Preparation method of spherical basic nickel carbonate

Abstract

The invention discloses a preparation method of spherical basic nickel carbonate, which comprises the following steps: by taking a nickel sulfate solution and a sodium carbonate solution as raw materials, synthesizing spherical or sphere-like basic nickel carbonate by adopting an ammonia-free chemical precipitation method, firstly adding pure water into a reaction kettle during reaction, then adding the sodium carbonate solution to adjust the conductivity of the solution to 6000-8000us / cm < 3 >, and taking the solution as a reaction base solution; the preparation method comprises the following steps: adding a nickel sulfate solution and a sodium carbonate solution into a reaction kettle, starting stirring, keeping the temperature at 35-45 DEG C, adding the nickel sulfate solution and the sodium carbonate solution into the reaction kettle according to a certain ratio, reacting for 2-8 hours to prepare spherical basic nickel carbonate, and washing and drying the prepared sample to obtain a spherical basic nickel carbonate sample. The apparent density is controllable, the impurity content is low, the dispersity is good, and the product can pass through a 200-mesh screen.

Description

Technical Field

[0001] The invention belongs to the technical field of nickel carbonate production, and particularly relates to a method for preparing spherical basic nickel carbonate. Background Art

[0002] Spherical basic nickel carbonate has been widely studied and applied in fields such as petroleum catalysis, surface treatment, and new energy. It has a low environmental impact. Its development and application will help promote the development of petroleum processing and other related industries in a greener and more sustainable direction, responding to the urgent global demand for environmental protection and energy conservation and emission reduction.

[0003] Spherical basic nickel carbonate has unique advantages in the catalysis industry, mainly in the following aspects: 1. Highly dispersed active sites: The spherical structure provides more surface area, making the nickel active centers evenly distributed, which is beneficial to improving the contact efficiency and selectivity of the catalytic reaction. This is especially important for catalytic processes that require high conversion efficiency and product purity.

[0004] 2. Excellent stability and regeneration: The spherical particles have a stable structure and can maintain good physical form and activity even after long-term catalytic reaction and multiple regeneration cycles, reducing catalyst loss and extending service life.

[0005] 3. Enhanced mass and heat transfer performance: The spherical shape optimizes the porosity of the bed, facilitates the diffusion of reactants and products, and also promotes the effective transfer of heat, which is a significant advantage for catalytic reactions that require efficient thermal management.

[0006] 4. Recovery and reuse: After the catalytic reaction is completed, spherical particles are easier to separate from the reaction medium than non-spherical particles, which simplifies the catalyst recovery process and reduces processing costs.

[0007] 5. Customized catalytic performance: By adjusting the synthesis conditions of spherical basic nickel carbonate, such as particle size and composition ratio, the catalytic performance can be customized to meet the specific needs of different catalytic applications.

[0008] The traditional synthesis method uses ammonia water as a complexing agent, and the product contains ammonia nitrogen residues, which will have a poisonous effect on petrochemical industry catalysts. Therefore, nickel carbonate prepared by ammonia complex precipitation method cannot be used in the field of petrochemical industry catalysts. Summary of the Invention

[0009] The object of the present invention is to overcome the shortcomings of the prior art and provide a method for preparing basic nickel carbonate with a spherical or quasi-spherical micromorphology by an ammonia-free chemical synthesis method. The method has a short process flow, low energy consumption, and a friendly production environment. The product produced has high purity, good fluidity, controllable bulk density, low impurities, and can pass through a 200-mesh sieve.

