Method for producing sodium electrooxide precursor by direct spray pyrolysis of copper-manganese slag leachate

Abstract

The invention relates to the technical field of sodium electric battery materials, and discloses a method for producing a sodium electric oxide precursor by direct spray pyrolysis of copper-manganese slag leachate. Comprising the following steps: immersing the copper-manganese slag generated by nickel-cobalt smelting into a high-purity leaching tank added with acid to obtain a leaching solution containing Cu and Mn; adding Ni, Fe and other elements according to the molar ratio of the elements required by the sodium electric material without separating the elements in the leachate, directly carrying out carrier gas atomization, feeding into a spray pyrolysis furnace, and obtaining a sodium electric oxide precursor through a one-step method of evaporation, drying and high-temperature pyrolysis; tail gas discharged from the pyrolyzing furnace is absorbed by an absorption tower and then returns to a leaching system for recycling, and waste heat passes through a heat exchanger and is used for heating leachate. According to the method, the sodium electrooxide precursor is produced through direct spray pyrolysis of the copper-manganese slag leachate, the technological process is shortened, the production efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium battery materials, and particularly relates to a method for directly spray pyrolyzing a sodium battery oxide precursor by using a copper-manganese slag leaching solution. Background Art

[0002] With the development of the nickel-cobalt industry, more and more copper-manganese slag is produced in nickel smelting. There is no good comprehensive utilization method for copper-manganese slag, and traditionally it is mostly stockpiled for treatment, resulting in waste of resources and environmental protection problems. Copper-manganese slag contains a large amount of Cu 2+ and Mn 2+ , a small amount of Ni 2+ and Fe 2+ valuable metals. Recycling and reusing valuable metals from copper-manganese slag has good economic benefits.

[0003] At present, the recycling of copper-manganese slag includes pyrometallurgical processes and hydrometallurgical processes. Traditional pyrometallurgical processes recover metals such as copper and manganese through high-temperature smelting, but there are problems such as high metal loss rate and easy secondary entry of manganese elements into the slag, resulting in poor economy and environmental protection. The hydrometallurgical process uses a stepwise precipitation method through pulping and leaching, and separates and recovers metals by using different precipitants or reducing agents to extract valuable metal ions therein respectively, but the process flow is long and the cost is high.

[0004] Therefore, how to comprehensively utilize copper-manganese slag efficiently, environmentally friendly and at low cost has become the core problem to be solved urgently in this field. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for directly spray pyrolyzing a sodium battery oxide precursor by using a copper-manganese slag leaching solution.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: A method for directly spray pyrolyzing a sodium battery oxide precursor by using a copper-manganese slag leaching solution, the chemical formula of the sodium battery oxide is Ni 1-x-y-z Fe x Mn y Cu z O2, where 0 < x < 1, 0 < y < 1, 0 < z < 1, 0 < x + y + z < 1; The method comprises the following steps: S1: Immerse the copper-manganese slag produced by nickel smelting into a high-purity leaching tank with acid added to obtain a leaching solution containing Cu and Mn; S2: Complement Cu, Mn, Ni, and Fe elements into the leaching solution according to the molar percentages of the elements required for sodium battery materials to prepare a metal solution required for sodium batteries; S3: Atomize the complemented leaching solution through a carrier gas and send it into a spray pyrolysis furnace, and obtain a sodium battery oxide precursor through evaporation, drying, and high-temperature pyrolysis; S4: The tail gas discharged from the spray pyrolysis furnace is absorbed and purified through an absorption tower to form recycled acid. When the concentration of the recycled acid meets the standard, the recycled acid is returned to the high-purity leaching tank in S1 for reuse; the waste heat in the tail gas is absorbed through a heat exchanger and used to heat the leaching solution before entering the spray pyrolysis furnace.

[0007] In the above solution, in S1, the nickel smelting slag contains a large amount of Cu 2+ and Mn 2+ ions, a small amount of Ni 2+ and Fe 2+ ions. After high-purity acid leaching, the Cu 2+ ion concentration is 25 - 35 g / L, the Mn 2+ ion concentration is 100 - 120 g / L, the Fe 2+ ion concentration < 0.5 g / L, and the Ni 2+ ion concentration is extremely low.

