Method for recovering nickel in smelting acid mud through microwave-enhanced thiosulfate leaching-electrodeposition

Abstract

The invention discloses a method for recovering nickel in smelting acid mud through microwave-enhanced thiosulfate leaching-electrodeposition. The method comprises the steps of raw material preparation, leaching agent preparation, microwave reaction mixing, electrodeposition treatment and regeneration treatment. According to the method, the microwave-enhanced thiosulfate leaching technology is adopted, the leaching efficiency of nickel can be remarkably improved, the nickel recovery rate can reach 98% or above after the reaction is carried out for 1 h in the microwave environment at the temperature of 118-122 DEG C, and compared with a traditional technology, the nickel extraction efficiency is greatly improved through the improvement, resource waste is reduced, and the method is suitable for industrial production. In the regeneration treatment step, a microwave regenerator is used for treating the waste electrolyte under the conditions of 120 DEG C and 2.45 GHz, S4O6 < 2-> is reduced into S2O3 < 2->, high-efficiency regeneration of thiosulfate is achieved, the regeneration rate reaches 95% or above and is improved by 137.5% compared with a traditional process, and therefore consumption of chemicals is reduced, and the generation amount of waste is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-ferrous metallurgy and solid waste resource utilization, and particularly relates to a method for recovering nickel in smelting acid sludge by microwave-enhanced thiosulfate leaching-electrodeposition. BACKGROUND

[0002] Hydrometallurgical recovery technology is a process that uses chemical solutions in liquid phase to extract and separate metals. This method is widely used in the recovery of valuable metals from ores, tailings, electronic waste and other materials. The main steps of hydrometallurgy include leaching, solution purification and concentration, metal recovery, etc.

[0003] This method is widely used in the recovery of valuable metals from ores, concentrates, waste slag, tailings and scrap metal products. The existing hydrometallurgical recovery technology has the following defects: low thiosulfate regeneration rate, the process operation is: acid sludge→leaching(70℃,2h)→filtration→electrodeposition→waste liquid supplemented with 30% new Na2SO3 and recycled, wherein the basic formula of leaching agent is: Na2S2O30.8mol / L+Na2SO30.2mol / L+CuSO40.03mol / L+NH3·H2O(pH=9.5), after 5 cycles, the concentration of S2O32- will decrease from 1.2mol / L to 0.4mol / L(loss 67%). After 10 cycles, the catalyst is deactivated, and the electrodeposition current efficiency is reduced to 33%, which is easy to cause secondary pollution and form hazardous waste sludge;

[0004] The generation of hazardous waste sludge will have the following hazards:

[0005] Environmental impact:

[0006] Soil and water pollution: harmful substances in hazardous waste sludge may seep into the soil or flow into the water, causing soil degradation, water quality deterioration, and further long-term harm to the ecosystem;

[0007] Reduced biodiversity: pollutants entering the natural environment will affect plant growth and animal survival, disrupt the ecological balance, and lead to a decrease in biodiversity;

[0008] Air pollution: if these sludge is improperly handled or disposed of, such as open-air stacking or simple incineration, harmful gas emissions into the atmosphere will further exacerbate air quality problems;

[0009] Economic burden

[0010] Increased governance cost: In order to prevent the occurrence of the above environmental pollution, enterprises need to invest a large amount of funds for sewage treatment, soil remediation and air purification and other environmental protection measures, which increases the operating cost;

[0011] Waste of resources: The traditional process not only fails to effectively recover all valuable metal components, but also produces a large amount of waste that is difficult to handle, which is actually a waste of resources;

[0012] Therefore, we propose a method for recovering nickel in smelting acid mud by microwave enhanced thiosulfate leaching-electrodeposition. SUMMARY

[0013] The purpose of the present application is to provide a method for recovering nickel in smelting acid mud by microwave enhanced thiosulfate leaching-electrodeposition, in order to solve the problems in the background art.

