Doubling treatment method for battery black powder and cobalt nickel hydroxide

Abstract

The invention provides a doubling treatment method of battery black powder and nickel cobalt hydroxide. The doubling treatment method comprises the following steps: carrying out reduction roasting and water immersion treatment on the battery black powder to obtain a first lithium-containing liquid and a solid product; carrying out acid leaching on the solid product to obtain a leaching solution; after removing impurities from the leachate, extracting the leachate with a first saponification extraction agent to obtain first raffinate and a first extraction organic phase; carrying out soap conversion reaction on the first raffinate and a second saponification extraction agent to obtain a second extracted and soap-converted organic phase and a second lithium-containing liquid; carrying out acid leaching and impurity removal on nickel cobalt hydroxide, and carrying out extraction reaction on the solution and the second extraction soap-converted organic phase to obtain a second extraction organic phase and a second raffinate; the second raffinate is subjected to Co extraction, Mg extraction and evaporative crystallization, and nickel sulfate is obtained; and the organic phase obtained after Co extraction is subjected to back extraction and evaporative crystallization, and cobalt sulfate is obtained. Compared with a traditional doubling treatment technology, the doubling treatment method avoids the problem of impurity pollution caused by doubling treatment of traditional battery black powder and nickel cobalt hydroxide raw materials.

Description

Technical Field

[0001] The invention relates to the field of battery materials, and in particular to a method for parallel processing of battery black powder and nickel cobalt hydroxide. Background Art

[0002] As lithium-ion batteries are widely used, a huge number of lithium-ion batteries will be scrapped. Recycling metals from scrapped lithium-ion batteries has certain recycling economics. At present, in the process of using different nickel-cobalt raw materials to produce battery-grade nickel sulfate, cobalt sulfate, etc., depending on the source of the raw materials and the content of impurity elements, it is often necessary to establish a separate production line for recycling and treatment. For example, battery black powder generally uses a two-stage low-high acid leaching process to remove iron and aluminum, extract manganese, extract cobalt, extract nickel, and precipitate lithium in the residual liquid to produce manganese sulfate, cobalt sulfate, nickel sulfate and crude lithium carbonate products. Nickel and cobalt hydroxide raw materials usually use a two-stage low-acid leaching process, remove iron and aluminum, extract and remove impurities, extract cobalt, extract magnesium, and deep extract magnesium to produce cobalt sulfate and nickel sulfate products. The cost of processing black powder and nickel and cobalt hydroxide separately on two production lines is high, and the economic efficiency is not significant.

[0003] In order to reduce costs, the parallel processing of battery black powder and nickel-cobalt hydroxide raw materials has become a mainstream research trend. At present, the parallel processing of battery black powder and nickel-cobalt hydroxide raw materials mostly uses battery black powder leachate to replace the traditional process of P204 raffinate or nickel sulfate evaporation crystallization mother liquor, and combines the valuable elements Co, Ni, Mn and other elements in the black powder with the valuable elements in the nickel-cobalt hydroxide raw materials in one extraction line for treatment and separation. However, the existing process directly uses the solution after the battery black powder is dissolved for the conversion of nickel-cobalt soap, resulting in serious impurity pollution problems in the parallel processing, affecting the product qualification rate. Summary of the invention

[0004] The invention provides a method for parallel processing of battery black powder and nickel cobalt hydroxide, which avoids the impurity pollution problem caused by parallel processing of battery black powder and nickel cobalt hydroxide raw materials.

[0005] In detail, the present invention provides a method for processing battery black powder and nickel cobalt hydroxide in parallel, comprising the following steps:

[0006] S1, roasting and water leaching a mixture of battery black powder and a reducing agent to obtain a first lithium-containing liquid and a solid product; acid leaching the solid product to obtain a leachate;

[0007] S2, extracting the leaching solution once with a first saponification extractant after removing impurities to obtain a first raffinate and a first extraction organic phase;

[0008] S3, the first raffinate and the second saponification extractant are subjected to a soap conversion reaction to obtain a second organic phase after extraction and soap conversion and a second lithium-containing liquid;

[0009] S4, the acid-leached and impurity-removed solution of nickel cobalt hydroxide is subjected to extraction reaction with the organic phase after the second extraction and soap conversion to obtain a second extraction organic phase and a second raffinate;

[0010] S5. The second raffinate is subjected to extraction of Co and Mg, and then evaporated and crystallized to obtain nickel sulfate; the organic phase obtained by extracting Co is subjected to back extraction, and then evaporated and crystallized to obtain cobalt sulfate.

[0011] Furthermore, the method further comprises: stripping the first extraction organic phase to obtain an extract A containing copper and manganese;

[0012] And / or, the second extracted organic phase is stripped to obtain an extract B containing copper and manganese.

[0013] Furthermore, the method further comprises: the copper-manganese-containing extract A and / or the copper-manganese-containing extract B are subjected to manganese powder replacement and sodium carbonate precipitation to obtain sponge copper and crude manganese carbonate.

[0014] Furthermore, the solution after acid leaching and impurity removal is obtained by: subjecting the nickel cobalt hydroxide raw material to slurry mixing, acid leaching, primary filtration, removal of silicon and scandium, and secondary filtration.