[0008] In the above solution, in S2, the "metal solution required for sodium battery" means a solution that meets the element ratio of sodium battery oxides. Complementary preparation of the leaching solution can avoid the problem that the Cu 2+ and Fe 2+ ion concentrations in the leaching solution obtained in step one are relatively low, resulting in the Cu 2+ and Mn 2+ ion concentrations not meeting the requirements of the spray pyrolysis metal solution ion concentration. Therefore, it is necessary to add complementary preparation raw materials to the leaching solution according to the molar percentage to adjust the ion concentrations of each element. The types of raw materials used for complementary preparation of the added Mn, Cu, Ni, and Fe elements include one of the corresponding nitrates, sulfates, or chlorides for each element.

[0009] In the above solution, in S4, the tail gas absorption liquid is selected from one or a mixture of deionized water and distilled water, preferably deionized water. The principle and structure of the tail gas absorption tower are common environmental protection equipment in the industry and will not be elaborated in this case.

[0010] Further technical solution, in S1, the acid is sulfuric acid, hydrochloric acid, or nitric acid, with a concentration of 80 - 120 g / L and a temperature of 70 - 80 °C.

[0011] Further technical solution, in S1, the solid-liquid ratio of the copper-manganese slag to the acid is 1:(3 - 6), preferably 1:4. The immersion time in the acid solution is 5 - 10 hours, preferably 7 - 10 hours. The copper-manganese slag is in powder form with a particle size of 1 - 500 um.

[0012] Further technical solution, in S2, the ion concentration in the complementary prepared leaching solution is 1 - 5 mol / L, and this ion concentration is the total concentration of the four metal ions of Ni, Fe, Mn, and Cu; the temperature of the leaching solution is 30 - 50 °C.

[0013] Further technical solution: in S3, the carrier gas is compressed air, nitrogen or oxygen, and the carrier gas flow rate is 20 - 40 m³ / h.

[0014] Further technical solution: in S3, the evaporation temperature is 300 - 400 °C, the drying temperature is 500 - 600 °C, and the pyrolysis temperature is 700 - 900 °C.

[0015] Further technical solution: in S4, the standard for the recovered acid concentration to meet the standard is that the acid concentration reaches 80 - 120 g / L. The system can be set to detect the concentration of the recovered acid every 24 hours. When the concentration reaches 80 - 120 g / L, the recovered acid is returned to the high-purity leaching tank for reuse, and at the same time, the tail gas absorption liquid is supplemented to the absorption tower. If the concentration is lower than 80 - 120 g / L, concentration or blending with high-concentration acids of the same category is required, and the preferred blending method is selected; if the concentration is higher than 80 - 120 g / L, deionized water or distilled water is added for dilution.

[0016] Further technical solution: in S1, the acid is nitric acid; in S2, the raw materials used for supplementary preparation are nitrates.

[0017] Regarding the use of "comprising", "including", "having", etc. in this article, they are all open-ended terms, meaning including but not limited to.

[0018] Regarding the terms used in this article, unless otherwise specified, they generally have their ordinary meanings in this field, in the context of this case, and in the context of special content. Some terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art regarding the description of this case.

[0019] The working principle and advantages of the present invention are as follows: Aiming at the problems of long process flow and high cost in the extraction and utilization of valuable metal elements in existing copper-manganese slag, the present invention provides a method for directly spray pyrolyzing a copper-manganese slag leaching solution to produce a sodium-ion battery oxide precursor, without separating valuable metal elements and producing the sodium-ion battery oxide precursor in one step.

[0020] The present invention aims to leach Cu 2+ and Mn 2+ and other valuable metal ions in nickel smelting slag with the shortest process flow, the lowest cost, and higher quality, eliminating the element separation link, and directly converting them into qualified products by a method of spray pyrolysis to prepare a sodium-ion battery oxide precursor.

[0021] The present invention immerses nickel smelting slag in acid to leach Cu 2+ and Mn 2+Ion leaching has a shorter process and lower cost compared to traditional metal refining methods.

[0022] In the present invention, by formulating the leaching solution into a sodium-ion battery metal salt solution and preparing qualified sodium-ion battery oxides from Cu 2+ and Mn 2+ ions therein, the losses during the separate treatment of Cu 2+ and Mn 2+ ions are reduced, enabling optimal control of energy and cost.

