Method and device for treating electrodeposited nickel anolyte

Abstract

The invention relates to the field of electrodeposited nickel anolyte treatment, and discloses a method and a device for treating electrodeposited nickel anolyte. The method comprises the following steps: mixing a calcium-containing neutralizer I with an electrodeposited nickel anolyte A for deacidification treatment to obtain deacidified slurry; carrying out first solid-liquid separation treatment on the deacidified slurry to obtain a nickel-containing solution and calcium sulfate residues; a calcium-containing neutralizer II and the nickel-containing solution are mixed for desilicication and lead removal treatment, and desilicication and lead removal slurry is obtained; carrying out second solid-liquid separation treatment on the desiliconized and lead-removed slurry to obtain desiliconized and lead-removed slag and nickel-containing impurity-removed pre-liquid with the silicon content of less than or equal to 50mg / L; and carrying out impurity removal treatment on the nickel-containing impurity removal pre-liquid to obtain a nickel-rich impurity removal post-liquid with the calcium content of less than or equal to 50mg / L. According to the method provided by the invention, the production cost can be reduced, and wastewater is not produced; according to the method, calcium introduced by calcium salt and impurity ions cyclically enriched in the anolyte can be removed together, and produced waste residues are used as building materials or neutralizers, so that the method is environment-friendly.

Description

Technical Field

[0001] The present application relates to the field of nickel electrolytic anode liquid treatment, and in particular to a method and device for treating nickel electrolytic anode liquid. Background Art

[0002] The electrowinning process can use an insoluble anode and a pure nickel starting plate as the cathode, allowing the metal to be extracted from the electrolyte to precipitate on the cathode, thereby achieving the purpose of extracting the metal. During the electrowinning process, the anode undergoes an electrolysis reaction of water, and the anolyte is continuously enriched in acid.

[0003] The anode liquid contains a large amount of acid and nickel, which can be recycled and used to prepare the cathode liquid. In the related technology, the nickel in the anode liquid is generally precipitated with alkali, and then the precipitate is dissolved with acid and used to prepare the cathode liquid. The related technology is difficult to take into account both technical economy and the quality of the cathode liquid. Summary of the invention

[0004] The purpose of the present application is to provide a method and device for treating nickel electrolytic anolyte to improve the anolyte treatment economy and anolyte quality.

[0005] In order to achieve the above-mentioned object, the first aspect of the present application provides a method for treating an electrolytic nickel anolyte, the method comprising:

[0006] Deacidification process: mixing calcium-containing neutralizing agent I with electrolytic nickel anolyte A to perform deacidification treatment to obtain deacidified slurry;

[0007] The first solid-liquid separation step: performing a first solid-liquid separation process on the deacidified slurry to obtain a nickel-containing solution and calcium sulfate slag;

[0008] Desiliconization and lead removal process: mixing the calcium-containing neutralizer II with the nickel-containing solution to perform desiliconization and lead removal treatment to obtain a desiliconized and lead-removed slurry;

[0009] The second solid-liquid separation step: performing a second solid-liquid separation treatment on the desiliconized and lead-removed slurry to obtain desiliconized and lead-removed slag and a nickel-containing impurity-removed pre-liquid with a silicon content of ≤50 mg / L;

[0010] Impurity removal process: the nickel-containing impurity removal pre-liquid is subjected to impurity removal treatment to obtain a nickel-rich impurity removal post-liquid with a calcium content of ≤50 mg / L.

[0011] Optionally, the method satisfies at least one of the following conditions:

[0012] A. The method further comprises a dissolving step: mixing the electrolytic nickel anolyte B with the nickel-containing raw material to carry out a leaching reaction to obtain a nickel-containing leaching solution;

[0013] B. The method further comprises a pH adjustment step: mixing the nickel-rich impurity-removed liquid with a pH buffer and a nickel sulfate solution to perform a pH adjustment treatment to obtain a pH-adjusted liquid with a pH value of 3-4.

[0014] Optionally, the method satisfies at least one of the following conditions:

[0015] A. Calcium-containing neutralizer I is mixed with the electrolytic nickel anolyte A in the form of powder for deacidification treatment;

[0016] B. the endpoint pH value of the deacidification treatment is 2.5-3.0;

[0017] C. The reaction time of the deacidification treatment is 3-6h;

[0018] D. the calcium-containing neutralizer I and the calcium-containing neutralizer II each independently include at least one of CaCO3, CaO and Ca(OH)2;

[0019] E. Calcium-containing neutralizer I includes limestone powder and desiliconized and lead-removing slag;

[0020] F. Particle size D of the calcium-containing neutralizer I and the calcium-containing neutralizer II 95 All less than 150μm;

[0021] G. the concentration of the calcium-containing neutralizer II is 10-30wt%;

[0022] H. the deacidification process comprises at least three stages of deacidification treatment, and at least 50% of the total amount of the calcium-containing neutralizing agent I is added in the first stage of deacidification treatment;

[0023] I. The composition of the electrolytic nickel anolyte A or the electrolytic nickel anolyte B comprises: Ni 40-70g / L, Ca4-10mg / L, Mg1000-1700mg / L, Si 50-150mg / L, Co 1-7mg / L, Cu 0.5-1.5mg / L, Zn 0.05-0.2mg / L, Fe 0.5-1mg / L, Pb 0.3-2mg / L, and sulfuric acid 40-60g / L;

[0024] J. The nickel sulfate solution comprises a nickel sulfate solution obtained by removing impurities from the nickel-containing leaching solution produced in the dissolution process.

[0025] Optionally, the first solid-liquid separation step includes:

[0026] The deacidified slurry is filtered to obtain a filtrate and a filter residue, and the filter residue is subjected to a first washing and a second washing in sequence, the washing water of the first washing is incorporated into the filtrate to form the nickel-containing solution, the filter residue after the first washing is subjected to the second washing to obtain calcium sulfate residue, the washing water of the second washing is recycled for the first washing, and the nickel content of the calcium sulfate residue is ≤0.05wt%.

[0027] Optionally, the desiliconization and lead removal process includes multiple stages of desiliconization and lead removal treatments performed sequentially.

[0028] Optionally, the method satisfies one or both of the following conditions:

[0029] A. The end point pH value of the first stage of desiliconization and lead removal treatment in the multi-stage desiliconization and lead removal treatment is 3.5-4, and the end point pH value of the multi-stage desiliconization and lead removal treatment is 5-6;

[0030] B. The desiliconization and lead removal treatment comprises a first-stage desiliconization and lead removal treatment, a second-stage desiliconization and lead removal treatment and a third-stage desiliconization and lead removal treatment which are performed in sequence, wherein the endpoint pH value of the first-stage desiliconization and lead removal treatment is 3.5-4, the endpoint pH value of the second-stage desiliconization and lead removal treatment is 4-5, and the endpoint pH value of the third-stage desiliconization and lead removal treatment is 5-6;

[0031] C. The reaction time of the desiliconization and lead removal treatment is 2-4 hours.

[0032] Optionally, the second solid-liquid separation step includes:

[0033] Filter pressing treatment: Filter pressing the slurry after desiliconization and lead removal to obtain desiliconization and lead removal slag and filter pressing filtrate;

[0034] Precision filtration treatment: The filter press filtrate is subjected to precision filtration to obtain a nickel-containing impurity removal pre-liquid.

[0035] Optionally, the calcium content of the nickel-containing impurity removal pre-liquid is 450-650 mg / L.

[0036] Optionally, the impurity removal process includes:

[0037] Extraction and impurity removal: extracting and impurity removal the nickel-containing impurity removal pre-liquid to obtain a nickel-containing raffinate;

[0038] Deoiling: Deoiling the nickel-containing raffinate to obtain a nickel-rich impurity-free liquid.

[0039] Optionally, the nickel-containing raffinate satisfies: pH value is 2.5-3.5, magnesium content is ≤2g / L; the nickel-rich impurity-removed liquid satisfies: oil content is ≤2mg / L.

[0040] Optionally, the extraction and impurity removal comprises:

[0041] The nickel-containing impurity removal pre-liquid is mixed with the saponified extractant to perform extraction and impurity removal treatment to obtain a nickel-containing raffinate; wherein the saponification rate of the extractant is 10-40%.

[0042] Optionally, the method further comprises mixing a portion of the nickel-containing raffinate with the filter press filtrate, wherein the weight of the portion of the nickel-containing raffinate is 3-7% of the weight of the filter press filtrate.

[0043] Optionally, the weight ratio of the electrolytic nickel anode liquid A to the electrolytic nickel anode liquid B is 1:0.6-1.5.

