A method for producing low-sulfate basic nickel carbonate

Abstract

The application discloses a method for preparing low-sulfate alkaline nickel carbonate, and belongs to the technical field of chemical industry. The method is designed by selecting a precipitator and adopting a three-stage grading washing process. Each stage has specific purposes and conditions. In particular, the competitive reaction between ammonium sulfate and residual sulfate in the second-stage washing effectively solves the problem of high sulfate content in alkaline nickel carbonate in the prior art, improves the purity and performance of the product, and has the advantages of simple operation, low cost and the like. The process method has good application prospect and market value, and can be widely used in the field of chemical material preparation.

Description

Technical Field

[0001] This invention relates to the field of chemical material preparation, specifically to a method for preparing low-sulfate basic nickel carbonate. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Basic carbonates have applications in photocatalysis, supercapacitors, and secondary batteries. Nickel and cobalt basic carbonates have important applications in electrode materials, catalysts, electronic materials, and additives for magnetic materials. Basic nickel carbonate is an important inorganic fine chemical, mainly used to prepare various nickel salts. High-quality basic nickel carbonate can be used in the electronics industry. In addition, basic nickel carbonate is widely used in electroplating, electroforming, ceramic pigments, and industrial catalysts.

[0004] In traditional basic nickel carbonate preparation processes, sodium carbonate is often used as a precipitant. However, basic nickel carbonate products prepared using sodium carbonate have a high sulfate ion content because sodium carbonate itself contains a small amount of sulfate ion impurities. Furthermore, imperfections in the precipitation separation and washing processes can affect the purity and performance of the product, limiting its application in fields with high purity requirements.

[0005] To address this issue, researchers have undertaken various attempts. For example, a combination of chemical precipitation and ion exchange has been used to reduce sulfate content; however, this method is complex, costly, and may introduce new impurities during ion exchange. Other studies have attempted to reduce sulfate introduction by optimizing the type of precipitant and reaction conditions, but the results have been less than ideal. Therefore, developing a simple and cost-effective preparation process to effectively reduce sulfate content in basic nickel carbonate is of significant practical importance. Summary of the Invention

[0006] To address the problem of high sulfate content in existing basic nickel carbonate, this invention provides a process for preparing low-sulfate basic nickel carbonate, which improves the purity and performance of the product while simplifying the process and reducing costs.

[0007] To achieve the above-mentioned objectives, the technical solution of the present invention includes the following steps:

[0008] 1. Raw material preparation

[0009] Nickel sulfate is prepared into a solution of a certain concentration, which is controlled between 0.5-2 mol / L.

[0010] Ammonium carbonate is prepared into a solution of a certain concentration, with the concentration of the ammonium carbonate solution controlled between 1 and 3 mol / L.

[0011] Prepare an appropriate amount of deionized water as a solvent.

[0012] 2. Precipitation reaction

[0013] Nickel sulfate solution and ammonium carbonate solution are added to the reactor at a certain molar ratio (the molar ratio of nickel ions to ammonium ions is 1:2-1:3), and an appropriate amount of deionized water is added at the same time.

[0014] Control the reaction temperature at 30-60℃, the stirring speed at 200-500 r / min, and the reaction time at 1-3 hours to allow nickel ions and ammonium ions to fully react and form basic nickel carbonate precipitate.

[0015] 3. Graded washing

[0016] First washing: The precipitate is washed for the first time with deionized water. The ratio of washing solution to precipitate mass is 3-5:1. The washing temperature is 20-30℃, the stirring speed is 100-200r / min, and the washing time is 20-30 minutes.

[0017] This step primarily removes most of the soluble impurities from the precipitate surface.

[0018] Secondary washing: The precipitate is washed a second time with deionized water containing a small amount of ammonium sulfate (ammonium sulfate concentration of 0.2-0.5 mol / L). The ratio of washing solution to precipitate mass is 2-4:1. The washing temperature is 30-40℃, the stirring speed is 150-300 r / min, and the washing time is 30-40 minutes.

[0019] This step utilizes the competitive reaction between ammonium sulfate and residual sulfate ions to further reduce the sulfate content. Excessive or insufficient ammonium sulfate content in the second-stage washing solution will affect the final washing effect.

[0020] Third-stage washing: The precipitate is washed a third time with deionized water. The ratio of washing solution to precipitate mass is 3-5:1. The washing temperature is 20-30℃, the stirring speed is 100-200 r / min, and the washing time is 20-30 minutes.