[0015] Furthermore, the removal of silicon and scandium obtains slag, which is incorporated into the slurry preparation process of the nickel hydroxide raw material, and the acid leaching, primary filtration, silicon and scandium removal, and secondary filtration are performed again.

[0016] Further, the first saponification extractant and the second saponification extractant are saponified P204;

[0017] And / or, in step S2, the flow ratio O / A of the extraction is 0.5-2:1, and the number of extraction stages is 8-10;

[0018] And / or, in step S3, the flow ratio O / A of the soap conversion reaction is 0.5-2:1, and the soap conversion stage is 8-10;

[0019] And / or, in step S4, the flow ratio O / A of the extraction reaction is 10-15:1, and the number of extraction stages is 6-8.

[0020] Further, the process of extracting Co is: extracting the second raffinate and saponified P507 at an O / A value of 0.5-2:1 for 7-10 steps to obtain a Co extraction raffinate and an organic phase obtained by the Co extraction;

[0021] The process of extracting Mg is as follows: extracting the Co raffinate and the C272 organic phase in 10-12 stages according to an O:A value of 0.8-2:1 to obtain a nickel sulfate solution and an organic phase obtained by extracting Mg.

[0022] Furthermore, the method further comprises the step of mixing the evaporation mother liquor obtained by evaporating and crystallizing the nickel sulfate solution with the first raffinate, and then performing the soap conversion reaction with the second saponification extractant.

[0023] Further, in step S1, the acid leaching treatment includes the following process:

[0024] The solid product is mixed with concentrated sulfuric acid to make the pH value of the mixed system less than 0.5, and a first-stage acid leaching is performed. The pH value of the mixed system is adjusted to 2.0-2.5, and a second-stage acid leaching is performed. Graphite slag and the leachate are obtained by filtration.

[0025] Furthermore, in step S1, the reducing agent includes activated carbon.

[0026] The processing method provided by the present invention realizes the parallel processing of battery black powder and nickel cobalt hydroxide, and avoids the impurity pollution problem caused by the parallel processing of battery black powder and nickel cobalt hydroxide raw materials compared with the traditional technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] Figure 1 It is a process flow diagram of a method for processing battery black powder and nickel cobalt hydroxide in parallel according to a specific embodiment of the present invention;

[0029] Figure 2 It is a schematic diagram of the process flow of the parallel processing method of battery black powder and nickel cobalt hydroxide according to Example 1 of the present invention. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below. The specific implementation methods listed below are only for describing the principles and features of the present invention. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0031] The present invention provides a parallel processing method for battery black powder and nickel cobalt hydroxide, see Figure 1 , including the following steps:

[0032] S1, roasting and water leaching a mixture of battery black powder and a reducing agent to obtain a first lithium-containing liquid and a solid product; acid leaching the solid product to obtain a leachate;

[0033] S2, extracting the leaching solution once with a first saponifying extractant after removing impurities to obtain a first raffinate and a first extracted organic phase S3, performing a soap conversion reaction on the first raffinate and a second saponifying extractant to obtain a second extracted soap conversion organic phase and a second lithium-containing solution;

[0034] S4, the acid-leached and impurity-removed solution of nickel cobalt hydroxide is subjected to extraction reaction with the organic phase after the second extraction and soap conversion to obtain a second extraction organic phase and a second raffinate;

[0035] S5. The second raffinate is subjected to extraction of Co and Mg, and then evaporated and crystallized to obtain nickel sulfate; the organic phase obtained by extracting Co is subjected to back extraction, and then evaporated and crystallized to obtain cobalt sulfate.

[0036] The treatment method of the present invention realizes the parallel processing of battery black powder and nickel cobalt hydroxide, and compared with the traditional technology, it omits three-stage extraction, shortens the process flow, and also avoids the impurity pollution problem caused by the parallel processing of battery black powder and nickel cobalt hydroxide raw materials. In detail: the present invention first performs preliminary lithium extraction on the black powder in step S1, which can improve the recovery rate of lithium. In step S2, the leaching solution is subjected to a first extraction with a first saponification extractant after impurities are removed, and impurities can be removed again in depth to obtain a first raffinate (nickel cobalt sulfate solution) with a low impurity content. The first raffinate is subjected to a soap conversion reaction with a second saponification extractant to obtain a second extracted soap conversion organic phase, which is used as the soap conversion liquid for the nickel hydroxide production line extraction of impurities in step S3, which greatly avoids the impurity pollution problem caused by the parallel processing of black powder. Moreover, this step can further purify the remaining lithium, so that the yield of lithium carbonate obtained by subsequent treatment is significantly improved.

[0037] It should be noted that the present invention does not limit the source of battery black powder. In some embodiments, battery black powder can be purchased directly or obtained by discharging, disassembling, crushing and separating waste lithium-ion batteries. The materials obtained after disassembly include at least one of waste lithium-ion battery positive electrode powder and waste lithium-ion battery positive and negative electrode mixed powder. The waste lithium-ion battery can be a single lithium-ion battery containing any one of nickel, cobalt and manganese or a binary lithium-ion battery containing any two of them, or a ternary lithium-ion battery containing nickel, cobalt and manganese or nickel, cobalt and aluminum.