[0044] A second aspect of the present application provides a device for treating an electrolytic nickel anolyte, the device comprising: a deacidification unit, comprising a plurality of deacidification tanks connected in series, the plurality of deacidification tanks connected in series are used to mix a calcium-containing neutralizing agent I with the electrolytic nickel anolyte A to perform a continuous multi-stage deacidification treatment to obtain a deacidified slurry;

[0045] A first filtering unit is used to perform solid-liquid separation on the deacidified slurry obtained by the deacidification unit to obtain a nickel-containing solution and calcium sulfate slag;

[0046] A desiliconization and lead removal unit comprises a plurality of desiliconization and lead removal tanks connected in series, wherein the plurality of desiliconization and lead removal tanks connected in series are used to mix the calcium-containing neutralizer II with the nickel-containing solution to perform continuous multi-stage desiliconization and lead removal treatment to obtain a desiliconized and lead-removed slurry;

[0047] A second filtering unit is used for performing solid-liquid separation treatment on the desiliconized and lead-removed slurry obtained by the desiliconized and lead-removed unit to obtain desiliconized and lead-removed slag and nickel-containing impurity-removed pre-liquid;

[0048] The first impurity removal unit is used to remove impurities from the nickel-containing impurity removal pre-liquid obtained by the second filtering unit to obtain a nickel-rich impurity removal post-liquid.

[0049] Optionally, the device satisfies at least one of the following conditions:

[0050] A. The device further comprises: a dissolving unit, which is used to mix the electrolytic nickel anode liquid B with the nickel-containing raw material to perform a leaching reaction to obtain a nickel-containing leaching solution;

[0051] B. The device further comprises: a pH adjusting unit, the pH adjusting unit comprises a pH adjusting reaction tank, and the pH adjusting unit is connected to the first impurity removal unit.

[0052] Furthermore, the device satisfies at least one of the following conditions:

[0053] A. The first filtering unit comprises a first belt filter press and a washing water storage tank, wherein the material inlet of the first belt filter press is connected to the deacidification unit, the filtrate outlet of the first belt filter press is connected to the washing water storage tank, and the washing water storage tank is connected to the desiliconization and lead removal unit;

[0054] B. Multiple desiliconization and lead removal tanks connected in series are distributed in a step-down manner;

[0055] C. The desiliconization and lead removal unit is connected to the slurrying unit, and the slurrying unit includes a powder bin, a screw feeder, a slurrying tank and a calcium neutralizer II slurry storage tank connected in sequence; the calcium neutralizer II slurry storage tank is connected to the desiliconization and lead removal tank, and is used to provide the calcium neutralizer II slurry to the desiliconization and lead removal tank;

[0056] D. The second filtering unit comprises a second belt filter press, a desiliconized and lead-removed liquid tank, and a precision filter connected in sequence; wherein the filter element of the precision filter is a PE filter element with a pore size of ≤0.5 μm;

[0057] E. The first impurity removal unit includes a box-type extraction device and an oil removal device, the material inlet of the box-type extraction device is connected to the precision filter, and the material outlet of the box-type extraction device is respectively connected to the oil removal equipment and the liquid tank after desiliconization and lead removal;

[0058] F. The device further comprises a second impurity removal unit for removing impurities from the nickel-containing leaching solution, and the second impurity removal unit is connected to the pH adjustment unit.

[0059] Compared with the prior art, this application has at least the following beneficial effects:

[0060] (1) The present application adopts a calcium-containing neutralizer to replace high-value neutralizers such as liquid alkali and sodium carbonate, which is cheap and easy to obtain, thereby reducing production costs.

[0061] (2) The method of the present application adopts a two-stage method: the first stage uses the lowest value calcium-containing neutralizer for neutralization and deacidification, and the calcium sulfate slag produced can be sold as a building material after washing and passing the test; the second stage uses the calcium-containing neutralizer to continue to increase the pH to remove silicon and lead, and the slag produced can be sent to other nickel sulfate production lines as a neutralizer after simple washing, which is environmentally friendly.

[0062] (3) In the method of the present application, the slurry after desiliconization and lead removal is subjected to solid-liquid separation for impurity removal, which can remove the calcium introduced by the calcium salt and the impurity ions circulated and enriched in the anode liquid.

[0063] (4) In the method of the present application, deacidification and desulfurization are mainly carried out through calcium sulfate slag opening, no wastewater is produced, and there is no need to build corresponding nickel recovery and MVR evaporator and other wastewater treatment equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1A partial schematic flow diagram of the method for treating electrolytic nickel anolyte provided in Example 1 is shown;

[0065] Figure 2 A partial flow diagram of the device for treating electrolytic nickel anode liquid provided in Example 1 is shown. DETAILED DESCRIPTION

[0066] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0067] As used herein, the terms "comprises," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0068] In this article, wt% refers to weight percentage, unless otherwise specified, the percentages are based on mass. Room temperature refers to a temperature of 20±5°C.

[0069] Herein, the particle size D 95 It refers to the particle size corresponding to 95% of the cumulative particle size distribution number of particles measured by a laser particle size analyzer, that is, 95% of the particles have a particle size less than (or equal to) this particle size.

[0070] In this document, unless otherwise specified or limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For example, the deacidification unit and the first filtration unit can be indirectly connected through a pipeline or a slurry pump.

[0071] In this article, the electrolytic nickel anolyte refers to the H generated by the electrolytic nickel anolyte reaction. + The nickel-containing solution, the nickel-electrolytic anolyte A and the nickel-electrolytic anolyte B are both nickel-electrolytic anolytes. For example, the nickel-electrolytic anolyte can be a mixture of the nickel-poor solution after electrolysis and the H-containing solution in the anode chamber. +The solution obtained by mixing the ion solutions, in some specific examples, the components of the electrolytic nickel anode solution include: Ni 40-70g / L, Ca4-10mg / L, Mg 1000-1700mg / L, Si 50-150mg / L, Co 1-7mg / L, Cu 0.5-1.5mg / L, Zn 0.05-0.2mg / L, Fe 0.5-1mg / L, Pb 0.3-2mg / L, sulfuric acid 40-60g / L.

[0072] In the related technology, the electrowinning process can use an insoluble anode and a pure nickel starting plate as the cathode, so that the metal to be extracted from the electrolyte is deposited and precipitated on the cathode, thereby achieving the purpose of extracting the metal. During the electrowinning process, the anode undergoes an electrolysis reaction of water, and the acid in the anode liquid is continuously enriched.

[0073] The anode liquid contains a large amount of acid and nickel, which can be recycled and used to prepare the cathode liquid. In the related technology, the nickel in the anode liquid is generally precipitated with alkali, and then the precipitate is dissolved with acid. The solution obtained after dissolution is used to prepare the cathode liquid. The related technology is difficult to take into account both technical economy and the quality of the cathode liquid.

[0074] Based on the above problems, as mentioned above, the first aspect of the present application provides a method for treating an electrolytic nickel anode liquid, the method comprising:

[0075] Deacidification process: mixing calcium-containing neutralizing agent I with electrolytic nickel anolyte A to perform deacidification treatment to obtain deacidified slurry;

[0076] The first solid-liquid separation step: performing a first solid-liquid separation process on the deacidified slurry to obtain a nickel-containing solution and calcium sulfate slag;

[0077] Desiliconization and lead removal process: mixing the calcium-containing neutralizer II with the nickel-containing solution to perform desiliconization and lead removal treatment to obtain a desiliconized and lead-removed slurry;

[0078] The second solid-liquid separation step: performing a second solid-liquid separation treatment on the desiliconized and lead-removed slurry to obtain desiliconized and lead-removed slag and a nickel-containing impurity-removed pre-liquid with a silicon content of ≤50 mg / L;

[0079] Impurity removal process: the nickel-containing impurity removal pre-liquid is subjected to impurity removal treatment to obtain a nickel-rich impurity removal post-liquid with a calcium content of ≤50 mg / L.

[0080] In some embodiments, the method for treating the electrolytic nickel anolyte provided in the present application includes a deacidification process, a first solid-liquid separation process, a desiliconization and lead removal process, a second solid-liquid separation process, and an impurity removal process, and the obtained nickel-rich impurity-removed liquid can be used to configure the cathode liquid. In the deacidification process, a calcium-containing neutralizer I is used to replace liquid alkali for deacidification treatment to reduce the treatment cost. The calcium sulfate slag produced in the first solid-liquid separation process can be sold as a building material, which can reduce the pressure of wastewater treatment, thereby reducing the construction of supporting nickel recovery and MVR and other wastewater treatment equipment, and further reducing the treatment cost. The impurity removal process can remove calcium ions and other impurity ions introduced by calcium-containing neutralizer I and calcium-containing neutralizer II from the system. In the desiliconization and lead removal process, the pH is continued to be increased using calcium-containing neutralizer II, silicon can be precipitated together with calcium sulfate, and suspended lead sulfate can also be adsorbed and precipitated, thereby reducing the adverse effects of silicon on the power consumption of the electrolytic nickel process, and the adverse effects of lead on the lead content in the electrolytic nickel product. The desiliconization and lead removal process and the impurity removal process can control the content of key impurity ions in the anode liquid, thereby improving the quality of the cathode liquid configured with the nickel-rich impurity-removed liquid.

