阅读说明：本技术 一种氢氧化镍钴硫酸体系快速浸出的方法 (Method for quickly leaching nickel hydroxide cobalt sulfuric acid system ) 是由 董存武 沈艳玲 龚继宝 麻在生 明键伟 于 2020-12-02 设计创作，主要内容包括：本发明公开了一种氢氧化镍钴硫酸体系快速浸出的方法,包括以下步骤：将粗氢氧化镍钴用水洗涤后固液分离,将洗涤后的粗氢氧化镍钴用浓硫酸溶解,得到溶解后的反应物料,向溶解后的反应物料中加水稀释再进行固液分离,得到氢氧化镍钴溶解液和低镍钴溶解渣；向氢氧化镍钴溶解液中加入硫磺,向加入硫磺后的氢氧化镍钴溶解液中加入洗涤后的粗氢氧化镍钴,至加入硫磺后的氢氧化镍钴溶解液的pH值为4.0-4.5,固液分离,得到低钠高镍浸出液和氢氧化镍钴溶解渣。本发明提高了氢氧化镍钴中钴的浸出率,而且不会额外引入钠离子进入浸出；采用浓硫酸溶解氢氧化镍钴可以进一步提高镍的收率,同时硫磺粉的加入可以改变浸出渣的渣型,有利于压滤。(The invention discloses a method for quickly leaching a nickel hydroxide cobalt sulfuric acid system, which comprises the following steps: washing the crude nickel cobalt hydroxide with water, carrying out solid-liquid separation, dissolving the washed crude nickel cobalt hydroxide with concentrated sulfuric acid to obtain a dissolved reaction material, adding water to the dissolved reaction material for dilution, and carrying out solid-liquid separation to obtain a nickel cobalt hydroxide solution and low nickel cobalt dissolved slag; adding sulfur into the nickel cobalt hydroxide solution, adding the washed crude nickel cobalt hydroxide into the nickel cobalt hydroxide solution after the sulfur is added until the pH value of the nickel cobalt hydroxide solution after the sulfur is added is 4.0-4.5, and carrying out solid-liquid separation to obtain a low-sodium high-nickel leaching solution and nickel cobalt hydroxide dissolving slag. The invention improves the leaching rate of cobalt in the nickel hydroxide cobalt, and sodium ions are not additionally introduced to leach; the concentrated sulfuric acid is adopted to dissolve the nickel hydroxide cobalt, so that the nickel yield can be further improved, and the addition of the sulfur powder can change the slag type of the leached slag, thereby being beneficial to filter pressing.)

1. A method for rapidly leaching a nickel hydroxide cobalt sulfuric acid system is characterized by comprising the following steps:

(1) washing the crude nickel cobalt hydroxide with water, and carrying out solid-liquid separation to obtain washed crude nickel cobalt hydroxide;

(2) dissolving the washed crude nickel cobalt hydroxide by concentrated sulfuric acid for 20-40 min to obtain a dissolved reaction material, wherein the liquid-solid ratio of the concentrated sulfuric acid to the washed crude nickel cobalt hydroxide is 1 (2-4); adding water into the dissolved reaction material for dilution, and then carrying out solid-liquid separation to obtain a nickel hydroxide cobalt dissolving solution and low nickel cobalt dissolving slag;

(3) adding sulfur into the nickel cobalt hydroxide solution at the temperature of 60-80 ℃ to obtain the nickel cobalt hydroxide solution added with the sulfur, wherein the mass ratio of the sulfur to the crude nickel cobalt hydroxide washed in the step (2) is (0.02-0.05): 1; adding the washed crude nickel cobalt hydroxide into the nickel cobalt hydroxide solution into which the sulfur is added until the pH value of the nickel cobalt hydroxide solution into which the sulfur is added is 4.0-4.5, and carrying out solid-liquid separation to obtain a low-sodium high-nickel leaching solution and nickel cobalt hydroxide dissolving slag.