[0023] The tail gas generated in the process flow of the present invention is absorbed by an absorption tower, can be reused, and reduces the emission of harmful substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the process flow chart of each embodiment of the present invention; Figure 2 is the scanning electron microscope of the sodium-ion battery oxide precursor obtained by spray pyrolysis in Example 1 of the present invention; Figure 3 is the scanning electron microscope of the sodium-ion battery oxide precursor obtained by spray pyrolysis in Example 2 of the present invention; Figure 4 is the scanning electron microscope of the sodium-ion battery oxide precursor obtained by spray pyrolysis in Comparative Example 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention will be further described below in conjunction with the drawings and embodiments: Embodiment: After understanding the embodiments of this case, those skilled in the art can make changes and modifications based on the techniques taught in this case without departing from the spirit and scope of this case.

[0026] The terms used in this article are only for describing specific embodiments and are not intended to limit this case. Singular forms such as "a", "this", "that", "the", and "said", as used herein, also include plural forms.

[0027] Example 1: Example 1 of the present invention discloses a method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution. As Figure 1 shown, it includes the following steps: S1: Immerse 2000 kg of nickel smelting slag in a hydrochloric acid solution with a concentration of 90 g / L, the volume of hydrochloric acid is 8 m³, the immersion time is 5 hours, and the temperature of hydrochloric acid is 30 °C.

[0028] S2: Detect the concentrations of Cu and Mn ions in the high-purity immersion solution, and supplement nickel chloride and iron chloride according to the detection results to prepare a mixed solution with a molar percentage of Ni:Fe:Mn:Cu of 25:33:33:9, with a concentration of 2 mol / L, and raise the temperature to 40 °C.

[0029] S3: Feed the supplemented leaching solution into the spray pyrolysis furnace body at a flow rate of 25 m³ / h of carrier gas, with evaporation, drying, and pyrolysis temperatures of 350 °C, 550 °C, and 800 °C respectively, to obtain the sodium-ion battery oxide precursor.

[0030] S4: The tail gas generated after the pyrolysis of the sodium-ion battery metal salt solution is collected in the absorption tower for 24 h, the hydrochloric acid concentration is detected, and it is returned to the reuse storage tank.

[0031] The prepared sodium-ion battery oxide precursor is tested and characterized. The physical and chemical data are as Figure 2 shown in Table 1. The prepared cathode material is tested for its electrochemical performance, as shown in Table 1.

[0032] Example 2: Example 2 of the present invention discloses a method for directly spray pyrolyzing a copper-manganese slag leaching solution to produce a sodium-ion battery oxide precursor, as Figure 1 shown, including the following steps: S1: Immerse 2000 kg of nickel smelting slag in a nitric acid solution with a concentration of 90 g / L, a nitric acid volume of 8 m³, an immersion time of 5 hours, and a temperature of 30 °C.

[0033] S2: Detect the concentrations of Cu and Mn ions in the high-purity immersion solution, and according to the detection results, add nickel nitrate and iron nitrate to prepare a mixed solution with a molar percentage of Ni:Fe:Mn:Cu of 25:33:33:9, a concentration of 2 mol / L, and the temperature is raised to 40 °C.

[0034] S3: Feed the supplemented leaching solution into the spray pyrolysis furnace body at a flow rate of 25 m³ / h of carrier gas, with evaporation, drying, and pyrolysis temperatures of 350 °C, 450 °C, and 600 °C respectively, to obtain the sodium-ion battery oxide precursor.

[0035] S4: The tail gas generated after the pyrolysis of the sodium-ion battery metal salt solution is collected in the absorption tower for 24 h, the hydrochloric acid concentration is detected, and it is returned to the reuse storage tank.

[0036] The prepared sodium-ion battery oxide precursor is tested and characterized. The physical and chemical data are as Figure 3 shown in Table 1. The prepared cathode material is tested for its electrochemical performance, as shown in Table 1.

