Method for recovering cobalt and nickel from tungsten smelting tailings

Abstract

The method comprises the following steps that tungsten slag and concentrated sulfuric acid are mixed to obtain mixed slurry, the mixed slurry is roasted to obtain a roasted product, the roasted product is subjected to solid-liquid separation after being crushed and soaked in water, and filter residues and a cobalt-nickel solution are obtained. Tungsten slag and concentrated sulfuric acid are mixed, metal elements such as cobalt and nickel in the tungsten slag react with acid and are converted into soluble metal salt, under the high-temperature roasting condition, molecular movement of the concentrated sulfuric acid is intensified, interaction between the concentrated sulfuric acid and cobalt and nickel is enhanced, and therefore the solubility of cobalt and nickel in the concentrated sulfuric acid is improved; and the chemical reaction rate of cobalt and nickel and ions or molecules in concentrated sulfuric acid is increased, dissolution of cobalt and nickel is facilitated, and the recovery rate of cobalt and nickel reaches 90% or above. The reaction speed is increased through roasting, the use amount of concentrated sulfuric acid is small, the production cost can be reduced, and the sewage treatment capacity is reduced.

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 tailings remaining after tungsten-containing waste from cemented carbide is extracted. The 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] Mixing tungsten slag with concentrated sulfuric acid to obtain a mixed slurry;

[0008] calcining the mixed slurry to obtain a calcined product;

[0009] crushing the roasted product to obtain crushed slag;

[0010] The crushed slag is immersed in water and then separated into solid and liquid to obtain filter residue and cobalt-nickel solution.

[0011] Implementing the embodiments of the present invention will have the following beneficial effects:

[0012] In this embodiment, tungsten slag is mixed with concentrated sulfuric acid to obtain a mixed slurry, and the mixed slurry is roasted. The tungsten slag is mixed with concentrated sulfuric acid to react metal elements such as cobalt and nickel in the tungsten slag with the acid to be converted into soluble metal salts. Under high-temperature roasting conditions, the molecular motion of concentrated sulfuric acid is intensified, and the interaction with cobalt and nickel is enhanced, thereby increasing the solubility of cobalt and nickel in concentrated sulfuric acid, and the rate of chemical reaction between cobalt and nickel and ions or molecules in concentrated sulfuric acid is accelerated, which is conducive to the dissolution of cobalt and nickel, and the recovery rate of cobalt and nickel is more than 90%. The present invention accelerates the reaction speed by roasting, uses less concentrated sulfuric acid, and can also reduce production costs and reduce the amount of sewage treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] 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.

[0014] in:

[0015] Figure 1 A flow chart of a method for recovering cobalt and nickel from tungsten smelting tailings provided by the present invention. DETAILED DESCRIPTION

[0016] 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.

[0017] Reference Figure 1 The present invention discloses a method for recovering cobalt and nickel from tungsten smelting tailings, comprising the following steps:

[0018] (1) Mix tungsten slag and concentrated sulfuric acid to obtain a mixed slurry.

[0019] The tungsten slag is mixed with concentrated sulfuric 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.

[0020] Furthermore, before the tungsten slag is mixed with concentrated sulfuric 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, making it easier to separate and purify it in the subsequent recovery of metal elements such as cobalt and nickel.

[0021] Furthermore, the cobalt oxide content in the tungsten slag is 3-5wt%, and the nickel oxide content is 2-3wt%.

[0022] Furthermore, the mass ratio of concentrated sulfuric acid to tungsten slag is 1:4-1:5. The concentration of concentrated sulfuric acid is 93%-98%.

[0023] (2) calcining the mixed slurry to obtain a calcined product.

[0024] Under high temperature roasting conditions, on the one hand, the molecular motion of the solvent (acid solution) intensifies, and the interaction with the solute (cobalt and nickel) is enhanced, thereby increasing the solubility of cobalt and nickel in concentrated sulfuric acid; the rate of chemical reaction between cobalt and nickel and the ions or molecules in the acid solution is accelerated, which helps cobalt and nickel dissolve in the acid solution. On the other hand, roasting speeds up the reaction rate, reduces the amount of concentrated sulfuric acid used, and can also reduce production costs and reduce the amount of sewage treatment.

[0025] Furthermore, the roasting time is 4h-6h, and the roasting temperature is 300℃-330℃. When the temperature is less than 300℃, the reaction conditions between concentrated sulfuric acid and part of the high-valent cobalt (Co3O4) in the tungsten slag cannot be met, resulting in a decrease in the cobalt conversion rate and a decrease in the recovery rate; when the temperature is greater than 330℃, since the boiling point of concentrated sulfuric acid is 338℃, a large amount of sulfuric acid that does not react in time will volatilize quickly after exceeding the boiling point, resulting in a low sulfuric acid utilization rate, thereby resulting in a decrease in the cobalt-nickel conversion rate and a decrease in the recovery rate.

[0026] (3) Crushing the calcined product to obtain crushed slag.

[0027] The roasted product is a solid product. After crushing, the large pieces of material are converted into small particles to increase the surface area, which is convenient for further water leaching to dissolve cobalt and nickel.

[0028] Further, the particle size of the crushed slag is not less than 200 mesh;

[0029] (4) soaking the crushed slag in water and then performing solid-liquid separation to obtain filter residue and cobalt-nickel filtrate;

[0030] It is understood that the calcined product is a solid product, which is crushed and then soaked in water to clean the nickel and cobalt in the calcined product, and the filter residue and the cobalt-nickel solution are obtained after solid-liquid separation. Furthermore, the water soaking temperature is 70°C-90°C and the water soaking time is 2h-3h.

