Method for treating reverse extract liquid

Abstract

Disclosed is a method for treating reverse extract liquid. This method utilizes the difference of the standard electrode potentials of various metals. Firstly, copper is recovered through cyclone electrolysis. At the same time, the chlorine gas generated by the electrolysis can remove TOC and avoid contaminating subsequent extractants. Then, zinc is separated using zinc precipitation reagents, and finally, manganese and calcium are separated using saponified Cyanex272 extractant to obtain manganese sulfate. The method of the present application is capable of graded recovery of valuable metals such as manganese, copper, zinc and the like. The purity of the recovered manganese sulfate reaches battery-grade. Compared to recovering copper in the form of copper sulfide, the sponge copper obtained in the present application has a purity greater than 98%, which has better application prospects and economic benefits. Moreover, by selectively abandoning sodium, calcium, and aluminum with low recovery value, the operation process can be simplified, unnecessary auxiliary material input can be reduced, and higher economic value can be achieved; at the same time, the method of the present application does not generate solid waste and has good environmental performance. Drawing of Abstract

Description

[0001] Specification

[0002] METHOD FOR TREATING REVERSE EXTRACT LIQUID

[0003] FIELD OF THE INVENTION

[0004] The present application relates to the field of hydrometallurgy technology, specifically to a method for treating a reverse extract liquid.

[0005] BACKGROUND OF THE INVENTION

[0006] Nickel is an important strategic material widely used in fields such as national defense, aerospace, traffic and transportation, petrochemicals, energy materials, etc., and nickel is an important raw material for producing stainless steel, alloy steel, special alloys, energy storage materials, magnetic materials, etc. China is facing a shortage of nickel resources and a high degree of external dependence. Therefore, it is very necessary to carry out resource treatment and comprehensive utilization of waste containing nickel, thereby not only reducing the import of primary nickel resources, but also avoiding environmental pollution, which has high economic value and social significance.

[0007] The chemical compositions of battery recycling materials with high content of nickel and low content of copper, nickel-containing intermediate slag after smelting, various recovered catalysts containing nickel that have been calcined to remove organic matter, electroplating sludge containing nickel, and other waste materials are mainly nickel element, accompanied by manganese element and small amounts of copper, zinc, and other elements. In the wet smelting process, steps such as leaching with dilute sulfuric acid, pre-removal of iron and aluminum, filtration, extraction-separation, etc. are generally used to purify the waste materials containing nickel. Among them, the extraction-separation step usually uses P204 (its chemical name is di(2 -ethylhexyl) phosphoric acid ester) as the extractant to extract impurity metals such as Mn, Cu, Zn, Ca, etc. from the leaching solution. In order to reuse the P204 organic phase loaded with impurity metals, acid solution is often used for reverse extraction, allowing impurity metals in the organic phase to enter the aqueous phase, and the aqueous phase is the reverse extract liquid. The treatment of the reverse extract liquid usually involves adding liquid alkali or lime to precipitate heavy metals, filtering and reusing the filtrate. However, the heavy metal precipitated slag obtained by the above treatment methods has low economic value and solid waste treatment is difficult. In addition, the heavy metal precipitated slag contains a large amount of Mn and a small amount of Cu, Zn and other valuable metals which have not been properly utilized.

[0008] SUMMARY

[0009] The present application provides a method for treating reverse extract liquid to solve the problem of poor environmental and economic efficiency of the existing method for treating P204 reverse extract liquid.

[0010] The method for treating reverse extract liquid provided in the present application comprises the following steps of:

[0011] 51. sending a P204 reverse extract liquid from a nickel wet smelting process into a cyclone electrolysis equipment for removing copper by electrolysis, and obtaining a copper-removal solution; wherein the P204 reverse extract liquid is an aqueous solution obtained by reversely extracting a P204 organic phase loaded with metal ions with hydrochloric acid, wherein the metal ions include manganese ions, copper ions, zinc ions, and calcium ions, and wherein the P204 reverse extract liquid has a concentration of hydrogen ions of at least Imol / L;

[0012] 52. adjusting a pH value of the copper-removal solution to a range from 5.0 to 5.5, adding a substance capable of providing sulfur ions for carrying out precipitation to remove zinc, and filtering to obtain a zinc-removal solution;

[0013] S3, extracting the zinc-removal solution with a saponified Cyanex272 extractant to obtain an organic phase loaded with manganese and a calcium-containing raffinate, washing and reversely extracting the organic phase loaded with manganese to obtain a manganese sulfate solution, evaporating and crystallizing the manganese sulfate solution to obtain a manganese sulfate product.

[0014] In an optional embodiment, the electrolysis is controlled to perform at a current density of 100A / m2to 300A / m2when copper ions in the P204 reverse extract reaches a concentration of greater than 2g / L, and the copper ions have a concentration of Ig / L to 2g / L at an endpoint of the electrolysis.

[0015] In an optional embodiment, the electrolysis is controlled to perform at a current density of 5A / m2to 50A / m2when the copper ions in the P204 reverse extract liquid reaches a concentration of less than or equal to 2g / L, and the copper ions have a concentration of 0.03g / L to 0.05g / L at an endpoint of the electrolysis.

[0016] In an optional embodiment, the hydrogen ions in the P204 reverse extract liquid have a concentration of Imol / L to 3mol / L.

[0017] In an optional embodiment, a cathode of the cyclone electrolysis equipment is made of graphite.

[0018] In an optional embodiment, the cyclone electrolysis equipment comprises at least 2 cyclone electrolysis cell pry blocks which are connected in parallel with each other.

[0019] In an optional embodiment, chlorine gas generated in SI is collected and converted into a sodium hypochlorite product for use in a water treatment system.

[0020] In an optional embodiment, a carbonate salt is added into a solution after evaporating and crystallizing the manganese sulfate in S3 to form a manganese carbonate precipitate which is filtered, washed and precipitated, and then slurried with deionized water to obtain a manganese carbonate slurry which is used to adjust the pH value of the copper-removal solution.

[0021] In an optional embodiment, S2 comprises controlling a reaction temperature to be in a range from 30 °C to 60 °C when adjusting the pH value of the copper-removal solution, and carrying out stirring for Ih to 2h.

[0022] In an optional embodiment, the substance capable of providing sulfur ions includes at least one of sodium sulfide, sodium hydrosulfide, or sodium dimethyl dithiocarbamate.

[0023] In an optional embodiment, the precipitation reaction in S2 is carried out at a temperature ranging from 30 °C to 60 °C for a time period ranging from Ih to 2h.

[0024] In an optional embodiment, the pH value is in a range from 5.0 to 6.0 at an endpoint of the precipitation reaction in S2.

[0025] In an optional embodiment, the zinc ions in the solution have a concentration of less than 0.005g / L at an endpoint of the precipitation reaction in S2.

[0026] In an optional embodiment, the saponified Cyanex272 extractant is obtained by reacting a commercially available and / or recovered Cyanex272 extractant with sodium hydroxide to obtain an organic phase and then performing manganese ions between the organic phase and a manganese sulfate aqueous solution.

[0027] In an optional embodiment, manganese ions in the calcium-containing raffinate have a concentration of 0.2g / L to l.Og / L.

