Modified magnesium oxide for wet nickel extraction and preparation method thereof
By using rare earth compound doping, chelating agent coating, and heterogeneous nucleating agent to modify magnesium oxide, the problems of slow dissolution and unstable pH adjustment of traditional magnesium oxide in wet nickel extraction have been solved, achieving improved nickel recovery efficiency and environmental friendliness, making it suitable for industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI BOZHONG NEW MAGNESIUM NEW MATERIAL TECHNOLOGY CO LTD
- Filing Date
- 2026-04-08
- Publication Date
- 2026-06-12
AI Technical Summary
Existing conventional magnesium oxide processes suffer from poor solubility and unstable pH adjustment during wet nickel extraction, affecting nickel recovery efficiency and impurity removal efficiency. Furthermore, conventional liquid alkali processes are costly and generate large amounts of saline wastewater, which does not align with the trend of green smelting.
Magnesium oxide was modified by a combination of rare earth compound doping, iminodiacetic acid chelating agent coating, and heterogeneous nucleating agent. The preparation method includes pretreatment, rare earth doping, chelation coating, and heterogeneous nucleation steps, forming a three-step synergistic modification system.
It improves the solubility and pH stability of magnesium oxide, enhances the selectivity of nickel recovery, reduces costs and decreases the generation of saline wastewater, making it suitable for industrial production.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of hydrometallurgical technology, specifically to a modified magnesium oxide for hydrometallurgical nickel extraction and its preparation method. Background Technology
[0002] Hydrometallurgical nickel extraction is an important process in the field of non-ferrous metal smelting. Magnesium oxide, due to its moderate alkalinity and readily available raw materials, is often used as a precipitant and adsorbent in the sulfuric acid leaching system of this process, becoming a key auxiliary agent in the hydrometallurgical nickel extraction process.
[0003] However, the traditional magnesium oxide used in the existing technology has many technical defects. Its solubility is poor and its reaction rate with the leaching solution is slow, which directly affects the overall process efficiency of wet nickel extraction. At the same time, the pH adjustment stability of traditional magnesium oxide is poor, which can easily cause large fluctuations in the acidity and alkalinity of the leaching system. This not only reduces the selective recovery effect of nickel ions, but also makes it difficult to meet the removal efficiency of impurities such as iron and aluminum to meet the requirements of industrial production.
[0004] To address the aforementioned issues, existing technologies have introduced single-modification magnesium oxide products, such as those modified solely through rare earth doping or chelation coating. However, such single-modification schemes can only optimize one specific defect and cannot achieve comprehensive performance improvement, making it difficult to meet the diverse performance requirements of magnesium oxide in industrial production.
[0005] Furthermore, the traditional liquid alkali process is still widely used in the field of wet nickel extraction. Although this process can achieve a certain nickel recovery effect, it suffers from high raw material costs and generates a large amount of saline wastewater during the reaction, resulting in high environmental treatment pressure, which is not in line with the current industry development trend of green smelting. Therefore, developing a magnesium oxide modified product for wet nickel extraction with excellent comprehensive performance, economic and environmental protection and suitable for industrial production and its preparation method has become an urgent technical problem to be solved in this field. Summary of the Invention
[0006] The primary objective of this invention is to provide a modified magnesium oxide for wet nickel extraction and its preparation method.
[0007] A further objective of this invention is to provide a modified magnesium oxide for wet nickel extraction, which is prepared by using magnesium oxide as a base and by doping with rare earth compounds, coating with iminodiacetic acid chelating agents, and modifying with heterogeneous nucleating agents. The rare earth compounds are cerium nitrate or lanthanum nitrate, and the amount of rare earth compounds is 0.5%-2.0% of the mass of magnesium oxide. The amount of iminodiacetic acid chelating agents is 0.8% of the mass of magnesium oxide. The heterogeneous nucleating agents are diatomaceous earth or γ-Al2O3, and the amount of heterogeneous nucleating agents is 2.0% of the mass of magnesium oxide.
[0008] Preferably, the purity of the magnesium oxide used as the substrate is 90%-99.9%.