[0010] To this end, the present invention adopts the following technical solutions: A method for preparing spherical basic nickel carbonate comprises the following steps: Step 1) Preparation of raw material solution: prepare nickel sulfate solution with a concentration of 1.3-2.3 mol / L and sodium carbonate solution with a concentration of 1.5-2.2 mol / L for later use; Step 2) Synthesis: Add pure water to the reactor, then add the sodium carbonate solution prepared in step 1) and adjust the bottom liquid conductivity to 6000-8000us / cm 3 After the mixture is qualified, start stirring and heat to 35-45°C; start the metering pump and add the nickel sulfate solution and sodium carbonate solution prepared in step 1) to the reactor at the same time. The synthesis reaction is carried out for 2-8 hours. The pH value of the synthesis reaction is controlled to 8.8-9.0 by fine-tuning the flow rate of the sodium carbonate solution; Step 3) Washing: After synthesis, the material is filtered and washed multiple times, with each washing volume of 4-6 L / kg and the washing water temperature of 35-45°C; Step 4) Drying: The product obtained in step 3) is dried in an oven for 8-10 hours at a drying temperature of 90-110° C., and spherical basic nickel carbonate is obtained after screening.

[0011] Furthermore, the stirring used in step 2) is a three-stage stirring, wherein the lower two stages of stirring lift the liquid upward, and the upper stage of stirring presses the liquid downward, the stirring speed is 80-120 rpm, and a guide baffle is provided on the inner wall of the reactor.

[0012] Furthermore, in step 2), the flow rate of the nickel sulfate solution is 1-300 L / h, and the flow rate of the sodium carbonate solution is 2-3 times the flow rate of the nickel sulfate solution.

[0013] Furthermore, in step 3), the synthesized material is washed 6 times, and the water from the last 4, 5, and 6 washes can be reused as the water from the 1st, 2nd, and 3rd washes, respectively, thereby reducing the amount of washing water.

[0014] The beneficial effects of the present invention are: The nickel carbonate samples prepared using this method have the advantages of spherical or quasi-spherical morphology, controllable bulk density, low impurities, good dispersibility, and the ability to pass through a 200-mesh sieve. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with specific embodiments: Example 1: Step 1) Preparation of raw material solution: prepare a nickel sulfate solution with a concentration of 1.3 mol / L and a sodium carbonate solution with a concentration of 1.5 mol / L for later use.

[0016] Step 2) Synthesis: Add 3L of pure water to a 20L reactor, then add sodium carbonate solution to adjust the bottom liquid conductivity to 6000-8000us / cm 3 After the mixture is qualified, start stirring and raise the temperature to 35-45°C. Start the metering pump and simultaneously add the nickel sulfate solution and sodium carbonate solution prepared in step 1) to the reactor for a reaction of 2-8 hours. The pH of the reaction is controlled to 8.8-9.0 by controlling the flow rate of the sodium carbonate solution. The stirring used in step 2) is a three-stage stirring method, with the lower two stages pulling upward and the upper stage pressing downward. The stirring speed is 80 rpm, and the stirring material is stainless steel. The inner wall of the reactor is equipped with a flow guide baffle. In step 2), the flow rate of the nickel sulfate solution is 1L / h, and the flow rate of the sodium carbonate solution is 2.3L / h.

[0017] Step 3) Washing: After synthesis, the material is filtered and washed six times, using 4-6 L / kg of water per wash. The water temperature is 35-45°C. The water from the last four, fifth, and sixth washes can be reused from the first, second, and third washes, respectively, to reduce wash water usage.

[0018] Step 4) Drying: Dry the product obtained in step 3) in an oven at 90-110° C. for 8-10 hours, and then sieve to obtain the spherical basic nickel carbonate of the present invention.

[0019] The resulting spherical basic nickel carbonate is a light green powder. Its bulk density can be controlled by reaction time, allowing production to meet the needs of various industries. It exhibits a spherical microstructure, good fluidity, and low impurity content, passing through a 200-mesh sieve. Table 1 below shows the bulk density at different synthesis times, while Table 2 shows the impurity content at different wash water volumes.