2. The method for rapidly leaching nickel cobalt hydroxide sulfuric acid system according to claim 1, wherein the process conditions for washing the crude nickel cobalt hydroxide with water in the step (1) are as follows: the liquid-solid ratio of water to the crude nickel cobalt hydroxide is (1-3):1, the washing temperature is 50-60 ℃, the washing time is 0.5-1 h, and the washing times are 1-2.

3. The method for rapidly leaching nickel hydroxide cobalt sulfuric acid system according to claim 1, wherein the process conditions of adding water to the dissolved reaction materials in the step (2) for dilution are as follows: adding water to dilute to 6-9 times of concentrated sulfuric acid volume, at 60-80 deg.C for 20-40 min.

4. The method for rapidly leaching nickel cobalt hydroxide sulfuric acid system according to claim 1, wherein the crude nickel cobalt hydroxide in step (1) comprises the following components in percentage by mass: 30-45% of Ni, less than 4% of Co, less than 0.1% of Na and less than 10% of the total amount of copper, manganese, zinc and iron.

Technical Field

The invention belongs to the technical field of nonferrous hydrometallurgy, and particularly relates to a method for quickly leaching a nickel hydroxide cobalt sulfuric acid system.

Background

With the rapid development of the battery industry in recent years, manufacturers for producing nickel cobalt sulfate in China have increasingly fierce competition, cobalt element in nickel cobalt hydroxide starts to be priced, the selling price of raw materials is increased, the selling price of nickel cobalt sulfate products is reduced, and the profit margin of the nickel cobalt sulfate products is greatly reduced. The method is characterized in that sodium sulfite is added in the leaching process in order to promote the leaching of cobalt in the original treatment process of nickel hydroxide cobalt, a large amount of sodium ions are introduced into the leachate, a sodium removal process is required to be added in the subsequent impurity removal process of the leachate, the process flow is long, the production cost is higher than the profit margin of nickel sulfate and cobalt products, and a new method is required to leach nickel hydroxide cobalt in order to reduce the production cost.

Disclosure of Invention

Aiming at the problems existing in the dissolution of nickel hydroxide and cobalt sulfate in the prior art, the invention provides a method for quickly leaching a nickel hydroxide and cobalt sulfate system, which can promote the leaching rate of nickel and cobalt elements in nickel hydroxide and reduce the sodium content in a nickel hydroxide and cobalt leaching solution.

The invention adopts the following technical scheme:

a method for rapidly leaching a nickel hydroxide cobalt sulfuric acid system is characterized by comprising the following steps:

(1) washing the crude nickel cobalt hydroxide with water, and carrying out solid-liquid separation to obtain washed crude nickel cobalt hydroxide;

(2) dissolving the washed crude nickel cobalt hydroxide by concentrated sulfuric acid for 20-40 min to obtain a dissolved reaction material, wherein the liquid-solid ratio of the concentrated sulfuric acid to the washed crude nickel cobalt hydroxide is 1 (2-4); adding water into the dissolved reaction material for dilution, and then carrying out solid-liquid separation to obtain a nickel hydroxide cobalt dissolving solution and low nickel cobalt dissolving slag;

(3) adding sulfur into the nickel cobalt hydroxide solution at the temperature of 60-80 ℃ to obtain the nickel cobalt hydroxide solution added with the sulfur, wherein the mass ratio of the sulfur to the crude nickel cobalt hydroxide washed in the step (2) is (0.02-0.05): 1; adding the washed crude nickel cobalt hydroxide into the nickel cobalt hydroxide solution into which the sulfur is added until the pH value of the nickel cobalt hydroxide solution into which the sulfur is added is 4.0-4.5, and carrying out solid-liquid separation to obtain a low-sodium high-nickel leaching solution and nickel cobalt hydroxide dissolving slag.