[0028] The technical solution of the present application has the following advantages.

[0029] The method for treating reverse extract liquid provided in the present application can gradedly recover valuable metals such as manganese, copper, zinc, etc. from the P204 reverse extract liquid generated by the nickel wet smelting process. The purity of the recovered manganese sulfate reaches battery-grade. Compared with the recovery of copper in the form of copper sulfide, the sponge copper obtained in the present application has a purity greater than 98%, which has better application prospects and economic benefits.

[0030] Moreover, by selectively abandoning recovery of low valued sodium, calcium and aluminum, the operation process can be simplified and unnecessary auxiliary material input can be reduced, thus having higher economic value; at the same time, the method of the present application does not generate heavy metal precipitated slag solid waste, and thus has good environmental performance.

[0031] The additional aspects and advantages of the embodiments of the present application will be partially described and showed in subsequent explanations, or explained through the implementation of the embodiments of the present application.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to provide a clearer explanation of the specific embodiments or technical solutions in the prior art, a brief introduction will be given below to the accompanying drawings required in the specific implementation methods or prior art description. It is obvious that the accompanying drawings in the following description are some of the embodiments of the present application. For those skilled ordinary in the art, other accompanying drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 is a process flow diagram of Example 1 of the present application.

[0035] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Reference will be made clearly and completely technical solutions in the embodiments of the present disclosure with accompanying drawings. The embodiments described here are only part of the embodiments of the present disclosure and are not all embodiments of the present disclosure. Based on the embodiments of the present disclosure, other embodiments obtained by those skilled in the art without creative work are within the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. The terms “includes” and “includes” and any variation thereof in the description and claims of the present disclosure are intended to indicate a non-exclusive inclusion.

[0037] In the description of the embodiments of the present disclosure, the technical terms “first”, “second” and the like are only used for distinction between different objects and are not to be understood as indicating or implying relative importance or implicitly indicating a number, a particular order or a primary or secondary relationship of the technical features. In the description of the embodiments of the present disclosure, “a plurality of’ means two or more, unless specified otherwise.

[0038] Reference to an “embodiment” herein means that a feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure. The “embodiment” in various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. One skilled in the art explicitly and implicitly understands that an embodiment described herein may be combined with other embodiments.

[0039] Term “range” disclosed in the present disclosure is defined in the form of a lower limit and an upper limit, a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The range defined in this way can be inclusive or exclusive, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is understood that ranges of 60-110 and 80-120 are also obtained. In addition, if the listed minimum values are 1 and 2, and if the listed maximum values are 3, 4 and 5, the ranges of 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5 may be obtained. In the present disclosure, unless otherwise specified, the numerical range “a-b” means the abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range “0-5” means that all the real numbers between “0-5” have been listed, and “0-5” is only the abbreviated representation of these numerical combinations. In addition, when a parameter is an integer >2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0040] In the description of the present disclosure, the term “and / or”, which describes an associated relationship of associated objects, means that there may be three relationships, for example, A and / or B, which may mean that A exists alone, A and B exist at the same time, and B exists alone. A character “ / ” generally indicates that contextual objects are in an “or” relationship.

[0041] When treating the P204 reverse extract liquid with relevant existing technologies, copper, aluminum and zinc are firstly transformed into corresponding precipitates using sodium thiosulfate and alkaline precipitants under the action of alternating electromagnetic fields, resulting in a impurity-removal solution with MnCF. NaCl and CaCF as the main component; then the impurity-removal solution is subjected to linkage optimized extraction using Cyanex272 (abbreviated as C272 or Cy272) to obtain a battery-grade MnSC solution, a CaCb solution, and a NaCl solution. Although the above technologies can also achieve the recovery of copper, manganese, calcium, zinc, aluminum and other resources in the P204 reverse extract liquid, the overall process operation is relatively cumbersome, and the recovery value of sodium, calcium and aluminum is not high. Moreover, the recovered copper sulfide cannot meet the requirements of high-end copper sulfide products in terms of purity, morphology, and bulk density, so it is mainly used as a raw ore of copper sulfide in the pyrometallurgy-sohible anode-electrolytic copper process, and thus its economic value is relatively low. In order to solve the problems existing in the above-mentioned related technologies, the present application provides a method for treating reverse extract liquid, including the following steps of:

[0042] 51. sending a P204 reverse extract liquid from a nickel wet smelting process into a cyclone electrolysis equipment for carrying out electrolysis to remove copper, obtaining a copper-removal solution; wherein the P204 reverse extract liquid is an aqueous solution obtained by reversely extracting a P204 organic phase loaded with metal ions with hydrochloric acid, wherein the metal ions include manganese ions, copper ions, zinc ions, and calcium ions, and wherein the P204 reverse extract liquid has a concentration of hydrogen ions of at least Imol / L;

[0043] 52. adjusting a pH value of the copper-removal solution to a range from 5.0 to 5.5, adding a substance capable of providing sulfur ions for carrying out precipitation to remove zinc, and filtering to obtain a zinc-removal solution;

[0044] S3, extracting the zinc-removal solution with a saponified Cyanex272 extractant to obtain an organic phase loaded with manganese and a calcium-containing raffinate, washing and reversely extracting the organic phase loaded with manganese to obtain a manganese sulfate solution, evaporating and crystallizing the manganese sulfate solution to obtain a manganese sulfate product.

[0045] It should be noted that the P204 reverse extract liquid in the present application refers to an aqueous solution obtained by using the P204 extractant to extract impurity metals such as Mn, Cu, Zn, Ca, etc. from the leaching solution during the nickel wet smelting process, and then using hydrochloric acid to reversely extracting the P204 organic phase loaded with the above-mentioned metal ions. Therefore, the concentration of hydrogen ions in the P204 reverse extract liquid is at least Imol / L. As an example, the concentration of hydrogen ions in the P204 reverse extract liquid of the present application may be Imol / L, 1.5mol / L, 2mol / L, 2.5mol / L, 3mol / L or higher. Considering that high acidity can accelerate the degradation of P204, although this loss is within an acceptable range, it is more appropriate to control the concentration of hydrogen ions in the P204 reverse extract liquid to be less than 3mol / L. At the same time, the P204 reverse extract liquid in the present application also contains manganese ions, copper ions, zinc ions, and calcium ions, and inevitably contains a small amount of TOC. It is understandable that, TOC refers to total organic carbon, which represents the total amount of organic matter in water in terms of carbon content; the higher the TOC value, the higher the organic matter content in the water. Therefore, TOC can be used as an indicator for evaluating organic pollution of water. The use of hydrochloric acid instead of sulfuric acid for the reversely extracting of P204 loaded organic phase can solve the problem of calcium sulfate scaling generated dining reversely extracting with sulfuric acid. Those skilled in the art can understand that the nickel wet smelting process includes an aluminum-removal process, so the content of aluminum in the P204 reverse extract liquid of the present application is negligible. Moreover, in the P204 extraction process, the content of cobalt can be controlled below O.lg / L, which also ensures that the presence of trace cobalt element in the P204 reverse extract liquid of the present application will not affect the recovery effect and quality of other products.