[0009] A method for preparing modified magnesium oxide for wet nickel extraction includes the following steps: (1) Raw material pretreatment: Take magnesium oxide powder and crush it to 100 mesh, dry it at 110℃ for 4 hours for later use; take heterogeneous nucleating agent and activate it for later use. (2) Rare earth doping modification: The dried magnesium oxide powder was added to the stirred reactor, deionized water was added to adjust the solid-liquid ratio to 1:10, the stirring speed was set to 300 r / min and the temperature was raised to 60℃, rare earth compound solution was added, and stirring was continued for 2 hours to obtain rare earth doped magnesium oxide slurry. (3) Chelation coating modification: Add iminodiacetic acid chelating agent to rare earth doped magnesium oxide slurry, maintain temperature at 60℃ and stirring speed at 300r / min, and continue stirring for 3h to obtain chelated modified slurry; (4) Heterogeneous nucleation composite modification: Add the activated heterogeneous nucleating agent to the chelated modified slurry, heat to 80℃ and increase the stirring speed to 400r / min, and continue stirring to obtain the composite modified slurry; (5) Post-processing: The composite modified slurry is filtered, the filter cake is washed with deionized water and dried at 110°C for 6 hours, then placed in a muffle furnace and heated at a rate of 5°C / min for 5 hours. After cooling to room temperature, it is pulverized to 120 mesh to obtain the modified magnesium oxide product for wet nickel extraction.
[0010] Preferably, the rare earth compound is cerium nitrate or lanthanum nitrate, and the amount of rare earth compound solution added is such that the rare earth compound accounts for 0.5%-2.0% of the mass of magnesium oxide.
[0011] Preferably, the amount of the iminodiacetic chelating agent added is 0.8% of the mass of magnesium oxide.
[0012] Preferably, the heterogeneous nucleating agent is diatomaceous earth or γ-Al2O3, and the amount of heterogeneous nucleating agent added is 2.0% of the mass of magnesium oxide; the activation treatment of diatomaceous earth is to pulverize it to 200 mesh and then calcine it at 550°C for 4 hours, and the activation treatment of γ-Al2O3 is to calcine it at 550°C for 4 hours.
[0013] Preferably, the continuous stirring time in the heterogeneous nucleation composite modification step is 3h-5h.
[0014] Preferably, in the post-processing step, the filter cake is washed three times with deionized water, and the calcination temperature in the muffle furnace is 400℃-600℃.
[0015] Preferably, the purity of the magnesium oxide powder is 90%-99.9%.
[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The modified magnesium oxide for wet nickel extraction and its preparation method provided by this invention fundamentally solves the core technical pain points of traditional magnesium oxide, such as poor solubility, unstable pH adjustment and poor selective recovery effect, through a three-step synergistic modification system of rare earth doping, chelation coating and heterogeneous nucleation, and achieves a comprehensive improvement in the overall performance of the product.
[0017] 2. The preparation process parameters of this invention have been scientifically optimized to adapt to magnesium oxide raw materials of different purities, greatly expanding the range of raw material selection and effectively reducing the production cost at the raw material end. At the same time, the process is simple to operate, and the parameters of each step are easy to control. There is no need to add complex production equipment, and it can be directly adapted to existing industrial production lines, showing good prospects for industrial application. The modified magnesium oxide product can be reused multiple times, improving the utilization efficiency of the product and further reducing the overall cost of the wet nickel extraction process.
[0018] 3. The modified magnesium oxide of this invention can effectively replace the precipitant used in the traditional liquid alkali process. While ensuring the nickel recovery and impurity removal effects, it significantly reduces the generation of saline wastewater, thereby reducing the environmental treatment costs for enterprises and improving the environmental friendliness of the process. Detailed Implementation
[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example
[0020] The preparation steps are as follows: (1) Raw material pretreatment: Take magnesium oxide powder with a purity of 95%, crush it to 100 mesh, place it in a drying oven at 110℃ for 4 hours to remove moisture and set aside; take diatomaceous earth, crush it to 200 mesh, and calcine it at 550℃ for 4 hours for activation treatment, and set aside after activation.