The method for rapidly leaching the nickel cobalt hydroxide sulfuric acid system is characterized in that the process conditions for washing the crude nickel cobalt hydroxide with water in the step (1) are as follows: the liquid-solid ratio of water to the crude nickel cobalt hydroxide is (1-3):1, the washing temperature is 50-60 ℃, the washing time is 0.5-1 h, and the washing times are 1-2.

The method for quickly leaching the nickel hydroxide cobalt sulfuric acid system is characterized in that the technological conditions for adding water to the dissolved reaction materials in the step (2) for dilution are as follows: adding water to dilute to 6-9 times of concentrated sulfuric acid volume, at 60-80 deg.C for 20-40 min.

The method for rapidly leaching the nickel cobalt hydroxide sulfuric acid system is characterized in that the crude nickel cobalt hydroxide in the step (1) comprises the following components in percentage by mass: 30-45% of Ni, less than 4% of Co, less than 0.1% of Na and less than 10% of the total amount of copper, manganese, zinc and iron.

The invention has the beneficial technical effects that: the invention relates to a leaching method of a low-sodium high-nickel solution obtained by leaching a nickel cobalt hydroxide raw material produced from a laterite-nickel ore with sulfuric acid. According to the invention, the sodium in the crude nickel cobalt hydroxide is washed, so that the sodium content in the crude nickel cobalt hydroxide leaching solution is reduced. According to the invention, the traditional sodium sulfite for promoting the leaching rate of cobalt is abandoned, and the leaching of cobalt is promoted by adopting two modes of sulfur and concentrated sulfuric acid, so that the leaching rate of cobalt in nickel hydroxide cobalt is improved, and sodium ions are not additionally introduced into the leaching solution; the invention adopts concentrated sulfuric acid to dissolve nickel hydroxide cobalt or nickel hydroxide cobalt slag, can further improve the yield of nickel, and simultaneously, the addition of the sulfur powder can change the slag type of the leached slag, thereby being beneficial to filter pressing.

Drawings

FIG. 1 is a schematic process flow diagram of the present invention.

Detailed Description

Referring to fig. 1, the method for rapidly leaching nickel hydroxide cobalt sulfuric acid system of the invention comprises the following steps:

(1) washing the crude nickel cobalt hydroxide with sodium: washing sodium in the crude nickel cobalt hydroxide by using tap water, washing the crude nickel cobalt hydroxide by using water, and carrying out solid-liquid separation to obtain washed crude nickel cobalt hydroxide; the process conditions for washing the crude nickel cobalt hydroxide by water are as follows: the liquid-solid ratio of water to crude nickel cobalt hydroxide is (1-3):1, the washing temperature is 50-60 ℃, the washing time is 0.5-1 h, stirring is started in the washing process, and the washing times are 1-2 times. The liquid-solid ratio of water to crude nickel cobalt hydroxide is the ratio of the volume of tap water to the weight of nickel cobalt hydroxide, the volume unit is L, and the weight unit is kg. The crude nickel cobalt hydroxide comprises the following components in percentage by mass: 30-45% of Ni, less than 4% of Co, less than 0.1% of Na and less than 10% of the total amount of copper, manganese, zinc and iron.

(2) Dissolving and washing nickel cobalt hydroxide by concentrated sulfuric acid: dissolving the washed crude nickel cobalt hydroxide by using concentrated sulfuric acid for 20-40 min, wherein the temperature is not controlled when the concentrated sulfuric acid is dissolved, stirring is started to obtain a dissolved reaction material, and the liquid-solid ratio of the concentrated sulfuric acid to the washed crude nickel cobalt hydroxide is 1 (2-4); the liquid-solid ratio of the concentrated sulfuric acid to the washed crude nickel cobalt hydroxide is the ratio of the volume (L) of the concentrated sulfuric acid to the weight (kg) of the washed crude nickel cobalt hydroxide. Adding water into the dissolved reaction material for dilution, and then carrying out solid-liquid separation to obtain a nickel hydroxide cobalt dissolving solution and low nickel cobalt dissolving slag; the content of nickel in the low nickel cobalt dissolution slag is less than 1 percent, and the content of cobalt in the low nickel cobalt dissolution slag is less than 1 percent (dry basis). The technological conditions for adding water to the dissolved reaction materials for dilution are as follows: adding water to dilute to 6-9 times of concentrated sulfuric acid volume, at 60-80 deg.C for 20-40 min. The water is added to dilute the mixture to 6 to 9 times of the volume of the concentrated sulfuric acid, which means that the volume of the mixed material liquid after dilution is 6 to 9 times of the volume of the concentrated sulfuric acid. The concentrated sulfuric acid is undiluted analytically pure concentrated sulfuric acid (the concentration is about 36 mol/L).