[0037] Example 3: Example 3 of the present invention discloses a method for directly spray pyrolyzing a copper-manganese slag leaching solution to produce a sodium-ion battery oxide precursor, as Figure 1 shown, including the following steps: S1: Immerse 2000 kg of nickel smelting slag in a sulfuric acid solution with a concentration of 90 g / L, a sulfuric acid volume of 8 m³, an immersion time of 5 hours, and a temperature of 30 °C.

[0038] S2: Detect the concentrations of Cu and Mn ions in the high-purity immersion liquid, and then supplement and add nickel sulfate and iron sulfate according to the detection results to prepare a mixed solution with a molar percentage of Ni:Fe:Mn:Cu of 25:33:33:9, with a concentration of 2 mol / L, and raise the temperature to 40 °C.

[0039] S3: Feed the supplemented leaching solution into the spray pyrolysis furnace body at a flow rate of the carrier gas of 25 m³ / h, and the evaporation, drying, and pyrolysis temperatures are 350 °C, 750 °C, and 900 °C respectively to obtain the sodium-ion battery oxide precursor.

[0040] S4: The tail gas generated after the pyrolysis of the sodium-ion battery metal salt solution is collected in the absorption tower for 24 h, the hydrochloric acid concentration is detected, and it is returned to the reuse storage tank.

[0041] Test and characterize the prepared sodium-ion battery oxide precursor. The physical and chemical data are shown in Table 1, and the prepared cathode material is tested for its electrochemical performance, as shown in Table 1.

[0042] Comparative Example 1 S1: Use nickel chloride, iron chloride, manganese chloride, and copper chloride to prepare a metal salt solution with a molar percentage of 25:33:33:9, with a concentration of 2 mol / L, and raise the temperature to 40 °C.

[0043] S2: Feed the prepared sodium-ion battery metal salt solution into the spray pyrolysis furnace body at a flow rate of the carrier gas of 25 m³ / h, and the evaporation, drying, and pyrolysis temperatures are 350 °C, 550 °C, and 800 °C respectively to obtain the sodium-ion battery oxide precursor.

[0044] Test and characterize the prepared sodium-ion battery oxide precursor. The physical and chemical data are as Figure 4 shown in Table 1, and the prepared cathode material is tested for its electrochemical performance, as shown in Table 1.

[0045] Comparative Example 2 S1: Use nickel nitrate, iron nitrate, manganese nitrate, and copper nitrate to prepare a metal salt solution with a molar percentage of 25:33:33:9, with a concentration of 2 mol / L, and raise the temperature to 40 °C.

[0046] S2: Feed the prepared sodium-ion battery metal salt solution into the spray pyrolysis furnace body at a flow rate of the carrier gas of 25 m³ / h, and the evaporation, drying, and pyrolysis temperatures are 350 °C, 450 °C, and 600 °C respectively to obtain the sodium-ion battery oxide precursor.

[0047] Test and characterize the prepared sodium-ion battery oxide precursor. The physical and chemical data are shown in Table 1, and the prepared cathode material is tested for its electrochemical performance, as shown in Table 1.

[0048] Table 1 Indexes of the sodium-ion battery oxide precursor

[0049] Comparing Example 1, Example 2 and Example 3, different acids were used for leaching copper-manganese slag. The primary particle size of the sodium-ion battery oxide precursor of the nitrate system was the smallest and the BET was the largest, indicating that the precursor of the nitrate system had higher activity. The primary particle size of the chloride-based precursor was the largest and the BET was the smallest, with lower precursor activity. The data of the sulfate-based precursor was in the middle, and other indicators were basically the same. It can be seen from Table 1 that the specific capacity of the cathode material prepared in Example 2 was the highest.

[0050] Comparing Example 1 with Comparative Example 1, the precursor indexes, electrochemical specific capacity and initial efficiency were basically the same, indicating that the leachate after immersion and supplementary preparation with nickel-cobalt smelting slag had the same precursor performance as that after spray pyrolysis of the solution prepared with chloride salt. It further indicated that the one-step method for preparing sodium-ion battery materials from copper-manganese slag leachate would not reduce the product indexes and electrochemical performance.

