Method for recovering cobalt and nickel from tungsten smelting tailings

Abstract

The invention discloses a method for recovering cobalt and nickel from tungsten smelting tailings. The method comprises the following steps: mixing tungsten slag with dilute acid to obtain mixed slurry, adding sodium thiosulfate into the mixed slurry for reaction to obtain a reaction product, and carrying out solid-liquid separation on the reaction product to obtain a cobalt-nickel solution and solid waste residues. The tungsten slag is mixed with dilute acid, so that metal elements such as cobalt and nickel in the tungsten slag react with acid and are converted into soluble metal ions, high-valence cobalt (Co3O4) which is insoluble in acid is reduced into CoO which is soluble in acid through sodium thiosulfate, and therefore the leaching rate is increased, dissolution of cobalt and nickel is facilitated, and the recovery rate of cobalt and nickel reaches 80% or above.

Description

Technical Field

[0001] The invention relates to the technical field of conversion and utilization of waste cemented carbide resources, and more specifically, to a method for recovering cobalt and nickel from tungsten smelting tailings. Background Art

[0002] Tungsten smelting tailings are the solid waste remaining after the resource recovery process of cemented carbide tungsten-containing waste. Tungsten smelting tailings contain a certain amount of valuable metal elements. Recycling them through certain technical means can not only improve resource utilization, but also reduce environmental pollution.

[0003] For tungsten slag containing metal elements such as cobalt and nickel, the existing technology uses acid leaching to recover cobalt and nickel. However, conventional acid leaching consumes a large amount of acid and the recovery rate is about 60%, which makes it difficult to achieve a good cobalt and nickel recovery effect.

[0004] Therefore, there is an urgent need to provide a method for recovering cobalt and nickel from tungsten smelting tailings to improve the recovery efficiency of cobalt and nickel. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a method for recovering cobalt and nickel from tungsten smelting tailings, comprising the following steps:

[0006] A method for recovering cobalt and nickel from tungsten smelting tailings, characterized in that it comprises the following steps:

[0007] (1) mixing tungsten slag with dilute acid to obtain a mixed slurry;

[0008] (2) adding sodium thiosulfate to the mixed slurry and mixing to react to obtain a reaction product;

[0009] (3) subjecting the reaction product to solid-liquid separation to obtain a cobalt-nickel solution and solid waste residue.

[0010] Implementing the embodiments of the present invention will have the following beneficial effects:

[0011] In this embodiment, tungsten slag is mixed with dilute acid to obtain a mixed slurry, sodium thiosulfate is added to the mixed slurry for reaction to obtain a reaction product, and the reaction product is subjected to solid-liquid separation to obtain a cobalt-nickel solution and solid waste slag. The tungsten slag is mixed with dilute acid so that metal elements such as cobalt and nickel in the tungsten slag react with the acid and are converted into soluble metal ions. The added sodium thiosulfate can reduce the high-valent cobalt (Co3O4) that is difficult to dissolve in acid to CoO that is easily soluble in acid, thereby improving the leaching rate, and the cobalt-nickel recovery rate reaches more than 80%. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] in:

[0014] Figure 1 A flow chart of a method for recovering cobalt and nickel from tungsten smelting tailings provided by the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Reference Figure 1 The present invention discloses a method for recovering cobalt and nickel from tungsten smelting tailings, comprising the following steps:

[0017] (1) Mix tungsten slag with dilute acid to obtain a mixed slurry.

[0018] The tungsten slag is mixed with dilute acid to make the metal elements such as cobalt and nickel in the tungsten slag react with the acid and transform into soluble metal ions.

[0019] Furthermore, before the tungsten slag is mixed with the dilute acid, the tungsten slag is dried and crushed; the drying process can be carried out by hot air drying or drying equipment (such as drying furnace, dryer, etc.), and the tungsten slag is placed in the drying equipment to remove the moisture and oil therein by heating and ventilation to prevent affecting the treatment effect. The crushing process can be carried out by crushing equipment (such as crusher, ball mill, etc.), and the particle size of the dried tungsten waste cobalt-nickel tungsten slag is reduced to make it easier to separate and purify it in the subsequent recovery of metal elements such as cobalt and nickel; the particle size of the tungsten slag is not less than 200 mesh.

