Method for separating and recycling valuable metal materials from waste alkaline dry batteries based on existing normal-pressure acid soaking wet-process zinc smelting process

Abstract

The invention relates to a method for separating and recycling valuable metal materials from waste alkaline dry batteries based on an existing normal-pressure acid soaking wet-method zinc smelting process, and belongs to the technical field of metallurgical engineering. The method comprises the following steps: S1, crushing treatment; s2, drying; s3, performing screening treatment; s4, magnetic separation; s5, primary water washing; s6, standing and settling the primary washing mixed solution; s7, drying the copper scale precipitate for direct export sales; s8, carrying out secondary water washing; s9, filtering the solution after secondary water washing; s10, firing the secondary mixed powder; s11, carrying out a neutralization reaction; s12, the aqueous solution containing K2CO3 and KHCO3 is subjected to distillation; s13, carrying out acid leaching; s14, purifying with a ZnSO4 solution; s15, zinc electrodeposition is carried out; and S16, casting. According to the method, all valuable elements in the dry battery can be fully separated and recycled, no new pollution element is brought in, carbon dioxide gas generated in the process becomes an additive for manufacturing potassium salt to be comprehensively recycled, and all waste water is comprehensively utilized.

Description

Technical Field

[0001] The present application relates to the field of metallurgical engineering technology, and in particular to a method for separating and recovering valuable metal materials from waste alkaline dry batteries based on an existing atmospheric pressure acid leaching zinc smelting process. Background Art

[0002] Alkaline dry batteries are an important power source for modern electronic products. They use alkaline electrolytes (usually potassium hydroxide) to generate electricity through chemical reactions. With high energy density and long shelf life, alkaline dry batteries provide reliable power for a variety of applications from home electronics to industrial equipment. Driven by rising disposable income and changing lifestyles, demand for consumer electronics such as electric toys, home appliances, smart homes, home medical equipment, and outdoor electronic devices continues to grow. At the same time, as consumers prioritize convenience and mobility, the demand for alkaline dry batteries to power portable devices and gadgets continues to increase.

[0003] Alkaline dry batteries contain potassium hydroxide and metals such as zinc, copper, iron, and manganese. From the structure of alkaline dry batteries and the chemical reaction equation of alkaline dry batteries:

[0004] Zn+2MnO2+2H2O=2MnO(OH)+Zn(OH)2

[0005] It can be seen that the components of alkaline dry batteries mainly include manganese powder, zinc powder, carbon rod, steel shell, copper needle, ion membrane and potassium hydroxide. After chemical discharge reaction, the discarded alkaline dry batteries mainly contain steel shell, MnO(OH), Zn(OH)2, KOH, C powder, unreacted Zn paste, MnO2, Cu needle, contaminated Cu(OH)2, part of K element, contaminated ion membrane and plastic packaging materials.

[0006] Since the above substances exist in mixture, improper handling will cause environmental risks and waste limited metal resources.

[0007] The disadvantages of the existing technology for separating and recycling waste alkaline dry batteries are that the valuable metal materials therein cannot be fully recovered, the separation of potassium, manganese and zinc is not complete, and some new three wastes (waste water, waste gas, and waste residue) are often generated during the separation and recycling process, which require further treatment, making it inconvenient for industrial application. Summary of the invention

[0008] In order to solve or partially solve the problems existing in the related art, the present application provides a method for separating and recovering valuable metal materials from waste alkaline dry batteries based on the existing atmospheric pressure acid leaching zinc smelting process. On the basis of utilizing the existing zinc smelting process production line, it reduces or even does not introduce new "three wastes" (waste water, waste gas, and waste residue), and fully recovers valuable metals such as copper, iron, and zinc separately, and completely separates potassium, manganese, and zinc. It is a recyclable comprehensive recovery method that is convenient for industrial application.

[0009] A method for separating and recovering valuable metal materials from waste alkaline dry batteries based on the existing atmospheric pressure acid leaching zinc smelting process in the present application comprises the following steps:

[0010] S1, dismantling and crushing the waste alkaline dry batteries to obtain a mixture;

[0011] On the one hand, the battery is disassembled by crushing; on the other hand, the battery steel shell, copper nails and ion membrane are crushed into iron chips, copper chips and broken ion membrane for subsequent recycling;

[0012] S2, drying the mixture obtained after crushing; by drying at 60-80°C, the water in the mixture is evaporated, which is beneficial to the subsequent screening of the mixture;

[0013] S3, the dried mixture is screened through an 80-mesh mining linear vibrating screen, where the larger metal chips after the dry battery shell and copper nails are crushed are separated from the paste-like and powdery metal dry materials such as the battery anode, cathode and alkaline electrolyte to obtain a primary mixed powder and mixed metal chips;

[0014] S4, magnetic separation is performed on the mixed metal scraps to separate the iron scraps from the copper scraps and the broken ion membrane mixture by magnetic separation, and two products, the copper scrap mixture and the iron scraps, are obtained after separation; the iron scraps can be directly exported;