[0081] In some embodiments, the method of treating the electrolytic nickel anolyte further comprises:

[0082] Dissolution process: The electrolytic nickel anode solution B is mixed with the nickel-containing raw material to carry out a leaching reaction to obtain a nickel-containing leaching solution.

[0083] It is understandable that the method for treating the electrolytic nickel anode liquid may also include liquid separation treatment, in which the electrolytic nickel anode liquid to be treated is divided into two parts, namely, the electrolytic nickel anode liquid A and the electrolytic nickel anode liquid B.

[0084] In the above embodiment, the electrolytic nickel anolyte is subjected to liquid separation treatment, and a part of the electrolytic nickel is used to mix with the nickel-containing raw material for leaching reaction to obtain a nickel-containing leaching solution, and then after extraction, degreasing and other impurity removal treatments, a nickel sulfate solution is obtained. On the one hand, it can be used to supplement the nickel in the electrolytic nickel system, and the acid in the electrolytic nickel anolyte B can be used in the leaching reaction, further improving the economy of the system; on the other hand, when the electrolytic nickel anolyte B is mixed with the nickel-containing raw material for leaching reaction, such as high-pressure leaching, a small amount of water can be evaporated in the pressurized section, which can also promote the water balance of the system. In addition, the treatment steps of the electrolytic nickel anolyte A and the electrolytic nickel anolyte B are combined, impurities can be discharged from the system through the desiliconization and lead removal steps and the impurity removal steps, and the acid in the electrolytic nickel anolyte B can be used through the dissolution step. At the same time, the water introduced in the first solid-liquid separation process of washing the filter residue can be partially evaporated during leaching, promoting the water balance of the system and reducing costs.

[0085] In the above embodiments, the nickel-containing raw material may be a sulfur-containing nickel material, and illustratively, may be high-matte nickel.

[0086] In some embodiments, the nickel-containing leachate is further treated to remove impurities to obtain a nickel sulfate solution. In some examples, P507 (Chinese name: 2-ethylhexyl phosphate mono-2-ethylhexyl ester) is used to extract and remove impurities from the nickel-containing leachate.

[0087] In some embodiments, the weight ratio of the electrolytic nickel anolyte A to the electrolytic nickel anolyte B is 1:0.6-1.5. A suitable weight ratio is beneficial to controlling the impurity content of the system and controlling the balance of water and sulfur elements in the system.

[0088] In some embodiments, the calcium-containing neutralizer I is mixed with the electrolytic nickel anode liquid A in the form of a powder for deacidification. The calcium-containing neutralizer I is selected as calcium carbonate, which has a lower tendency to agglomerate during the mixing process, does not need to be slurried before use, can avoid the introduction of slurry water, and the cost of using the calcium-containing neutralizer I powder is also lower.

[0089] In some embodiments, the end point pH value of the deacidification treatment is 2.5-3.0, for example, it can be 2.5, 2.6, 2.7, 2.8, 2.9, 3.0 or any value between 2.5 and 3.0. A suitable end point pH value of the deacidification treatment is conducive to further improving the economic efficiency. Too low pH value will lead to more residual acid, and too high pH value will produce nickel crystal particles, thereby causing nickel loss.

[0090] The time of the deacidification treatment can be adjusted according to the amount of the electrolytic nickel anode liquid to be treated. In some embodiments, the reaction time of the deacidification treatment is 3-6 hours, for example, it can be 3 hours, 4 hours, 5 hours, 6 hours or any value in the range of 3-6 hours.

[0091] In some embodiments, calcium-containing neutralizer I and calcium-containing neutralizer II each independently include at least one of CaCO3, CaO, and Ca(OH)2.

[0092] In some embodiments, the calcium-containing neutralizing agent I includes limestone powder and desiliconized lead-removing slag. When the desiliconized lead-removing slag is used for the calcium-containing neutralizing agent I, the Ni contained in the desiliconized lead-removing slag can be recovered in the deacidification process, and the silicon and lead impurities contained in the slag can be removed from the system along with the calcium sulfate slag, which can further reduce the Ni loss and improve the process economy. In some embodiments, CaCO3 is provided by limestone powder, CaO is provided by quicklime powder, and Ca(OH)2 is provided by slaked lime powder. Selecting suitable raw materials not only has lower costs, but also can be used without pulping, which can avoid the introduction of pulping water, further reducing costs.

[0093] In some embodiments, the particle size D of the calcium-containing neutralizer I and the calcium-containing neutralizer II is 95 Less than 150μm.

[0094] In some embodiments, the calcium-containing neutralizer II is slurried before use, and the slurrying includes: mixing the calcium-containing neutralizer II and water to obtain a neutralizer slurry; the concentration of the calcium-containing neutralizer II is 10-30wt%.

[0095] In some embodiments, the deacidification process includes at least a first deacidification treatment and a second deacidification treatment. Further, at least 50% of the total amount of the calcium-containing neutralizing agent I is added in the first deacidification treatment.

[0096] It is understandable that the deacidification process may include one or more other deacidification processes in addition to the first and second deacidification processes. Dividing the deacidification process into multiple processes may further reduce nickel loss during the deacidification process.

[0097] Optionally, the first solid-liquid separation step includes:

[0098] The deacidified slurry is filtered to obtain a filtrate and a filter residue; the filter residue is sequentially subjected to a first washing and a second washing, the washing water of the first washing is incorporated into the filtrate to form a nickel-containing solution, the filter residue after the first washing is subjected to the second washing to obtain calcium sulfate residue, the washing water generated by the second washing is recycled for the first washing, and the nickel content of the calcium sulfate residue obtained by the second washing is ≤0.05wt%.

[0099] In some embodiments, the first washing is performed using water equivalent to the weight of the filter residue.

[0100] It should be noted that the calcium sulfate slag obtained by the second washing can be sold as a building material.

[0101] The time of the desiliconization and lead removal treatment can be adjusted according to the amount of the electrolytic nickel anode liquid to be treated. In some embodiments, the total reaction time of the desiliconization and lead removal treatment is 2-4 hours.

[0102] Optionally, the desiliconization and lead removal process includes a multi-stage desiliconization and lead removal process performed sequentially. Exemplarily, the desiliconization and lead removal process may include 2, 3, 4 or 5 stages of desiliconization and lead removal. The multi-stage desiliconization and lead removal process can further reduce the nickel loss in the desiliconization and lead removal process.

[0103] In some embodiments, the endpoint pH value of the first stage of desiliconization and lead removal treatment in the multi-stage desiliconization and lead removal treatment is 3.5-4, and the endpoint pH value of the multi-stage desiliconization and lead removal treatment is 5-6.

[0104] In some embodiments, the desiliconization and lead removal treatment includes a first-stage desiliconization and lead removal treatment, a second-stage desiliconization and lead removal treatment, and a third-stage desiliconization and lead removal treatment, and the endpoint pH value of the first-stage desiliconization and lead removal treatment is less than or equal to the endpoint pH value of the second-stage desiliconization and lead removal treatment, and the endpoint pH value of the second-stage desiliconization and lead removal treatment is less than or equal to the endpoint pH value of the third-stage desiliconization and lead removal treatment. Slowly adding the calcium-containing neutralizer II in separate tanks to gradually adjust the pH value can reduce nickel precipitation caused by local over-alkali, thereby further reducing nickel loss.

[0105] In some embodiments, the endpoint pH value of the first stage desiliconization and lead removal treatment is 3.5-4, for example, it can be 3.5, 3.6, 3.7, 3.8, 3.9, 4 or any value between 3.5-4;

[0106] The endpoint pH value of the second stage desiliconization and lead removal treatment is 4-5, for example, it can be 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5 or any value between 4 and 5;

[0107] The endpoint pH value of the third stage desiliconization and lead removal treatment is 5-6, for example, it can be 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6 or any value between 5 and 6. In this embodiment, when the pH is 5-6, silicon can be precipitated together with the produced calcium sulfate, and the suspended lead sulfate is also adsorbed and precipitated at the same time.

[0108] In some embodiments, the reaction time of the desiliconization and lead removal treatment is 2-4 hours, for example, it can be 2 hours, 3 hours, 4 hours or any value between 2-4 hours.

[0109] In some embodiments, the reaction temperature of the desiliconization and lead removal treatment is room temperature.

[0110] Optionally, the second solid-liquid separation step includes:

[0111] Filter pressing treatment: Filter pressing the slurry after desiliconization and lead removal to obtain desiliconization and lead removal slag and filter pressing filtrate;

[0112] Precision filtration treatment: The filter press filtrate is subjected to precision filtration to obtain a nickel-containing impurity removal pre-liquid.