[0021] (2) Rare earth doping modification: The dried magnesium oxide powder is placed in a stirred reactor, deionized water is added, the solid-liquid ratio is adjusted to 1:10, the stirring speed is set to 300 r / min, the temperature is raised to 60℃, and cerium nitrate solution is slowly added. The amount of cerium nitrate is 1.0% of the mass of magnesium oxide. Stirring is continued for 2 hours to complete the rare earth doping and obtain rare earth doped magnesium oxide slurry.
[0022] (3) Chelation coating modification: Slowly add iminodiacetic acid chelating agent to the above slurry. The amount of chelating agent is 0.8% of the mass of magnesium oxide. Maintain the temperature at 60℃ and the stirring speed at 300r / min. Continue stirring for 3h to make the chelating agent uniformly coat the surface of rare earth doped magnesium oxide and obtain chelated modified slurry.
[0023] (4) Heterogeneous nucleation composite modification: Activated diatomaceous earth is added to the chelated modified slurry. The amount of diatomaceous earth is 2.0% of the mass of magnesium oxide. The temperature is raised to 80℃, the stirring speed is increased to 400r / min, and stirring is continued for 4h to complete the heterogeneous nucleation composite modification and obtain the composite modified slurry.
[0024] (5) Post-processing: The composite modified slurry is filtered, and the filter cake is washed three times with deionized water to remove unreacted impurities and free ions. Then it is placed in a drying oven at 110℃ for 6 hours, and then placed in a muffle furnace and heated to 550℃ at a heating rate of 5℃ / min. It is then calcined for 5 hours, cooled to room temperature, and pulverized to 120 mesh to obtain the modified magnesium oxide product for wet nickel extraction. Example
[0025] This embodiment is based on Example 1, only the type of rare earth compound is adjusted. All other preparation steps and process parameters are completely consistent with Example 1, as follows: In the rare earth doping modification step, lanthanum nitrate solution is slowly added, and the amount of lanthanum nitrate is 1.0% of the mass of magnesium oxide. The parameters of the remaining steps are exactly the same as in Example 1, and the modified magnesium oxide product for wet nickel extraction is finally obtained. Example
[0026] This embodiment is based on Example 1, only the amount of rare earth compound is adjusted. The rest of the preparation steps and process parameters are completely the same as in Example 1, as detailed below: In the rare earth doping modification step, the amount of cerium nitrate used is 0.5% of the mass of magnesium oxide, and the parameters of the remaining steps are exactly the same as in Example 1, to obtain the modified magnesium oxide product for wet nickel extraction. Example
[0027] Continuing the dosage investigation from Example 3, this example only adjusts the amount of rare earth compound used compared to Example 1. All other preparation steps and process parameters are completely consistent with Example 1, as detailed below: In the rare earth doping modification step, the amount of cerium nitrate used is 2.0% of the mass of magnesium oxide, and the parameters of the remaining steps are exactly the same as in Example 1, to obtain the modified magnesium oxide product for wet nickel extraction. Example
[0028] This embodiment is based on Example 1, only the calcination temperature is adjusted. All other preparation steps and process parameters are completely consistent with Example 1, as follows: In the post-processing steps, the calcination temperature of the muffle furnace is 400℃, the calcination time is 5h, and the heating rate is 5℃ / min. The parameters of the remaining steps are exactly the same as in Example 1, and the modified magnesium oxide product for wet nickel extraction is obtained. Example
[0029] This embodiment is based on Example 1, only the calcination temperature is adjusted. All other preparation steps and process parameters are completely consistent with Example 1, as follows: In the post-processing steps, the calcination temperature of the muffle furnace is 600℃, the calcination time is 5h, and the heating rate is 5℃ / min. The parameters of the remaining steps are exactly the same as in Example 1, and the modified magnesium oxide product for wet nickel extraction is obtained. Example
[0030] This embodiment is based on Example 1, only adjusting the stirring time in this stage. The remaining preparation steps and process parameters are completely consistent with Example 1, as detailed below: In the heterogeneous nucleation composite modification step, the stirring time was 3 hours, the stirring speed was 400 r / min, and the temperature was 80℃. The parameters of the remaining steps were exactly the same as in Example 1, and the modified magnesium oxide product for wet nickel extraction was obtained. Example
