A method for preparing nanoscale barium carbonate

Abstract

The present application relates to barium carbonate preparation technical field, disclose a kind of preparation method of nanoscale barium carbonate, comprising the following steps: (1) sodium carbonate is weighed and added to deionized water, obtain sodium carbonate solution, (2) barite powder is added to sodium carbonate aqueous solution, heated to boiling state reaction, filtration is obtained filter residue, (3) ammonium chloride solution is added to filter residue, heated to boiling state reaction, filtration is obtained first reaction liquid, while recovering fraction, obtain second reaction liquid, (4) first adjusting agent is added to first reaction liquid, then air is introduced by membrane dispersion method, obtain nanobubble reaction liquid, (5) second adjusting agent is added to second reaction liquid, obtain third reaction liquid, (6) third reaction liquid is slowly added to nanobubble reaction liquid, stir at room temperature, then filter, wash, dry, obtain nanoscale barium carbonate;The present application has the effect of no tail gas emission, high purity, reduce production cost.

Description

Technical Field

[0001] This invention relates to the field of barium carbonate preparation technology, and particularly to a method for preparing nano-sized barium carbonate. Background Technology

[0002] Barium carbonate is an important inorganic salt product with wide applications in industries such as ceramics and electronics. Different industrial sectors have different requirements for the morphology of barium carbonate particles, and the quality requirements for barium carbonate are becoming increasingly stringent.

[0003] In industry, barium carbonate is usually prepared by the carbonation method, which uses barite (BaSO4) as raw material, reduces it to barium sulfide at high temperature, and then reacts it with carbon dioxide to produce barium carbonate. However, the H2S gas produced by the carbonation method is toxic and needs to be properly treated afterward. At the same time, the barium carbonate prepared by the carbonation method contains more impurities, and when used in the manufacture of electronic devices, it needs to be further purified by ion exchange or membrane separation, which increases the production cost. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing nano-sized barium carbonate, which has the advantages of zero tail gas emissions, high purity, and reduced production costs.

[0005] The above-mentioned technical objective of this invention is achieved through the following technical solution: a method for preparing nano-sized barium carbonate, comprising the following steps:

[0006] (1) Weigh out sodium carbonate and add it to deionized water. Heat to 30°C and stir to dissolve to obtain sodium carbonate solution.

[0007] (2) Add barite powder to the sodium carbonate aqueous solution obtained in step (1), wherein the weight ratio of barite powder to sodium carbonate is 2:1, heat to boiling and stir for 70 min, then filter to obtain filter residue.

[0008] (3) Add a 25% ammonium chloride solution to the filter residue obtained in step (2), wherein the volume ratio of the ammonium chloride solution to the sodium carbonate solution is 3:2, heat to boiling and stir for 4 hours, then filter to obtain the first reaction solution, and recover the distillate during the reaction to obtain the second reaction solution.

[0009] (4) Add the first regulator to the first reaction solution obtained in step (3), stir evenly, and then introduce air through the membrane dispersion method to obtain the nano bubble reaction solution;

[0010] (5) Add the second regulator to the second reaction solution obtained in step (3), stir evenly, and obtain the third reaction solution;

[0011] (6) Slowly add the third reaction solution obtained in step (5) to the nanobubble reaction solution obtained in step (4), stir at room temperature for 1.5-2 hours, then filter, wash with deionized water 2-3 times, and dry to obtain nano-sized barium carbonate.

[0012] A further provision of the present invention is that the concentration of nanobubbles in the nanobubble reaction solution is 2.8–3.0 × 10⁻⁶. 8 per mL.

[0013] A further provision of the present invention is that the first regulator is a 50% ethanol solution, and the volume ratio of the ethanol solution to the first reaction solution is 1:1.

[0014] A further provision of the present invention is that the second regulator is sodium alginate, and the weight ratio of sodium alginate to sodium carbonate is 1:40.

[0015] A further provision of the present invention is that the sodium carbonate solution has a mass fraction of 28.4%.