[0046] The S 1 of the present application is to separate and recover copper by utilizing the characteristic that the standard electrode potential of copper is positive while the electrode potential of other metals is negative. That is, under high concentration conditions (with a concentration of hydrogen ions of at least Imol / L), the P204 reverse extract liquid is subjected to cyclone electrolysis, and only elemental copper is precipitated from the cathode to achieve the purpose of precise separation of copper. The use of cyclone electrolysis process can generate sponge copper with larger particles and loose texture without adding any additives, and the sponge copper is easily carried away from the cathode surface by the cyclone force provided by the pump to facilitate the collection of copper products (with a purity greater than 98%). At the same time, the chlorine gas generated by the electrolysis of anode can remove TOC from the P204 reverse extract liquid during the escape process, thereby avoiding contamination of subsequent extractants and ensuring the selection specificity of extractants. The S2 is to separate zinc. In order to avoid the generation of highly toxic hydrogen sulfide gas during this separation process and at the same time to reduce the use amount of auxiliary materials such as sodium sulfide, etc., the pH value of the copper-removal solution is adjusted to a range from 5.0 to 5.5 before zinc precipitation. Then, a substance capable of providing sulfur ions is added to precipitate the zinc, resulting in zinc sulfide products and a zinc-removal solution after separation. The S3 is to use the saponified Cyanex272 extractant to separate manganese and calcium from the zinc-removal solution. The organic phase loaded with manganese is washed and reversely extracted to obtain a manganese sulfate solution, which is then evaporated and crystallized to obtain a battery-grade manganese sulfate product.

[0047] Therefore the method of the present application is capable of realizing graded recovery of valuable metals such as manganese, copper, zinc and the like from the P204 reverse extract liquid generated by the nickel wet smelting process. The purity of the recovered manganese sulfate reaches battery-grade. Compared with the recovery of copper in the form of copper sulfide, the sponge copper obtained in the present application has a purity greater than 98%, which has better application prospects and economic benefits. Moreover, by selectively abandoning the sodium, calcium, and aluminum without high recovery value, the operation process can be simplified and unnecessary auxiliary material input can be reduced, thus having higher economic value. At the same time, the method of the present application does not generate heavy metal precipitated slag solid waste, and thus has good environmental performance.

[0048] It should be noted that in the preparation process of electrolytic copper, some additives such as guar gum, gelatin, thiourea, etc. are usually used to form a dense copper plate. However in the cyclone electrolysis process of the present application, the sponge copper is desired. By utilizing the cyclone force provided by the electrolysis equipment, the sponge copper product can be removed from the cathode surface without the need for manual peeling. Moreover, no use of additives can also avoid contaminating the manganese sulfate product.

[0049] It can be understood that when the pH value of the copper-removal solution is less than 5.0, there will be a small amount of H+present in the solution. At this time, adding a substance capable of providing sulfur ions will produce trace amounts of hydrogen sulfide gas, which will have a negative impact on workers and the environment. At the same time, the pH value of the copper-removal solution shall not be too high, otherwise some manganese carbonate will precipitate in solid form and enter the zinc-removal slag, causing manganese loss. Therefore, in the present application the pH value of the copper-removal solution is adjusted to a range from 5.0 to 5.5, such as 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, or within a range composed of the above any values.

[0050] In some optional embodiments, the P204 reverse extract liquid comes from at least one nickel wet smelting process selected from battery recycling materials with high content of nickel and low content of copper, nickel-containing intermediate slag after smelting, various recovered nickel-containing catalysts that have been calcined to remove organic matter, and nickel-containing electroplating sludge. The mass ratio of nickel to copper in the battery recycling materials with high content of nickel and low content of copper is greater than 40:1. It should be understood that when the copper content in the battery recycling material is high, the general practice is to pre-extract to remove copper and add additives during copper electrolysis to obtain cathode copper with a Cu content of greater than or equal to 99.9%. The present application is applicable to the resource treatment and comprehensive utilization of P204 reverse extract liquid generated in various forms of nickel wet smelting processes, and has the advantages of wide application range, good economy and environmental protection.

[0051] The cathode material of the cyclone electrolysis equipment used in the present application is graphite. As an inert material, graphite has good acid resistance and is more suitable for the high acid electrolysis environment of the present application to ensure the smooth progress of electrolysis. However, the existing cyclone electrolysis equipment uses titanium mesh as the cathode, which can increase the specific surface area, but is prone to acid corrosion. Even if the surface of the titanium mesh is oxidized, it is difficult to avoid acid corrosion. In an optional embodiment, the cyclone electrolysis device adopted in the present application has a column anode and a cylindrical cathode, both the anode and the cathode are made of graphite, and the shell is made of glass fiber reinforced plastics.

[0052] In an optional embodiment, the cyclone electrolysis equipment adopted in the present application includes at least 2 cyclone electrolysis cell pry blocks, for example 2, 3, 5, 7 or more cyclone electrolysis cell pry blocks. Respective pry blocks are connected in parallel with each other, and each pry block is integrated with standard interfaces such as power supply joints, electrolyte inlet and outlet pipelines, exhaust gas discharge ports, and the like. The number of pry blocks used can be flexibly selected according to the volume of the P204 reverse extract liquid to be processed, thereby improving treating efficiency. It can be understood that the cyclone electrolysis equipment is an existing electrolysis device, and its structure and configuration can be known by those skilled in the art, so it will not be repeated in the present application.

[0053] In the cyclone electrolysis process of the present application, in order to avoid that the cathode cannot capture copper ions, the current density can be controlled to accurately precipitate copper instead of hydrogen, ensuring the yield and recovery rate of copper. In an optional embodiment, the current density during electrolysis is determined based on the concentration of copper ions in the P204 reverse extract liquid. When the concentration of copper ions in the P204 reverse extract liquid is greater than 2g / L, the current density is controlled to be in a range from 100A / m2to 300A / m2, and the concentration of copper ions at the electrolysis endpoint is in a range from Ig / L to 2g / L. When the concentration of copper ions in the P204 reverse extract liquid is less than or equal to 2g / L, the current density is controlled to be in a range from 5A / m2to 50A / m2, and the concentration of copper ions at the electrolysis endpoint is in a range from 0.03g / L to 0.05g / L. As an example, when the concentration of copper ions in the P204 reverse extract liquid is greater than 2g / L, for example is 3g / L, 5g / L, lOg / L, 20g / L or greater, the current density is controlled to be in a range from 100

[0054] A / m2to 300 A / m2, for example, it can be 100 A / m2, 150 A / m2, 200 A / m2, 250 A / m2, 300 A / m2, or within a range composed of the above any values; and the concentration of copper ions at the electrolysis endpoint is in a range from Ig / L to 2g / L, for example, Ig / L, 1.2g / L, 1.4g / L, 1.6g / L, 1.8g / L, 2g / L, or within a range composed of the above any values. When the concentration of copper ions in the P204 reverse extract liquid is less than or equal to 2g / L, for example is 2g / L, 1.6g / L, 1.3g / L, Ig / L, 0.7g / L, 0.4g / L, O.lg / L or smaller, the current density is controlled to be in a range from 5 A / m2to 50 A / m2, for example, it can be 5 A / m2, 10 A / m2, 15 A / m2, 30 A / m2, 50 A / m2or within a range composed of the above any values; and the concentration of copper ions at the electrolysis endpoint is in a range from 0.03g / L to 0.05g / L, for example, 0.03g / L, 0.04g / L, 0.05g / L, or within a range composed of the above any values. Although the lower the copper concentration at the electrolysis endpoint, the less zinc precipitation reagents are required in the future, continuing electrolysis at a too low copper concentration will result in failure of copper ions capturing on the cathode surface, wasting electrical energy. That is to say, if the concentration of copper ions in the P204 reverse extract liquid is relatively high, a two-stage electrolysis method can be used to achieve the effect of deep copper-removal.

