Method for preparing low-sulfate basic nickel carbonate

Abstract

The invention discloses a method for preparing low-sulfate basic nickel carbonate, and belongs to the technical field of chemical engineering, a three-stage grading washing process is designed through precipitant selection and grading washing processes, each stage of washing has specific purposes and conditions, and particularly, ammonium sulfate and residual sulfate radicals are subjected to competitive reaction in secondary washing, so that the low-sulfate basic nickel carbonate is prepared. The method effectively solves the problem of high sulfate radical content of basic 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 prospects and market value and is expected to be widely applied to the field of chemical material preparation.

Description

Technical Field

[0001] The present invention relates to the field of chemical material preparation, and in particular to a method for preparing low-sulfate basic nickel carbonate. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

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

[0004] In traditional nickel carbonate basic production processes, sodium carbonate is often used as a precipitant. However, the sulfate ion content in nickel carbonate basic products produced using sodium carbonate is high because sodium carbonate itself contains a small amount of sulfate ion impurities, and the precipitation, separation, and washing processes are imperfect. This affects the purity and performance of the product, limiting its application in areas with high purity requirements.

[0005] To solve this problem, researchers have made various attempts. For example, chemical precipitation combined with ion exchange is used to reduce the sulfate content, but this method is complex and costly, and new impurities may be introduced during the ion exchange process. In addition, there are also studies that attempt to reduce the introduction of sulfate by optimizing the type of precipitant and reaction conditions, but the results are not ideal. Therefore, it is of great practical significance to develop a preparation process that can effectively reduce the sulfate content in basic nickel carbonate, is simple to operate, and has low cost. Summary of the Invention

[0006] In order to solve the problem of high sulfate content in basic nickel carbonate in the prior art, the present 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] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention includes the following steps:

[0008] 1. Raw Materials Preparation

[0009] Nickel sulfate is prepared into a solution of a certain concentration, and the concentration of the nickel sulfate solution is controlled at 0.5-2 mol / L.

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

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

[0012] 2. Precipitation reaction

[0013] Nickel sulfate solution and ammonium carbonate solution are added to the reactor in 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] The reaction temperature is controlled at 30-60°C, the stirring speed is 200-500 r / min, and the reaction time is 1-3 hours, so that the nickel ions and ammonium ions fully react to form basic nickel carbonate precipitate.

[0015] 3.Graded washing

[0016] Primary washing: Use deionized water to wash the precipitate for the first time. The mass ratio of the washing liquid to the precipitate is 3-5:1. The washing temperature is 20-30°C, the stirring speed is 100-200r / min, and the washing time is 20-30 minutes.

[0017] This step is mainly to remove most of the soluble impurities on the surface of the precipitate.

[0018] Secondary washing: Use deionized water containing a small amount of ammonium sulfate (ammonium sulfate concentration is 0.2-0.5 mol / L) to wash the precipitate for the second time. The mass ratio of the washing liquid to the precipitate is 2-4:1, the washing temperature is 30-40°C, 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 radicals to further reduce the sulfate radical content. If the ammonium sulfate content in the second-stage washing liquid is too high or too low, it will affect the final washing effect.

[0020] Three-stage washing: Use deionized water to wash the precipitate for the third time. The mass ratio of washing liquid to precipitate 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.

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

[0022] 4. Solid-liquid separation

[0023] The basic nickel carbonate precipitate after the three-stage washing is passed through a centrifuge for solid-liquid separation. The speed of the centrifuge is controlled at 3000-5000 r / min and the centrifugation time is 10-20 minutes to obtain a wet basic nickel carbonate solid.

[0024] 5. Drying

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

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

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

[0028] (b) The present invention effectively reduces the sulfate content. Through graded washing, particularly the competitive reaction between ammonium sulfate and residual sulfate in the secondary washing step, the sulfate content in the basic nickel carbonate product can be significantly reduced to a relatively low level (less than 0.01%), thereby improving the purity of the product.

[0029] (c) Ammonium carbonate is relatively inexpensive, has higher purity, and has a relatively low impurity content. The interaction between ammonium ions in ammonium carbonate and nickel ions differs from that of sodium ions in sodium carbonate. The ammonium ions have a lower charge density and a relatively weaker binding ability with sulfate ions. Therefore, during precipitation, sulfate ions are less likely to combine with nickel ions to form a coprecipitate. Furthermore, the overall raw material utilization rate is high throughout the preparation process, reducing raw material waste and thus lowering production costs. The entire preparation process is relatively simple, requiring no complex equipment or tedious steps, making it easy to operate and readily adapt to industrial production. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solution, the present invention is described in detail below in conjunction with embodiments. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

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

[0035] (2) Precipitation reaction:

[0036] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reactor, followed by 250 mL of deionized water. Control the reaction temperature to 40°C, the stirring speed to 300 rpm, and the reaction time to 2 hours.

[0037] (3) Gradual washing:

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

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

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

[0041] (4) Solid-liquid separation:

[0042] The basic nickel carbonate precipitate after the three-stage washing is placed in a centrifuge and centrifuged at a speed of 4000 r / min for 15 minutes to obtain a wet basic nickel carbonate solid.

[0043] (5) Drying treatment:

[0044] The wet basic nickel carbonate solid 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 to prepare a nickel sulfate solution with a concentration of 2 mol / L. Weigh 522g of ammonium carbonate to prepare an ammonium carbonate solution with a concentration of 3 mol / L.