[0031] This embodiment is based on Example 1, only adjusting the stirring time in the heterogeneous nucleation composite modification stage. All other preparation steps and process parameters are completely consistent with Example 1, as follows: In the heterogeneous nucleation composite modification step, the stirring time was 5 hours, the stirring speed was 400 r / min, and the temperature was 80°C. The parameters of the remaining steps were exactly the same as in Example 1, and the modified magnesium oxide product for wet nickel extraction was obtained. Example
[0032] This embodiment is based on Example 1, only the type of heterogeneous nucleating agent is adjusted. All other preparation steps and process parameters are completely consistent with Example 1, as follows: In the heterogeneous nucleation composite modification step, activated γ-Al2O3 is added. The γ-Al2O3 is activated by calcination at 550℃ for 4 hours. The amount of γ-Al2O3 is 2.0% of the mass of magnesium oxide. The parameters of the remaining steps are exactly the same as in Example 1, and the modified magnesium oxide product for wet nickel extraction is obtained. Example
[0033] To verify the modification effect of magnesium oxide with different purities, expand the range of magnesium oxide raw material selection, and reduce raw material costs, this embodiment only adjusts the purity of the magnesium oxide raw material based on Example 1. The remaining preparation steps and process parameters are completely consistent with Example 1, as follows: In the raw material pretreatment step, magnesium oxide powder with a purity of 90% was used, pulverized to 100 mesh, and dried for later use. The parameters of the remaining steps were exactly the same as in Example 1, and the modified magnesium oxide product for wet nickel extraction was obtained.
[0034] Example 11: This embodiment is based on Example 1, only adjusting the purity of the magnesium oxide raw material. All other preparation steps and process parameters are completely consistent with Example 1, as detailed below: In the raw material pretreatment step, magnesium oxide powder with a purity of 99.9% was used, pulverized to 100 mesh, and dried for later use. The parameters of the remaining steps were exactly the same as in Example 1, and the modified magnesium oxide product for wet nickel extraction was obtained.
[0035] Comparative Example 1: Unmodified magnesium oxide was used, corresponding to conventional magnesium oxide in the prior art. Specifically, 95% pure magnesium oxide powder was taken, pulverized to 100 mesh, and dried in a drying oven at 110°C for 4 hours. No modification treatment was required, and it was directly used as magnesium oxide for wet nickel extraction. The other application conditions were completely consistent with those in Example 1.
[0036] Comparative Example 2: Magnesium oxide modified with a single rare earth element, corresponding to the single modification technology in the prior art, is prepared using the following specific steps: (1) Raw material pretreatment: Take magnesium oxide powder with a purity of 95%, crush it to 100 mesh, place it in a drying oven at 110℃ and dry it for 4 hours, and set it aside.
[0037] (2) Single rare earth doping modification: The dried magnesium oxide powder was placed in a stirred reactor, deionized water was added, the solid-liquid ratio was adjusted to 1:10, the stirring speed was 300 r / min, the temperature was raised to 60℃, and cerium nitrate solution was slowly added. The amount of cerium nitrate was 1.0% of the mass of magnesium oxide, and the stirring was continued for 2 hours.
[0038] (3) Post-processing: filtration, washing, drying, and calcination at a temperature of 550℃ for 5 hours, followed by pulverization to 120 mesh to obtain single rare earth modified magnesium oxide.
[0039] Comparative Example 3: Magnesium oxide modified with a two-component composite without rare earth doping, corresponding to the existing two-component composite modification technology, is prepared using the following specific steps: (1) Raw material pretreatment: Take magnesium oxide powder with a purity of 95%, crush it to 100 mesh, and dry it in a drying oven at 110℃ for 4 hours for later use; take diatomaceous earth, crush it to 200 mesh, and calcine it at 550℃ for 4 hours for activation treatment. After activation, it is ready for use.
[0040] (2) Chelating and coating modification: Magnesium oxide powder is placed in a stirred reactor, deionized water is added, the solid-liquid ratio is adjusted to 1:10, the temperature is raised to 60℃, iminodiacetic acid chelating agent is added, the amount is 0.8% of the mass of magnesium oxide, and the mixture is stirred for 3 hours.
[0041] (3) Heterogeneous nucleation composite modification: Add activated diatomaceous earth at a rate of 2.0% of the mass of magnesium oxide, heat to 80°C, and stir for 4 hours.