[0055] To avoid the impact of chlorine gas volatilization on the environment, in an optional implementation method, the chlorine gas generated by electrolysis is absorbed by a liquid alkali and transformed into a sodium hypochlorite product, which is used in subsequent water treatment systems to remove TOC and TN, further improving the economic and environmental friendliness of the present application. It is understandable that, TN refers to total nitrogen, which is defined as the total amount of various forms of inorganic and organic nitrogen in water, including inorganic nitrogen such as NO3", NO2", and NHC, as well as organic nitrogen such as proteins, amino acids, and organic amines. The total nitrogen content in water is an important indicator for measuring water quality, and is often used to indicate the degree of nutrient pollution in water.

[0056] In an optional embodiment, a carbonate salt is added to solution after evaporating and crystallizing the manganese sulfate in S3 to form manganese carbonate precipitate, which is filtered, washed and precipitated, and then slurried with deionized water to obtain a manganese carbonate slurry. The manganese carbonate slurry is further used for adjusting the pH value of the copper-removal solution. Due to the presence of residual manganese ions and the enrichment of some impurities such as fluorine, chlorine, sodium ions and the like in the solution after evaporating and crystallizing the manganese sulfate, and by taking use of different precipitation abilities of these ions, only manganese ions are selectively transformed into manganese carbonate precipitates. The manganese carbonate slurry is used for adjusting the pH value of the copper-removal solution. On the one hand, waste reuse is achieved, environmental performance is improved, and on the other hand, manganese resources are further recovered, improving the yield of the manganese sulfate products and recovery rate of manganese.

[0057] In an optional embodiment, in S2, when adjusting the pH value of the copper-removal solution, the reaction temperature is controlled to be in a range from 30 °C to 60 °C, and stirring is performed for Ih to 2h. As an example, the reaction temperature in S2 can be 30 °C, 40 °C, 50 °C, 60 °C, etc. or within the range composed of the above any values, and the stirring can be performed for Ih, 1.2h, 1.5h, 1.8h, 2h, etc. or within the time period range composed of the above any values. The inventor's research found that if the reaction temperature is too low or the stirring time is too short, some manganese carbonate will precipitate in solid form into the zinc-removal slag, causing manganese loss. Conversely, if the reaction temperature is too high or the stirring time is too long, it will waste energy.

[0058] In an optional embodiment, the substance capable of providing sulfur ions includes at least one of sodium sulfide, sodium hydrosulfide, and sodium dimethyl dithiocarbamate. Compared with sodium thiosulfate, the above substances can deeply precipitate zinc, which is beneficial for improving the yield of zinc sulfide and the recovery rate of zinc.

[0059] In an optional embodiment, the precipitation reaction in S2 is carried out at a temperature of 30 °C to 60 °C for a period of Ih to 2h. As an example, the precipitation reaction temperature can be 30 °C, 40 °C, 50 °C, 60 °C, etc. or within a range composed of the above any values, and the reaction time can be Ih, 1.2h, 1.5h, 1.8h, 2h, etc. or within a range composed of the above any values.

[0060] In an optional embodiment, the pH value at endpoint of the precipitation reaction in S2 is in a range from 5.0 to 6.0, which can ensure the qualified removal of zinc ions. If the pH value of the precipitation reaction is too low, it indicates that the amount of the substance capable of providing sulfur ions is insufficient and needs to be further added. On the contrary, if the pH value of the precipitation reaction is too high, it indicates that an excessive amount of the substance capable of providing sulfur ions are added, resulting in a relatively large amount of manganese sulfide precipitate, thus it is necessary to add back an appropriate amount of copper-removal solution. As an example, the pH value at endpoint of the precipitation reaction can be 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, etc. or within a range composed of the above any values.

[0061] In an optional embodiment, the concentration of zinc ions in the solution at endpoint of the precipitation reaction in S2 is less than 0.005g / L, which can ensure that the subsequent Cyanex272 extraction of the loaded organic phase can produce a manganese sulfate solution with a suitable ratio of main and impurity elements after washing and acid reversely extracting, thereby ensuring the production of qualified battery-grade manganese sulfate products. If the concentration of zinc ions in the solution is too low, it indicates that a relatively large amount of manganese sulfide precipitates are generated and contained in the zinc slag, which will cause manganese loss. On the contrary, if the concentration of zinc ions in the solution is too high, it indicates that the amount of substance that can provide sulfur ions is insufficient and needs to be further added.

[0062] In an optional embodiment, the saponified Cyanex272 extractant is obtained by reacting a commercially available and / or recovered Cyanex272 extractant with sodium hydroxide to obtain an organic phase and then performing manganese ions exchanging between the organic phase and a manganese sulfate aqueous solution, wherein the organic phase after reversely extracting in S3 is washed using a strong acid to obtain the recovered Cyanex272 extractant. Preparing manganese soap Cyanex272 using the recovered Cyanex272 extractant and carrying out manganese-calcium separation using the manganese soap Cyanex272 can reducing the input of auxiliary materials and further improve the economic and environmental friendliness of the present application.

[0063] It is understandable that, the chemical name of Cyanex272 is bis(2,4,4-trimethylpentyl) phosphonic acid. Due to economic considerations, Cyanex272 sodium soap is often used as an extractant, i.e., a sodium soap formed by reacting Cyanex272 with sodium hydroxide. The present application involves exchanging Cyanex272 sodium soap with manganese sulfate aqueous solution to form manganese soap by adding manganese ions into the organic phase, the purpose of which is to increase the manganese content in the extracted loaded organic phase and reduce the sodium content.

[0064] In an optional embodiment, the concentration of manganese ions in the calcium-containing raffinate is in a range from 0.2g / L to l.Og / L, which can ensure that the subsequent Cyanex272 extraction of the loaded organic phase can produce a manganese sulfate solution with a suitable ratio of main and impurity elements after washing and acid reversely extracting, thereby ensuring the production of qualified battery-grade manganese sulfate products. If the concentration of manganese ions in the calcium-containing raffinate is too high, it indicates a decrease in the recovery rate of manganese element, and it is necessary to timely adjust the phase ratio in the extraction box. If the concentration of manganese ions in the calcium-containing raffinate is too low, it indicates that there is a risk of calcium element exceeding the standard in subsequent battery-grade manganese sulfate products, and it is necessary to timely adjust the phase ratio in the extraction box. As an example, the concentration of manganese ions in the calcium-containing raffinate can be 0.2g / L, 0.4g / L, 0.6g / L, 0.8g / L, l.Og / L, etc. or within a range composed of the above any values.

