Chemical leaching method for leaching battery black powder with sulfuric acid

Abstract

The invention relates to a chemical leaching method for leaching battery black powder with sulfuric acid, which comprises the following steps of: roasting the ground black powder to obtain a roasted sample; adding the roasted sample into dilute sulphuric acid, carrying out primary leaching under the conditions that the water bath heating temperature is 90 DEG C and the reaction time is 2 hours, controlling the pH at the leaching reaction end point to be 3.5-4.0 and the final liquid-solid mass ratio to be 2.8-3.0: 1, and carrying out suction filtration after the leaching is finished to respectively obtain primary leaching liquid and primary leaching residues; the primary leaching residues are added into dilute sulfuric acid, secondary leaching is carried out under the conditions that the water bath heating temperature is 90 DEG C and the reaction time is 2 h, the pH of the leaching reaction end point is controlled to be 1.0, and secondary leaching liquid and secondary leaching residues are obtained through suction filtration after leaching is finished; and combining the second immersion liquid with the first immersion liquid. The method is efficient, safe and environment-friendly.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal smelting, and in particular to a chemical leaching method for leaching battery black powder with sulfuric acid. Background Art

[0002] In recent years, with the continuous updating and development of new energy vehicle technology, the manufacturing of new energy vehicles has received widespread attention from countries around the world. The replacement of fuel vehicles by new energy vehicles is an important improvement to environmental pollution and the shortage of oil resources. After 2000, a large number of electronic products have emerged, especially in the field of new energy vehicles. The application of lithium-ion batteries (including lithium cobalt oxide batteries, lithium manganese oxide batteries, ternary batteries, lithium iron phosphate batteries, etc.) has become more and more extensive, and the demand has also increased, resulting in a sharp increase in scrapped lithium-ion batteries. On the one hand, waste lithium-ion batteries are discarded or directly buried at will, and the toxic substances and heavy metal elements in them are harmful to the environment and human health; on the other hand, if they are not effectively recycled, the many valuable metals (Li, Ni, Co, Mn, Cu and Al, etc.) contained in the battery will cause a great waste of resources. Therefore, waste lithium-ion batteries need to be efficiently recycled and harmlessly treated to achieve the recycling of valuable metals such as lithium, nickel, cobalt and manganese.

[0003] Nickel-cobalt-manganese ternary precursor is a lithium-ion battery positive electrode material with excellent performance, and is increasingly widely used in the lithium-ion battery industry. Its conventional production method requires expensive purified chemical raw materials, and the production cost is relatively high. The direct preparation of nickel-cobalt-manganese ternary materials from raw ores or waste materials can not only save expensive metal resources and reduce environmental pollution, but also significantly reduce production costs. Ternary batteries are rich in high-value nickel-cobalt-manganese metal resources, and their recycling research is more focused on the separation and extraction of nickel-cobalt-manganese metals. The treatment methods can generally be divided into two categories: pyrometallurgy and hydrometallurgy. Wet recovery technology has received widespread attention due to its relatively low energy consumption and environmental protection. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an efficient, safe and environmentally friendly chemical leaching method for leaching battery black powder with sulfuric acid.

[0005] To solve the above problems, the present invention discloses a chemical leaching method for leaching battery black powder with sulfuric acid, characterized in that: the method refers to calcining the ground black powder to obtain a calcined sample; the calcined sample is added to dilute sulfuric acid with a hydrogen ion concentration of 6 g / L at a liquid-solid mass ratio of 4:1, and a first leaching is performed under the conditions of a water bath heating temperature of 90°C and a reaction time of 2 h, and the pH at the end of the leaching reaction is controlled to be 3.5-4.0, and the final liquid-solid mass ratio is 2.8-3.0:1. After the leaching is completed, a first leaching liquid and a first leaching residue are obtained by suction filtration; the first leaching residue is added to dilute sulfuric acid with a hydrogen ion concentration of 6 g / L at a liquid-solid mass ratio of 4:1, and a second leaching is performed under the conditions of a water bath heating temperature of 90°C and a reaction time of 2 h, and the pH at the end of the leaching reaction is controlled to be 1.0. After the leaching is completed, a second leaching liquid and a second leaching residue are obtained by suction filtration; the second leaching liquid is combined with the first leaching liquid.

[0006] The calcination treatment conditions are to use a muffle furnace, first heat to 800°C at a rate of 25°C / min, and then calcine in an air atmosphere for 90 min.

[0007] Compared with the prior art, the present invention has the following advantages: 1. The present invention pre-treats the black powder by high-temperature roasting, thereby converting the high-valent metal oxide salts in the black powder into metal oxides, thereby improving the leaching rate.

[0008] 2. In the present invention, the black powder material after roasting is subjected to acid leaching twice and the pH is controlled, the purpose is to improve the leaching rate of the black powder material. If only one leaching is performed, more acid will be used to achieve the same leaching rate, and the pH value at the reaction end point will be lower, which is not conducive to the subsequent process production requirements.

[0009] 3. In the present invention, less acid is used than in the traditional method, and less acid gas and harmful gas are released during the leaching process. Therefore, the present invention has the characteristics of safety and environmental protection.