[0042] (4) Post-processing: Same as in Example 1, to obtain composite modified magnesium oxide without rare earth doping.
[0043] Comparative Example 4: The traditional liquid alkali process was adopted, which corresponds to the mainstream process in the existing technology. Specifically, the traditional wet nickel extraction liquid alkali process was adopted, with 40% sodium hydroxide as the precipitant, and the pH of the sulfuric acid leaching solution was adjusted to 8.5. The other application conditions were completely consistent with those in Example 1. The performance indicators such as nickel recovery rate and impurity removal rate were tested.
[0044] Comparative Example 5: The modifier dosage, which exceeds the scope of protection of this invention, is used as follows: Based on Example 1, the dosage of cerium nitrate is adjusted to 6.0% of the mass of magnesium oxide, the dosage of chelating agent is adjusted to 2.0% of the mass of magnesium oxide, and the dosage of diatomaceous earth is adjusted to 8.0% of the mass of magnesium oxide. The remaining preparation steps and process parameters are the same as in Example 1, and the modified magnesium oxide product is obtained.
[0045] Comparative Example 6: The calcination temperature used is beyond the scope of protection of this invention, specifically as follows: Based on Example 1, the calcination temperature was adjusted to 250℃, and the remaining preparation steps and process parameters were the same as in Example 1, to obtain the modified magnesium oxide product; another set of samples was taken, and the calcination temperature was adjusted to 850℃, and the remaining preparation steps and process parameters were the same as in Example 1, to obtain another set of modified magnesium oxide products.
[0046] Comparative Example 7: The existing technology combination scheme is to simply superimpose single rare earth modification and single chelating agent modification. The specific combination form corresponding to the existing technology is as follows: Based on Comparative Example 2, a chelation coating modification step is added. The amount of chelating agent is 0.8% of the mass of magnesium oxide. The temperature is maintained at 60℃, the stirring speed is 300r / min, and the stirring is carried out for 3h. The remaining steps and process parameters are the same as those in Comparative Example 2, and the modified magnesium oxide product is obtained.
[0047] The iminodiacetic acid chelating agent used in this invention is specifically iminodiacetic acid (IDA), with the molecular formula C2H7NO4 and a purity ≥99%. It is a water-soluble chelating agent that can form stable coordination bonds with the surface of rare earth-doped magnesium oxide, achieving uniform coating. In this invention, the rare earth compound solution is prepared using deionized water as the solvent, and the mass concentrations of cerium nitrate solution and lanthanum nitrate solution are both 15%-20%. The rare earth compound solution is added by constant-rate dropping at a rate of 1-2 mL / min. The iminodiacetic acid in the chelation coating modification step is also added by constant-rate dropping at a rate of 1 mL / min. The above-mentioned dropping rate can ensure the uniformity of rare earth doping and the coating effect of the chelating agent, avoiding the problem of poor modification effect caused by excessively high local concentrations.
[0048] In all embodiments and comparative examples of this invention, the “slow addition” operation is performed using the constant-rate dropping method and corresponding rate parameters described above. The iminodiacetic acid chelating agent used in all embodiments is the iminodiacetic acid defined above.
[0049] Performance testing and results analysis: Test sample The test samples included all the modified magnesium oxide finished products of Examples 1 to 11, magnesium oxide or control samples of Comparative Examples 1 to 7, and three parallel samples of each group of samples to ensure the accuracy and repeatability of the test data, provide reliable data support for inventive comparison, and meet the requirements of the Patent Law for the examination of the utility of the invention.
[0050] Test conditions: A simulated industrial wet nickel extraction sulfuric acid leaching system was used. The leachate composition included a nickel ion concentration of 100 mg / L, an iron ion concentration of 50 mg / L, an aluminum ion concentration of 30 mg / L, a pH of 2.0, a liquid-to-solid ratio of 50:1, a reaction temperature of 50℃, a stirring speed of 200 r / min, a reaction time of 120 min, and a settling period of 30 min after the reaction for solid-liquid separation. These test conditions closely resemble actual industrial processes, ensuring the practicality and reference value of the test results.