[0020] Furthermore, the cobalt content in the tungsten slag is 3wt%-5wt%, and the nickel content is 2wt%-3wt%.

[0021] Furthermore, the dilute acid includes dilute hydrochloric acid and / or dilute sulfuric acid. The concentration of the dilute acid is 0.7 mol / L-1 mol / L; the amount of the dilute acid added is: the tungsten slag = 100g: 250-300ml.

[0022] (2) adding sodium thiosulfate to the mixed slurry for mixed reaction; the amount of sodium thiosulfate added: tungsten slag = 100g: 2-2.5g.

[0023] Sodium thiosulfate can reduce the acid-insoluble high-valent cobalt (Co3O4) to acid-soluble CoO, thereby increasing the leaching rate. If the amount of sodium thiosulfate is too little, the reduction is not thorough and the leaching rate is low. If the amount of sodium thiosulfate is too much, it will cause waste, and the subsequent cobalt-nickel solution needs to be neutralized with an oxidant, which increases the processing cost.

[0024] Furthermore, the reaction temperature is 70°C-90°C, and the reaction time is 2h-3h.

[0025] (3) The mixed slurry after the reaction is subjected to solid-liquid separation to obtain a cobalt-nickel solution and solid waste residue.

[0026] The mixed slurry after the reaction is a solid-liquid mixture, which is filtered, centrifuged, or separated to obtain a cobalt-nickel solution and solid waste residue. The cobalt-nickel solution mainly contains an enriched solution of metal ions such as cobalt and nickel, while the solid waste residue is mainly an enriched slag of tungsten.

[0027] Furthermore, the cobalt-nickel solution can be further processed, such as precipitation, extraction, electrolysis, etc., to recover metal elements such as cobalt and nickel. The solid waste residue can be recycled or processed to recover the tungsten element.

[0028] It can be understood that in this embodiment, tungsten slag is mixed with dilute acid to obtain a mixed slurry, sodium thiosulfate is added to the mixed slurry for mixed reaction, and the mixed slurry after the reaction is separated into solid and liquid to obtain a cobalt-nickel solution and solid waste slag. The tungsten slag is mixed with dilute acid so that metal elements such as cobalt and nickel in the tungsten slag react with the acid and are converted into soluble metal ions. Sodium thiosulfate can reduce high-valent cobalt (Co3O4) that is difficult to dissolve in acid to CoO that is easily soluble in acid, thereby improving the leaching rate and facilitating the dissolution of cobalt and nickel. The recovery rate of cobalt and nickel is more than 80%. Specific embodiment:

[0030] Embodiment 1:

[0031] (1) 100 g of tungsten slag is mixed with 300 ml of dilute hydrochloric acid to obtain a mixed slurry. The cobalt oxide content of the tungsten slag is 4.5 wt%, the nickel oxide content is 2.8 wt%, and the concentration of the dilute hydrochloric acid is 0.8 mol / L.

[0032] (2) Add 2 g of sodium thiosulfate to the mixed slurry for mixed reaction. The reaction time is 3 h and the reaction temperature is 80° C. to obtain a reaction product.

[0033] (3) Filter the reaction product to obtain a cobalt-nickel solution and solid waste residue.

[0034] Embodiment 2:

[0035] (1) 100 g of tungsten slag is mixed with 300 ml of dilute hydrochloric acid to obtain a mixed slurry. The cobalt oxide content of the tungsten slag is 4.5 wt%, the nickel oxide content is 2.8 wt%, and the concentration of the dilute hydrochloric acid is 0.8 mol / L.

[0036] (2) Add 2.25 g of sodium thiosulfate to the mixed slurry for mixed reaction. The reaction time is 3 h and the reaction temperature is 80° C. to obtain a reaction product.

[0037] (3) Filter the reaction product to obtain a cobalt-nickel solution and solid waste residue.

[0038] Embodiment 3:

[0039] (1) 100 g of tungsten slag is mixed with 300 ml of dilute hydrochloric acid to obtain a mixed slurry. The cobalt oxide content of the tungsten slag is 4.5 wt%, the nickel oxide content is 2.8 wt%, and the concentration of the dilute hydrochloric acid is 0.8 mol / L.

[0040] (2) Add 2.5 g of sodium thiosulfate to the mixed slurry for mixed reaction. The reaction time is 3 h and the reaction temperature is 80° C. to obtain a reaction product.