[0038] In some embodiments, since the battery black powder itself contains substances such as carbon powder, the carbon powder can also be used as a reducing agent for reduction.

[0039] It can be understood that after the battery black powder undergoes carbon thermal reduction roasting in step S1, the nickel / cobalt compounds will be reduced to nickel / cobalt metals, while lithium exists in the form of lithium carbonate soluble in water; since the solubility of the formed lithium carbonate is not very high, in some embodiments, dilute sulfuric acid is introduced into the water immersion solution to convert the lithium carbonate into lithium sulfate which is more soluble in water.

[0040] In some embodiments, in step S2, the impurities removed from the leachate include iron and aluminum, and the impurity removal process includes: the leachate solution is pumped into an iron-aluminum removal reactor, hydrogen peroxide is added, and the temperature is raised to 85°C, and then sodium carbonate is added to remove iron and aluminum. The pH value of the iron-aluminum removal endpoint is controlled at about 3.5. After the reaction is completed, the iron-aluminum slag and the leachate after impurities are removed are obtained by filter pressing.

[0041] In a specific embodiment, the parallel processing method further comprises: stripping the first extraction organic phase to obtain an extract A containing copper and manganese;

[0042] And / or, the second extracted organic phase is stripped to obtain an extract B containing copper and manganese.

[0043] In a specific embodiment, the parallel processing method further comprises: the copper-manganese containing extract A and / or the copper-manganese containing extract B are replaced with manganese powder and precipitated with sodium carbonate to obtain sponge copper and crude manganese carbonate.

[0044] In another specific embodiment, the copper-manganese containing extract A and / or the copper-manganese containing extract B are subjected to manganese powder replacement for copper removal, sulfidation for impurity removal, manganese extraction, stripping, and evaporation and crystallization to obtain battery-grade manganese sulfate.

[0045] According to the implementation method described above, not only can battery-grade nickel sulfate, battery-grade cobalt sulfate and battery-grade lithium carbonate that meet industry requirements be obtained, but also at least one product of sponge copper, crude manganese carbonate, battery-grade manganese sulfate, etc. is produced as a by-product, thereby achieving product diversification.

[0046] In some embodiments, the parallel processing method of the present invention has a nickel and cobalt yield of more than 99%, a copper and manganese yield of more than 98%, and a lithium yield of more than 92%. In some embodiments, the extractant used in the above manganese extraction is C272.

[0047] In a specific embodiment, in the above parallel processing method, the nickel cobalt hydroxide is acid-leached and impurity-removed by: subjecting the nickel cobalt hydroxide raw material to slurry preparation, acid leaching, primary filtration, removal of silicon and scandium, and secondary filtration to obtain it.

[0048] In the above-described implementation mode, the purity of subsequent products can be further improved by removing silicon and scandium from the nickel cobalt hydroxide raw material.

[0049] In a specific embodiment, in the above parallel processing method, the removal of silicon and scandium obtains slag, and the slag is incorporated into the slurry preparation process of the nickel hydroxide raw material, and the acid leaching, primary filtration, silicon and scandium removal, and secondary filtration are performed again.

[0050] Among them, the concentrations of silicon and scandium in the nickel cobalt hydroxide raw material are not high, but when removing silicon and scandium, the pH value of the solution will usually rise to above 5.5. At this time, nickel and cobalt will enter the silicon-scandium slag. If the circuit is opened directly, about 1% of nickel and about 0.5% of cobalt will be lost in the slag. By incorporating the silicon-scandium slag into the slurry mixing process of the nickel hydroxide raw material, the yield of nickel and cobalt can be improved.

[0051] In a specific embodiment, in the above parallel processing method, the first saponification extractant and the second saponification extractant are saponified P204;

[0052] And / or, in step S2, the flow ratio O / A of the extraction is 0.5-2:1, and the number of extraction stages is 8-10;

[0053] And / or, in step S3, the flow ratio O / A of the soap conversion reaction is 0.5-2:1, and the soap conversion stage is 8-10;

[0054] And / or, in step S4, the flow ratio O / A of the extraction reaction is 10-15:1, and the number of extraction stages is 6-8.

[0055] The above-mentioned embodiment can ensure that the extraction reaction is carried out thoroughly by limiting the flow ratio O / A and the specific extraction stages, thereby ensuring a high degree of impurity removal or soap conversion reaction.

[0056] In order to further improve the purity of nickel sulfate and cobalt sulfate, in a specific embodiment, in the above parallel processing method, the process of extracting Co is: the second raffinate and saponified P507 are subjected to 7-10 stage extraction at an O / A value of 0.5-2:1 to obtain a Co extraction raffinate and an organic phase obtained by the Co extraction;

[0057] The process of extracting Mg is as follows: extracting the Co raffinate and the C272 organic phase in 10-12 stages according to an O:A value of 0.8-2:1 to obtain a nickel sulfate solution and an organic phase obtained by extracting Mg.