(3) Adjusting the pH value of the washed nickel cobalt hydroxide: adding additive sulfur into the nickel cobalt hydroxide solution, controlling the reaction temperature to be 60-80 ℃, and uniformly stirring the sulfur to obtain the nickel cobalt hydroxide solution added with the sulfur, wherein the mass ratio of the sulfur to the crude nickel cobalt hydroxide washed in the step (2) is (0.02-0.05): 1; adding the washed crude nickel cobalt hydroxide into the nickel cobalt hydroxide solution into which the sulfur is added until the pH value of the nickel cobalt hydroxide solution into which the sulfur is added is 4.0-4.5, and carrying out solid-liquid separation to obtain a low-sodium high-nickel leaching solution and nickel cobalt hydroxide dissolving slag. The nickel content of the low-sodium high-nickel leachate is more than or equal to 80g/L, pH, the value is 4.0-4.5, and the Na content is less than or equal to 0.1 g/L.

The reaction principle of the invention is as follows:

1. conversion of trivalent cobalt into divalent cobalt

6Co(OH)₃+S+10H⁺＝＝6Co²⁺+14H₂O+SO₄ ^2-

4Co(OH)₃+4H₂SO₄(concentrated sulfuric acid) ═ 4CoSO₄+O₂↑+10H₂O

2. Mechanism of dissolution

Ni(OH)₂+2H⁺＝Ni²⁺+2H₂O

Co(OH)₂+2H⁺＝Co²⁺+2H₂O

Example 1

Washing 1kg of crude nickel cobalt hydroxide by using 3L of tap water for one time, wherein the washing temperature is 50 ℃, the washing time is 0.5h, stirring is started in the washing process, and the crude nickel cobalt hydroxide comprises the following components in percentage by mass: ni 42.27%, Co 2.78%, the sum of the contents of Cu, Mn, Zn, Fe and other impurities is 9.18%, and Na is 0.061%. And carrying out suction filtration after washing to obtain the washed crude nickel cobalt hydroxide.

Dissolving the washed 0.6kg of crude nickel cobalt hydroxide by using 0.2L of concentrated sulfuric acid for 20min, and stirring to obtain a dissolved reaction material. And adding water into the dissolved reaction material to dilute the reaction material to 1.4L, wherein the dilution temperature is 60 ℃, the dilution time is 20min, and after dilution, carrying out solid-liquid separation to obtain a nickel cobalt hydroxide solution and low nickel cobalt dissolving slag.

Adding 30g of additive sulfur into the nickel cobalt hydroxide solution, controlling the reaction temperature to be 60 ℃, uniformly stirring the sulfur to obtain the nickel cobalt hydroxide solution added with the sulfur, adding the washed crude nickel cobalt hydroxide into the nickel cobalt hydroxide solution added with the sulfur until the pH value of the nickel cobalt hydroxide solution added with the sulfur is 4.0, and carrying out solid-liquid separation to obtain a low-sodium high-nickel leaching solution and nickel cobalt hydroxide dissolving slag. The pH of the low sodium high nickel leachate was 4.0 and the composition and concentration of the low sodium high nickel leachate are shown in table 1.