[0051] Comparing Example 2 with Comparative Example 2, the precursor indexes, electrochemical specific capacity and initial efficiency were basically the same, indicating that the leachate after immersion and supplementary preparation with nickel-cobalt smelting slag had the same precursor performance as that after spray pyrolysis of the solution prepared with nitrate. It further indicated that the one-step method for preparing sodium-ion battery materials from copper-manganese slag leachate would not reduce the product indexes and electrochemical performance.

[0052] In summary, for the copper-manganese slag leachate of the present invention, there is no need to separate and recover valuable metal elements. The sodium-ion battery oxide precursor is directly produced by the spray pyrolysis method, which can significantly shorten the process flow of the recycling and reuse of valuable metals. The sodium-ion battery oxide precursor produced has the same product performance as that produced by the existing metal salt raw materials, and the cost is greatly reduced.

[0053] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for directly spray pyrolyzing a sodium - ion battery oxide precursor using a copper - manganese slag leaching solution, characterized in that: The chemical formula of the sodium-based oxide is Ni 1-x-y-z Fe x Mn y Cu z O2, where 0 < x < 1, 0 < y < 1, 0 < z < 1, 0 < x + y + z < 1; The method comprises the following steps: S1: Immerse the copper-manganese slag generated from nickel smelting into a high-purity leaching tank with acid added to obtain a leaching solution containing Cu and Mn; S2: Complement Cu, Mn, Ni, and Fe elements into the leaching solution according to the molar percentages of the elements required for sodium battery materials to prepare a metal solution required for sodium batteries; S3: Atomize the complemented leaching solution through carrier gas and send it into a spray pyrolysis furnace. After evaporation, drying, and high-temperature pyrolysis, a sodium battery oxide precursor is obtained; S4: Absorb and purify the tail gas discharged from the spray pyrolysis furnace through an absorption tower to form recycled acid. When the concentration of the recycled acid meets the standard, return the recycled acid to the high-purity leaching tank in S1 for reuse; absorb the waste heat in the tail gas through a heat exchanger and use it to heat the leaching solution before entering the spray pyrolysis furnace.

2. The method for directly spray pyrolyzing the sodium-ion battery oxide precursor by using the copper-manganese slag leaching solution according to claim 1, characterized in that: In S1, the acid is sulfuric acid, hydrochloric acid, or nitric acid, with a concentration of 80 - 120 g / L and a temperature of 70 - 80 °C.

3. A method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution according to claim 1, characterized in that: In S1, the solid-liquid ratio of the copper-manganese slag to the acid is 1:(3 - 6), and the immersion time in the acid solution is 5 - 10 hours.

4. A method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution according to claim 1, characterized in that: In S2, the raw material categories used for complementing include one or a combination of several of nitrates, sulfates, or chlorides.

5. A method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution according to claim 1, characterized in that: In S2, the ion concentration in the complemented leaching solution is 1 - 5 mol / L, and this ion concentration is the total concentration of the four metal ions of Ni, Fe, Mn, and Cu; the temperature of the leaching solution is 30 - 50 °C.

6. The method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution according to claim 1, characterized in that: In S3, the carrier gas is compressed air, nitrogen, or oxygen, and the carrier gas flow rate is 20 - 40 m³ / H.

7. A method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution according to claim 1, characterized in that: In S3, the evaporation temperature is 300 - 400 °C, the drying temperature is 500 - 600 °C, and the pyrolysis temperature is 700 - 900 °C.

8. A method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution according to claim 1, characterized in that: In S4, the standard for the recycled acid concentration to meet the standard is that the acid concentration reaches 80 - 120 g / L.

9. A method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution according to claim 8, characterized in that: In S4, detect the concentration of the recycled acid every 24 hours. When the concentration reaches 80 - 120 g / L, return the recycled acid to the high-purity leaching tank for reuse, and at the same time, supplement the tail gas absorption liquid in the absorption tower; if the concentration is lower than 80 - 120 g / L, concentrate the recycled acid or blend it with a high-concentration acid of the same type; if the concentration is higher than 80 - 120 g / L, dilute it with deionized water or distilled water.

10. A method for directly spray pyrolyzing a sodium-ion battery oxide precursor using a copper-manganese slag leaching solution according to claim 4, characterized in that: In S1, the acid is nitric acid; in S2, the raw material used for complementing is nitrate.

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