[0058] In a specific embodiment, the parallel processing method further includes the step of mixing the evaporation mother liquor obtained by evaporating and crystallizing the nickel sulfate solution with the first raffinate, and then performing the soap conversion reaction with the second saponification extractant.

[0059] Among them, the nickel and cobalt contents in the first raffinate are relatively low. After being mixed with the evaporated mother liquor, the nickel ion concentration of the solution is significantly increased, so that the soap conversion reaction is more economical.

[0060] In a specific embodiment, in the above parallel processing method, in step S1, the acid leaching treatment includes the following process:

[0061] The solid product is mixed with concentrated sulfuric acid to make the pH value of the mixed system less than 0.5, and a first-stage acid leaching is performed. The pH value of the mixed system is adjusted to 2.0-2.5, and a second-stage acid leaching is performed. Graphite slag and the leachate are obtained by filtration.

[0062] The present invention does not limit the type of the reducing agent, as long as it is a reducing agent that can thermally reduce black powder. In a specific embodiment, in the above parallel processing method, in step S1, the reducing agent includes activated carbon.

[0063] In a specific embodiment, the calcination is carried out in an atmosphere of protective gas, and the calcination temperature is 500-550° C. For example, it can be any value of 500° C., 510° C., 520° C., 530° C., 540° C., 550° C., etc., or a range consisting of any two of them. The calcination time is not particularly limited in the present invention, and can generally be 1h, 2h, 3h, 4h, 5h, 6h, or any value between 1h and 6h.

[0064] In a specific embodiment, the liquid-to-solid ratio of water to solid used for water immersion treatment is 2 mL / g-10 mL / g, for example, it can be 2 mL / g, 3 mL / g, 4 mL / g, 5 mL / g, 6 mL / g, 7 mL / g, 8 mL / g, 9 mL / g, 10 mL / g or any value between 2 mL / g and 10 mL / g.

[0065] In order to further understand the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] Unless otherwise specified, the reagents involved in the embodiments of the present invention are all commercially available products and can be purchased through commercial channels.

[0067] Example 1

[0068] This example provides a parallel processing method for battery black powder and nickel cobalt hydroxide, see Figure 2 , including the following steps:

[0069] In the first step, the battery black powder and activated carbon are mixed according to the weight of activated carbon added being 5% of the weight of the black powder. After mixing, they are reduced and roasted in a steel belt furnace (a total of seven temperature zones). The reduction roasting process is protected by nitrogen, and the nitrogen flow rate is 1.2Nm 3 / h, the roasting temperature of the steel belt furnace from zone 1 to zone 7 is 514℃, 524℃, 547℃, 510℃, 514℃, 550℃ and 550℃ respectively, and the roasting time is 1 hour. After the roasting is completed, the black powder is continuously discharged into the water immersion tank for circulating water immersion. When the lithium content in the washing water is 15g / L, it is filtered, and the filtrate is the first lithium-containing liquid, and the solid product is the nickel-cobalt material after lithium extraction;

[0070] In the second step, the nickel-cobalt material after lithium extraction is added with concentrated sulfuric acid for two-stage acid leaching (the pH value is controlled at 0.3 in the first stage and at 2.0 in the second stage), the acid leaching temperature is 85°C, and the acid leaching time is 2h. After the reaction is completed, the leaching solution and graphite slag are obtained by filtration;

[0071] In the third step, the leaching liquid is pumped into the iron-aluminum removal reactor, and 27.5% hydrogen peroxide with a mass concentration of 15% of the black powder is added to oxidize the divalent iron, the steam is heated to 85°C, and sodium carbonate is added to remove the iron and aluminum. The reaction time is 2h, and the pH value of the iron-aluminum removal endpoint is controlled at 3.5. After the reaction is completed, the iron-aluminum slag and the black powder extraction pre-liquid are obtained by pressure filtration;

[0072] The fourth step is to extract the black powder pre-extraction liquid with a saponified P204 extractant (flow ratio O: A = 1: 1, extraction stage 8) to obtain a first raffinate and a first extraction organic phase, wash the first extraction organic phase with 0.6 mol / L sulfuric acid, remove copper and manganese with 2 mol / L sulfuric acid, and wash iron with 6 mol / L hydrochloric acid to obtain a copper-manganese-containing extract, and replace the copper-manganese-containing extract with manganese powder and precipitate with sodium carbonate to obtain sponge copper and crude manganese carbonate products;

[0073] The fifth step is to add concentrated sulfuric acid to nickel cobalt hydroxide for two-stage acid leaching (the first stage controls the pH value to 0.5, and the second stage controls the pH value to 2.5), the reaction temperature is 85°C, the reaction time is 2h, and after the reaction is completed, filter to obtain an acid solution and manganese slag, and the acid solution is pumped to the iron and aluminum removal reactor, and 25% hydrogen peroxide with a mass fraction of 1.2 times the content of divalent iron in the acid solution is added to oxidize the divalent iron, and the steam is heated to 85°C, and then the solution pH is adjusted to 4.5 by adding nickel hydroxide slurry to remove iron and aluminum, and the reaction time is 2h. After the reaction is completed, filter to obtain silicon scandium slag and impurity-removed liquid;