[0041] (3) Filter the reaction product to obtain a cobalt-nickel solution and solid waste residue.

[0042] Comparative Example 1:

[0043] (1) 100 g of tungsten slag was mixed with 300 ml of dilute hydrochloric acid to obtain a mixed slurry, and the reaction time was 3 h at a reaction temperature of 80° C. The cobalt oxide content in the tungsten slag was 4.5 wt%, the nickel oxide content was 2.8 wt%, and the concentration of the dilute hydrochloric acid was 0.8 mol / L.

[0044] (2) Filter the mixed slurry after the reaction to obtain a cobalt-nickel solution and solid waste residue.

[0045] Comparative Example 2:

[0046] (1) 100 g of tungsten slag is mixed with 300 ml of dilute hydrochloric acid to obtain a mixed slurry. The cobalt oxide content of the tungsten slag is 4.5 wt%, the nickel oxide content is 2.8 wt%, and the concentration of the dilute hydrochloric acid is 0.8 mol / L.

[0047] (2) Add 0.5 g of sodium thiosulfate to the mixed slurry for mixed reaction. The reaction time is 3 h and the reaction temperature is 80° C. to obtain a reaction product.

[0048] (3) Filter the reaction product to obtain a cobalt-nickel solution and solid waste residue.

[0049] Comparative Example 3:

[0050] (1) 100 g of tungsten slag is mixed with 300 ml of dilute hydrochloric acid to obtain a mixed slurry. The cobalt oxide content of the tungsten slag is 4.5 wt%, the nickel oxide content is 2.8 wt%, and the concentration of the dilute hydrochloric acid is 0.5 mol / L.

[0051] (2) Add 2 g of sodium thiosulfate to the mixed slurry for mixed reaction. The reaction time is 3 h and the reaction temperature is 80° C. to obtain a reaction product.

[0052] (3) Filter the reaction product to obtain a cobalt-nickel solution and solid waste residue.

[0053] Table 1: Cobalt and nickel dissolution rates of Examples 1-3 and Comparative Examples 1-3

[0054] Cobalt and nickel dissolution rate Example 1 81％ Example 2 83％ Example 3 82％ Comparative Example 1 64％ Comparative Example 2 73％ Comparative Example 3 68％

[0055] In Examples 1 to 3, the leaching rate was increased by adding sodium thiosulfate, and the dissolution rate of cobalt and nickel was more than 80%. In Comparative Example 1, sodium thiosulfate was not added, and the dissolution rate of cobalt and nickel was significantly reduced. In Comparative Example 2, the amount of sodium thiosulfate was too small, and the reduction was not thorough, resulting in a leaching rate of less than 80%. In Comparative Example 3, the concentration of hydrochloric acid was too low, and the solubility of metal ions such as cobalt and nickel was reduced, resulting in difficulty in effectively leaching cobalt and nickel metal ions from tungsten slag, resulting in a low dissolution rate of cobalt and nickel.

[0056] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for recovering cobalt and nickel from tungsten smelting tailings, characterized in that: The following steps are involved: (1) mixing tungsten slag with dilute acid to obtain a mixed slurry; (2) adding sodium thiosulfate to the mixed slurry to react and obtain a reaction product; (3) subjecting the reaction product to solid-liquid separation to obtain a cobalt-nickel solution and solid waste residue.

2. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 1, characterized in that: The amount of the diluted acid added: the tungsten slag = 100g: 250-300ml.

3. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 2, characterized in that , the amount of sodium thiosulfate added: the tungsten slag = 100g: 2-2.5g.

4. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 2, characterized in that The cobalt oxide content in the tungsten slag is 3wt%-5wt%, and the nickel oxide content is 2wt%-3wt%.

5. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 2, characterized in that: The concentration of the dilute acid is 0.7 mol / L-1 mol / L.

6. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 1, characterized in that: The dilute acid includes dilute hydrochloric acid and / or dilute sulfuric acid.

7. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 1, characterized in that: The reaction temperature in step (2) is 70°C-90°C.

8. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 7, characterized in that: The reaction time is 2h-3h.

9. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 1, characterized in that: The particle size of the tungsten slag is not less than 200 meshes.

10. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 1, characterized in that: The solid-liquid separation includes one or more of filtration and centrifugation.

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