[0021] This step mainly removes the small amount of impurities remaining after the secondary washing.

[0022] 4. Solid-liquid separation

[0023] The basic nickel carbonate precipitate, after three stages of washing, was subjected to solid-liquid separation by centrifugation. The centrifugation speed was controlled at 3000-5000 r / min, and the centrifugation time was 10-20 minutes to obtain wet basic nickel carbonate solid.

[0024] 5. Drying treatment

[0025] The wet basic nickel carbonate solid is placed in an oven and dried at a temperature of 80-120℃ for 8-12 hours to reduce the moisture content of the solid to below 1%, thus obtaining a low-sulfate basic nickel carbonate product.

[0026] The specific embodiments of the present invention have the following beneficial effects:

[0027] (a) This invention uses ammonium carbonate instead of traditional sodium carbonate as the main precipitant, and combines it with ammonium sulfate of a specific concentration (ammonium sulfate concentration of 0.2-0.5 mol / L) and proportion for graded washing. This innovative precipitant system can effectively reduce the sulfate content in basic nickel carbonate and improve product purity.

[0028] (b) This invention effectively reduces the sulfate content. By using a graded washing method, especially the competitive reaction between ammonium sulfate and residual sulfate in the secondary washing, the sulfate content in basic nickel carbonate products can be significantly reduced to a low level (below 0.01%), thereby improving the purity of the product.

[0029] (c) Ammonium carbonate has a relatively low price, higher purity, and relatively low impurity content. The interaction between ammonium ions and nickel ions in ammonium carbonate differs from that in sodium ions in sodium carbonate. Ammonium ions have a lower charge density and a relatively weaker ability to combine with sulfate ions. Therefore, during precipitation, sulfate ions are less likely to combine with nickel ions to form co-precipitates. Furthermore, the utilization rate of raw materials is high throughout the preparation process, reducing waste and thus lowering production costs. The entire preparation process is relatively simple, requiring no complex equipment or cumbersome operating procedures, making it easy to operate and readily applicable for industrial production. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solution, the present invention will be described in detail below with reference to embodiments. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0031] The present invention will be further described below with reference to the embodiments.

[0032] Example 1

[0033] (1) Raw material preparation:

[0034] Weigh 100g of nickel sulfate and prepare a nickel sulfate solution with a concentration of 1mol / L. Weigh 261g of ammonium carbonate and prepare an ammonium carbonate solution with a concentration of 2mol / L.

[0035] (2) Precipitation reaction:

[0036] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reaction vessel, then add 250 mL of deionized water. Control the reaction temperature at 40℃, the stirring speed at 300 r / min, and the reaction time at 2 hours.

[0037] (3) Graded washing:

[0038] First washing: The precipitate obtained in step (2) was washed for the first time with 1500g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 25 minutes.

[0039] Secondary washing: The precipitate was washed a second time with 1000g of 0.3mol / L ammonium sulfate deionized water solution at a temperature of 35℃, a stirring speed of 200r / min, and a washing time of 35 minutes.

[0040] Third-stage washing: The precipitate was washed a third time with 1500g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 25 minutes.

[0041] (4) Solid-liquid separation:

[0042] The basic nickel carbonate precipitate, after three stages of washing, was placed in a centrifuge and centrifuged at 4000 r / min for 15 minutes to obtain wet basic nickel carbonate solid.

[0043] (5) Drying treatment:

[0044] The wet solid basic nickel carbonate was placed in an oven and dried at 100°C for 10 hours to obtain a low-sulfate basic nickel carbonate product. Testing showed that the sulfate content in the product was 0.008%.

[0045] Example 2

[0046] (1) Raw material preparation:

[0047] Weigh 200g of nickel sulfate and prepare a nickel sulfate solution with a concentration of 2mol / L. Weigh 522g of ammonium carbonate and prepare an ammonium carbonate solution with a concentration of 3mol / L.

[0048] (2) Precipitation reaction:

[0049] Add 100 mL of nickel sulfate solution and 100 mL of ammonium carbonate solution to a 500 mL reaction vessel, then add 300 mL of deionized water. Control the reaction temperature at 60℃, the stirring speed at 500 r / min, and the reaction time at 3 hours.

[0050] (3) Graded washing:

[0051] First washing: The precipitate was washed for the first time with 2500g of deionized water at a temperature of 30℃, a stirring speed of 200r / min, and a washing time of 30 minutes.