[0051] Test metrics and methods: (1) Nickel adsorption capacity: The concentration of nickel ions in the leachate before and after the reaction was measured using a flame atomic absorption spectrophotometer. The adsorption capacity qe was calculated according to the formula. The calculation method is to subtract the equilibrium nickel ion concentration from the initial nickel ion concentration, multiply by the volume of the leachate, and finally divide by the sample mass. The unit is mg / g.
[0052] (2) Nickel recovery rate: The nickel recovery rate is calculated based on the change in nickel ion concentration before and after the reaction. The calculation method is to subtract the equilibrium nickel ion concentration from the initial nickel ion concentration, divide by the initial nickel ion concentration, and finally multiply by 100%.
[0053] (3) Impurity removal rate: The concentrations of iron ions and aluminum ions in the leachate before and after the reaction were measured using a flame atomic absorption spectrophotometer. The impurity removal rate was calculated by subtracting the equilibrium ion concentration from the initial ion concentration, dividing by the initial ion concentration, and finally multiplying by 100%.
[0054] (4) pH adjustment stability: During the reaction, the pH of the leachate was measured every 20 minutes, and the pH change range was recorded to judge the pH adjustment stability. The smaller the change range, the better the stability.
[0055] (5) Dissolution rate: The dissolution time of modified magnesium oxide in the leachate is measured, that is, the time from the addition of the sample to complete dissolution, in min. The shorter the dissolution time, the faster the dissolution rate.
[0056] (6) Number of times it can be reused: After the modified magnesium oxide is filtered, washed and dried, it can be reused in the wet nickel extraction experiment. The number of times it can be reused when the nickel recovery rate drops below 90% is recorded.
[0057] (7) Cost calculation: Calculate the unit preparation cost of each sample group, compare it with the unit processing cost of the traditional liquid alkali process, and evaluate the economic efficiency of the present invention.
[0058] Test results and analysis: The test results of Examples 1 to 11 are shown in Table 1 below: Table 1:
[0059] The test results of Comparative Examples 1 to 7 are shown in Table 2 below: Table 2:
[0060] Results analysis: The test results of Examples 1 to 11 show that the modified magnesium oxide prepared by this invention exhibits excellent performance in terms of nickel adsorption capacity, nickel recovery rate, impurity removal rate, pH adjustment stability, dissolution rate, and number of reuses. Furthermore, it maintains good performance under different raw material types, purity levels, and process parameters, confirming the practicality of the technical solution of this invention. All examples revolve around a three-step synergistic modification system of rare earth doping, chelating agent coating, and heterogeneous nucleating agent composite. Example 2 verifies the applicability of different rare earth compounds; Examples 3 and 4 verify the effects of different amounts of rare earth compounds; Examples 5 and 6 verify the influence of different calcination temperatures; Examples 7 and 8 verify the effect of different stirring times; Example 9 verifies the applicability of different heterogeneous nucleating agents; and Examples 10 and 11 verify the effects of magnesium oxide with different purities.
[0061] Comparative analysis with existing technologies and combinations thereof shows that Comparative Example 1 corresponds to existing traditional magnesium oxide, exhibiting the worst performance, thus proving the necessity of the modification process of this invention and highlighting the improvement of this invention compared to traditional technologies. Comparative Example 2 corresponds to existing single rare earth modification technologies, Comparative Example 3 corresponds to existing two-component composite modification technologies, and Comparative Example 7 corresponds to a combination of existing technologies. The performance of all three is far lower than that of the embodiments of this invention, and none of them can achieve the comprehensive performance advantages of this invention, proving the inventiveness of the three-component synergistic modification system of this invention. Its technical effect cannot be achieved by existing technologies or combinations thereof, nor can it be obtained through conventional improvements to existing technologies. Comparative Example 4 corresponds to existing traditional liquid alkali processes. This invention has significant advantages in terms of cost, environmental friendliness, and stability, aligning with industry development trends and further highlighting the inventiveness and practicality of this invention. Comparative Examples 5 and 6 demonstrate that exceeding the raw material dosage and process parameter ranges defined by this invention will significantly reduce performance, highlighting the scientific validity and necessity of the raw material ratio and process parameter limitations of this invention.