[0016] The beneficial effects of this invention are:

[0017] 1. This invention uses barite and sodium carbonate as raw materials. First, barite powder and saturated sodium carbonate (saturated concentration of sodium carbonate at 30℃ is 28.4%) undergo a first conversion under prolonged boiling, converting barium sulfate precipitate into barium carbonate precipitate. Then, ammonium chloride is added to the filtered residue for ammonolysis. The first reaction solution obtained by filtration is barium chloride solution, and the collected second reaction solution is ammonium carbonate solution. Then, the recovered distillate ammonium carbonate solution is added to the barium chloride solution for a second conversion, converting barium ions in the solution into barium carbonate precipitate. In this process, after the first conversion, the barite powder is dissolved and filtered with ammonium chloride solution, which can remove impurities (such as silicon dioxide) from the barite powder, greatly improving the purity of the product sodium carbonate. At the same time, the reaction conditions are mild throughout the entire reaction process, with conversion in a completely solution state, no high-temperature calcination, and no tail gas emission, resulting in high-purity barium carbonate. Using barite and sodium carbonate as raw materials can also greatly reduce production costs.

[0018] 2. In this invention, after preparing the first reaction solution, an appropriate amount of ethanol solution is added. Then, air is introduced using a membrane dispersion method to prepare the nanobubble reaction solution. Since the first reaction solution is a barium chloride solution, the addition of ethanol solution followed by air introduction using a membrane dispersion method ensures that, on the one hand, barium chloride molecules are dispersed in the ethanol solution, and on the other hand, ethoxy groups react with Ba... 2+ Electrostatic interaction increases the reaction rate, generating highly reactive barium ethoxylate [Ba(OC2H5)2]. This prevents barium ions from adsorbing onto the surface of the nanobubbles and disrupting their original electric double-layer structure. Furthermore, the presence of OH groups from a large number of ethanol molecules...- Adsorbed on the surface of bubbles, increasing the thickness of the electric double layer, further enhancing the stability of the nanobubble reaction solution; subsequently, after the third reaction solution is added, ammonium carbonate in OH... - CO3 is generated under the action 2- Ammonia hydrates with water, while CO3... 2- Barium carbonate reacts with barium ethoxylate to form amorphous barium carbonate, but due to its loose internal structure, it rapidly transforms into a spherulitic form. During this process, charged nanobubbles can adhere to the barium carbonate surface, altering the solid-liquid interfacial tension and helping to reduce the subsequent crystal nucleation rate. The surface nanobubbles also act as dispersants, preventing non-uniform nucleation of barium carbonate crystals and avoiding lateral growth on the barium carbonate surface. Simultaneously, the nanobubbles can physically adsorb Ba at the nanobubble interface. 2+ Reduce Ba 2+ With CO3 2- The ion-bonding opportunity reduces the nucleation rate and crystal growth rate of barium carbonate, thereby refining the barium carbonate grains. Due to the slow growth rate of barium carbonate nuclei, the grains do not grow. Under the influence of the strong electric field of -OH in the solvent ethanol, the particles do not grow, resulting in a decrease in particle surface energy and the dissolution of fine and uniform spheroidal barium carbonate. The -COO- groups in sodium alginate can also adsorb on specific crystal faces of barium carbonate, inhibiting crystal face growth. At the same time, alginate and ethoxy groups are impurities for each other, which can also interfere with some barium carbonate nucleation, forming amorphous barium carbonate, which is then transformed into spheroidal barium carbonate. Meanwhile, aragonite-type barium carbonate grows in a splitting manner. Alginate can adsorb on specific surfaces of aragonite grains through -COO-, inhibiting the growth of needle-like structures formed by splitting, and can also control the barium carbonate particle size to be smaller, forming a spherical morphology. In summary, by adding ethanol solution to prepare a stable nanobubble reaction solution, and then using nanobubbles, ethanol, and sodium alginate to regulate the crystal form of barium carbonate, high-purity nanoscale spheroidal barium carbonate can be induced.

[0019] 3. The spheroidal barium carbonate nanoparticles prepared by this invention have low production costs, concentrated particle size distribution, and spheroidal barium carbonate morphology, showing good application prospects. Attached Figure Description

[0020] Figure 1 This is a SEM image of the barium carbonate nanoparticles prepared in Example 1 of this invention. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] Example 1

[0023] (1) Weigh out sodium carbonate and add it to deionized water. Heat to 30°C and stir to dissolve, to obtain a sodium carbonate solution with a mass fraction of 28.4%.

[0024] (2) Add barite powder with a particle size of 80mm-100mm to the obtained sodium carbonate aqueous solution, wherein the weight ratio of barite powder to sodium carbonate is 2:1, heat to boiling and stir for 70min, then filter to obtain filter residue.