[0113] In some embodiments, the calcium content of the nickel-containing impurity removal pre-liquid is 450-650 mg / L.

[0114] Optionally, the impurity removal process includes:

[0115] Extraction and impurity removal: extracting and impurity removal the nickel-containing impurity removal pre-liquid to obtain a nickel-containing raffinate;

[0116] Deoiling: Deoiling the nickel-containing raffinate to obtain a nickel-rich impurity-free liquid.

[0117] In some embodiments, the nickel-containing raffinate satisfies: pH value is 2.5-3.5, magnesium content ≤ 2g / L; the nickel-rich impurity-removed liquid satisfies: oil content ≤ 2mg / L.

[0118] Optionally, the pH value of the nickel-containing raffinate can be 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5 or any value between 2.5 and 3.5.

[0119] Optionally, the magnesium content in the nickel-containing raffinate can be 0.5-2 g / L, for example, it can be 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, 0.9 g / L, 1 g / L, 1.2 g / L, 1.3 g / L, 1.4 g / L, 1.5 g / L, 1.6 g / L, 1.7 g / L, 1.8 g / L, 1.9 g / L, 2 g / L or any value between 0.5-2 g / L.

[0120] Reasonable control of the calcium and magnesium content in the nickel-containing raffinate is beneficial to balance the electrolytic efficiency and cost. Controlling a lower calcium ion content is beneficial to avoid crystallization in the system after calcium ion oversaturation. Controlling a reasonable magnesium content level is beneficial to improving the conductivity of the solution and balancing the processing cost.

[0121] Optionally, the extraction and impurity removal treatment includes:

[0122] The nickel-containing impurity removal pre-liquid is mixed with the saponified extractant to perform extraction and impurity removal treatment to obtain a nickel-containing raffinate; wherein the saponification rate of the extractant is 10-40%.

[0123] Optionally, the saponification rate of the extractant may be 10%, 15%, 20%, 25%, 30%, 35%, 40% or any value between 10-40%.

[0124] It should be noted that the extractant includes P204 (Chinese name: di(2-ethylhexyl) phosphate) and / or P507. The extractant can remove the calcium introduced by the calcium-containing neutralizer and the impurity ions circulated and enriched in the anolyte.

[0125] In some embodiments, the pH value of the nickel-containing raffinate is 2.5-3.5. The pH value of the nickel-containing raffinate within the above range can be helpful for preparing the electrolytic nickel cathode liquid.

[0126] In some embodiments, the degreasing is performed using activated carbon.

[0127] Optionally, the oil content in the nickel-rich impurity-removed liquid can be 0.2 mg / L, 0.4 mg / L, 0.6 mg / L, 0.8 mg / L, 1 mg / L, 1.2 mg / L, 1.4 mg / L, 1.6 mg / L, 1.8 mg / L, 2 mg / L or any value less than or equal to 2 mg / L.

[0128] In some embodiments, the method further includes mixing a portion of the nickel-containing raffinate with the filter press filtrate. In some examples, the weight of the portion of the nickel-containing raffinate is 3-7% of the weight of the filter press filtrate. Mixing the nickel-containing raffinate with the filter press filtrate can dilute the calcium in the filter press filtrate to avoid crystallization of the calcium-saturated nickel-containing impurity removal pre-liquid during transportation. In these embodiments, the precision filtration treatment includes precision filtration of the mixed solution of the filter press filtrate and the nickel-containing raffinate to obtain the nickel-containing impurity removal pre-liquid.

[0129] In some embodiments, the method of treating the electrolytic nickel anolyte further comprises:

[0130] pH adjustment process: the nickel-rich impurity-removed liquid is mixed with a pH buffer and a nickel sulfate solution to perform pH adjustment treatment to obtain a pH-adjusted liquid with a pH value of 3-4. The pH-adjusted liquid is used as a cathode liquid for nickel electrowinning.

[0131] In some embodiments, the nickel sulfate solution includes a nickel sulfate solution obtained by removing impurities from a nickel-containing leaching solution produced in a dissolution process.

[0132] In some embodiments, the pH buffer is boric acid.

[0133] As mentioned above, the second embodiment of the present application provides a device for treating an electrolytic nickel anode liquid, the device comprising:

[0134] A deacidification unit, comprising a plurality of deacidification tanks connected in series, wherein the plurality of deacidification tanks connected in series are used to mix the calcium-containing neutralizing agent I with the electrolytic nickel anode liquid A to perform a continuous multi-stage deacidification treatment to obtain a deacidified slurry;

[0135] A first filtering unit is used to perform solid-liquid separation on the deacidified slurry obtained by the deacidification unit to obtain a nickel-containing solution and calcium sulfate slag;

[0136] A desiliconization and lead removal unit comprises a plurality of desiliconization and lead removal tanks connected in series, wherein the plurality of desiliconization and lead removal tanks connected in series are used to mix the calcium-containing neutralizer II with the nickel-containing solution to perform continuous multi-stage desiliconization and lead removal treatment to obtain a desiliconized and lead-removed slurry;

[0137] A second filtering unit is used for performing solid-liquid separation treatment on the desiliconized and lead-removed slurry obtained by the desiliconized and lead-removed unit to obtain desiliconized and lead-removed slag and nickel-containing impurity-removed pre-liquid;

[0138] The first impurity removal unit is used to remove impurities from the nickel-containing impurity removal pre-liquid obtained by the second filtering unit to obtain a nickel-rich impurity removal post-liquid.

[0139] In some embodiments, a plurality of deacidification tanks connected in series are arranged in a stepped manner, which is conducive to the slurry after the reaction to enter the next reaction tank from the first tank and finally enter the tail tank.

[0140] In some embodiments, at least two deacidification tanks are connected to a powder feeding device, which includes a powder silo and a screw feeder connected in sequence. The powder silo can be used to store the calcium-containing neutralizing agent I, and the screw feeder is used to deliver the calcium-containing neutralizing agent I to the deacidification tank.

[0141] In some embodiments, the first filter unit includes a first belt filter press and a wash water storage tank. The material inlet of the first belt filter press is connected to the deacidification unit, the filtrate outlet of the first belt filter press is connected to the wash water storage tank, and the wash water storage tank is connected to the desiliconization and lead removal unit. When in use, the deacidified slurry produced by the deacidification unit is pumped into the first belt filter press, and the first belt filter press filters and washes the deacidified slurry to obtain filtrate and wash water. The generated filtrate and wash water enter the wash water storage tank through a connecting pipeline, and the filtrate and wash water are mixed in the wash water storage tank to form a nickel-containing solution. The wash water storage tank is connected to the desiliconization and lead removal unit, so that the nickel-containing solution in the wash water storage tank can enter the desiliconization and lead removal unit.

[0142] In some embodiments, the first filter unit further comprises a stirring and washing tank, which is connected to the filter residue outlet of the first belt filter press. When in use, the filter residue enters the stirring and washing tank for a second washing.

[0143] In some embodiments, a plurality of desiliconization and lead removal tanks connected in series are arranged in a stepped manner, which is conducive to the material in the desiliconization and lead removal tanks to flow from the first desiliconization and lead removal tank to the next desiliconization and lead removal tank and finally to the desiliconization and lead removal tail tank.

[0144] In some embodiments, the desiliconization and lead removal unit is connected to a slurrying unit, and the slurrying unit includes a powder bin, a screw feeder, a slurrying tank and a calcium neutralizer II slurry storage tank connected in sequence; the calcium neutralizer II slurry storage tank is connected to the desiliconization and lead removal tank, and is used to provide the calcium neutralizer II slurry to the desiliconization and lead removal tank.

[0145] In some embodiments, the second filtration unit includes a second belt filter press, a liquid tank after desiliconization and lead removal, and a precision filter connected in sequence; wherein the filter element of the precision filter is a PE filter element with a pore size of ≤0.5μm.

[0146] When in use, the desiliconized and lead-removed slurry produced by the desiliconization and lead-removing unit is pumped into the second belt filter press, and the second belt filter press performs filter pressing on the desiliconized and lead-removed slurry. The resulting filter press filtrate enters the desiliconized and lead-removed liquid tank, is mixed with the nickel-containing raffinate in the desiliconized and lead-removed liquid tank, and then enters the precision filter. After being treated by the precision filter, the nickel-containing impurity-removed pre-liquid is obtained.

[0147] In some embodiments, the first impurity removal unit includes a box-type extraction device and an oil removal device. The material inlet of the box-type extraction device is connected to the precision filter, and the material outlet of the box-type extraction device is respectively connected to the oil removal equipment and the liquid tank after desiliconization and lead removal.