[0014] To achieve the above purpose, the present application provides the following technical solution: a method for recovering nickel in smelting acid mud by microwave enhanced thiosulfate leaching-electrodeposition, which comprises the following steps:

[0015] Step 1: raw material preparation: using acid mud containing 8-9% nickel as starting material;

[0016] Step 2: preparation of leaching agent: the leaching agent manufacturing material is sodium thiosulfate solution and copper ion solution, and sodium thiosulfate and copper ion solution are fully stirred and mixed by using a stirring device;

[0017] Step 3: reaction mixing: the acid mud and the leaching agent are stirred and mixed to obtain mixture A, and mixture A is placed in a microwave environment, and is reacted at a temperature of 118-122℃ for more than 1h to obtain mixture B;

[0018] Step 4: electrodeposition treatment: using electrolysis method to treat and deposit mixture B to obtain metallic nickel and solution C;

[0019] Step 5: regeneration treatment: solution C after electrodeposition treatment is introduced into a microwave regenerator for regeneration treatment.

[0020] The hydrometallurgical recovery technology is widely used in the recovery of valuable metals from ores, concentrates, waste residues, tailings and waste metal products. The existing hydrometallurgical recovery technology has the following defects: the thiosulfate regeneration rate is low, and the process operation is: acid mud→leaching (70℃, 2h)→filtration→electrodeposition→waste liquid supplemented with 30% new Na2SO3 and recycled, wherein the basic formula of the leaching agent is: Na2S2O30.8mol / L+Na2SO30.2mol / L+CuSO40.03mol / L+NH3·H2O (pH=9.5), and after 5 cycles, the concentration of S2O32- will decrease from 1.2mol / L to 0.4mol / L (loss 67%). After 10 cycles, the catalyst is deactivated, and the electrodeposition current efficiency is reduced to 33%, which is easy to cause secondary pollution and form hazardous waste sludge. The present application uses microwave enhanced thiosulfate leaching technology, which can significantly improve the leaching efficiency of nickel. In the microwave environment at a temperature of 118-122℃, the nickel recovery rate can reach more than 98% after 1 hour of reaction. Compared with the traditional process, this improvement greatly improves the extraction efficiency of nickel and reduces resource waste. Moreover, in the regeneration treatment step, the microwave regenerator is used to treat the waste electrolyte at 118-122℃ and 2.45GHz to reduce S4O62- to S2O32-, realizing high-efficiency regeneration of thiosulfate, and the regeneration rate reaches more than 95%, which is 137.5% higher than that of the traditional process, which not only reduces the consumption of chemicals, but also reduces the generation amount of waste; and the present application adds sodium metabisulfite as a free radical quencher to effectively inhibit the occurrence of side reactions and avoid the generation of harmful substances. At the same time, the regenerated solution is neutralized by Ca(OH)2 to precipitate SO42-, generating CaSO4 byproduct, further reducing the emission of pollutants; finally, the present application not only improves the recovery rate of nickel, but also greatly reduces the treatment cost. Compared with the traditional process, the treatment cost of the present application is reduced by about 44%, which brings considerable economic benefits to enterprises. In addition, the stability and repeatability of the process are good, and even after multiple cycles of use, the leaching rate of nickel can still remain above 90%, ensuring the economic feasibility of long-term operation.

[0021] As a further description of the above technical solution:

[0022] The copper ion solution is set as a copper sulfate solution, and the thiosulfate sodium solution and the copper sulfate solution are 1.0mol / L and 0.02mol / L respectively.

[0023] As a further description of the above technical solution:

[0024] The electrodeposition treatment in step three includes the following steps:

[0025] Step A1: monitor the nickel content of mixture B, so that the nickel ion content in mixture B is greater than 50g / L;

[0026] Step A2: Start the electrowinning process: Put mixture B into the electrowinning tank, connect the power supply to the anode and cathode in the electrolytic cell, and pass the current through mixture B to cause a reduction reaction at the cathode, reducing nickel ions to metallic nickel and depositing them on the cathode.

[0027] Step A3: End of collection: Set a threshold for the amount of nickel in mixture B, and stop the electrowinning process when the amount of nickel in the solution of mixture B is below the set threshold, and remove the cathode, clean it and collect the pure nickel metal deposited on the cathode.

[0028] Further description of the above technical solution:

[0029] The electrowinning process in step three also includes monitoring the electrowinning environment: the voltage of the electrowinning process is set to 1.5-4V, the current density is 200A / ㎡, and the pH of mixture B is 3.5-6.5.

[0030] Further description of the above technical solution:

[0031] During the regeneration process in step five, the microwave regenerator power is set to 1.5KW, the microwave frequency is set to 2.45GHz, the microwave regenerator processing temperature is 120℃, and the processing time is 30-40min.