[0062] This invention effectively solves the problems of slow dissolution, inaccurate pH adjustment, and poor selectivity of traditional magnesium oxide by using a three-component synergistic modification system. At the same time, it replaces the traditional liquid alkali process, which can reduce costs by more than 30% and reduce the generation of saline wastewater. It has significant industrial application value, and its technical solution cannot be easily obtained through existing technologies or combinations of existing technologies.
[0063] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.
Claims
1. A modified magnesium oxide for wet nickel extraction, characterized in that, The product is prepared by using magnesium oxide as a substrate, through rare earth compound doping, iminodiacetic acid chelating agent coating, and heterogeneous nucleating agent composite modification. The rare earth compound is cerium nitrate or lanthanum nitrate, and the amount of rare earth compound is 0.5%-2.0% of the mass of magnesium oxide. The amount of iminodiacetic acid chelating agent is 0.8% of the mass of magnesium oxide. The heterogeneous nucleating agent is diatomaceous earth or γ-Al2O3, and the amount of heterogeneous nucleating agent is 2.0% of the mass of magnesium oxide.
2. The modified magnesium oxide for wet nickel extraction according to claim 1, characterized in that, The purity of the magnesium oxide used as the base is 90%-99.9%.
3. A method for preparing modified magnesium oxide for wet nickel extraction, characterized in that, Includes the following steps: (1) Raw material pretreatment: Take magnesium oxide powder and crush it to 100 mesh, dry it at 110℃ for 4 hours for later use; take heterogeneous nucleating agent and activate it for later use. (2) Rare earth doping modification: The dried magnesium oxide powder was added to the stirred reactor, deionized water was added to adjust the solid-liquid ratio to 1:10, the stirring speed was set to 300 r / min and the temperature was raised to 60℃, rare earth compound solution was added, and stirring was continued for 2 hours to obtain rare earth doped magnesium oxide slurry. (3) Chelation coating modification: Add iminodiacetic acid chelating agent to rare earth doped magnesium oxide slurry, maintain temperature at 60℃ and stirring speed at 300r / min, and continue stirring for 3h to obtain chelated modified slurry; (4) Heterogeneous nucleation composite modification: Add the activated heterogeneous nucleating agent to the chelated modified slurry, heat to 80℃ and increase the stirring speed to 400r / min, and continue stirring to obtain the composite modified slurry; (5) Post-processing: The composite modified slurry is filtered, the filter cake is washed with deionized water and dried at 110°C for 6 hours, then placed in a muffle furnace and heated at a rate of 5°C / min for 5 hours. After cooling to room temperature, it is pulverized to 120 mesh to obtain the modified magnesium oxide product for wet nickel extraction.
4. The method for preparing modified magnesium oxide for wet nickel extraction according to claim 3, characterized in that, The rare earth compound is cerium nitrate or lanthanum nitrate, and the amount of rare earth compound solution added is such that the rare earth compound accounts for 0.5%-2.0% of the mass of magnesium oxide.
5. The method for preparing modified magnesium oxide for wet nickel extraction according to claim 3, characterized in that, The amount of the iminodiacetic chelating agent added is 0.8% of the mass of magnesium oxide.
6. The method for preparing modified magnesium oxide for wet nickel extraction according to claim 3, characterized in that, The heterogeneous nucleating agent is diatomaceous earth or γ-Al2O3, and the amount of heterogeneous nucleating agent added is 2.0% of the mass of magnesium oxide; the activation treatment of diatomaceous earth is to pulverize it to 200 mesh and then calcine it at 550℃ for 4 hours, and the activation treatment of γ-Al2O3 is to calcine it at 550℃ for 4 hours.
7. The method for preparing modified magnesium oxide for wet nickel extraction according to claim 3, characterized in that, The continuous stirring time in the heterogeneous nucleation composite modification step is 3h-5h.
8. The method for preparing modified magnesium oxide for wet nickel extraction according to claim 3, characterized in that, In the post-processing step, the filter cake is washed three times with deionized water, and the calcination temperature in the muffle furnace is 400℃-600℃.
9. The method for preparing modified magnesium oxide for wet nickel extraction according to claim 3, characterized in that, The purity of the magnesium oxide powder is 90%-99.9%.