[0020] Table 1- Statistics of bulk density at different synthesis times Reaction time (h) 2 3 4 5 Bulk density (g / cm3) 0.35-0.38 0.38-0.42 0.42-0.46 0.46-0.5 Reaction time (h) 6 7 8 Bulk density (g / cm3) 0.5-0.54 0.54-0.58 0.58-0.62 Table 2 - Statistics of impurity elements at different washing water volumes Washing water volume (L / kg) 4 4.5 5 5.5 6 Sodium content (%) 0.0095 0.0092 0.0085 0.0064 0.0052 Sulfate content (%) 0.012 0.0098 0.009 0.0082 0.0073 Example 2: Step 1) Preparation of raw material solution: prepare a nickel sulfate solution with a concentration of 2.3 mol / L and a sodium carbonate solution with a concentration of 2.2 mol / L for later use.

[0021] Step 2) Synthesis: Add 3L of pure water to a 20L reactor, then add sodium carbonate solution to adjust the bottom liquid conductivity to 6000-8000us / cm 3After the mixture is qualified, start stirring and raise the temperature to 35-45°C. Start the metering pump and simultaneously add the nickel sulfate solution and sodium carbonate solution prepared in step 1) to the reactor for a reaction of 2-8 hours. The pH of the reaction is controlled to 8.8-9.0 by controlling the flow rate of the sodium carbonate solution. The stirring used in step 2) is a three-stage stirring method, with the lower two stages pulling upward and the upper stage pressing downward. The stirring speed is 80 rpm, and the stirring material is stainless steel. The inner wall of the reactor is equipped with a flow guide baffle. In step 2), the flow rate of the nickel sulfate solution is 0.8 L / h, and the flow rate of the sodium carbonate solution is 1.6 L / h.

[0022] Step 3) Washing: After synthesis, the material is filtered and washed six times, using 4-6 L / kg of water per wash. The water temperature is 35-45°C. The water from the last four, fifth, and sixth washes can be reused from the first, second, and third washes, respectively, to reduce wash water usage.

[0023] Step 4) Drying: Dry the product obtained in step 3) in an oven at 90-110° C. for 8-10 hours, and then sieve to obtain the spherical basic nickel carbonate of the present invention.

[0024] The resulting spherical basic nickel carbonate is a light green powder. Its bulk density can be controlled by reaction time, allowing production to meet the needs of various industries. It exhibits a spherical microstructure, good fluidity, and low impurity content, passing through a 200-mesh sieve. Table 3 below shows the bulk density at different synthesis times, while Table 4 shows the impurity content at different wash water volumes.

[0025] Table 3 - Statistics of bulk density at different synthesis times Reaction time (h) 2 3 4 5 Bulk density (g / cm3) 0.34-0.38 0.38-0.42 0.42-0.46 0.46-0.50 Reaction time (h) 6 7 8 Bulk density (g / cm3) 0.50-0.54 0.54-0.58 0.58-0.62 Table 4 - Statistics of impurity elements at different washing water volumes Washing water volume (L / kg) 4 4.5 5 5.5 6 Sodium content (%) 0.0092 0.0092 0.0080 0.0061 0.0050 Sulfate content (%) 0.013 0.0095 0.0092 0.0081 0.0070 Example 3: Step 1) Preparation of raw material solution: prepare a nickel sulfate solution with a concentration of 2.1 mol / L and a sodium carbonate solution with a concentration of 1.8 mol / L for later use.

[0026] Step 2) Synthesis: Towards 5m 3 Add 1ml of pure water into the reactor 3 , then add sodium carbonate solution to adjust the bottom liquid conductivity to 6000-8000us / cm 3After the mixture is qualified, start stirring and raise the temperature to 35-45°C. Start the metering pump and simultaneously add the nickel sulfate solution and sodium carbonate solution prepared in step 1) to the reactor for a reaction of 2-8 hours. The pH of the reaction is controlled to 8.8-9.0 by controlling the flow rate of the sodium carbonate solution. The stirring used in step 2) is a three-stage stirring method, with the lower two stages pulling upward and the upper stage pressing downward. The stirring speed is 60 rpm and the stirring material is stainless steel. The inner wall of the reactor is equipped with a stainless steel flow guide baffle. In step 2), the flow rate of the nickel sulfate solution is 200L / h, and the flow rate of the sodium carbonate solution is 460L / h.