[0032] Further description of the above technical solution:

[0033] After the regeneration process in step five is completed, 0.05-0.08mol / L of sodium pyrosulfite solution is added to solution C.

[0034] Further description of the above technical solution:

[0035] The method for increasing the amount of nickel in mixture B in step A1 includes evaporative concentration of mixture B, membrane separation of mixture B, organic solvent stripping and multiple leaching of acid sludge treatment of combined mixture B.

[0036] Further description of the above technical solution:

[0037] The leaching agent preparation in step two includes the following steps:

[0038] Step B1: Dissolve sodium thiosulfate: Weigh the required amount of sodium thiosulfate solid and disperse it into deionized water, stirring until the sodium thiosulfate solid and deionized water are completely dissolved to obtain mixture D;

[0039] Step B2: Add copper sulfate: Weigh the required amount of copper sulfate solution, and adjust the Cu 2+When the concentration reaches 0.02 mol / L, the copper sulfate solution is added to the mixture D while stirring until the mixture D and the copper sulfate solution are completely dissolved to obtain a mixture E;

[0040] Step B3: adjusting the pH value: using ammonia water with a concentration of 28-30% to adjust the pH value of the solution to 9-10 to obtain the leaching solution.

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] 1. The present application uses the microwave enhanced thiosulfate leaching technology, which can significantly improve the leaching efficiency of nickel. In a microwave environment at a temperature of 118-122℃, the reaction is carried out for 1 hour, and the recovery rate of nickel can reach more than 98%. Compared with the traditional process, this improvement greatly improves the extraction efficiency of nickel and reduces resource waste.

[0043] 2. Moreover, in the regeneration treatment step, the microwave regenerator is used to treat the waste electrolyte at 120℃ and 2.45GHz to reduce S4O62- to S2O32-, realizing high-efficiency regeneration of thiosulfate, and the regeneration rate reaches more than 95%, which is 137.5% higher than the traditional process. This not only reduces the consumption of chemicals, but also reduces the amount of waste generated.

[0044] 3. Moreover, the present application adds sodium pyrosulfite as a free radical quencher, effectively inhibiting the occurrence of side reactions and avoiding the generation of harmful substances. At the same time, the regenerated solution is neutralized by Ca(OH)2 to precipitate SO42-, generating CaSO4 byproduct, further reducing the emission of pollutants.

[0045] 4. Finally, the present application not only improves the recovery rate of nickel, but also greatly reduces the treatment cost. Compared with the traditional process, the treatment cost of the present application is reduced by about 44%, which brings considerable economic benefits to the enterprise. In addition, the stability and repeatability of the process are good. Even after multiple cycles of use, the leaching rate of nickel can still remain above 90%, ensuring the economic feasibility of long-term operation. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 It is a schematic diagram of the system principle of the present application. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0048] Embodiment One:

[0049] Referring to Figure 1 The present application provides a technical solution: a method for recovering nickel from smelting acid mud by microwave-enhanced thiosulfate leaching-electrodeposition, which comprises the following steps:

[0050] Step One: Raw material preparation: using acid mud containing 8-9% of nickel as the starting material;

[0051] Step Two: Preparation of leaching agent: the leaching agent manufacturing material is sodium thiosulfate solution and copper ion solution, and sodium thiosulfate and copper ion solution are fully stirred and mixed by using a stirring device;

[0052] Step Three: Reaction mixing: the acid mud and the leaching agent are stirred and mixed to obtain mixture A, and mixture A is placed in a microwave environment, and is reacted at a temperature of 118-122℃ for more than 1h to obtain mixture B;

[0053] Step Four: Electrodeposition treatment: using electrolysis to treat and deposit mixture B to obtain metallic nickel and solution C;

[0054] Step Five: Regeneration treatment: solution C after electrodeposition treatment is introduced into a microwave regenerator for regeneration treatment.