[0148] In some embodiments, the apparatus for treating the electrolytic nickel anolyte further comprises:

[0149] The dissolution unit is used to mix the electrolytic nickel anode liquid B with the nickel-containing raw material to perform a leaching reaction to obtain a nickel-containing leachate. The dissolution unit includes a reaction vessel for the leaching reaction, which may include a reaction vessel such as a normal pressure reactor and a high pressure reactor, and is not particularly limited here.

[0150] In some embodiments, a second impurity removal unit for removing impurities from the nickel-containing leachate is further included. The second impurity removal unit is used to remove impurities from the nickel-containing leachate to obtain a nickel sulfate solution. The second impurity removal unit may include one or more devices that can remove impurities from the solution, including but not limited to extraction, oil removal, filtration and other equipment, which are not particularly limited herein.

[0151] In some embodiments, the apparatus for treating the electrolytic nickel anolyte further comprises:

[0152] A pH adjustment unit, comprising a pH adjustment reaction tank, is connected to the first impurity removal unit. The pH adjustment unit is used to perform pH adjustment on the nickel-rich impurity-removed liquid obtained by the first impurity removal unit to obtain a pH-adjusted liquid with a pH value of 3-4, and the pH-adjusted liquid is used as a cathode liquid for nickel electrowinning.

[0153] In some embodiments, the pH adjustment unit is connected to the second impurity removal unit. The nickel sulfate solution produced by the second impurity removal unit can enter the pH adjustment unit and be mixed with the nickel-rich impurity-removed liquid and the pH buffer to prepare the pH-adjusted liquid.

[0154] The present application will be described in detail below through examples. In the following examples, unless otherwise specified, the raw materials, equipment and instruments involved are all commercially available.

[0155] In the following examples, the particle size D of limestone powder and quicklime powder is 95 All below 150μm.

[0156] In the following examples, the compositions of the electrolytic nickel anolyte, limestone powder, and quicklime powder used are shown in Table 1, Table 2, and Table 3, respectively.

[0157] Table 1: Composition of nickel electrodeposition anolyte (in mg / L)

[0158]

[0159] Table 2: Limestone powder composition (in wt%)

[0160]

[0161] Table 3: Quicklime powder composition (in wt%)

[0162]

[0163] Example 1

[0164] (1) The nickel electrodeposition anode liquid produced by the electrolytic cell in the electrolysis system contains acid. The nickel electrodeposition anode liquid B (48 wt%) is introduced into the dissolution unit of the system for preparing nickel sulfate from high nickel matte and mixed with the nickel-containing raw material (high nickel matte) to carry out a leaching reaction to obtain a nickel-containing leachate. The nickel-containing leachate is subjected to impurity removal treatment in the second impurity removal unit of the system for preparing nickel sulfate from high nickel matte to obtain a nickel sulfate solution. The nickel electrodeposition anode liquid A (i.e., the remaining 52 wt%) is sent to the deacidification process.

[0165] (2) The deacidification process uses four stirred deacidification tanks of the same volume and connected in series. The deacidification tanks are arranged in a stepped manner so that the slurry after the reaction can enter the next reaction tank from the first deacidification tank and finally enter the deacidification tail tank. The process reaction temperature is room temperature. The electrolytic nickel anode liquid A of step (1) is pumped into the first deacidification tank. The first deacidification tank is charged with limestone powder accounting for about 60% of the total amount of limestone powder (including desiliconization and lead removal slag) added to carry out the first stage of deacidification treatment. The rest is respectively added to the second deacidification tank and the third deacidification tank for the second stage of deacidification treatment and the third stage of deacidification treatment respectively. No addition is made to the deacidification tail tank. The end point pH value of the deacidification tail tank is controlled to be 2.6. The total reaction time is 6 hours to obtain the deacidified slurry.

[0166] (3) The deacidified slurry after the reaction is completed is pumped into a belt filter press for solid-liquid separation to obtain a filtrate and a filter residue, and the filter residue is subjected to a first washing and a second washing in sequence, that is, a spray water equivalent to the weight of the filter residue is used for machine washing on the first belt filter press, and the washing water and the filtrate are mixed to form a nickel-containing solution and sent to the next process; the filter residue produced by the first belt filter press enters a stirring and washing tank, and is stirred and washed according to a mass liquid-solid ratio of 4mL:1g. After stirring and washing, the first belt filter press is used again for filtration, and part of the stirring and washing filtrate is opened as spray water for machine washing, and the remaining stirring and washing liquid is supplemented with an equal amount of clean water and circulated as washing water; the calcium sulfate residue produced by stirring, washing and filtering is gypsum residue, containing 0.05wt% nickel, which is sold for disposal.

[0167] (4) The desiliconization and lead removal process uses three stirred continuous desiliconization and lead removal tanks of the same volume and connected in series, and the desiliconization and lead removal tanks are arranged in a stepped manner so that the slurry after the reaction can enter the next desiliconization and lead removal tank from the first desiliconization and lead removal tank and finally enter the desiliconization and lead removal tail tank; the nickel-containing solution produced in step (3) is pumped into the first desiliconization and lead removal tank, and quicklime slurry with a concentration of 20wt% obtained by mixing quicklime powder and water is added to the three desiliconization and lead removal tanks respectively, and the pH of the first desiliconization and lead removal tank is controlled to be 4.0 for the first stage of desiliconization and lead removal treatment, the pH of the second desiliconization and lead removal tank is controlled to be 4.5 for the second stage of desiliconization and lead removal treatment, and the pH of the last desiliconization and lead removal tank is controlled to be 5.1 for the third stage of desiliconization and lead removal treatment. The total reaction time is 3h to obtain the slurry after desiliconization and lead removal.

[0168] (5) The slurry after desiliconization and lead removal is pumped into a second belt filter press for filter pressing to obtain desiliconization and lead removal slag and filter press filtrate; the filter press filtrate is mixed with the nickel-containing raffinate, and then treated with a precision filter to obtain a nickel-containing impurity removal pre-liquid, which is sent to the next process. The nickel-containing impurity removal pre-liquid contains: 33 mg / L silicon, 0.15 mg / L lead, and 480 mg / L calcium; the produced desiliconization and lead removal slag is washed with clean water, unloaded, packaged, and sent to the deacidification process as a neutralizing agent.

[0169] (6) The nickel-containing impurity-removing pre-liquid produced in step (5) is sent to an extraction line for impurity removal. The extraction line uses P204 extractant, the saponification rate of the extractant is 15%, the pH value of the nickel-containing raffinate is controlled to be 3.0, the calcium content in the produced nickel-containing raffinate is 28 mg / L, and the magnesium content is 1435 mg / L. 5wt% of the nickel-containing raffinate is returned to the desiliconized and lead-removed liquid tank to dilute the calcium in the nickel-containing impurity-removing pre-liquid to avoid crystallization of the calcium-saturated nickel-containing impurity-removing pre-liquid during transportation. The extracted nickel-containing raffinate is then deoiled by multi-stage activated carbon to produce a nickel-rich impurity-removing post-liquid, and the oil content of the nickel-rich impurity-removing post-liquid is 0.8 mg / L.

[0170] (7) The nickel-rich impurity-free solution produced in step (6) is added to the nickel sulfate solution produced by the second impurity removal unit, and boric acid is appropriately added to control the pH value at 3.4 to obtain a cathode liquid with a nickel concentration of 92 g / L. The cathode liquid can be fed into the cathode chamber of the electrolytic cell as the cathode liquid for nickel electrolysis to continue electrolysis and produce nickel.

[0171] The method for treating the electrolytic nickel anode liquid is as follows: Figure 1 shown.

[0172] A second aspect of the present embodiment provides an apparatus for treating an electrolytic nickel anode liquid, which is used to perform the above method, and includes: a dissolution unit, a deacidification unit, a first filtering unit, a desiliconization and lead removal unit, a second filtering unit, a first impurity removal unit, a pH adjustment unit, and a second impurity removal unit;

[0173] The dissolving unit is connected to the second impurity removal unit;

[0174] The deacidification unit includes a first deacidification tank, a second deacidification tank, a third deacidification tank and a deacidification tail tank which are distributed in a step-down manner. The first deacidification tank, the second deacidification tank and the third deacidification tank are connected to a powder feeding device, and the powder feeding device includes a powder bin and a screw feeder which are connected in sequence;

[0175] The first filtering unit includes a first belt filter press, a stirring and washing tank, and a washing water storage tank. The material inlet of the first belt filter press is connected to the deacidification tail tank, the filtrate outlet of the first belt filter press is connected to the stirring and washing tank, and the filter residue outlet of the first belt filter press is connected to the washing water storage tank.