[0065] It should be noted that both the manganese precipitation wastewater (pH value 7.5-8.0, Mn content is in a range from 0.01 g / L to 0.05g / L, with almost no calcium precipitation) generated during the preparation of manganese carbonate from the calcium-containing raffinate and the solution after evaporating and crystallizing the manganese sulfate obtained in S3 of the present application, and the wastewater generated during the recovery process of Cyanex272 extractant enter the water treatment system for further treatment. The sodium hypochlorite produced in the electrolysis process can be used for water treatment to remove TCO and TN.

[0066] It should be noted that the manganese sulfate product recovered in the present application complies with the provisions of HG / T 4823-2015 Manganese Sulfate for Batteries, indicating that the method used in the present application can obtain high-purity battery-grade manganese sulfate with high economic value. Moreover, the sponge copper recovered in the present application has a selling price which is 90% to 95% of that of copper element, while the selling price of copper sulfide obtained by related existing technologies is only 60% to 70% of that of copper element. Therefore, overall, the method of the present application has better economic benefits.

[0067] It is undeniable that the purity of the zinc sulfide recovered in the present application will not be too high, within a range of 10% to 55%, and copper and manganese elements will be entrained. However, the presence of these elements does not affect the subsequent electrolytic zinc process, as the electrolytic zinc process already includes the process of replacing sponge copper with zinc powder. It is acceptable for the zinc sulfide recovered in the present application to contain a small amount of copper. At the same time, during the electrolytic zinc process, the manganese element can generate manganese bioxide which can also protect the electrolytic anode, which is beneficial for the smooth progress of the electrolytic zinc process.

[0068] The following provides a further detailed description of the present application in conjunction with specific examples, which cannot be understood as limiting the scope of protection claimed by the present application. In the present application, unit wt% represents the percentage content of mass.

[0069] Example 1

[0070] The method for treating reverse extract liquid provided in this example, as shown in Figure 1, comprises the following steps.

[0071] 1. 2L of the P204 reverse extract liquid (chloride salt system) generated dining the treatment of nickel hydrometallurgical intermediate was measured to have following parameters: a Mn ion concentration of 33.26g / L, a Cu ion concentration of 3.52g / L, a Zn ion concentration of 1.08g / L, a Ca ion concentration of 0.35g / L, a H+ion concentration of 2.26mol / L, and a TOC content of 246ppm.

[0072] 2. The P204 reverse extract liquid (chloride salt system) was pumped into a first stage cyclone electrolysis equipment, and electrolysis was performed without any additives at a current density set as 200A / m2to obtain a sponge copper (containing a small amount of copper oxide and trace graphite electrode flake falloff material, resulting in a purity of 98.5%, slightly lower than that of cathode copper). The electrolytic solution at the endpoint of the electrolysis was sampled from the equipment outlet and was measured to have a Cu ion concentration of 1.12g / L.

[0073] 3. The first stage cyclone electrolyte was pumped into a second stage cyclone electrolysis equipment, and electrolysis was perform without any additives at a current density set as 50A / m2to obtain a sponge copper (purity of 98.6%) and a copper-removal solution. The electrolytic solution at the endpoint of electrolysis was sampled from the equipment outlet and was measured to have a Cu ion concentration of

[0074] 0.048g / L and a TOC content of 56ppm. The chlorine gas generated by electrolysis (the detection frequency was once every two horns) was absorbed using 15wt% liquid alkali to obtain sodium hypochlorite (effective chlorine content was 5.32wt%) by-product, which was used for removing TOC and TN in water treatment systems.

[0075] 4. The pH value of the copper-removal solution obtained in 3 was adjusted to 5.2 using a manganese carbonate slurry. Dining this process, the reaction temperature was controlled at 45 °C, stirring was performed for reacting for 1.5 hours, and the material was used directly for the next step without filtration. Wherein, the manganese carbonate slurry was obtained by precipitating the solution after evaporating and crystallizing the manganese sulfate with sodium carbonate to obtain a slag, washing the slag, and slurrying the slag using deionized water.

[0076] 5. 10wt% sodium sulfide aqueous solution was added into the copper-removal solution obtained in 4 for carrying out zinc precipitation, the temperature was controlled at 45 °C, stirring was performed for reacting for 1.5 hours, and the pH value at reaction endpoint was 5.4, obtaining a zinc-removal solution and a crude zinc sulfide product. The zinc-removal solution at endpoint was measured to have a Zn ion concentration of 0.0045g / L. The crude zinc sulfide product was filtered and washed, and measured to have a zinc content of 42.65wt% based on dry product.

[0077] 6. Cyanex272 (manganese soap) was added into the zinc-removal solution obtained in 5 for carrying out manganese-calcium separation, obtaining an organic phase loaded with manganese and a calcium-containing raffinate. The calcium-containing raffinate enters the water treatment system. The organic phase loaded with manganese was washed and reversely extracted to obtain a high-purity manganese sulfate solution. The calcium-containing raffinate was measured to have a Mn ion concentration of 0.23g / L and a Ca ion concentration of 0.28g / L. The high-purity manganese sulfate solution was measured to have a Mn ion concentration of 112g / L, a Cu ion concentration of 0.00085g / L, and a Zn ion concentration of 0.0002g / L.

[0078] 7. The high-purity manganese sulfate solution obtained in 6 was evaporated and crystallized to obtain a battery-grade manganese sulfate product, which was measured to have a Mn content of 32.69wt%, a Cu content of less than 0.0001wt%, a Zn content of less than 0.0001wt%, and a Ca content of 0.0003wt%, meeting the requirements of the chemical industry standard HG / T 4823-2015 Manganese Sulfate for Batteries.

[0079] Example 2

[0080] The method for treating reverse extract liquid provided in this example includes the following steps:

[0081] 1. 2L of the P204 reverse extract liquid (chloride salt system) generated during the treatment of battery material was measured to have following parameters: a Mn ion concentration of 36.12g / L, a Cu ion concentration of 0.61g / L, a Zn ion concentration of 0.38g / L, a Ca ion concentration of 0.17g / L, a H+ion concentration of 2.18mol / L, and a TOC content of 326 ppm.

[0082] 2. The P204 reverse extract liquid (chloride salt system) was pumped into a cyclone electrolysis equipment, and electrolysis was performed without any additives at a current density set as 30A / m2to obtain a sponge copper (purity 98.5%). The electrolytic solution at the endpoint of electrolysis was sampled from the equipment outlet and was measured to have a Cu ion concentration of 0.036g / L and a TOC content of 52ppm. 15wt% liquid alkali was used to absorb the chlorine gas generated by electrolysis (the detection frequency was once every two horns) to obtain a sodium hypochlorite (effective chlorine content was 5.62wt%) by-product, which was used for removing TOC and TN in water treatment systems.

[0083] 3. The pH value of the copper-removal solution obtained in 2 was adjusted to 5.0 using a manganese carbonate slurry. Dining this process, the reaction temperature was controlled at 30 °C, stirring was performed for reacting for 2 hours, and the material was used directly for the next step without filtration. Wherein, the manganese carbonate slurry was obtained by precipitating the solution after evaporating and crystallizing the manganese sulfate with sodium carbonate, washing the slag, and slurrying the slag using deionized water.