[0055] Among them, the leaching agent is composed of sodium thiosulfate solution and copper ion solution, and is fully mixed by a stirring device. This combination not only helps to improve the leaching effect of nickel, but also enhances the stability and activity of the solution. Specifically, the presence of copper ions can promote the effective leaching of nickel by thiosulfate, and sodium thiosulfate acts as an effective complexing agent, enhancing the solubility of nickel ions in the solution. The application of microwave technology is a highlight of this method, which not only accelerates the chemical reaction rate and shortens the treatment time, but also uniformly heats the materials, avoiding local overheating phenomenon, improving the selectivity and efficiency of the reaction. High temperature environment helps to increase the activity of thiosulfate ions, further improving the leaching effect of nickel. Metallic nickel and solution C are obtained by electrodeposition from mixture B. Through strict control of the electrodeposition conditions, the deposition efficiency of nickel can be effectively improved, and the stability of the solution is maintained. Solution C after electrodeposition treatment is introduced into a microwave regenerator for regeneration treatment, so that S4O6 2- is reduced to S2O3 2- , realizing efficient regeneration of thiosulfate solution. This method not only improves the regeneration rate of thiosulfate to more than 95%, but also reduces the consumption of chemicals and the discharge of waste liquid, and reduces the risk of environmental pollution.

[0056] Embodiment Two:

[0057] The copper ion solution is set as a copper sulfate solution, the sodium thiosulfate solution and the copper sulfate solution are 1.0 mol / L and 0.02 mol / L respectively.

[0058] The copper ion as a catalyst can promote the formation of a stable complex of thiosulfate and nickel, improve the dissolution efficiency of nickel, and under appropriate concentration, help to selectively extract nickel and reduce the co-dissolution of other impurity metals, thereby improving the purity of the product. Moreover, copper sulfate is low in cost and easy to obtain, which is convenient for large-scale industrial application.

[0059] The electrodeposition treatment in step three includes the following steps:

[0060] Step A1: Monitor the nickel content of the mixture B, so that the nickel ion content in the mixture B is greater than 50 g / L;

[0061] Step A2: Start the electrodeposition process: put the mixture B into the electrodeposition tank, connect the power supply to the anode and cathode in the electrolytic cell, and pass the current through the mixture B to cause a reduction reaction on the cathode, so that the nickel ions are reduced to metallic nickel and deposited on the cathode;

[0062] Step A3: End of collection: set a threshold value for the nickel content of the mixture B, and stop the electrodeposition process when the monitored nickel content of the mixture B solution is lower than the set threshold value, and then take out the cathode, clean and collect the pure nickel metal deposited on the cathode. The voltage of the electrodeposition treatment process is set to 1.5-4V, the current density is 200A / ㎡, and the pH value of the mixture B is 3.5-6.5.

[0063] The high nickel ion concentration can ensure the maximum current efficiency of the electrodeposition process, avoid the decrease of deposition rate caused by low concentration, and improve the product quality. The electrodeposition is carried out after the nickel ion concentration meets the standard, which is beneficial to obtain a dense, smooth and high-purity nickel layer. Moreover, by monitoring the nickel ion concentration in real time, the subsequent treatment parameters can be dynamically adjusted to achieve precise control. When starting the electrodeposition process, the voltage is set to 1.5-4V, the current density is 200A / ㎡, and the pH value is controlled at 3.5-6.5. Within this voltage and current density range, the reduction rate of nickel is moderate, which can quickly deposit without producing dendrites or powdery deposits that affect product quality. The current efficiency can reach more than 90% under this condition, which is significantly higher than that of traditional processes. The pH value is controlled between 3.5 and 6.5, which can effectively prevent the hydrogen evolution side reaction and maintain the stability of thiosulfate, thereby prolonging its service life. By setting the nickel content threshold, the electrodeposition can be stopped in time and the metallic nickel can be collected. When the nickel content decreases to a certain threshold, the electrodeposition is stopped to avoid invalid energy consumption and equipment wear and tear. By setting an automatic stop mechanism, intelligent production is realized, manual intervention is reduced, the electrodeposition time of different batches is consistent, and the quality and thickness of the obtained metallic nickel are similar.

[0064] The microwave regenerator power is set to 1.5KW, the microwave frequency is set to 2.45GHz, the microwave regenerator processing temperature is 120℃, and the processing time is 30-40min.

[0065] In the process of limiting the processing environment of the microwave regenerator, S4O62- is efficiently reduced to S2O32- under this condition, and the regeneration rate reaches more than 95%, which is much higher than that of the traditional pyrolysis method. Moreover, the microwave regenerator can process uniformly, quickly, and with low energy consumption, and no harmful gas is discharged. In addition, the microwave regenerator can accurately control the microwave parameters to repeatedly obtain high-quality regenerated liquid, which is suitable for industrial continuous operation.

