloric acid concentration to 12%, and other aspects remain unchanged. After tungsten-tin separation, the recovery rate of tungsten is less than 97%, which is unqualified; In Comparative Example 4, based on Example 2, step 1 is changed to control the hydrochloric acid concentration to 24%, and step 3 reduces the amount of sodium hydroxide added, and other aspects remain unchanged. After tungsten-tin separation, the recovery rates of tungsten and tin are both less than 97%, which is unqualified.

[0113] (4) In Comparative Example 5, based on Example 3, the temperature control in step 1 was changed to control the temperature in the range of 60±5°C, while other factors remained unchanged. After tungsten-tin separation, the recovery rate of tungsten was less than 97%, which was unqualified. In Comparative Example 6, based on Example 3, the temperature control in step 1 was changed to control the temperature in the range of 102±3°C, while other factors remained unchanged. After tungsten-tin separation, the recovery rate of tin was less than 97%, which was unqualified.

[0114] It can be seen that the method for efficiently separating tungsten and tin from tungsten-tin ore by acid smelting of tungsten-tin ore of the present invention is an organic whole. Changes in process parameters will greatly affect the effect of tungsten-tin separation from tungsten-tin ore and affect the tungsten-tin recovery rate of the final product.

[0115] The foregoing has broadly described the features and technical advantages of the present invention so that the detailed description of the present invention can be better understood. Other features and advantages of the present invention will be described below. It should be understood by those skilled in the art that the disclosed concepts and specific embodiments can be easily used as a basis for modifying or designing other structures to accomplish the same purpose of the present invention. It should also be recognized by those skilled in the art that such equivalent constructions do not deviate from the spirit and scope of the present invention. The novel features, structures and methods of operation thereof, and further objects and advantages that are considered to be characteristic of the present invention will be better understood from the following description. However, it should be deeply recognized that each feature provided is only for description and illustration, and is not intended to limit the definition of the present invention.

Claims

1. A method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting, characterized in that: The following steps are involved: Step 1: After grinding the tungsten-tin ore, add water and stir evenly, then drop hydrochloric acid into it for decomposition, then add water to control the concentration of hydrochloric acid, keep warm and stir until the reaction is complete, and obtain a mixed precipitate of solid tungstic acid and tin; Step 2: Filter the mixed precipitate of solid tungstic acid and tin obtained in step 1, then wash with water to adjust the pH, and obtain a mixed precipitate of solid tungstic acid and tin slag; Step 3: Add the solid tungstic acid and tin slag mixed precipitate obtained in step 2 into the sodium hydroxide solution, keep warm and stir until the reaction is completed, and obtain sodium tungstate solution and tin slag; Step 4: Separate the sodium tungstate solution and tin residue obtained in step 3 by filtering, and then wash the tin residue with water to adjust the pH; Step 5: drying the tin slag obtained in step 4 to obtain a by-product tin concentrate; Step 6: The sodium tungstate solution obtained in step 4 is prepared into a pre-liquid, and after ion exchange and molybdenum removal, the ammonium paratungstate product is obtained by evaporation and crystallization.

2. The method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting according to claim 1 is characterized in that: In step 1, the WO3 content of the tungsten-tin ore is 15%-35%, and the Sn content is 7%-25%.

3. The method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting according to claim 1 is characterized in that: In step 1, after the tungsten-tin ore is ground, the grinding fineness of the tungsten-tin ore is -250 mesh ≥95%.

4. The method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting according to claim 1 is characterized in that: The hydrochloric acid described in step 1 is industrial hydrochloric acid, with a specific gravity of 1.185 g / ml, and the hydrochloric acid consumption is 1.4-2 m 3 / ton of tungsten-tin ore.

5. The method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting according to claim 1 is characterized in that: The specific process of step 1 is to add water according to a volume twice the weight of the tungsten-tin ore, add the tungsten-tin ore while stirring, and then add a corresponding amount of hydrochloric acid. After adding the hydrochloric acid, add water, control the concentration of hydrochloric acid at 15%-20%, increase the temperature, and stir at 75-95°C for 2-5 hours.

6. A method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting according to claim 1, characterized in that: In step 2, washing with water is performed to adjust the pH to 6-6.

5.

7. The method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting according to claim 1 is characterized in that: In step 3, the sodium hydroxide concentration is 40-50 g / l, and the amount of sodium hydroxide solution added is 1.5 times the theoretical alkali consumption of solid tungstic acid containing tungsten, and the mixture is stirred at 50-60° C. for 1-2 hours.

8. The method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting according to claim 1 is characterized in that: In step 4, the tin slag is washed with water to adjust the pH to 7-8, and the tungsten content in the slag is controlled to be less than 1%.

9. The method for efficiently separating tungsten and tin from tungsten tin ore by acid smelting according to claim 1 is characterized in that: The temperature of drying the tin slag in step 5 is 85-105°C.

10. Ammonium paratungstate and tin concentrate obtained according to the method according to any one of claims 1 to 9.

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