[0084] 4. 10wt% sodium sulfide aqueous solution was added into the copper-removal solution obtained in 3 for carrying out zinc precipitation, the temperature was controlled at 30 °C, stirring was performed for reacting for 2 hours, and the pH value at reaction endpoint in the zinc-removal solution was 5.2, obtaining a zinc-removal solution and a crude zinc sulfide product. The zinc-removal solution at endpoint was measured to have a Zn ion concentration of 0.0016g / L. The crude zinc sulfide product was filtered and washed, and measured to have a zinc content of 36.42wt% based on dry product.

[0085] 5. Cyanex272 (manganese soap) was added into the zinc-removal solution obtained in 4 for carrying out manganese-calcium separation, obtaining an organic phase loaded with manganese and a calcium-containing raffinate. The calcium-containing raffinate enters the water treatment system, and the organic phase loaded with manganese was washed and reversely extracted to obtain a high-purity manganese sulfate solution. The calcium-containing raffinate was measured to have a Mn ion concentration of 0.28g / L and a Ca ion concentration of 0.15g / L. The high-purity manganese sulfate solution was measured to have a Mn ion concentration of 116g / L, a Cu ion concentration of 0.00092g / L, and a Zn ion concentration of 0.00023g / L.

[0086] 6. The high-purity manganese sulfate solution obtained in 5 was evaporated and crystallized to obtain a battery-grade manganese sulfate product, which was measured to have a Mn content of 32.46wt%, a Cu content of less than 0.0001wt%, a Zn content of less than 0.0001wt%, and a Ca content of 0.0002wt%, meeting the requirements of the chemical industry standard HG / T 4823-2015 Manganese Sulfate for Batteries.

[0087] Example 3 The only difference from Example 2 was that the current density was set to 50A / m2.

[0088] Example 4

[0089] The only difference from Example 2 was that the current density was set to 40 A / m2.

[0090] Example 5

[0091] The only difference from Example 2 was that the current density was set to 20 A / m2.

[0092] Example 6

[0093] The only difference from Example 2 was that the current density was set to 10 A / m2.

[0094] Example 7

[0095] The only difference from Example 2 was that the current density was set to 5 A / m2.

[0096] Example 8

[0097] The method for treating reverse extract liquid provided in this example includes the following steps:

[0098] 1. 2L of the P204 reverse extract liquid (chloride salt system) generated during the treatment of the recovered nickel-containing catalyst that has been calcined to remove organic matter was measured to have following parameters: a Mn ion concentration of 10.32g / L, a Cu ion concentration of 12.25g / L, a Zn ion concentration of 18.27g / L, a Ca ion concentration of 0.41g / L, a H+ion concentration of 2.32mol / L, and a TOC content of 348ppm.

[0099] 2. The P204 reverse extract liquid (chloride salt system) was pumped into a first stage cyclone electrolysis equipment, and electrolysis was performed without any additives at a current density set as 100A / m2to obtain a sponge copper (purity 98.6%). The electrolytic solution at the endpoint of electrolysis was sampled from the equipment outlet and was measured to have a Cu ion concentration of 1.35g / L.

[0100] 3. The first stage cyclone electrolyte was pumped into a second stage cyclone electrolysis equipment, and electrolysis was performed without any additives at a current density set as 20A / m2to obtain a sponge copper (purity of 98.7%). The electrolytic solution at the endpoint of electrolysis was sampled from the outlet of the equipment and was measured to have a Cu ion concentration of 0.042g / L and a TOC content of 48ppm. 10wt% liquid alkali was used to absorb the chlorine gas generated by electrolysis (the detection frequency was once every two horns) to obtain a sodium hypochlorite (effective chlorine content was 6.12wt%) by-product, which was used for removing TOC and TN in water treatment systems.

[0101] 4. The pH value of the copper-removal solution obtained in 3 was adjusted to 5.2 using a manganese carbonate slurry. Dining this process, the reaction temperature was controlled at 45 °C, stirring was performed for reacting for 1.5 hours, and the material was used directly for the next step without filtration. Wherein, the manganese carbonate slurry was obtained by precipitating the solution after evaporating and crystallizing the manganese sulfate with sodium carbonate, washing the slag, and slurrying the slag using deionized water.

[0102] 5. 10wt% sodium hydrosulfide aqueous solution was added into the copper-removal solution obtained in 4 for carrying out zinc precipitation, the temperature was controlled at 45 °C, stirring was performed for reacting for 1.5 hours, and the pH value at reaction endpoint was 5.5, obtaining a zinc-removal solution and a crude zinc sulfide product. The zinc-removal solution at endpoint was measured to have a Zn ion concentration of 0.0032g / L. The crude zinc sulfide product was filtered and washed, and measured to have a zinc content of 40.52wt% based on dry product.

[0103] 6. Cyanex272 (manganese soap) was added into the zinc-removal solution obtained in 5 for carrying out manganese-calcium separation, obtaining an organic phase loaded with manganese and a calcium-containing raffinate. The calcium-containing raffinate enters the water treatment system, and the organic phase loaded with manganese was washed and reversely extracted to obtain a high-purity manganese sulfate solution. The calcium-containing raffinate was measured to have a Mn ion concentration of 0.21g / L and a Ca ion concentration of 0.33g / L. The high-purity manganese sulfate solution was measured to have a Mn ion concentration of 115g / L, a Cu ion concentration of 0.00075g / L, and a Zn ion concentration of 0.00022g / L.

[0104] 7. The high-purity manganese sulfate solution obtained in 6 was evaporated and crystallized to obtain a battery-grade manganese sulfate product which was measured to have a Mn content of 32.38wt%, a Cu content of less than 0.0001wt%, a Zn content of less than 0.0001wt%, and a Ca content of 0.0002wt%, meeting the requirements of the chemical industry standard HG / T 4823-2015 Manganese Sulfate for Batteries.

[0105] Example 9

[0106] The method for treating reverse extract liquid provided in this example includes the following steps:

[0107] 1. 2L of the P204 reverse extract liquid (chloride salt system) generated dining the treatment of nickel-containing electroplating sludge was measured to have following parameters: a Mn ion concentration of 12.26g / L, a Cu ion concentration of 17.42g / L, a Zn ion concentration of 2.68g / L, a Ca ion concentration of 0.38g / L, a H+ion concentration of 2.48mol / L, and a TOC content of 423ppm.

[0108] 2. The P204 reverse extract liquid (chloride salt system) was pumped into a first stage cyclone electrolysis equipment, and electrolysis was performed without any additives at a current density set as 300A / m2to obtain a sponge copper (purity 98.7%). The electrolytic solution at the endpoint of electrolysis was sampled from the equipment outlet and was measured to have a Cu ion concentration of 1.45g / L.

[0109] 3. The first stage cyclone electrolyte was pumped into a second stage cyclone electrolysis equipment, and electrolysis was performed without any additives at a current density set as 5A / m2to obtain a sponge copper (purity of 98.7%). The electrolytic solution at the endpoint of electrolysis was sampled from the outlet of the equipment and was measured to have a Cu ion concentration of 0.043g / L and a TOC content of 46ppm.