[0066] After the regeneration process in step five is completed, 0.05-0.08mol / L of sodium metabisulfite solution is added to solution C.

[0067] After the regeneration is completed, the addition of 0.05-0.08mol / L of sodium metabisulfite solution can inhibit the free radical reaction. Sodium metabisulfite, as a free radical quencher, can effectively prevent the oxidative decomposition of thiosulfate under light or high temperature. Moreover, after adding it, the recycling number of the regenerated liquid can be significantly prolonged, the chemical consumption can be reduced, and the secondary precipitation or complexation failure of metal ions can also be effectively prevented.

[0068] The method for increasing the nickel content of mixture B in step A1 includes evaporation and concentration of mixture B, membrane separation of mixture B, organic solvent back extraction, and multiple leaching of acid sludge treatment of combined mixture B.

[0069] The increase of the nickel content of mixture B can improve the electrodeposition efficiency: by enriching nickel ions in multiple ways, the electrodeposition liquid can reach the ideal concentration, thereby improving the deposition efficiency and metal recovery rate. Moreover, the use of multiple leaching combined liquid can maximize the recovery of nickel resources in acid sludge and reduce waste.

[0070] The leaching agent preparation in step two includes the following steps:

[0071] Step B1: Dissolve sodium thiosulfate: weigh the required amount of sodium thiosulfate solid, and disperse the sodium thiosulfate solid into deionized water, and stir and mix until the sodium thiosulfate solid and deionized water are completely dissolved to obtain mixture D;

[0072] Step B2: Add copper sulfate: weigh the required amount of copper sulfate solution, so that the Cu 2+ concentration in the copper sulfate solution reaches 0.02mol / L, and then add the copper sulfate solution to mixture D while stirring and mixing until mixture D and the copper sulfate solution are completely dissolved to obtain mixture E;

[0073] Step B3: pH adjustment: using ammonia water with a concentration of 28-30% to adjust the pH value of the mixture E to 9-10 to obtain the leaching solution.

[0074] Wherein, during the preparation of the leaching agent, the pH value is adjusted by using ammonia water, which can enhance the complexing effect. The basic environment is conducive to the complexation reaction of thiosulfate and nickel, which can improve the leaching rate of nickel and inhibit side reactions. In the pH range of 9-10, the decomposition of thiosulfate can be effectively inhibited, prolonging its service life. The control range of pH value can prevent metal precipitation or oxidation, ensuring long-term storage and circulation of the leaching solution.

[0075] Example Three:

[0076] A method for recovering nickel from smelting acid mud by microwave-enhanced thiosulfate leaching-electrodeposition, comprising the following steps:

[0077] Step one: raw material preparation: using acid mud with a nickel content of 8% as the starting material;

[0078] Step two: leaching agent preparation: the leaching agent manufacturing material is sodium thiosulfate solution and copper ion solution, which are fully stirred and mixed by using a stirring device;

[0079] Step three: reaction mixing: the acid mud and the leaching agent are stirred and mixed to obtain mixture A, which is placed in a microwave environment, and a temperature of 118°C is used for reaction for more than 1h to obtain mixture B;

[0080] Step four: electrodeposition treatment: using electrolysis to treat mixture B to deposit metal nickel and solution C;

[0081] Step five: regeneration treatment: solution C after electrodeposition treatment is introduced into a microwave regenerator for regeneration treatment.

[0082] The copper ion solution is set as copper sulfate solution, and the sodium thiosulfate solution and the copper sulfate solution are set as sodium thiosulfate solution 1.0 mol / L and copper sulfate solution 0.02 mol / L.

[0083] The electrodeposition treatment in step three includes the following steps:

[0084] Step A1: monitor the nickel content of mixture B, so that the nickel ion content in mixture B is 51g / L;

[0085] Step A2: start the electrodeposition process: put mixture B into the electrodeposition tank, connect the power supply to the anode and cathode in the electrolytic cell, and pass the current through mixture B. Reduction reaction occurs on the cathode, reducing nickel ions to metal nickel and depositing on the cathode;

[0086] Step A3: End of collection: Set the threshold of the nickel content of mixture B, stop the electrodeposition process when the nickel content of mixture B solution is lower than the set threshold, and take out the cathode, clean and collect the pure nickel metal material deposited on the cathode.