[0176] The desiliconization and lead removal unit comprises a first desiliconization and lead removal tank, a second desiliconization and lead removal tank, a third desiliconization and lead removal tank and a desiliconization and lead removal tail tank which are distributed in a step-down manner, wherein the three desiliconization and lead removal tanks are all connected to a slurrying unit, the first desiliconization and lead removal tank is connected to a washing water storage tank, and the slurrying unit comprises a powder silo, a screw feeder, a slurrying tank and a calcium neutralizer II ore slurry storage tank which are connected in sequence;

[0177] The second filtering unit comprises a second belt filter press, a liquid tank after desiliconization and lead removal, and a precision filter (PE filter element, pore size ≤ 0.5 μm) which are connected in sequence, wherein the material inlet of the second belt filter press is connected to the third desiliconization and lead removal tank, the filtrate outlet of the second belt filter press is connected to the liquid tank after desiliconization and lead removal, and the liquid tank after desiliconization and lead removal is connected to the precision filter;

[0178] The first impurity removal unit includes a box-type extraction device and an oil removal device, the material inlet of the box-type extraction device is connected to the precision filter, and the material outlet of the box-type extraction device is respectively connected to the oil removal equipment and the liquid tank after desiliconization and lead removal;

[0179] The pH regulating unit comprises a value regulating reaction tank, and the pH regulating unit is connected with the first impurity removing unit and the second impurity removing unit.

[0180] The working principle of the device for treating the electrolytic nickel anolyte includes:

[0181] The electrolytic nickel anode liquid B enters the dissolution unit and is mixed with the high nickel matte for leaching reaction. The obtained nickel-containing leaching liquid enters the second impurity removal unit for impurity removal treatment to obtain a nickel sulfate solution.

[0182] The calcium-containing neutralizing agent I in the powder silo is transported to the first deacidification tank, the second deacidification tank, and the third deacidification tank in the deacidification unit through a screw feeder, mixed with the electrolytic nickel anode liquid A, and enters the first belt filter press of the first filtering unit through the deacidification tail tank. The filtrate and wash water produced by the first belt filter press enter the wash water storage tank to form a nickel-containing solution. The filter residue produced by the first belt filter press enters the stirring and washing tank, and the calcium sulfate residue produced by the stirring and washing tank is sold externally.

[0183] The nickel-containing solution is transported to the first desiliconization and lead removal tank of the desiliconization and lead removal process through a pipeline, and is mixed with the calcium-containing neutralizer II output from the slurry unit in the first desiliconization and lead removal tank, the second desiliconization and lead removal tank, and the third desiliconization and lead removal tank to obtain a desiliconization and lead removal slurry;

[0184] The slurry after desiliconization and lead removal is transported to the second belt filter press of the second filtering unit through a pipeline for filtration treatment. The filtrate produced by the second belt filter press enters the liquid tank after desiliconization and lead removal and enters the precision filter for filtration to obtain a nickel-containing impurity removal pre-liquid.

[0185] The nickel-containing pre-impurity removal liquid is transported to the first impurity removal unit through a pipeline, and is treated by the box-type extraction device of the first impurity removal unit to obtain a nickel-containing raffinate. Part of the nickel-containing raffinate is returned to the desiliconization and lead removal liquid tank, and the other part of the nickel-containing raffinate is treated by the deoiling device to obtain a nickel-rich impurity removal liquid.

[0186] The nickel-rich impurity-removed liquid and the nickel sulfate solution are transported to the pH adjustment reaction tank of the pH adjustment unit through a pipeline and mixed with the pH buffer to obtain the pH-adjusted liquid.

[0187] The schematic diagram of the partial device process for treating the electrolytic nickel anode liquid is as follows Figure 2 shown.

[0188] Example 2

[0189] This embodiment provides a method for treating an electrolytic nickel anolyte, and the device used is consistent with that in embodiment 1, including:

[0190] (1) The nickel electrodeposition anode liquid produced by the electrolytic cell in the electrolysis system contains acid. The nickel electrodeposition anode liquid B (50 wt%) is introduced into the dissolution unit of the system for preparing nickel sulfate from high nickel matte and mixed with the nickel-containing raw material (high nickel matte) to carry out a leaching reaction to obtain a nickel-containing leachate. The nickel-containing leachate is subjected to impurity removal treatment in the second impurity removal unit in the system for preparing nickel sulfate from high nickel matte to obtain a nickel sulfate solution. The nickel electrodeposition anode liquid A (i.e., the remaining 50 wt%) is sent to the deacidification process.

[0191] (2) The deacidification process uses 5 stirred deacidification tanks of the same volume and connected in series. The deacidification tanks are arranged in a stepped manner so that the slurry after the reaction can enter the next deacidification tank from the first deacidification tank and finally enter the deacidification tail tank; the process reaction temperature is room temperature, the electrolytic nickel anode liquid A of step (1) is pumped into the first deacidification tank, 60% of the total amount of limestone powder added is added to the first deacidification tank for the first stage of deacidification treatment, and the rest is added to the subsequent deacidification tanks for deacidification treatment. No addition is made to the deacidification tail tank. The end point pH value of the deacidification tail tank is controlled to be 2.9. The total reaction time is 4.7 hours to obtain the deacidified slurry.

[0192] (3) The deacidified slurry after the reaction is completed is pumped into the first belt filter press for solid-liquid separation to obtain filtrate and filter residue; the filter residue is subjected to the first washing and the second washing in sequence, that is, the filter residue is machine-washed on the first belt filter press using spray water equivalent to the weight of the filter residue, and the washing water and the filtrate are mixed to form a nickel-containing solution and sent to the next process; the filter residue produced by the first belt filter press enters the stirring and washing tank, is stirred and washed according to a mass liquid-solid ratio of 4mL:1g, and is filtered again using the first belt filter press after stirring and washing, and part of the stirring and washing filtrate is opened as spray water for machine washing, and the remaining stirring and washing liquid is supplemented with an equal amount of clean water and then circulated as washing water; the calcium sulfate residue produced by stirring, washing and filtering is gypsum residue (containing 0.03wt% nickel) for sale and disposal.

[0193] (4) The desiliconization and lead removal process uses three stirred continuous desiliconization and lead removal tanks of the same volume and connected in series, and the desiliconization and lead removal tanks are arranged in a stepped manner so that the slurry after the reaction can enter the next desiliconization and lead removal tank from the first desiliconization and lead removal tank and finally enter the desiliconization and lead removal tail tank; the nickel-containing solution produced in step (3) is pumped into the first desiliconization and lead removal tank, and quicklime slurry with a concentration of 28wt% obtained by mixing quicklime powder and water is added to the three desiliconization and lead removal tanks respectively, and the pH of the first desiliconization and lead removal tank is controlled to be 3.6 for the first stage of desiliconization and lead removal treatment, the pH of the second desiliconization and lead removal tank is controlled to be 4.5 for the second stage of desiliconization and lead removal treatment, and the pH of the last desiliconization and lead removal tank is controlled to be 5.5 for the third stage of desiliconization and lead removal treatment. The total reaction time is 2.5h to obtain the slurry after desiliconization and lead removal.

[0194] (5) The slurry after desiliconization and lead removal is pumped into a second belt filter press for filter pressing to obtain desiliconization and lead removal slag and filter press filtrate; the filter press filtrate is mixed with the nickel-containing raffinate, and then treated with a precision filter as a nickel-containing impurity removal pre-liquid to be sent to the next process, wherein the nickel-containing impurity removal pre-liquid contains: 48 mg / L silicon, 0.18 mg / L lead, and 591 mg / L calcium; the produced desiliconization and lead removal slag is washed with clean water, unloaded, packaged, and sent to the deacidification process as a neutralizing agent.

[0195] (6) The nickel-containing impurity-removing pre-liquid produced in step (5) is sent to an extraction line for impurity removal. The extraction line uses P204 extractant, the saponification rate of the extractant is 25%, the pH value of the nickel-containing raffinate is controlled to be 3.4, the calcium content in the produced nickel-containing raffinate is 5 mg / L, and the magnesium content is 1165 mg / L. 5wt% of the nickel-containing raffinate is returned to the desiliconized and lead-removed liquid tank to dilute the calcium in the nickel-containing impurity-removing pre-liquid to avoid crystallization of the calcium-saturated nickel-containing impurity-removing pre-liquid during transportation. The extracted nickel-containing raffinate is then deoiled by multi-stage activated carbon to produce a nickel-rich impurity-removing post-liquid, and the oil content of the nickel-rich impurity-removing post-liquid is 0.5 mg / L.

[0196] (7) The nickel-rich impurity-free solution produced in step (6) is added to the nickel sulfate solution produced by the second impurity removal unit, and boric acid is appropriately added to control the pH at 3.2 to obtain a cathode liquid with a nickel concentration of 89.5 g / L. The cathode liquid can be fed into the cathode chamber of the electrolytic cell as the cathode liquid for nickel electrolysis to continue electrolysis and produce nickel.