[0074] In the sixth step, the first raffinate and the evaporation mother liquor of nickel sulfate evaporation crystallization are mixed with P204 in a volume ratio of 1:1 to carry out a soap conversion reaction, the mixed liquid and the saponification extractant O / A are 1:1, the soap conversion stage is 6, the soap conversion flow ratio O / A is 10:1, and the soap conversion mixing time is 5min, to obtain the second organic phase after the extraction and soap conversion and the second lithium-containing liquid;

[0075] Step 7: The organic phase after the second extraction and soap conversion is subjected to countercurrent extraction and impurity removal with the impurity removal liquid (flow ratio O:A=1:1, extraction stage 8, mixing time 5min, 0.6mol / L sulfuric acid for washing, 2mol / L sulfuric acid for copper and manganese removal, and 6mol / L hydrochloric acid for iron washing) to obtain a second raffinate and a second extracted organic phase;

[0076] In the eighth step, the second raffinate is extracted with P507 (flow ratio O: A = 1: 1, extraction stage 8, mixing time 5min, 0.6mol / L sulfuric acid for washing, 2mol / L sulfuric acid for decobaltization, and 6mol / L hydrochloric acid for iron washing), and stripping is performed to obtain a crude cobalt sulfate solution and a P507 raffinate; the P507 raffinate is extracted and stripped with C272 (C272 extraction flow ratio O: A = 1: 1, extraction stage 10, mixing time 5min, 0.6mol / L sulfuric acid for washing, 2mol / L sulfuric acid for demagnesiumization, and 6mol / L hydrochloric acid for iron washing) to obtain a nickel sulfate solution and magnesium-containing wastewater, and the nickel sulfate solution is deoiled and evaporated and crystallized to obtain battery-grade nickel sulfate;

[0077] In the ninth step, the crude cobalt sulfate is subjected to P204 extraction and stripping (P204 extraction flow ratio O:A=1:1, extraction stage 6, mixing time 5min, 0.6mol / L sulfuric acid for washing, 2mol / L sulfuric acid for stripping copper and manganese, and 6mol / L hydrochloric acid for iron washing) to obtain a cobalt sulfate solution, and the cobalt sulfate solution is subjected to oil removal and evaporation crystallization to obtain battery-grade cobalt sulfate;

[0078] In the tenth step, the lithium-containing extract obtained in the sixth step is concentrated and evaporated to obtain alum and lithium-containing mother liquor; the lithium-containing mother liquor and the first lithium-containing liquid obtained in the first step are subjected to carbonate precipitation to obtain crude lithium carbonate.

[0079] IPC was used to test the composition and concentration of the intermediate products in some of the above steps. The results are shown in Tables 1-10.

[0080] Table 1 Black powder pre-extraction solution (g / L)

[0081] Ni Co Mn Cu Fe Ca Li 20.24 9.62 14.07 1.31 0.005 0.036 1.44

[0082] Table 2 The first raffinate (g / L)

[0083] Ni Co Cu Mn Ca pH 9.39 4.58 0.00093 0.0012 0.0039 3.3

[0084] Table 3 The second lithium-containing solution (g / L)

[0085] Ni Co Cu Mn Ca Na Li pH 0.001 0.001 0.0001 0.0001 0.0001 12.6 0.35 8.0

[0086] Table 4 Manganese slag composition (%)

[0087] Ni Co Mn Zn Fe Cu 0.22 0.49 47.40 0.046 1.39 0.34 Ca Mg Al Si <![CDATA[H2O]]> 0.16 0.015 0.30 0.016 31.99

[0088] Table 5: Liquid after impurity removal (g / L)

[0089] Ni Co Cu Mn Ca Mg Fe 101.4 9.46 0.18 7.42 0.34 3.04 0.0045

[0090] Table 6 Crude cobalt sulfate solution (g / L)

[0091] Ni Co Mn Zn Fe Cu Ca Mg 0.017 117.62 0.0001 0.0001 0.0001 0.0001 0.00044 0.0078

[0092] Table 7 Nickel sulfate solution composition (%)

[0093] Ni Co Mn Zn Fe Cu Ca Mg 102.87 0.0001 0.0001 0.0001 0.0001 0.0001 0.00035 0.0004

[0094] Table 8 Battery grade nickel sulfate composition (%)

[0095] Ni Zn Fe Na ≥22.00 ≤0.0005 ≤0.001 ≤0.02 Cu Ca Mg MI ≤0.0005 ≤0.005 ≤0.005 ≤100 ppb

[0096] Table 9 Cobalt sulfate solution composition (%)

[0097]

[0098]

[0099] Table 10 Battery grade cobalt sulfate composition (%)

[0100] Co Zn Fe Na ≥20.50 ≤0.0005 ≤0.001 ≤0.01 Cu Ca Mg MI ≤0.0005 ≤0.005 ≤0.005 ≤100 ppb

[0101] Example 2

[0102] This example provides a method for processing battery black powder and nickel cobalt hydroxide in parallel, including the following steps:

[0103] In the first step, the battery black powder and activated carbon are mixed according to the weight of activated carbon added being 10% of the weight of the black powder. After mixing, they are reduced and roasted in a steel belt furnace (a total of seven temperature zones). The reduction roasting process is protected by nitrogen, and the nitrogen flow rate is 1.5Nm 3 / h, the roasting temperature of the steel belt furnace from zone 1 to zone 7 is 520℃, 530℃, 550℃, 510℃, 508℃, 550℃ and 550℃ respectively, and the roasting time is 2 hours. After the roasting is completed, the black powder is continuously discharged into the water immersion tank for circulating water immersion. When the lithium content in the washing water is 16g / L, it is filtered, and the filtrate is the first lithium-containing liquid, and the solid product is the nickel-cobalt material after lithium extraction;

[0104] In the second step, the nickel-cobalt material after lithium extraction is added with concentrated sulfuric acid for two-stage acid leaching (the pH value is controlled at 0.5 in the first stage and at 2.5 in the second stage), the acid leaching temperature is 90°C, and the acid leaching time is 3 hours. After the reaction is completed, the leaching solution and graphite slag are obtained by filtration;

[0105] In the third step, the leaching liquid is pumped into the iron-aluminum removal reactor, and hydrogen peroxide with a mass concentration of 27.5% and a 20% amount of black powder is added to oxidize the divalent iron, the steam is heated to 90°C, and sodium carbonate is added to remove the iron and aluminum. The reaction time is 4 hours, and the pH value of the iron-aluminum removal endpoint is controlled at 4.0. After the reaction is completed, the iron-aluminum slag and the black powder extraction pre-liquid are obtained by filter pressing;

[0106] The fourth step is to extract the black powder pre-extraction liquid with a saponified P204 extractant (flow ratio O: A = 2: 1, extraction stage 10) to obtain a first raffinate and a first extraction organic phase, wash the first extraction organic phase with 0.8 mol / L sulfuric acid, remove copper and manganese with 2.5 mol / L sulfuric acid, and wash iron with 7 mol / L hydrochloric acid to obtain a copper-manganese-containing extract, and replace the copper-manganese-containing extract with manganese powder and precipitate with sodium carbonate to obtain sponge copper and crude manganese carbonate products;

[0107] The fifth step is to add concentrated sulfuric acid to nickel cobalt hydroxide for two-stage acid leaching (the first stage controls the pH value to 0.3, and the second stage controls the pH value to 2.0), the reaction temperature is 90°C, the reaction time is 3h, and after the reaction is completed, filter to obtain an acid solution and manganese slag, and the acid solution is pumped to the iron and aluminum removal reactor, and hydrogen peroxide with a mass fraction of 27.5% is added according to 1.1 times the content of divalent iron in the acid solution to oxidize the divalent iron, and the steam is heated to 90°C, and then the solution pH is adjusted to 5.5 by adding nickel hydroxide slurry to remove iron and aluminum, and the reaction time is 4h. After the reaction is completed, filter to obtain silicon scandium slag and impurity-removed liquid;

[0108] In the sixth step, the first raffinate and the evaporation mother liquor of part of the nickel sulfate evaporation crystallization are mixed with P204 in a volume ratio of 1:1 to carry out a soap conversion reaction, the mixed liquid and the saponification extractant O / A are 2:1, the soap conversion stage is 8, the soap conversion flow ratio O / A is 15:1, and the soap conversion mixing time is 6 minutes to obtain the second organic phase after the extraction and soap conversion and the second lithium-containing liquid;

[0109] Step 7: The organic phase after the second extraction and soap conversion is subjected to countercurrent extraction and impurity removal with the impurity removal liquid (flow ratio O:A=2:1, extraction stage 10, mixing time 6min, 0.8mol / L sulfuric acid for washing, 2.5mol / L sulfuric acid for copper and manganese removal, and 7mol / L hydrochloric acid for iron washing) to obtain a second raffinate and a second extracted organic phase;

[0110] In the eighth step, the second raffinate is extracted with P507 (flow ratio O: A = 2: 1, extraction stage 10, mixing time 6min, 0.8mol / L sulfuric acid for washing, 2.5mol / L sulfuric acid for decobaltization, and 7mol / L hydrochloric acid for iron washing), and stripping is performed to obtain a crude cobalt sulfate solution and a P507 raffinate; the P507 raffinate is extracted and stripped with C272 (C272 extraction flow ratio O: A = 2: 1, extraction stage 12, mixing time 6min, 0.8mol / L sulfuric acid for washing, 2.5mol / L sulfuric acid for demagnesiumization, and 7mol / L hydrochloric acid for iron washing) to obtain a nickel sulfate solution and magnesium-containing wastewater, and the nickel sulfate solution is deoiled and evaporated and crystallized to obtain battery-grade nickel sulfate;

[0111] In the ninth step, the crude cobalt sulfate is subjected to P204 extraction and stripping (P204 extraction flow ratio O:A=2:1, extraction stage 8, mixing time 5min, 0.8mol / L sulfuric acid for washing, 2.5mol / L sulfuric acid for stripping copper and manganese, and 7mol / L hydrochloric acid for iron washing) to obtain a cobalt sulfate solution, and the cobalt sulfate solution is subjected to oil removal and evaporation crystallization to obtain battery-grade cobalt sulfate;

[0112] In the tenth step, the lithium-containing extract obtained in the sixth step is concentrated and evaporated to obtain alum and lithium-containing mother liquor; the lithium-containing mother liquor and the first lithium-containing liquid obtained in the first step are subjected to carbonate precipitation to obtain crude lithium carbonate.