[0052] Secondary washing: The precipitate was washed a second time with 1500g of 0.5mol / L ammonium sulfate deionized water at a temperature of 40℃, a stirring speed of 300r / min, and a washing time of 40 minutes.

[0053] Third-stage washing: The precipitate was washed a third time with 2000g of deionized water at a temperature of 30℃, a stirring speed of 200r / min, and a washing time of 30 minutes.

[0054] (4) Solid-liquid separation:

[0055] The basic nickel carbonate precipitate, after three stages of washing, was placed in a centrifuge and centrifuged at 5000 r / min for 20 minutes to obtain wet basic nickel carbonate solid.

[0056] (5) Drying treatment:

[0057] The wet solid basic nickel carbonate was placed in an oven and dried at 120°C for 12 hours to obtain a low-sulfate basic nickel carbonate product. Testing showed that the sulfate content in the product was 0.007%.

[0058] Comparative Example 1

[0059] (1) Raw material preparation:

[0060] Weigh 100g of nickel sulfate and prepare a nickel sulfate solution with a concentration of 1mol / L. Weigh 261g of ammonium carbonate and prepare an ammonium carbonate solution with a concentration of 2mol / L.

[0061] (2) Precipitation reaction:

[0062] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reaction vessel, then add 250 mL of deionized water. Control the reaction temperature at 40℃, the stirring speed at 300 r / min, and the reaction time at 2 hours.

[0063] (3) Graded washing:

[0064] First washing: The precipitate obtained in step (2) was washed for the first time with 1500g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 25 minutes.

[0065] Secondary washing: The precipitate was washed a second time with 1000g of deionized water at a temperature of 35℃, a stirring speed of 200r / min, and a washing time of 35 minutes.

[0066] Third-stage washing: The precipitate was washed a third time with 1500g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 25 minutes.

[0067] (4) Solid-liquid separation:

[0068] The basic nickel carbonate precipitate, after three stages of washing, was placed in a centrifuge and centrifuged at 4000 r / min for 15 minutes to obtain wet basic nickel carbonate solid.

[0069] (5) Drying treatment:

[0070] The wet solid basic nickel carbonate was placed in an oven and dried at 100°C for 10 hours to obtain a low-sulfate basic nickel carbonate product. Testing showed that the sulfate content in the product was 0.032%.

[0071] Comparative Example 2

[0072] (1) Raw material preparation:

[0073] Weigh 100g of nickel sulfate and prepare a nickel sulfate solution with a concentration of 1mol / L. Weigh 261g of ammonium carbonate and prepare an ammonium carbonate solution with a concentration of 2mol / L.

[0074] (2) Precipitation reaction:

[0075] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reaction vessel, then add 250 mL of deionized water. Control the reaction temperature at 40℃, the stirring speed at 300 r / min, and the reaction time at 2 hours.

[0076] (3) Washing:

[0077] The precipitate obtained in step (2) was washed for the first time with 4000g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 85 minutes.

[0078] (4) Solid-liquid separation:

[0079] The basic nickel carbonate precipitate, after three stages of washing, was placed in a centrifuge and centrifuged at 4000 r / min for 15 minutes to obtain wet basic nickel carbonate solid.

[0080] (5) Drying treatment:

[0081] The wet solid basic nickel carbonate was placed in an oven and dried at 100°C for 10 hours to obtain a low-sulfate basic nickel carbonate product. Testing showed that the sulfate content in the product was 0.043%.

[0082] Comparative Example 3

[0083] (1) Raw material preparation:

[0084] Weigh 100g of nickel sulfate and prepare a nickel sulfate solution with a concentration of 1mol / L. Weigh 261g of ammonium carbonate and prepare an ammonium carbonate solution with a concentration of 2mol / L.

[0085] (2) Precipitation reaction:

[0086] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reaction vessel, then add 250 mL of deionized water. Control the reaction temperature at 40℃, the stirring speed at 300 r / min, and the reaction time at 2 hours.

[0087] (3) Graded washing:

[0088] First washing: The precipitate obtained in step (2) was washed for the first time with 1500g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 25 minutes.

[0089] Secondary washing: The precipitate was washed a second time with 1000g of 0.1mol / L ammonium sulfate deionized water solution at a temperature of 35℃, a stirring speed of 200r / min, and a washing time of 35 minutes.

[0090] Third-stage washing: The precipitate was washed a third time with 1500g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 25 minutes.

[0091] (4) Solid-liquid separation:

[0092] The basic nickel carbonate precipitate, after three stages of washing, was placed in a centrifuge and centrifuged at 4000 r / min for 15 minutes to obtain wet basic nickel carbonate solid.