[0087] The electrodeposition process in step three also includes electrodeposition environment monitoring: the voltage of the electrodeposition process is set to 1.5V, the current density is 200A / m2, and the pH value of mixture B is 3.5.

[0088] During the regeneration process in step five, the microwave regenerator power is set to 1.5KW, the microwave frequency is set to 2.45GHz, the microwave regenerator processing temperature is 120℃, and the processing time is 30min.

[0089] After the regeneration process in step five is completed, 0.05mol / L of sodium pyrosulfite solution is added to solution C.

[0090] The method for increasing the nickel content of mixture B in step A1 includes evaporative concentration of mixture B, membrane separation of mixture B, organic solvent back extraction, and multiple leaching of acid sludge treatment of combined mixture B.

[0091] The leaching agent preparation in step two includes the following steps:

[0092] Step B1: Dissolve sodium thiosulfate: weigh the required amount of sodium thiosulfate solid and disperse the sodium thiosulfate solid into deionized water, stir and mix until the sodium thiosulfate solid and deionized water are completely dissolved to obtain mixture D;

[0093] Step B2: Add copper sulfate: weigh the required amount of copper sulfate solution, and add the copper sulfate solution to mixture D while stirring and mixing until mixture D and the copper sulfate solution are completely dissolved to obtain mixture E; 2+

[0094] Step B3: Adjust the pH value: adjust the pH value of mixture E to 9 using ammonia water with a concentration of 28% to obtain the leaching solution.

[0095] Example Four:

[0096] A microwave-enhanced thiosulfate leaching-electrodeposition method for recovering nickel from smelting acid sludge, the microwave-enhanced thiosulfate leaching-electrodeposition method for recovering nickel from smelting acid sludge includes the following steps:

[0097] Step One: Raw material preparation: use acid sludge with a nickel content of 9% as the starting material;

[0098] ​Step two: preparation of leaching agent: the leaching agent manufacturing material is sodium thiosulfate solution and copper ion solution, sodium thiosulfate and copper ion solution are fully stirred and mixed by using stirring device;

[0099] Step three: reaction mixing: the acid sludge is stirred and mixed with the leaching agent to obtain mixture A, mixture A is placed in a microwave environment, and mixture B is obtained by using a temperature of 122℃ for reaction for more than 1h;

[0100] Step four: electro-deposition treatment: mixture B is treated by deposition by using electrolysis to obtain metallic nickel and solution C;

[0101] Step five: regeneration treatment: solution C after the electro-deposition treatment is introduced into a microwave regenerator for regeneration treatment.

[0102] The copper ion solution is set as copper sulfate solution, the sodium thiosulfate solution and the copper sulfate solution are set as follows: the sodium thiosulfate solution is 1.0 mol / L, and the copper sulfate solution is 0.02 mol / L.

[0103] Further description of the above technical solution:

[0104] The electro-deposition treatment in step three includes the following steps:

[0105] Step A1: monitoring the nickel content of mixture B, so that the nickel ion content in mixture B is 60g / L;

[0106] Step A2: starting the electro-deposition process: mixture B is placed into an electro-deposition tank, a power supply is connected to supply power to the anode and the cathode in the electrolytic tank, current passes through mixture B, and a reduction reaction occurs on the cathode, so that nickel ions are reduced to metallic nickel and deposited on the cathode;

[0107] Step A3: ending collection: a threshold value of the nickel content of mixture B is set, and when the monitored nickel content of mixture B solution is lower than the set threshold value, the electro-deposition process is stopped, the cathode is taken out, and the pure nickel metal material deposited on the cathode is cleaned and collected.

[0108] The electro-deposition treatment in step three further includes electro-deposition environment monitoring: the voltage of the electro-deposition treatment process is set to 4V, the current density is 200A / ㎡, and the PH value of mixture B is 6.5.

[0109] Further description of the above technical solution:

[0110] In the regeneration treatment of step five, the power of the microwave regenerator is set to 1.5KW, the microwave frequency is set to 2.45GHz, the treatment temperature of the microwave regenerator is 120℃, and the treatment time is 40min.