[0027] Step 3) Washing: The synthesized material is washed 6 times using a centrifuge, with a water volume of 4-6m3 per wash. 3 / t. Washing water temperature is 35-45℃; the water from the last 4, 5 and 6 washes can be reused for the 1, 2 and 3 washes respectively to reduce the amount of washing water.

[0028] Step 4) Drying: The product obtained in step 3) is dried by air flow drying equipment at a mixing temperature of 90-110° C., and sieving to obtain the spherical basic nickel carbonate of the present invention.

[0029] The resulting spherical basic nickel carbonate is a light green powder. Its bulk density can be controlled by reaction time, allowing production to meet the needs of various industries. It exhibits a spherical micromorphology, good fluidity, and low impurity content, passing through a 200-mesh sieve. Table 5 below shows the bulk density at different synthesis times, while Table 6 shows the impurity content at different wash water volumes.

[0030] Table 5 - Statistics of bulk density at different synthesis times Reaction time (h) 2 3 4 5 Bulk density (g / cm3) 0.34-0.38 0.38-0.42 0.42-0.46 0.46-0.50 Reaction time (h) 6 7 8 Bulk density (g / cm3) 0.50-0.54 0.54-0.58 0.58-0.62 Table 6 - Statistics of impurity elements at different washing water volumes Washing water volume (L / kg) 4 4.5 5 5.5 6 Sodium content (%) 0.0082 0.0079 0.0075 0.0068 0.0056 Sulfate content (%) 0.0098 0.0093 0.0090 0.0081 0.0070

Claims

1. A method for preparing spherical basic nickel carbonate, characterized in that: The following steps are involved: Step 1) Preparation of raw material solution: prepare a nickel sulfate solution with a concentration of 1.3-2.3 mol / L and a sodium carbonate solution with a concentration of 1.5-2.2 mol / L for standby use; Step 2) Synthesis: Add pure water to the reactor, then add the sodium carbonate solution prepared in step 1) and adjust the bottom liquid conductivity to 6000-8000us / cm 3 ; After the preparation is qualified, start stirring and heat to 35-45°C; start the metering pump and add the nickel sulfate solution and sodium carbonate solution prepared in step 1) into the reactor at the same time, and react for 2-8 hours. The pH of the reaction is controlled to 8.8-9.0 by fine-tuning the flow rate of the sodium carbonate solution; Step 3) Washing: After synthesis, the material is filtered and washed multiple times, with the washing water volume of each time being 4-6L / kg and the washing water temperature being 35-45°C; Step 4) Drying: The product obtained in step 3) is dried in an oven for 8-10 hours at a drying temperature of 90-110° C., and spherical basic nickel carbonate is obtained after screening.

2. The method for preparing spherical basic nickel carbonate according to claim 1, characterized in that: The stirring used in step 2) is three-stage stirring, the lower two stages of stirring lift the liquid upward, and the upper stage of stirring presses the liquid downward, the stirring speed is 80-120 rpm, and the inner wall of the reactor is provided with a guide baffle.

3. The method for preparing spherical basic nickel carbonate according to claim 1, characterized in that: In step 2), the flow rate of the nickel sulfate solution is 1-300 L / h, and the flow rate of the sodium carbonate solution is 2-3 times the flow rate of the nickel sulfate solution.

4. The method for preparing spherical basic nickel carbonate according to claim 1, characterized in that: In step 3), the synthesized material is washed 6 times, and the water from the last 4, 5, and 6 washes can be reused as the water from the 1st, 2nd, and 3rd washes, respectively, to reduce the amount of washing water.