[0113] IPC was used to test the composition and concentration of the intermediate products in some of the above steps. The results are shown in Tables 11-20.

[0114] Table 11 Black powder pre-extraction solution (g / L)

[0115] Ni Co Mn Cu Fe Ca Li 22.35 9.08 15.53 1.45 0.0055 0.039 1.44

[0116] Table 12 First Raffinate (g / L)

[0117] Ni Co Cu Mn Ca pH 11.28 5.56 0.00098 0.0014 0.0041 3.5

[0118] Table 13 Second lithium-containing solution (g / L)

[0119] Ni Co Cu Mn Ca Na Li pH 0.001 0.001 0.0001 0.0001 0.0001 13.56 0.44 8.0

[0120] Table 14 Manganese slag composition (%)

[0121] Ni Co Mn Zn Fe Cu 0.25 0.51 49.43 0.043 1.42 0.35 Ca Mg Al Si <![CDATA[H2O]]> 0.18 0.017 0.31 0.019 33.46

[0122] Table 15: Liquid after impurity removal (g / L)

[0123] Ni Co Cu Mn Ca Mg Fe 103.43 10.46 0.19 8.45 0.37 3.25 0.0048

[0124] Table 16 Crude cobalt sulfate solution (g / L)

[0125] Ni Co Mn Zn Fe Cu Ca Mg 0.019 116.48 0.0001 0.0001 0.0001 0.0001 0.00046 0.0082

[0126] Table 17 Nickel sulfate solution composition (%)

[0127] Ni Co Mn Zn Fe Cu Ca Mg 105.76 0.0001 0.0001 0.0001 0.0001 0.0001 0.00025 0.0005

[0128] Table 18 Battery grade nickel sulfate composition (%)

[0129] Ni Zn Fe Na ≥22.00 ≤0.0005 ≤0.001 ≤0.02 Cu Ca Mg MI ≤0.0005 ≤0.005 ≤0.005 ≤100 ppb

[0130] Table 19 Cobalt sulfate solution composition (%)

[0131] Ni Co Mn Zn Fe Cu Ca Mg 0.001 119.52 0.0001 0.0001 0.0001 0.0001 0.0004 0.0008

[0132] Table 20 Battery grade cobalt sulfate composition (%)

[0133] Co Zn Fe Na ≥20.50 ≤0.0005 ≤0.001 ≤0.01 Cu Ca Mg MI ≤0.0005 ≤0.005 ≤0.005 ≤100 ppb

[0134] Comparative Example 1

[0135] This example provides a method for processing battery black powder and nickel cobalt hydroxide in parallel, including the following steps:

[0136] The pH value of the low-acid leaching solution of battery black powder is adjusted to 3.5 with lime milk, the liquid after iron, aluminum and fluoride removal is 1:1 with the liquid after P204 saponification, the overflow soap transfer stage is 5, the flow ratio is 10:1, the mixing time is 4 minutes for countercurrent soap transfer, and 20% sodium carbonate solution with 1.1 times the molar amount of lithium is added to the liquid after soap transfer, and the lithium precipitation rate can reach 99.2%, the organic P204 after soap transfer is 1:1 with the laterite nickel ore leaching solution, the overflow extraction stage is 6, the flow ratio is 1.5:1, and the mixing time is 4 minutes for countercurrent extraction, the organic after P204 extraction is washed with 1N sulfuric acid countercurrent for 8 stages at a flow ratio of 10:1, and the organic after washing is stripped with 6N hydrochloric acid, the P204 raffinate is 1:1 with the organic P507 after soap transfer, the overflow extraction stage is 6, the flow ratio is 1.5:1, and the mixing time is 4 minutes for countercurrent extraction, the organic after P507 extraction is 10 :1 is washed with 1N sulfuric acid countercurrent for 16 stages, and the organic compound is stripped with 4N sulfuric acid after washing. The stripping solution is deeply cleaned, evaporated and crystallized to obtain battery-grade cobalt sulfate. The P507 raffinate is again washed with P507 after soap conversion at a ratio of 1:1 for organic phase, 6 levels of overflow extraction, a flow ratio of 1.5:1, and a mixing time of 4 minutes for countercurrent extraction. The organic compound after P507 extraction is washed with 1N sulfuric acid countercurrent for 8 stages at a flow ratio of 10:1, and the organic compound is stripped with 4N sulfuric acid after washing. The stripping solution is evaporated and crystallized to obtain battery-grade magnesium sulfate. The second P507 raffinate is washed with Cy272 after soap conversion at a ratio of 1:1, 6 levels of overflow extraction, a flow ratio of 1.5:1, and a mixing time of 4 minutes for countercurrent extraction. The organic compound after Cy272 extraction is washed with 1N sulfuric acid countercurrent for 8 stages at a flow ratio of 10:1, and the organic compound is stripped with 4N sulfuric acid after washing. The stripping solution is evaporated and crystallized to obtain battery-grade nickel sulfate.