[0031] The solid-liquid mixture after water immersion is subjected to solid-liquid separation treatment such as filtration or centrifugal separation to obtain a cobalt-nickel solution and a filter residue. The cobalt-nickel solution mainly contains an enriched solution of metal ions such as cobalt and nickel, while the filter residue is mainly an enriched residue of tungsten. Further, the cobalt-nickel solution is further treated, such as precipitation, extraction, electrolysis, etc., to recover metal elements such as cobalt and nickel therein. The filter residue is recovered or treated to recover the tungsten element therein.

[0032] It can be understood that in this embodiment, tungsten slag is mixed with concentrated sulfuric acid to obtain a mixed slurry, and the mixed slurry is roasted. The tungsten slag is mixed with concentrated sulfuric acid to react metal elements such as cobalt and nickel in the tungsten slag with the acid and converted into soluble metal salts. Under high-temperature roasting conditions, the molecular motion of the acid solution is intensified, and the interaction with cobalt and nickel is enhanced, thereby increasing the solubility of cobalt and nickel in concentrated sulfuric acid, and the rate of chemical reaction between cobalt and nickel and ions or molecules in concentrated sulfuric acid is accelerated, which is conducive to the dissolution of cobalt and nickel, and the recovery rate of cobalt and nickel is more than 90%. The reaction speed is accelerated by roasting, the amount of concentrated sulfuric acid used is small, and the production cost can be reduced, as well as the amount of sewage treatment. Specific embodiment:

[0034] Embodiment 1:

[0035] (1) 1000 g of tungsten slag is mixed with 250 g of concentrated sulfuric acid to obtain a mixed slurry. The cobalt content of the tungsten slag is 3.5 wt%, the nickel content is 2.8 wt%, and the concentration of the concentrated sulfuric acid is 98%.

[0036] (2) The mixed slurry is calcined at 300° C. for 5 h to obtain a calcined product.

[0037] (3) Crushing the calcined product to obtain crushed slag.

[0038] (4) The crushed slag is soaked in water and then filtered to obtain a cobalt-nickel solution and a filter residue.

[0039] Embodiment 2:

[0040] (1) 1000 g of tungsten slag is mixed with 250 g of concentrated sulfuric acid to obtain a mixed slurry. The cobalt content of the tungsten slag is 3.5 wt%, the nickel content is 2.8 wt%, and the concentration of the concentrated sulfuric acid is 98%.

[0041] (2) The mixed slurry was calcined at 320° C. for 5 h to obtain a calcined product.

[0042] (3) Crushing the calcined product to obtain crushed slag.

[0043] (4) The crushed slag is soaked in water and then filtered to obtain a cobalt-nickel solution and a filter residue.

[0044] Embodiment 3:

[0045] (1) 1000 g of tungsten slag is mixed with 250 g of concentrated sulfuric acid to obtain a mixed slurry. The cobalt content of the tungsten slag is 3.5 wt%, the nickel content is 2.8 wt%, and the concentration of the concentrated sulfuric acid is 98%.

[0046] (2) The mixed slurry was calcined at 330° C. for 5 h to obtain a calcined product.

[0047] (3) Crushing the calcined product to obtain crushed slag.

[0048] (4) The crushed slag is soaked in water and then filtered to obtain a cobalt-nickel solution and a filter residue.

[0049] Comparative Example 1:

[0050] (1) 1000 g of tungsten slag is mixed with 250 g of concentrated sulfuric acid to obtain a mixed slurry. The cobalt content of the tungsten slag is 3.5 wt%, the nickel content is 2.8 wt%, and the concentration of the concentrated sulfuric acid is 98%.

[0051] (2) Filter the mixed slurry to obtain a cobalt-nickel solution and a filter residue.

[0052] Comparative Example 2:

[0053] In step (2), the mixed slurry is calcined at 200° C. The other steps are the same as those in Example 1.

[0054] Comparative Example 3:

[0055] In step (2), the mixed slurry is calcined at 380° C. The other steps are the same as those in Example 1.

[0056] Table 1: Cobalt and nickel dissolution rates of Examples 1-3 and Comparative Examples 1-3

[0057] Cobalt and nickel dissolution rate Example 1 94％ Example 2 93％ Example 3 95％ Comparative Example 1 55％ Comparative Example 2 69％ Comparative Example 3 75％

[0058] 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: Mixing tungsten slag with concentrated sulfuric acid to obtain a mixed slurry; calcining the mixed slurry to obtain a calcined product; crushing the roasted product to obtain crushed slag; The crushed slag is immersed in water and then separated into solid and liquid to obtain filter residue and cobalt-nickel filtrate.

2. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 1, characterized in that: The calcination temperature is 300°C-330°C.

3. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 2, characterized in that: The calcination time is 4h-6h.

4. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 1, characterized in that: The mass ratio of the concentrated sulfuric acid to the tungsten slag is 1:4-1:

5.

5. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 4, characterized in that The cobalt content in the tungsten slag is 4wt%-6wt%, and the nickel content is 2wt%-3wt%.

6. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 5, characterized in that: The concentration of the concentrated sulfuric acid is 93%-98%.

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

8. The method for recovering cobalt and nickel from tungsten smelting tailings according to claim 1, characterized in that: The water immersion temperature is 70°C-90°C.

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

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