[0048] (2) Precipitation reaction:

[0049] Add 100 mL of nickel sulfate solution and 100 mL of ammonium carbonate solution to a 500 mL reactor, followed by 300 mL of deionized water. Control the reaction temperature to 60°C, the stirring speed to 500 rpm, and the reaction time to 3 hours.

[0050] (3) Gradual washing:

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

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

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

[0054] (4) Solid-liquid separation:

[0055] The basic nickel carbonate precipitate after the three-stage washing is placed in a centrifuge and centrifuged at a speed of 5000 r / min for 20 minutes to obtain a wet basic nickel carbonate solid.

[0056] (5) Drying treatment:

[0057] The wet basic nickel carbonate solid 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 to prepare a nickel sulfate solution with a concentration of 1 mol / L. Weigh 261g of ammonium carbonate to prepare an ammonium carbonate solution with a concentration of 2 mol / L.

[0061] (2) Precipitation reaction:

[0062] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reactor, followed by 250 mL of deionized water. Control the reaction temperature to 40°C, the stirring speed to 300 rpm, and the reaction time to 2 hours.

[0063] (3) Gradual washing:

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

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

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

[0067] (4) Solid-liquid separation:

[0068] The basic nickel carbonate precipitate after the three-stage washing is placed in a centrifuge and centrifuged at a speed of 4000 r / min for 15 minutes to obtain a wet basic nickel carbonate solid.

[0069] (5) Drying treatment:

[0070] The wet basic nickel carbonate solid 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 to prepare a nickel sulfate solution with a concentration of 1 mol / L. Weigh 261g of ammonium carbonate to prepare an ammonium carbonate solution with a concentration of 2 mol / L.

[0074] (2) Precipitation reaction:

[0075] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reactor, followed by 250 mL of deionized water. Control the reaction temperature to 40°C, the stirring speed to 300 rpm, and the reaction time to 2 hours.

[0076] (3) Washing:

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

[0078] (4) Solid-liquid separation:

[0079] The basic nickel carbonate precipitate after the three-stage washing is placed in a centrifuge and centrifuged at a speed of 4000 r / min for 15 minutes to obtain a wet basic nickel carbonate solid.

[0080] (5) Drying treatment:

[0081] The wet basic nickel carbonate solid 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 to prepare a nickel sulfate solution with a concentration of 1 mol / L. Weigh 261g of ammonium carbonate to prepare an ammonium carbonate solution with a concentration of 2 mol / L.

[0085] (2) Precipitation reaction:

[0086] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reactor, followed by 250 mL of deionized water. Control the reaction temperature to 40°C, the stirring speed to 300 rpm, and the reaction time to 2 hours.

[0087] (3) Gradual washing:

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

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

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

[0091] (4) Solid-liquid separation:

[0092] The basic nickel carbonate precipitate after the three-stage washing is placed in a centrifuge and centrifuged at a speed of 4000 r / min for 15 minutes to obtain a wet basic nickel carbonate solid.

[0093] (5) Drying treatment:

[0094] The wet basic nickel carbonate solid 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 to prepare a nickel sulfate solution with a concentration of 1 mol / L. Weigh 261g of ammonium carbonate to prepare an ammonium carbonate solution with a concentration of 2 mol / L.

[0098] (2) Precipitation reaction:

[0099] Add 100 mL of nickel sulfate solution and 150 mL of ammonium carbonate solution to a 500 mL reactor, followed by 250 mL of deionized water. Control the reaction temperature to 40°C, the stirring speed to 300 rpm, and the reaction time to 2 hours.

[0100] (3) Gradual washing:

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

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

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

[0104] (4) Solid-liquid separation:

[0105] The basic nickel carbonate precipitate after the three-stage washing is placed in a centrifuge and centrifuged at a speed of 4000 r / min for 15 minutes to obtain a wet basic nickel carbonate solid.

[0106] (5) Drying treatment:

[0107] The wet basic nickel carbonate solid 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 article, the terms: include, contain and any other variations are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or device. Specific examples are used herein to illustrate the principles and implementation methods of the technical solution of the present invention. The above examples are only used to help understand the method of the present invention and its core idea. The above is only a preferred embodiment of the present invention. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements, modifications or changes can be made, and the above technical features can be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the present invention to other occasions without improvement, should be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing low-sulfate basic nickel carbonate, characterized in that: The following steps are involved: S1. Prepare raw materials and prepare nickel sulfate and ammonium carbonate solution; S2, precipitation reaction, reacting nickel sulfate and ammonium carbonate solution to obtain a precipitate; S3, graded washing, washing the precipitate obtained in step S2; S4, solid-liquid separation, centrifugation of the precipitate obtained in step S3; S5, drying treatment; The graded washing is a three-stage washing process, wherein the washing liquids for the first and third stage washings are deionized water, and the washing liquid for the second stage washing is deionized water containing ammonium sulfate.

2. The method according to claim 1, characterized in that The concentration of ammonium sulfate is 0.2-0.5 mol / L.

3. 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.

4. The method according to claim 1, wherein In step S2, the molar ratio of nickel ions to ammonium ions is 1:2-1:

3.

5. The method according to claim 1, wherein In step S2, the reaction temperature is 30-60° C., the stirring speed is 200-500 r / min, and the reaction time is 1-3 hours.

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

7. The method according to claim 1, characterized in that In step S3, the mass ratio of the second-stage washing liquid to the precipitate is 2-4:1, the washing temperature is 30-40° C., the stirring speed is 150-300 r / min, and the washing time is 30-40 minutes.

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

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

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