[0111] After the regeneration treatment of step five is completed, 0.08mol / L of sodium pyrosulfite solution is added to solution C.

[0112] The method for increasing the nickel content of the mixture B in step A1 includes evaporative concentration of the mixture B, membrane separation of the mixture B, organic solvent back extraction, and multiple leaching of the acid sludge treatment of the combined mixture B.

[0113] The leaching agent preparation in step two includes the following steps:

[0114] Step B1: Dissolution of sodium thiosulfate: weigh the required amount of sodium thiosulfate solid and disperse the sodium thiosulfate solid into deionized water, stir and mix until the sodium thiosulfate solid and deionized water are completely dissolved to obtain mixture D;

[0115] Step B2: Add copper sulfate: weigh the required amount of copper sulfate solution, and add the copper sulfate solution to the mixture D while stirring until the mixture D and copper sulfate solution are completely dissolved to obtain mixture E; 2+

[0116] Step B3: Adjust the pH value: adjust the pH value of the solution to 10 using 30% ammonia water to obtain the leaching solution.

[0117] Example five:

[0118] A microwave-enhanced thiosulfate leaching-electrodeposition method for recovering nickel from smelting acid sludge, the microwave-enhanced thiosulfate leaching-electrodeposition method for recovering nickel from smelting acid sludge includes the following steps:

[0119] Step one: raw material preparation: use acid sludge with a nickel content of 8.5% as the starting material;

[0120] Step two: leaching agent preparation: the leaching agent manufacturing material is a sodium thiosulfate solution and a copper ion solution, and the sodium thiosulfate and copper ion solution are fully stirred and mixed using a stirring device;

[0121] Step three: reaction mixing: stir and mix the acid sludge with the leaching agent to obtain mixture A, place the mixture A in a microwave environment, and use a temperature of 120°C for reaction for more than 1h to obtain mixture B;

[0122] Step four: electrodeposition treatment: use electrolysis to treat and deposit the mixture B to obtain metallic nickel and solution C;

[0123] Step five: regeneration treatment: pass the solution C after electrodeposition treatment into a microwave regenerator for regeneration treatment.

[0124] The copper ion solution is set as a copper sulfate solution, and the sodium thiosulfate solution and the copper sulfate solution are set as a sodium thiosulfate solution of 1.0 mol / L and a copper sulfate solution of 0.02 mol / L. ​

[0125] The electro-deposition process in the third step includes the following steps:

[0126] Step A1: Monitor the nickel content of mixture B, so that the nickel ion content in mixture B is 65g / L;

[0127] Step A2: Start the electro-deposition process: place mixture B into the electro-deposition tank, connect the power supply to the anode and cathode in the electrolytic cell, and pass current through mixture B to cause a reduction reaction at the cathode, reducing nickel ions to metallic nickel and depositing them on the cathode;

[0128] Step A3: End of collection: set a threshold value for the nickel content of mixture B, and stop the electro-deposition process when the monitored nickel content of mixture B solution falls below the set threshold value, and remove the cathode, clean it, and collect the pure nickel metal deposited on the cathode.

[0129] The electro-deposition process in the third step also includes electro-deposition environment monitoring: the voltage of the electro-deposition process is set to 2.75V, the current density is 200A / ㎡, and the pH value of mixture B is 5.

[0130] During the regeneration process in the fifth step, the microwave regenerator power is set to 1.5KW, the microwave frequency is set to 2.45GHz, the microwave regenerator processing temperature is 120℃, and the processing time is 35min.

[0131] Further description of the above technical solutions:

[0132] After the regeneration process in the fifth step is completed, 0.6mol / L of sodium pyrosulfite solution is added to solution C.

[0133] The method for increasing the nickel content of mixture B in the first step A1 includes evaporative concentration of mixture B, membrane separation of mixture B, organic solvent stripping, and multiple leaching of acid sludge treatment of the combined mixture B.

[0134] The leaching agent preparation in the second step includes the following steps:

[0135] Step B1: Dissolve sodium thiosulfate: weigh the required amount of sodium thiosulfate solid and disperse it into deionized water, stirring until the sodium thiosulfate solid and deionized water are completely dissolved to obtain mixture D;

[0136] Step B2: Add copper sulfate: weigh the required amount of copper sulfate solution so that the Cu 2+ concentration in the copper sulfate solution reaches 0.02mol / L, and add the copper sulfate solution to mixture D while stirring until mixture D and the copper sulfate solution are completely dissolved to obtain mixture E;

[0137] Step B3: pH adjustment: To the mixture E, pH of the solution was adjusted to 9.5 using ammonia water of 29% concentration to obtain the leach liquor.