[0015] S5, washing the copper scrap mixture once, adding industrial water to the copper scrap mixture and stirring, cleaning pollutants such as MnO(OH) and zinc paste attached to the surface of the copper scrap, and obtaining a primary washing mixed solution;

[0016] S6, the primary water-washing mixed liquid is allowed to settle, and the broken ion membrane floating on the surface of the primary water-washing mixed liquid is fished out and dried for use as fuel. After the broken ion membrane is fished out, the primary water-washing mixed liquid is subjected to solid-liquid separation to obtain copper scrap precipitate and industrial wastewater;

[0017] S7. Copper scraps can be directly exported after drying;

[0018] S8, washing the primary mixed powder obtained in step S3 twice to obtain a secondary water-washed liquid; by washing, KOH is dissolved in water to form a KOH solution based on the principle that KOH is easily soluble in water; at the same time, KOH is separated based on the principle that MnO(OH), Zn(OH)2, C powder, Zn powder, and MnO2 are insoluble in water; the pH value of the solution can be controlled to be less than 8 by the amount of water to prevent corrosion of the mixing barrel and the pipeline;

[0019] In order to make full use of water resources, the industrial waste water obtained in S6 is used during the stirring and washing in S8.

[0020] S9, filtering the solution after the second water washing to obtain a KOH aqueous solution and a mixture containing MnO(OH), Zn(OH)2, C powder, Zn and MnO2, which is called a secondary mixed powder;

[0021] S10, burning the secondary mixed powder, after burning, the C powder in the "secondary mixed powder" turns into CO2 gas and separates from the mixture, MnO(OH) turns into MnO2, and Zn(OH)2 can be decomposed into ZnO. After burning, a mixed solid containing MnO2 and ZnO and CO2 gas are obtained;

[0022] S11, passing the CO2 gas obtained in step S10 into the KOH aqueous solution obtained in step S9 for neutralization reaction to obtain an aqueous solution containing K2CO3 and KHCO3;

[0023] S12, distilling the aqueous solution containing K2CO3 and KHCO3, and after distillation and dehydration, a neutral mixture of K2CO3 and KHCO3 is obtained, which is exported as a raw material for making KOH;

[0024] S13, the mixed solid containing MnO2 and ZnO obtained in step S10 is returned to the existing atmospheric pressure acid leaching wet zinc smelting process for acid leaching to obtain a ZnSO4 solution;

[0025] S14, ZnSO4 solution purification;

[0026] S15, zinc electrowinning to obtain zinc flakes;

[0027] S16. The cathode zinc sheets obtained by zinc electrowinning are melted and cast into zinc ingots for export.

[0028] Compared with the prior art, the beneficial effects of this application are:

[0029] (1) Through the above 16 steps, all valuable elements Fe, Zn, Cu, Mn, K, and C in alkaline dry batteries are separated and recovered without introducing new polluting elements. The carbon dioxide gas generated in the process is recycled as an additive for making potassium salt, and all wastewater is comprehensively utilized.

[0030] (2) Steps S13-S16 involved in the recycling process can all utilize the existing process technology of wet zinc smelting, without the need for additional investment in new equipment and plant, which is beneficial to cost savings and facilitates industrial utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0032] Figure 1 It is a schematic diagram of the process flow in this application. DETAILED DESCRIPTION

[0033] The embodiments of the present application will be described in more detail below with reference to examples. Although the embodiments of the present application are shown in the examples, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and the scope of the present application can be fully communicated to those skilled in the art.

[0034] Example 1

[0035] The present application discloses a method for separating and recovering valuable metal materials from waste alkaline dry batteries based on the existing atmospheric pressure acid leaching zinc smelting process, and the process flow is as follows: Figure 1 As shown, the specific steps include:

[0036] S1, dismantling and crushing the waste alkaline dry batteries to obtain a mixture;

[0037] On the one hand, the battery is disassembled by crushing; on the other hand, the battery steel shell, copper nails and ion membrane are crushed into iron chips, copper chips and broken ion membrane for subsequent recycling;

[0038] S2, drying the mixture obtained after crushing; by drying at 60-80°C, the water in the mixture is evaporated, which is beneficial to the subsequent screening of the mixture;

[0039] S3, the dried mixture is screened through an 80-mesh mining linear vibrating screen, and the coarse-grained iron chips, copper chips and broken ion membranes after crushing can be separated from the positive and negative electrolytes (mainly in the form of paste and powder mixture) by screening to obtain a primary mixed powder and mixed metal chips;

[0040] S4, magnetic separation is performed on the mixed metal scraps to separate the iron scraps from the copper scraps and the broken ion membrane mixture by magnetic separation, and two products, the copper scrap mixture and the iron scraps, are obtained after separation; the iron scraps can be directly exported;

[0041] S5, washing the copper scrap mixture once, adding industrial water to the copper scrap mixture and stirring, cleaning pollutants such as MnO(OH) and zinc paste attached to the surface of the copper scrap, and obtaining a primary washing mixed solution;