[0093] (5) Drying treatment:

[0094] The wet solid basic nickel carbonate was placed in an oven and dried at 100°C for 10 hours to obtain a low-sulfate basic nickel carbonate product. Testing showed that the sulfate content in the product was 0.014%.

[0095] Comparative Example 4

[0096] (1) Raw material preparation:

[0097] Weigh 100g of nickel sulfate and prepare a nickel sulfate solution with a concentration of 1mol / L. Weigh 261g of ammonium carbonate and prepare an ammonium carbonate solution with a concentration of 2mol / L.

[0098] (2) Precipitation reaction:

[0099] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reaction vessel, then add 250 mL of deionized water. Control the reaction temperature at 40℃, the stirring speed at 300 r / min, and the reaction time at 2 hours.

[0100] (3) Graded washing:

[0101] First washing: The precipitate obtained in step (2) was washed for the first time with 1500g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 25 minutes.

[0102] Secondary washing: The precipitate was washed a second time with 1000g of 0.6mol / L ammonium sulfate deionized water solution at a temperature of 35℃, a stirring speed of 200r / min, and a washing time of 35 minutes.

[0103] Third-stage washing: The precipitate was washed a third time with 1500g of deionized water at a temperature of 25℃, a stirring speed of 150r / min, and a washing time of 25 minutes.

[0104] (4) Solid-liquid separation:

[0105] The basic nickel carbonate precipitate, after three stages of washing, was placed in a centrifuge and centrifuged at 4000 r / min for 15 minutes to obtain wet basic nickel carbonate solid.

[0106] (5) Drying treatment:

[0107] The wet solid basic nickel carbonate was placed in an oven and dried at 100°C for 10 hours to obtain a low-sulfate basic nickel carbonate product. Testing showed that the sulfate content in the product was 0.012%.

[0108] It should be noted that, in this document, the terms "comprising," "including," and any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Specific examples have been used in this document to illustrate the principles and implementation methods of the present invention. These examples are merely for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be pointed out that, due to the limitations of written expression and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or variations without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, variations, or combinations, or the direct application of the concept and technical solution of the present invention to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A method for preparing low-sulfate basic nickel carbonate, characterized in that, Includes the following steps: S1. Raw material preparation, preparation of nickel sulfate and ammonium carbonate solution; S2, Precipitation reaction: Nickel sulfate and ammonium carbonate solution are reacted to obtain a precipitate; S3. Graded washing, washing the precipitate obtained in step S2; S4. Solid-liquid separation: Centrifuge the precipitate obtained in step S3. S5. Drying treatment; The graded washing is a three-stage washing process. The washing solution for the first and third stages is deionized water, and the washing solution for the second stage is deionized water containing ammonium sulfate. The concentration of ammonium sulfate is 0.2-0.5 mol / L; In step S2, the molar ratio of nickel ions to ammonium ions is 1:2-1:3; In step S3, the ratio of the amount of washing liquid to the mass of the precipitate in the second-stage washing is 2-4:1, the washing temperature is 30-40℃, the stirring speed is 150-300r / min, and the washing time is 30-40 minutes.

2. The method according to claim 1, characterized in that, In step S1, the concentration of nickel sulfate is controlled at 0.5-2 mol / L, and the concentration of ammonium carbonate solution is controlled at 1-3 mol / L.

3. The method according to claim 1, characterized in that, In step S2, the reaction temperature is 30-60℃, the stirring speed is 200-500 r / min, and the reaction time is 1-3 hours.

4. The method according to claim 1, characterized in that, In step S3, the ratio of the amount of washing liquid to the mass of the precipitate in the first-stage washing is 3-5:1, the washing temperature is 20-30℃, the stirring speed is 100-200r / min, and the washing time is 20-30 minutes.

5. The method according to claim 1, characterized in that, In step S3, the ratio of the washing liquid to the precipitate in the third-stage washing process is 3-5:1, the washing temperature is 20-30℃, the stirring speed is 100-200 r / min, and the washing time is 20-30 minutes.

6. The method according to claim 1, characterized in that, In step S4, the centrifugation speed is controlled at 3000-5000 r / min, and the centrifugation time is 10-20 minutes.

7. The method according to claim 1, characterized in that, In step S5, the drying temperature is 80-120℃ and the drying time is 8-12 hours, so that the moisture content in the solid is reduced to below 1%.