[0197] Example 3

[0198] This embodiment provides a method for treating an electrolytic nickel anolyte, and the device used is consistent with that in embodiment 1, including:

[0199] (1) The nickel electrodeposition anode liquid produced by the electrolytic cell in the electrolysis system contains acid. The nickel electrodeposition anode liquid B (51 wt%) is introduced into the dissolution unit of the system for preparing nickel sulfate from high nickel matte, mixed with the nickel-containing raw material (high nickel matte) to carry out a leaching reaction, and a nickel-containing leachate is obtained. The nickel-containing leachate is subjected to impurity removal treatment in the second impurity removal unit of the system for preparing nickel sulfate from high nickel matte to obtain a nickel sulfate solution. The nickel electrodeposition anode liquid A (i.e., the remaining 49 wt%) is sent to the deacidification process.

[0200] (2) The deacidification process uses four deacidification tanks of the same volume connected in series, and the deacidification tanks are arranged in a stepped manner so that the slurry after the reaction can enter the next deacidification tank from the first deacidification tank and finally enter the deacidification tail tank; the electrolytic nickel anode liquid A of step (1) is pumped into the first deacidification tank, and 60% of the total amount of limestone powder added is added to the first deacidification tank for the first stage of deacidification treatment, and the rest is added to the subsequent deacidification tanks for deacidification treatment, and no addition is made to the deacidification tail tank. The end point pH of the deacidification tail tank is controlled to be 2.8, and the total reaction time is 3.5 hours to obtain the deacidified slurry.

[0201] (3) The deacidified slurry after the reaction is completed is pumped into the first belt filter press for solid-liquid separation to obtain filtrate and filter residue; the filter residue is subjected to the first washing and the second washing in sequence, that is, the filter residue is machine-washed on the first belt filter press using spray water equivalent to the weight of the filter residue, and the washing water and the filtrate are mixed to form a nickel-containing solution and sent to the next process; the filter residue produced by the first belt filter press enters the stirring and washing tank, is stirred and washed according to a mass liquid-solid ratio of 4mL:1g, and is filtered again using the first belt filter press after stirring and washing, and part of the stirring and washing filtrate is opened as spray water for machine washing, and the remaining stirring and washing liquid is supplemented with an equal amount of clean water and then circulated as washing water; the calcium sulfate residue produced by stirring, washing and filtering is gypsum residue (containing 0.04wt% nickel), which is used for sale and treatment.

[0202] (4) The desiliconization and lead removal process uses four stirred continuous desiliconization and lead removal tanks of the same volume and connected in series, and the desiliconization and lead removal tanks are arranged in a stepped manner so that the slurry after the reaction can enter the next desiliconization and lead removal tank from the first desiliconization and lead removal tank and finally enter the desiliconization and lead removal tail tank; the nickel-containing solution produced in step (3) is pumped into the first desiliconization and lead removal tank, and quicklime slurry with a concentration of 12wt% obtained by mixing quicklime powder and water is added to the three desiliconization and lead removal tanks respectively, and the pH of the first desiliconization and lead removal tank is controlled to be 3.9, the pH of the second desiliconization and lead removal tank is controlled to be 4.5, and the pH of the last desiliconization and lead removal tank is controlled to be 6.0. The total reaction time is 4h to obtain the slurry after desiliconization and lead removal.

[0203] (5) The slurry after desiliconization and lead removal is pumped into a second belt filter press for filter pressing to obtain desiliconization and lead removal slag and filter press filtrate; the filter press filtrate is sent to the next process as a nickel-containing impurity removal pre-liquid after passing through a precision filter, and the nickel-containing impurity removal pre-liquid contains: 16 mg / L silicon, 0.04 mg / L lead, and 626 mg / L calcium; the produced desiliconization slag is washed with clean water, unloaded, packaged, and sent to the deacidification process as a neutralizing agent.

[0204] (6) The nickel-containing impurity-removing pre-liquid produced in step (5) is sent to an extraction line for impurity removal. The extraction line uses P204 extractant, the saponification rate of the extractant is 35%, the pH value of the nickel-containing raffinate is controlled to be 2.6, and the calcium content in the produced nickel-containing raffinate is 47 mg / L and the magnesium content is 1865 mg / L. 3wt% of the nickel-containing raffinate is returned to the desiliconized and lead-removed liquid tank to dilute the calcium in the nickel-containing impurity-removing pre-liquid to avoid crystallization of the calcium-saturated nickel-containing impurity-removing pre-liquid during transportation. The extracted nickel-containing raffinate is then deoiled by multi-stage activated carbon to produce a nickel-rich impurity-removing post-liquid, and the oil content of the nickel-rich impurity-removing post-liquid is 0.6 mg / L.

[0205] (7) The nickel-rich impurity-free solution produced in step (6) is added to the nickel sulfate solution produced by the second impurity removal unit, and boric acid is appropriately added to control the pH at 3.8 to obtain a cathode liquid with a nickel concentration of 90.8 g / L. The cathode liquid can be fed into the cathode chamber of the electrolytic cell as the cathode liquid for nickel electrolysis to continue electrolysis and produce nickel.

[0206] Comparative Example 1

[0207] (1) Adding a liquid alkali solution to the nickel electrodeposition anolyte, controlling the pH value to 7-8 during the reaction (the stable pH can be adjusted by using the liquid alkali and the nickel electrodeposition anolyte), reacting at 60°C for 3 hours, filtering and washing (removing the sodium in the filter cake by backwashing during filtration, or re-slurrying the filter cake after filtration, stirring and washing, and then filtering by pressure. The sodium sulfate concentration of the cathode liquid during electrolysis will affect the appearance quality and yield of the nickel plate), obtaining a nickel hydroxide / nickel carbonate filter cake and a post-nickel precipitation liquid (filtrate), and the post-nickel precipitation liquid is successively subjected to resin deweighting (recovering nickel and cobalt), magnesium precipitation (adding calcium carbonate), and decarbonization (decarbonization tower) to obtain sodium sulfate wastewater.

[0208] (2) Add the nickel hydroxide / nickel carbonate filter cake to another part of the nickel electrodeposition anolyte to dissolve the slurry, control the Ni concentration to about 90 g / L, and add a pH buffer to stabilize the end point pH value to 3-4 (after nickel precipitation, some impurities in the original anolyte are opened out and go with the filtrate, and then the nickel hydroxide / nickel carbonate is used as an alkali to neutralize another part of the nickel electrodeposition anolyte, reduce the amount of liquid alkali, and return nickel to the system). After the reaction is completed, the cathode liquid can be filtered to obtain the cathode liquid for nickel electrodeposition. The composition of the cathode liquid is shown in Table 4 below:

[0209] The device for treating the electrolytic nickel anode liquid in this comparative example includes: a nickel precipitation stirring tank, a nickel precipitation filter press, a nickel washing tank, a washing filter press, a washing water storage tank, a wastewater nickel precipitation tank and a wastewater filter press.

[0210] Table 4: Cathodic liquid composition of Comparative Example 1 (mg / L)

[0211] Ni Co Ca Mg Si Fe Cu Zn Al Cd Pb Cr Oil content — ≤20 ≤100 — ≤100 ≤1 ≤0.6 ≤0.5 ≤1 ≤1 ≤1 ≤1 ≤2

[0212] In this comparative example, the wastewater needs to be treated separately, the wastewater treatment process is long and the cost is high; in addition, a large amount of water is introduced into the system, and the amount of wastewater produced is too large. Larger water treatment equipment is required to prepare the wastewater into low-value chemical by-products, and the equipment investment cost is high.

[0213] From the above results, it can be seen that the method and device for treating electrolytic nickel anode liquid provided in the present application use a calcium-containing neutralizing agent to perform deacidification treatment and desiliconization and lead removal treatment in sequence through a two-stage method, which can not only reduce production costs but also produce no wastewater, and there is no need to build corresponding nickel recovery and MVR and other wastewater treatment equipment.

[0214] At the same time, the method of the present application can remove the calcium introduced by the calcium salt and the impurity ions circulated and enriched in the anode liquid. The calcium sulfate slag produced by the deacidification treatment is washed and sold as a building material, and the slag produced by the desiliconization and lead removal treatment is washed and sent to other nickel sulfate production lines as a neutralizing agent, which is environmentally friendly.

[0215] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, the technical solution of the present application can be subjected to a variety of simple modifications, including combining various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed in the present application and belong to the protection scope of the present application.