[0110] 12wt% liquid alkali was used to absorb the chlorine gas generated by electrolysis (the detection frequency was once every two hours) to obtain a sodium hypochlorite (effective chlorine content was 6.12wt%) by-product, which was used for removing TOC and TN in water treatment systems.

[0111] 4. The pH value of the copper-removal solution obtained in 3 was adjusted to 5.0 using a manganese carbonate slurry. During this process, the reaction temperature was controlled at 60 °C, stirring was performed for reacting for 1 hour, and the material was used directly for the next step without filtration. Wherein, the manganese carbonate slurry was obtained by precipitating the solution after evaporating and crystallizing the manganese sulfate with sodium carbonate, washing the slag, and slurrying the slag using deionized water.

[0112] 5. 10wt% sodium hydrosulfide aqueous solution was added into the copper-removal solution obtained in 4 for carrying out zinc precipitation, the temperature was controlled at 60 °C, stirring was performed for reacting for 1 hour, and the pH value at reaction endpoint was 6.0, obtaining a zinc-removal solution and a crude zinc sulfide product. The zinc-removal solution at endpoint was measured to have a Zn ion concentration of 0.0038g / L. The crude zinc sulfide product was filtered and washed, and measured to have a zinc content of 41.25wt% based on dry product.

[0113] 6. Cyanex272 (manganese soap) was added into the zinc-removal solution obtained in 5 for carrying out manganese-calcium separation, obtaining an organic phase loaded with manganese and a calcium-containing raffinate. The calcium-containing raffinate enters the water treatment system, and the organic phase loaded with manganese was washed and reversely extracted to obtain a high-purity manganese sulfate solution. The calcium-containing raffinate was measured to have a Mn ion concentration of 0.35g / L and a Ca ion concentration of 0.31g / L. The high-purity manganese sulfate solution was measured to have a Mn ion concentration of 113g / L, a Cu ion concentration of 0.00088g / L, and a Zn ion concentration of 0.00026g / L.

[0114] 7. The high-purity manganese sulfate solution obtained in 6 was evaporated and crystallized to obtain a battery-grade manganese sulfate product which was measured to have a Mn content of 32.56wt%, a Cu content of less than 0.0001wt%, a Zn content of less than 0.0001wt%, and a Ca content of 0.0002wt%, meeting the requirements of the chemical industry standard HG / T 4823-2015 Manganese Sulfate for

[0115] Batteries.

[0116] Example 10

[0117] The method for treating reverse extract liquid provided in this example includes the following steps:

[0118] 1. 2L of the P204 reverse extract liquid (chloride salt system) generated during the treatment of battery material was measured to have following parameters: a Mn ion concentration of 31.25g / L, a Cu ion concentration of 5.25g / L, a Zn ion concentration of 0.26g / L, a Ca ion concentration of 0.12g / L, a H+ion concentration of 2.98mol / L, and the TOC content was 456ppm.

[0119] 2. The P204 reverse extract liquid (chloride salt system) was pumped into a first stage cyclone electrolysis equipment, and electrolysis was performed without any additives at a current density set as 150A / m2to obtain a sponge copper (purity of 98.6%). The electrolytic solution at the endpoint of electrolysis was sampled from the equipment outlet and was measured to have a Cu ion concentration of 1.28g / L.

[0120] 3. The first stage cyclone electrolyte was pumped into a second stage cyclone electrolysis equipment, and electrolysis was performed without any additives at a current density set as 10A / m2to obtain a sponge copper (purity of 98.7%). The electrolytic solution at the endpoint of electrolysis was sampled from the outlet of the equipment and was measured to have a Cu ion concentration of 0.03 Ig / L and a TOC content of 52ppm. 10wt% liquid alkali was used to absorb the chlorine gas generated by electrolysis (the detection frequency was once every two horns) to obtain a sodium hypochlorite (effective chlorine content was 5.42wt%) by-product, which was used for removing TOC and TN in water treatment systems.

[0121] 4. The pH value of the copper-removal solution obtained in 3 was adjusted to 5.5 using a manganese carbonate slurry. Dining this process, the reaction temperature was controlled at 50 °C, stirring was performed for reacting for 2 hours, and the material was used directly for the next step without filtration. Wherein, the manganese carbonate slurry was obtained by precipitating the solution after evaporating and crystallizing the manganese sulfate with sodium carbonate, washing the slag, and slurrying the slag using deionized water.

[0122] 5. 10wt% sodium sulfide aqueous solution was added into the copper-removal solution obtained in 4 for carrying out zinc precipitation, the temperature was controlled at 50 °C, stirring was performed for reacting for 1 hour, and the pH value at reaction endpoint was 5.6, obtaining a zinc-removal solution and a crude zinc sulfide product. The zinc-removal solution at endpoint was measured to have a Zn ion concentration of 0.0015g / L. The crude zinc sulfide product was filtered and washed, and measured to have a zinc content of 26.18wt% based on dry product.

[0123] 6. Cyanex272 (manganese soap) was added into the zinc-removal solution obtained in 5 for carrying out manganese-calcium separation, obtaining an organic phase loaded with manganese and a calcium-containing raffinate. The calcium-containing raffinate enters the water treatment system, and the organic phase loaded with manganese was washed and reversely extracted to obtain a high-purity manganese sulfate solution. The calcium-containing raffinate was measured to have a Mn ion concentration of 0.38g / L and a Ca ion concentration of 0.092g / L. The high-purity manganese sulfate solution was measured to have a Mn ion concentration of 112g / L, a Cu ion concentration of 0.00086g / L, and a Zn ion concentration of 0.0002g / L.

[0124] 7. The high-purity manganese sulfate solution obtained in 6 was evaporated and crystallized to obtain a battery-grade manganese sulfate product which was measured to have a Mn content of 32.36wt%, a Cu content of less than 0.0001wt%, a Zn content of less than 0.0001wt%, and a Ca content of 0.0002wt%, meeting the requirements of the chemical industry standard HG / T 4823-2015 Manganese Sulfate for Batteries.

[0125] Example 11 The only difference from Example 10 was that the current density of the first stage cyclone electrolysis equipment was 100A / m2.

[0126] Example 12

[0127] The only difference from Example 10 was that the current density of the first stage cyclone electrolysis equipment was 200 A / m2.

[0128] Example 13

[0129] The only difference from Example 10 was that the current density of the first stage cyclone electrolysis equipment was 250 A / m2.

[0130] Example 14

[0131] The only difference from Example 10 was that the current density of the first stage cyclone electrolysis equipment was 300 A / m2.

[0132] Comparative Example 1

[0133] The method for treating reverse extract liquid provided in this comparative example includes the following steps:

[0134] 2L of the P204 reverse extract liquid (chloride salt system) generated during the treatment of battery material was measured to have following parameters: a Mn ion concentration of 36.12g / L, a Cu ion concentration of 0.61g / L, a Zn ion concentration of 0.38g / L, a Ca ion concentration of 0.17g / L, a H+ion concentration of 2.18mol / L, and a TOC content of 326ppm. The treating method was described as follows.