TABLE 1 Low sodium high nickel leachate composition and its concentration

Example 2

Washing 1.0kg of crude nickel cobalt hydroxide by using 2L of tap water for one time, wherein the washing temperature is 55 ℃, the washing time is 1h, stirring is started in the washing process, and the crude nickel cobalt hydroxide comprises the following components in percentage by mass: 37.38 percent of Ni, 1.32 percent of Co, 6.63 percent of the sum of the contents of Cu, Mn, Zn, Fe and other impurities and 0.043 percent of Na. And carrying out suction filtration after washing to obtain the washed crude nickel cobalt hydroxide.

Dissolving the washed 0.2kg of crude nickel cobalt hydroxide with 0.2L of concentrated sulfuric acid for 30min, and stirring to obtain a dissolved reaction material. And adding water into the dissolved reaction material to dilute the reaction material to 1.6L, wherein the dilution temperature is 70 ℃, the dilution time is 30min, and after dilution, carrying out solid-liquid separation to obtain a nickel cobalt hydroxide solution and low nickel cobalt dissolved slag. The components and the mass percentage content of the low nickel cobalt dissolution slag are shown in the table 2.

TABLE 2 Low Nickel cobalt dissolved slag composition%

Adding 16g of additive sulfur into the nickel cobalt hydroxide solution, controlling the reaction temperature to be 70 ℃, uniformly stirring the sulfur to obtain the nickel cobalt hydroxide solution added with the sulfur, adding the washed crude nickel cobalt hydroxide into the nickel cobalt hydroxide solution added with the sulfur until the pH value of the nickel cobalt hydroxide solution added with the sulfur is 4.5, and carrying out solid-liquid separation to obtain a low-sodium high-nickel leaching solution and nickel cobalt hydroxide dissolving slag. The pH of the low sodium high nickel leachate was 4.5 and the composition and concentration of the low sodium high nickel leachate are shown in table 3.

TABLE 3 Low sodium high nickel leachate composition and its concentration

Example 3

1kg of crude nickel cobalt hydroxide is washed once by using 1L of tap water, the washing temperature is 60 ℃, the washing time is 0.5h, stirring is started in the washing process, and the crude nickel cobalt hydroxide comprises the following components in percentage by mass: 31.03 percent of Ni, 3.54 percent of Co, 0.0093 percent of Na and 5.01 percent of the sum of the contents of impurities such as copper, manganese, zinc, iron and the like. And carrying out suction filtration after washing to obtain the washed crude nickel cobalt hydroxide.

Dissolving 0.4kg of the washed crude nickel cobalt hydroxide in 0.1L of concentrated sulfuric acid for 25min, and stirring to obtain a dissolved reaction material. And adding water into the dissolved reaction material to dilute the reaction material to 0.7L, wherein the dilution temperature is 80 ℃, the dilution time is 25min, and after dilution, carrying out solid-liquid separation to obtain a nickel cobalt hydroxide solution and low nickel cobalt dissolving slag. The components and the mass percentage content of the low nickel cobalt dissolution slag are shown in the table 4.

TABLE 4 Low Nickel cobalt dissolved slag composition%

Adding 8g of additive sulfur into the nickel cobalt hydroxide solution, controlling the reaction temperature to be 80 ℃, uniformly stirring the sulfur to obtain the nickel cobalt hydroxide solution added with the sulfur, adding the washed crude nickel cobalt hydroxide into the nickel cobalt hydroxide solution added with the sulfur until the pH value of the nickel cobalt hydroxide solution added with the sulfur is 4.0, and carrying out solid-liquid separation to obtain a low-sodium high-nickel leaching solution and nickel cobalt hydroxide dissolving slag. The pH of the low sodium high nickel leachate was 4.0 and the composition and concentration of the low sodium high nickel leachate are shown in table 5.

TABLE 5 Low sodium high nickel leachate composition and concentration