[0042] S6, the primary water-washing mixed liquid is allowed to settle, and the broken ion membrane floating on the surface of the primary water-washing mixed liquid is fished out and dried for use as fuel. After the broken ion membrane is fished out, the primary water-washing mixed liquid is subjected to solid-liquid separation to obtain copper scrap precipitate and industrial wastewater;

[0043] S7. Copper scraps can be directly exported after drying;

[0044] S8, washing the primary mixed powder obtained in step S3 twice to obtain a secondary water-washed liquid; by washing, KOH is dissolved in water to form a KOH solution based on the principle that KOH is easily soluble in water; at the same time, KOH is separated based on the principle that MnO(OH), Zn(OH)2, C powder, Zn powder, and MnO2 are insoluble in water; the pH value of the solution can be controlled to be less than 8 by the amount of water to prevent corrosion of the mixing barrel and the pipeline;

[0045] S9, filtering the solution after the second water washing to obtain a KOH aqueous solution and a mixture containing MnO(OH), Zn(OH)2, C powder, Zn and MnO2, which is called a secondary mixed powder;

[0046] S10, burning the secondary mixed powder, after burning, the C powder in the "secondary mixed powder" turns into CO2 gas and separates from the mixture, MnO(OH) turns into MnO2, and Zn(OH)2 can be decomposed into ZnO. After burning, a mixed solid containing MnO2 and ZnO and CO2 gas are obtained;

[0047] S11, passing the CO2 gas obtained in step S10 into the KOH aqueous solution obtained in step S9 for neutralization reaction to obtain an aqueous solution containing K2CO3 and KHCO3;

[0048] S12, distilling the aqueous solution containing K2CO3 and KHCO3, and after distillation and dehydration, a neutral mixture of K2CO3 and KHCO3 is obtained, which is exported as a raw material for making KOH;

[0049] S13, the mixed solid containing MnO2 and ZnO obtained in step S10 is returned to the existing atmospheric pressure acid leaching wet zinc smelting process for acid leaching to obtain a ZnSO4 solution;

[0050] S14, ZnSO4 solution purification;

[0051] S15, zinc electrowinning to obtain zinc flakes;

[0052] S16. The cathode zinc sheets obtained by zinc electrowinning are melted and cast into zinc ingots for export.

[0053] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for separating and recovering valuable metal materials from waste alkaline dry batteries based on the existing atmospheric pressure acid leaching zinc smelting process, characterized in that: The following steps are involved: S1, dismantling and crushing the waste alkaline dry batteries to obtain a mixture; S2, drying the mixture obtained after crushing; S3, screening the dried mixture through an 80-mesh mining linear vibrating screen to obtain a primary mixed powder and mixed metal chips; S4, magnetically separating the mixed metal scraps to separate the iron scraps from the copper scraps and the broken ion membrane mixture, and obtaining two products, the copper scrap mixture and the iron scraps, after separation; S5, washing the copper scrap mixture once to obtain a washed mixed solution; S6, the primary water-washing mixed liquid is allowed to settle, and the broken ion membrane floating on the surface of the primary water-washing mixed liquid is fished out and dried for use as fuel. After the broken ion membrane is fished out, the primary water-washing mixed liquid is subjected to solid-liquid separation to obtain copper scrap precipitate and industrial wastewater; S7. Copper scraps can be directly exported after drying; S8, washing the primary mixed powder obtained in step S3 for a second time to obtain a secondary washed liquid; S9, filtering the solution after the secondary washing to obtain a KOH aqueous solution and a secondary mixed powder; S10, calcining the secondary mixed powder to obtain a mixed solid containing MnO2 and ZnO and CO2 gas; S11, passing the CO2 gas obtained in step S10 into the KOH aqueous solution obtained in step S9 for neutralization reaction to obtain an aqueous solution containing K2CO3 and KHCO3; S12, distilling the aqueous solution containing K2CO3 and KHCO3, and after distillation and dehydration, a neutral mixture of K2CO3 and KHCO3 is obtained, which is exported as a raw material for making KOH; S13, the mixed solid containing MnO2 and ZnO obtained in step S10 is returned to the existing atmospheric pressure acid leaching wet zinc smelting process for acid leaching to obtain a ZnSO4 solution; S14, ZnSO4 solution purification; S15, zinc electrowinning to obtain zinc flakes; S16. The cathode zinc sheets obtained by zinc electrowinning are melted and cast into zinc ingots for export.

2. A method for separating and recovering valuable metal materials from waste alkaline dry batteries based on the existing atmospheric pressure acid leaching zinc smelting process according to claim 1, characterized in that: The drying temperature in S2 is 60-80°C.

3. A method for separating and recovering valuable metal materials from waste alkaline dry batteries based on the existing atmospheric pressure acid leaching zinc smelting process according to claim 1, characterized in that: The burning temperature in S10 is 500-1000°C.

4. A method for separating and recovering valuable metal materials from waste alkaline dry batteries based on the existing atmospheric pressure acid leaching zinc smelting process according to claim 1, characterized in that: When stirring and washing is performed in S8, the industrial waste water obtained in S6 is used.

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