Claims

1. A method for treating an electrolytic nickel anolyte, characterized in that: The method includes: Deacidification process: mixing calcium-containing neutralizing agent I with electrolytic nickel anolyte A to perform deacidification treatment to obtain deacidified slurry; The first solid-liquid separation step: performing a first solid-liquid separation process on the deacidified slurry to obtain a nickel-containing solution and calcium sulfate slag; Desiliconization and lead removal process: mixing the calcium-containing neutralizer II with the nickel-containing solution to perform desiliconization and lead removal treatment to obtain a desiliconized and lead-removed slurry; The second solid-liquid separation step: performing a second solid-liquid separation treatment on the desiliconized and lead-removed slurry to obtain desiliconized and lead-removed slag and a nickel-containing impurity-removed pre-liquid with a silicon content of ≤50 mg / L; Impurity removal process: the nickel-containing impurity removal pre-liquid is subjected to impurity removal treatment to obtain a nickel-rich impurity removal post-liquid with a calcium content of ≤50 mg / L.

2. The method according to claim 1, characterized in that The method satisfies at least one of the following conditions: A. The method further comprises a dissolving step: mixing the electrolytic nickel anolyte B with the nickel-containing raw material to carry out a leaching reaction to obtain a nickel-containing leaching solution; B. The method further comprises a pH adjustment step: mixing the nickel-rich impurity-removed liquid with a pH buffer and a nickel sulfate solution to perform a pH adjustment treatment to obtain a pH-adjusted liquid with a pH value of 3-4.

3. The method according to claim 1 or 2, characterized in that: The method satisfies at least one of the following conditions: A. containing the calcium neutralizing agent I in the form of powder and mixed with the electrolytic nickel anode liquid A for deacidification treatment; B. the endpoint pH value of the deacidification treatment is 2.5-3.0; C. The reaction time of the deacidification treatment is 3-6h; D. the calcium-containing neutralizer I and the calcium-containing neutralizer II each independently include at least one of CaCO3, CaO and Ca(OH)2; E. The calcium-containing neutralizing agent I comprises limestone powder and desiliconized and lead-removing slag; F. Particle size D of the calcium-containing neutralizer I and the calcium-containing neutralizer II 95 All less than 150μm; G. the concentration of the calcium-containing neutralizer II is 10-30wt%; H. the deacidification process comprises at least three stages of deacidification treatment, and at least 50% of the total amount of the calcium-containing neutralizing agent I is added in the first stage of deacidification treatment; I. The components of the electrolytic nickel anolyte A or the electrolytic nickel anolyte B include: Ni 40-70g / L, Ca 4-10mg / L, Mg 1000-1700mg / L, Si 50-150mg / L, Co 1-7mg / L, Cu0.5-1.5mg / L, Zn 0.05-0.2mg / L, Fe0.5-1mg / L, Pb 0.3-2mg / L, and sulfuric acid 40-60g / L; J. The nickel sulfate solution includes the nickel sulfate solution obtained by removing impurities from the nickel-containing leaching solution produced in the dissolution step.

4. The method according to claim 1 or 2, characterized in that: The first solid-liquid separation step comprises: The deacidified slurry is filtered to obtain a filtrate and a filter residue, and the filter residue is subjected to a first washing and a second washing in sequence, the washing water of the first washing is incorporated into the filtrate to form the nickel-containing solution, the filter residue after the first washing is subjected to the second washing to obtain the calcium sulfate residue, the washing water of the second washing is recycled for the first washing, and the nickel content of the calcium sulfate residue is ≤0.05wt%.

5. The method according to claim 1 or 2, characterized in that: The desiliconization and lead removal process includes multiple stages of desiliconization and lead removal treatments performed sequentially.

6. The method according to claim 5, characterized in that The method satisfies at least one of the following conditions: A. The endpoint pH value of the first stage of the multi-stage desiliconization and lead removal treatment is 3.5-4, and the endpoint pH value of the multi-stage desiliconization and lead removal treatment is 5-6; B. The desiliconization and lead removal treatment comprises a first-stage desiliconization and lead removal treatment, a second-stage desiliconization and lead removal treatment and a third-stage desiliconization and lead removal treatment which are performed in sequence, wherein the endpoint pH value of the first-stage desiliconization and lead removal treatment is 3.5-4, the endpoint pH value of the second-stage desiliconization and lead removal treatment is 4-5, and the endpoint pH value of the third-stage desiliconization and lead removal treatment is 5-6; C. The reaction time of the desiliconization and lead removal treatment is 2-4 hours.

7. The method according to claim 1 or 2, characterized in that: The second solid-liquid separation step comprises: Filter pressing treatment: filter pressing the desiliconized and lead-removed slurry to obtain the desiliconized and lead-removed slag and filter pressing filtrate; Precision filtration treatment: The filter press filtrate is subjected to precision filtration to obtain the nickel-containing impurity-removing pre-liquid.

8. The method according to claim 7, characterized in that The impurity removal process comprises: Extraction and impurity removal: extracting and impurity removal the nickel-containing impurity removal pre-liquid to obtain a nickel-containing raffinate; Deoiling: Deoiling the nickel-containing raffinate to obtain the nickel-rich impurity-removed liquid.

9. The method according to claim 8, characterized in that The method satisfies at least one of the following conditions: A. The nickel-containing raffinate satisfies: pH value is 2.5-3.5, magnesium content ≤ 2g / L; the nickel-rich impurity-removed liquid satisfies: oil content ≤ 2mg / L; B. The extraction and impurity removal comprises: mixing the nickel-containing impurity removal pre-liquid with the saponified extractant to perform extraction and impurity removal treatment to obtain the nickel-containing raffinate; wherein the saponification rate of the extractant is 10-40%; C. further comprising mixing a portion of the nickel-containing raffinate with a filter press filtrate, wherein the weight of the portion of the nickel-containing raffinate is 3-7% of the weight of the filter press filtrate; D. The weight ratio of the electrolytic nickel anolyte A to the electrolytic nickel anolyte B is 1:0.6-1.5; E. The calcium content of the nickel-containing impurity removal pre-liquid is 450-650 mg / L.

10. A device for treating nickel electrodeposition anolyte, characterized in that: The device includes: A deacidification unit, comprising a plurality of deacidification tanks connected in series, wherein the plurality of deacidification tanks connected in series are used to mix the calcium-containing neutralizing agent I with the electrolytic nickel anode liquid A to perform a continuous multi-stage deacidification treatment to obtain a deacidified slurry; A first filtering unit is used to perform solid-liquid separation on the deacidified slurry obtained by the deacidification unit to obtain a nickel-containing solution and calcium sulfate slag; A desiliconization and lead removal unit comprises a plurality of desiliconization and lead removal tanks connected in series, wherein the plurality of desiliconization and lead removal tanks connected in series are used to mix the calcium-containing neutralizer II with the nickel-containing solution to perform continuous multi-stage desiliconization and lead removal treatment to obtain a desiliconized and lead-removed slurry; A second filtering unit is used for performing solid-liquid separation treatment on the desiliconized and lead-removed slurry obtained by the desiliconized and lead-removed unit to obtain desiliconized and lead-removed slag and nickel-containing impurity-removed pre-liquid; The first impurity removal unit is used to remove impurities from the nickel-containing impurity removal pre-liquid obtained by the second filtering unit to obtain a nickel-rich impurity removal post-liquid.

11. The device according to claim 10, characterized in that The device satisfies at least one of the following conditions: A. The device further comprises: a dissolving unit, which is used to mix the electrolytic nickel anode liquid B with the nickel-containing raw material to perform a leaching reaction to obtain a nickel-containing leaching solution; B. The device further comprises: a pH adjusting unit, the pH adjusting unit comprises a pH adjustment reaction tank, and the pH adjusting unit is connected to the first impurity removal unit.

12. The device according to claim 11, characterized in that The device satisfies at least one of the following conditions: A. The first filtering unit comprises a first belt filter press and a washing water storage tank, wherein the material inlet of the first belt filter press is connected to the deacidification unit, the filtrate outlet of the first belt filter press is connected to the washing water storage tank, and the washing water storage tank is connected to the desiliconization and lead removal unit; B. the plurality of desiliconization and lead removal tanks connected in series are distributed in a stepped manner; C. The desiliconization and lead removal unit is connected to a slurrying unit, and the slurrying unit includes a powder bin, a screw feeder, a slurrying tank and a calcium neutralizer II slurry storage tank connected in sequence; the calcium neutralizer II slurry storage tank is connected to the desiliconization and lead removal tank, and is used to provide the calcium neutralizer II slurry to the desiliconization and lead removal tank; D. The second filtering unit comprises a second belt filter press, a desiliconized and lead-removed liquid tank, and a precision filter connected in sequence; wherein the filter element of the precision filter is a PE filter element with a pore size of ≤0.5 μm; E. The first impurity removal unit includes a box-type extraction device and an oil removal device, the material inlet of the box-type extraction device is connected to a precision filter, and the material outlet of the box-type extraction device is respectively connected to the oil removal equipment and the liquid tank after desiliconization and lead removal; F. The device further comprises a second impurity removal unit for removing impurities from the nickel-containing leaching solution, and the second impurity removal unit is connected to the pH adjustment unit.

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