[0138] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and spirit of the application and that numerous modifications, changes, substitutions, and alterations can be undertaken by one skilled in the art without departing from the principles and spirit of the application, which is defined by the claims as appended hereto and their equivalents.

Claims

1. A method for recovering nickel from smelting acid sludge by microwave enhanced thiosulfate leaching-electrowinning, characterized in that: The method comprises the following steps: Step one: raw material preparation: using acid mud containing 8-9% of nickel as starting material; Step two: leaching agent preparation: the leaching agent manufacturing material is sodium thiosulfate solution and copper ion solution, using stirring device to fully stir and mix sodium thiosulfate and copper ion solution; Step three: reaction mixing: stirring and mixing acid mud and leaching agent to obtain mixture A, placing mixture A in microwave environment, using temperature 118-122℃ to react for more than 1h to obtain mixture B; Step four: electrodeposition treatment: using electrolysis method to treat mixture B to deposit metal nickel and solution C; Step five: regeneration treatment: passing solution C after electrodeposition treatment into microwave regenerator for regeneration treatment.

2. The method for recovering nickel from smelting acid sludge by microwave enhanced thiosulfate leaching-electrowinning according to claim 1, characterized in that: The copper ion solution is set as copper sulfate solution, the sodium thiosulfate solution and the copper sulfate solution are that the sodium thiosulfate solution is 1.0mol / L, and the copper sulfate solution is 0.02mol / L.

3. The method according to claim 2, wherein the method is characterized by: The electrodeposition treatment in step three comprises the following steps: Step A1: monitoring the nickel content of mixture B, so that the nickel ion content in mixture B is greater than 50g / L; Step A2: starting electrodeposition process: placing mixture B into electrodeposition tank, connecting power supply to supply power to anode and cathode in electrolytic cell, current passing through mixture B, reduction reaction occurring on cathode, nickel ion being reduced to metal nickel and deposited on cathode; Step A3: ending collection: setting nickel content threshold value of mixture B, stopping electrodeposition process when the nickel content of mixture B solution is lower than the set threshold value, taking out cathode, cleaning and collecting pure nickel metal material deposited on cathode.

4. The method according to claim 3, wherein the method is characterized by: The electrodeposition treatment in step three further comprises electrodeposition environment monitoring: the voltage of electrodeposition treatment process is set as 1.5-4V, the current density is 200A / m2, and the PH value of mixture B is 3.5-6.

5.

5. The method according to claim 4, wherein the method is characterized by: In step five, the power of microwave regenerator is set as 1.5KW, the microwave frequency is set as 2.45GHz, the treatment temperature of microwave regenerator is 120℃, and the treatment time is 30-40min.

6. The method according to claim 5, wherein the method is characterized by: After step five, 0.05-0.08mol / L of sodium metabisulfite solution is added to solution C.

7. The method according to claim 6, wherein the method is characterized by: The method for increasing the nickel content of mixture B in step A1 comprises evaporation and concentration of mixture B, membrane separation of mixture B, organic solvent back extraction and multiple leaching of acid mud to combine mixture B.

8. The method according to claim 7, wherein the method is characterized by: The leaching agent preparation in step two comprises the following steps: Step B1: dissolving sodium thiosulfate: weighing required amount of sodium thiosulfate solid, dispersing sodium thiosulfate solid into deionized water, stirring and mixing until sodium thiosulfate solid and deionized water are completely dissolved to obtain mixture D; Step B2: Addition of copper sulfate: Weigh the required amount of copper sulfate solution, and add the copper sulfate solution into the mixture D while stirring until the mixture D and the copper sulfate solution are completely dissolved to obtain a mixture E. 2+ The concentration of the copper sulfate solution reaches 0.02 mol / L, and the copper sulfate solution is added into the mixture D while stirring until the mixture D and the copper sulfate solution are completely dissolved to obtain a mixture E. Step B3: adjusting PH value: using ammonia water with concentration of 28-30% to adjust the PH value of solution to 9-10 to obtain leaching solution.

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