[0137] IPC was used to test the composition and concentration of the intermediate products in some of the above steps. The results are shown in Tables 21-22.

[0138] Table 21 Iron, aluminum, fluoride post-liquid (g / L)

[0139] Ni Co Cu Mn Ca Mg Fe 103.43 10.46 0.19 8.45 0.37 3.25 0.0048

[0140] Table 22 Soap-transfer liquid (g / L)

[0141] Ni Co Cu Mn Ca Na Li pH 0.0056 0.0089 0.00069 0.0046 0.0035 15.51 0.32 8.2

[0142] By comparison, the nickel and cobalt yields of the parallel processing method of Example 1 are both above 99%, the copper and manganese yields are above 98%, and the lithium yield is above 92%. Both cobalt sulfate and nickel sulfate are battery grade.

[0143] The lithium yield of the comparative example is only about 85%, and the impurity content of the obtained lithium carbonate is relatively high. The nickel sulfate and cobalt sulfate obtained in the experiment are industrial grade, and the impurity content is higher than that of the example.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for processing battery black powder and nickel cobalt hydroxide in parallel, characterized in that: The following steps are involved: S1, roasting and water leaching a mixture of battery black powder and a reducing agent to obtain a first lithium-containing liquid and a solid product; acid leaching the solid product to obtain a leachate; S2, extracting the leaching solution after impurities removal with a first saponification extractant to obtain a first raffinate and a first extraction organic phase; S3, the first raffinate and the second saponification extractant are subjected to a soap conversion reaction to obtain a second organic phase after extraction and soap conversion and a second lithium-containing liquid; S4, the acid-leached and impurity-removed solution of nickel cobalt hydroxide is subjected to extraction reaction with the organic phase after the second extraction and soap conversion to obtain a second extraction organic phase and a second raffinate; S5, extracting Co and Mg from the second raffinate, and evaporating and crystallizing to obtain nickel sulfate; The organic phase obtained by extracting Co is stripped and then evaporated and crystallized to obtain cobalt sulfate.

2. The line parallel processing method according to claim 1, characterized in that: Also includes: Re-extracting the first extracted organic phase to obtain an extract A containing copper and manganese; And / or, the second extracted organic phase is stripped to obtain an extract B containing copper and manganese.

3. The line parallel processing method according to claim 2, characterized in that: Also includes: The copper-manganese containing extract A and / or the copper-manganese containing extract B are replaced by manganese powder and precipitated with sodium carbonate to obtain sponge copper and crude manganese carbonate.

4. The line parallel processing method according to any one of claims 1 to 3, characterized in that: The acid-leached and impurity-removed solution of nickel cobalt hydroxide is obtained by subjecting the nickel cobalt hydroxide raw material to slurry mixing, acid leaching, primary filtration, silicon and scandium removal, and secondary filtration.

5. The line parallel processing method according to claim 4, characterized in that: The slag is obtained by removing silicon and scandium, and the slag is incorporated into the slurry preparation process of the nickel cobalt hydroxide raw material, and the acid leaching, primary filtration, silicon and scandium removal and secondary filtration are performed again.

6. The line parallel processing method according to any one of claims 1 to 5, characterized in that: The first saponification extractant and the second saponification extractant are saponified P204; And / or, in step S2, the flow ratio O / A of the extraction is 0.5-2:1, and the number of extraction stages is 8-10; And / or, in step S3, the flow ratio O / A of the soap conversion reaction is 0.5-2:1, and the soap conversion stage is 8-10; And / or, in step S4, the flow ratio O / A of the extraction reaction is 10-15:1, and the number of extraction stages is 6-8.

7. The line parallel processing method according to any one of claims 1 to 5, characterized in that: The process of extracting Co is: extracting the second raffinate and saponified P507 at an O / A value of 0.5-2:1 for 7-10 steps to obtain a Co extraction raffinate and an organic phase obtained by the Co extraction; The process of extracting Mg is as follows: extracting the Co raffinate and the C272 organic phase in 10-12 stages according to an O:A value of 0.8-2:1 to obtain a nickel sulfate solution and an organic phase obtained by extracting Mg.

8. The line parallel processing method according to claim 7, characterized in that: The method further comprises the step of mixing the evaporation mother liquor obtained by evaporating and crystallizing the nickel sulfate solution with the first raffinate, and then performing the soap conversion reaction with the second saponification extractant.

9. The line parallel processing method according to any one of claims 1 to 5, characterized in that: In step S1, the acid leaching treatment includes the following process: The solid product is mixed with concentrated sulfuric acid to make the pH value of the mixed system less than 0.5, and a first-stage acid leaching is performed. The pH value of the mixed system is adjusted to 2.0-2.5, and a second-stage acid leaching is performed. Graphite slag and the leachate are obtained by filtration.

10. The line parallel processing method according to any one of claims 1 to 5, characterized in that: In step S1, the reducing agent includes activated carbon.

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