[0135] (1) Electromagnetic field assisted impurity removal: Under the action of an alternating electromagnetic field with a frequency of 60kHz, Na2S20s was added into a P204 reverse extract liquid, followed by the addition of NaOH. The mixture was stirred at a speed of 120r / min for a period of time, separated by filtration to obtain a copper sulfide slag, a zinc-aluminum slag, and an impurity-removal solution. The specific steps were as follows.

[0136] (1-1) Copper-removal: the alternating electromagnetic field was turned on, sodium thiosulfate was added at an amount 1.0 time the theoretical amount, stirring was performed for 1 hour, and then solid-liquid separation was performed to obtain a solid phase which was a copper sulfide slag having a purity of greater than 98% and a liquid phase which was the copper-removal solution;

[0137] (1-2) Zinc-removal: sodium thiosulfate solution was added at an amount 1.1 times the theoretical amount and stirring was performed for 3 hours to convert Zn2+and the remaining small amount of Cu2+into zinc sulfide and copper sulfide. When the Cu concentration and Zn concentration was lower than Img / L, solid-liquid separation was carried out, obtaining a solid phase which was zinc slag mainly composed of zinc sulfide and a small amount of copper sulfide and manganese sulfide, and a liquid phase which was the impurity-removal solution mainly comprising MnCT. NaCl, and CaCT:

[0138] (2) Cyanex272 linkage optimized extraction: the impurity-removal solution obtained in (1) was subjected to Cyanex272 linkage optimized extraction to obtain a battery-grade MnSC solution, CaCT solution and NaCl solution. The manganese sulfate solution was evaporated and crystallized to obtain a manganese sulfate product.

[0139] The property of materials recovered from Examples 1 to 14 of the present application and Comparative

[0140] Example 1 were shown in Table 1.

[0141] Table 1. Property of materials recovered

[0142] The "direct yield" in Table 1 reflects the recovery effect, and the calculation formula is: direct yield = product metal amount / raw material metal amount * 100%.

[0143] From Table 1, it can be seen that the direct yields of manganese and copper in the P204 reverse extract liquid in Examples 1 to 14 are all higher than those in Comparative Example 1. This indicates that the method of the present application can high-efficiently recover valuable metals such as manganese, copper, zinc and the like in the P204 reverse extract liquid produced by the nickel wet smelting process, and the purity of the recovered manganese sulfate reaches battery-grade. Compared to recovering copper in the form of copper sulfide in Comparative Example 1, the sponge copper obtained in the present application has a purity greater than 98%, which has better application prospects and economic benefits. Compared to Example 2, the methods in Examples 3 to 7 only adjusted the current density during cyclone electrolysis, which would only have a significant impact on the time for electrolytic copper-removal, and had almost no impact on the copper-removal effect, sponge copper grade, as well as manganese and zinc recovery effect. The same rules also appeared in Examples 10 to 14. This indicates that the method of the present application has broad adaptability.

[0144] Obviously, the above examples are only provided for the purpose of clearly illustrating the examples, rather than limiting the embodiments. For ordinary technical personnel in their respective fields, different forms of changes or variations can be made based on the above explanation. It is not necessary and impossible to exhaustively list all embodiments here. The obvious changes or variations arising from this are still within the scope of protection created by the present application.

Claims

Claims1. A method for treating reverse extract liquid, characterized in that the method comprises the following steps of:

51. sending a P204 reverse extract liquid from a nickel wet smelting process into a cyclone electrolysis equipment for removing copper by electrolysis, obtaining a copper-removal solution; wherein the P204 reverse extract liquid is an aqueous solution obtained by reversely extracting a P204 organic phase loaded with metal ions with hydrochloric acid, wherein the metal ions include manganese ions, copper ions, zinc ions, and calcium ions, and wherein the P204 reverse extract liquid has a concentration of hydrogen ions of at least Imol / L;52. adjusting a pH value of the copper-removal solution to a range from 5.0 to 5.5, adding a substance capable of providing sulfur ions for carrying out precipitation reaction to remove zinc, and filtering to obtain a zinc-removal solution;53. extracting the zinc-removal solution with a saponified Cyanex272 extractant to obtain an organic phase loaded with manganese and a calcium-containing raffinate, washing and reversely extracting the organic phase loaded with manganese to obtain a manganese sulfate solution, evaporating and crystallizing the manganese sulfate solution to obtain a manganese sulfate product.

2. The method for treating reverse extract liquid according to claim 1, characterized in that, the electrolysis is controlled to perform at a current density of 100A / m2to 300A / m2when the copper ions in the P204 reverse extract liquid reaches a concentration of greater than 2g / L, and the copper ions have a concentration of Ig / L to 2g / L at an endpoint of the electrolysis.

3. The method for treating reverse extract liquid according to claim 1 or 2, characterized in that, the electrolysis is controlled to perform at a current density of 5A / m2to 50A / m2when the copper ions in the P204 reverse extract liquid reaches a concentration of less than or equal to 2g / L, and the copper ions have a concentration of 0.03g / L to 0.05g / L at an endpoint of the electrolysis.

4. The method for treating reverse extract liquid according to claim 1, characterized in that the hydrogen ions in the P204 reverse extract liquid have a concentration of Imol / L to 3mol / L; and / or, a cathode of the cyclone electrolysis equipment is made of graphite.

5. The method for treating reverse extract liquid according to claim 1 or 4, characterized in that, the cyclone electrolysis equipment comprises at least 2 cyclone electrolysis cell pry blocks which are connected in parallel with each other.

6. The method for treating reverse extract liquid according to claim 1, characterized in that, chlorine gas generated in SI is collected and converted into a sodium hypochlorite product for use in a water treatment system.

7. The method for treating reverse extract liquid according to claim 1, characterized in that, a carbonate salt is added into a solution after evaporating and crystallizing the manganese sulfate in S3 to form a manganese carbonate precipitate which is filtered, washed and precipitated, and then slurried with deionized water to obtain a manganese carbonate slurry which is used to adjust the pH value of the copper-removal solution.

8. The method for treating reverse extract liquid according to claim 1, characterized in that, the S2 comprises controlling a temperature to be in a range from 30 °C to 60 °C when adjusting the pH value of the copper-removal solution, and carrying out stirring for Ih to 2h; and / or, wherein the substance capable of providing sulfur ions includes at least one of sodium sulfide, sodium hydrosulfide, or sodium dimethyl dithiocarbamate; and / or, wherein the precipitation reaction in S2 is carried out at a temperature ranging from 30 °C to 60 °C for a time period ranging from Ih to 2h; and / or, the pH value is in a range from 5.0 to 6.0 at an endpoint of the precipitation reaction in S2; and / or, the zinc ions in the solution have a concentration of less than 0.005g / L at an endpoint of the precipitation reaction in S2.

9. The method for treating reverse extract liquid according to claim 1, characterized in that, the saponified Cyanex272 extractant is obtained by reacting a commercially available and / or recovered Cyanex272 extractant with sodium hydroxide to obtain an organic phase and then performing manganese ions exchanging between the organic phase and a manganese sulfate aqueous solution.

10. The method for treating reverse extract liquid according to claim 1, characterized in that, manganese ions in the calcium-containing raffinate have a concentration of 0.2g / L to l.Og / L.

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