[0010] 4. The process of the present invention is simple, easy to industrialize, and effectively improves the utilization rate of acid in the leaching process. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0012] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0013] like Figure 1As shown, a chemical leaching method for leaching battery black powder with sulfuric acid is provided. The method is to heat the ground black powder to 800°C at a rate of 25°C / min in a muffle furnace, and then calcine it in an air atmosphere for 90 min to obtain a calcined sample; the calcined sample is added to dilute sulfuric acid with a hydrogen ion concentration of 6 g / L at a liquid-to-solid mass ratio (g / g) of 4:1, and leached once under the conditions of a water bath heating temperature of 90°C and a reaction time of 2 h, and the pH of the leaching reaction endpoint is controlled to be 3.5-4.0, and the final liquid-to-solid mass ratio is 2.8-3.0:1. After the leaching is completed, an leaching solution and a leaching residue are obtained by filtration; the leaching residue is added to dilute sulfuric acid with a hydrogen ion concentration of 6 g / L at a liquid-to-solid mass ratio (g / g) of 4:1, and the water bath heating temperature is 90°C and the reaction time is 2 h. h, and the end point pH of the leaching reaction was controlled to be 1.0. After the leaching was completed, the second leaching liquid and the second leaching residue were obtained by filtration. The second leaching liquid was combined with the first leaching liquid.

[0014] Example 1 200 g of the ground black powder sample was calcined in a muffle furnace at 800 °C for 90 min to obtain the pretreated sample. The composition of the calcined black powder was: Ni 37.46%, Co 7.26%, Mn 24.01%, Li 0.27%, Al 1.07%, Cu 0.085%.

[0015] Take 100 g of the sample after calcination pretreatment and slowly add it to 400 mL of dilute sulfuric acid with a hydrogen ion concentration of 6 g / L. The reaction temperature is controlled at 90 °C. After 2 h of reaction, add the calcined sample to adjust the pH to 3.5-4.0. After filtration, a leaching solution and a leaching residue are obtained. The concentration of each metal ion in the leaching solution is: Ni 75.21 g / L, Co 16.49 g / L, Mn 61.74 g / L, Li0.82 g / L, Al 2.02 g / L, Cu 0.0005 g / L. The leaching rate of nickel, cobalt and manganese in the first leaching is 77.12%.

[0016] The first leaching residue was added to 400 mL of dilute sulfuric acid with a hydrogen ion concentration of 6 g / L, the reaction temperature was controlled at 90 °C, the reaction was stopped when the pH was 1, and the second leaching solution and the second leaching residue were obtained by filtration. The metal ion concentrations of the second leaching solution were: Ni 39.16 g / L, Co 6.84 g / L, Mn 9.87 g / L, Li 1.32 g / L, Al 0.12 g / L, Cu 0.11 g / L. The element composition of the second leaching residue was: Ni 1.046%, Co 1.33%, Mn 1.02%, Li 0.076%, Al 0.52%, Cu 1.64%.

[0017] The total leaching rate of nickel, cobalt and manganese in the first and second leaching is 99.41%, and the slag rate is 4.5%.

[0018] Example 2 200 g of the ground black powder sample was calcined in a muffle furnace at 800 °C for 90 min to obtain the pretreated sample. The composition of the calcined black powder was: Ni 21.53%, Co 6.77%, Mn 10.08%, Li 4.44%, Al 2.69%, Cu 2.1%.

[0019] Take 100 g of the sample after calcination pretreatment and slowly add it to 400 mL of dilute sulfuric acid with a hydrogen ion concentration of 6 g / L. The reaction temperature is controlled at 90 °C. After 2 h of reaction, add the calcined sample to adjust the pH to 3.5-4.0. After filtration, a leaching solution and a leaching residue are obtained. The concentration of each metal ion in the leaching solution is: Ni 49.5 g / L, Co 18.12 g / L, Mn 37.46 g / L, Li15.01 g / L, Al 4.43 g / L, Cu < 0.0005 g / L. The leaching rate of nickel, cobalt and manganese in the first leaching is 65.55%.

[0020] The first leaching residue was added to 400 mL of dilute sulfuric acid with a hydrogen ion concentration of 6 g / L, the reaction temperature was controlled at 90 °C, the reaction was stopped when the pH was 1, and the second leaching solution and the second leaching residue were obtained by filtration. The metal ion concentrations of the second leaching solution were: Ni 36.65 g / L, Co 10.40 g / L, Mn 5.97 g / L, Li 6.13 g / L, Al 2.71 g / L, Cu 0.70 g / L. The element composition of the second leaching residue was: Ni 2.07%, Co 0.51%, Mn 0.25%, Li 0.15%.

[0021] The total leaching rate of nickel, cobalt and manganese in the first and second leaching is 98.96%, and the slag rate is 28.8%.

Claims

1. A chemical leaching method for leaching battery black powder with sulfuric acid, characterized in that: The method comprises the following steps: calcining the ground black powder to obtain a calcined sample; adding the calcined sample to dilute sulfuric acid with a hydrogen ion concentration of 6 g / L at a liquid-solid mass ratio of 4:1, performing a primary leaching under the conditions of a water bath heating temperature of 90°C and a reaction time of 2 h, controlling the pH value at the end point of the leaching reaction to be 3.5-4.0, and finally controlling the liquid-solid mass ratio to be 2.8-3.0:1; filtering after the leaching to obtain a first leaching solution and a first leaching residue; adding the first leaching residue to dilute sulfuric acid with a hydrogen ion concentration of 6 g / L at a liquid-solid mass ratio of 4:1, performing a secondary leaching under the conditions of a water bath heating temperature of 90°C and a reaction time of 2 h, controlling the pH value at the end point of the leaching reaction to be 1.0, and filtering after the leaching to obtain a second leaching solution and a second leaching residue; the second leaching solution is combined with the first leaching solution.

2. A chemical leaching method for leaching battery black powder with sulfuric acid as claimed in claim 1, characterized in that: The calcination treatment conditions are to use a muffle furnace, first heat to 800°C at a rate of 25°C / min, and then calcine in an air atmosphere for 90 min.

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