[0025] (3) Add a 25% ammonium chloride solution to the obtained filter residue, wherein the volume ratio of the ammonium chloride solution to the sodium carbonate solution is 3:2, heat to boiling and stir for 4 hours, then filter to obtain the first reaction solution (i.e., barium chloride solution), and recover the distillate during the reaction to obtain the second reaction solution (i.e., ammonium carbonate solution).

[0026] (4) Add the same volume of 50% ethanol solution to the obtained first reaction solution, stir until homogeneous, and then introduce air through a membrane dispersion method to obtain a nanobubble reaction solution. The concentration of nanobubbles in the nanobubble reaction solution is 2.8 × 10⁻⁶. 8 cells / mL;

[0027] (5) Add sodium alginate to the obtained second reaction solution. The amount of sodium alginate added is 2.5% of the weight of sodium carbonate. Stir well to obtain the third reaction solution.

[0028] (6) The third reaction solution was slowly added dropwise to the obtained nanobubble reaction solution, stirred at room temperature for 1.5 h, then filtered, washed twice with deionized water, and dried at 105-110℃ to obtain nano-sized barium carbonate.

[0029] like Figure 1 As shown, the barium carbonate nanoparticles prepared in this embodiment are spherical, with a purity of 99.8% and an average particle size of 186 nm.

[0030] Example 2

[0031] (1) Weigh out sodium carbonate and add it to deionized water. Heat to 30°C and stir to dissolve, to obtain a sodium carbonate solution with a mass fraction of 28.4%.

[0032] (2) Add barite powder with a particle size of 80mm-100mm to the sodium carbonate aqueous solution obtained in step (1), wherein the weight ratio of barite powder to sodium carbonate is 2:1, heat to boiling and stir for 70min, then filter to obtain filter residue.

[0033] (3) Add a 25% ammonium chloride solution to the filter residue obtained in step (2), wherein the volume ratio of the ammonium chloride solution to the sodium carbonate solution is 3:2, heat to boiling and stir for 4 hours, then filter to obtain the first reaction solution, and recover the distillate during the reaction to obtain the second reaction solution.

[0034] (4) Add the same volume of 50% ethanol solution to the first reaction solution obtained in step (3), stir until homogeneous, and then introduce air through a membrane dispersion method to obtain a nanobubble reaction solution. The concentration of nanobubbles in the nanobubble reaction solution is 2.9 × 10⁻⁶. 8 cells / mL;

[0035] (5) Add sodium alginate to the second reaction solution obtained in step (3). The amount of sodium alginate added is 2.5% of the weight of sodium carbonate. Stir evenly to obtain the third reaction solution.

[0036] (6) Slowly add the third reaction solution obtained in step (5) to the nanobubble reaction solution obtained in step (4), stir at room temperature for 2 hours, then filter, wash three times with deionized water, and dry at 105-110℃ to obtain nano-sized barium carbonate.

[0037] The barium carbonate nanoparticles prepared in this embodiment are spherical, with a purity of 99.8% and an average particle size of 193 nm.

[0038] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0039] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A method for preparing nano-sized barium carbonate, characterized in that, Includes the following steps: (1) Weigh out sodium carbonate and add it to deionized water. Heat the solution to 30°C and stir to dissolve it, thus obtaining a sodium carbonate solution. (2) Add barite powder to the sodium carbonate aqueous solution obtained in step (1), wherein the weight ratio of barite powder to sodium carbonate is 2:1, heat to boiling and stir for 70 min, then filter to obtain filter residue; (3) Add a 25% ammonium chloride solution to the filter residue obtained in step (2), wherein the volume ratio of the ammonium chloride solution to the sodium carbonate solution is 3:2, heat to boiling and stir for 4 hours, then filter to obtain the first reaction solution, and recover the distillate during the reaction to obtain the second reaction solution, wherein the second reaction solution is an ammonium carbonate solution. (4) Add the first regulator to the first reaction solution obtained in step (3), stir evenly, and then introduce air through the membrane dispersion method to obtain the nanobubble reaction solution; (5) Add the second regulator to the second reaction solution obtained in step (3), stir evenly, and obtain the third reaction solution; (6) Slowly add the third reaction solution obtained in step (5) to the nanobubble reaction solution obtained in step (4), stir at room temperature for 1.5-2 hours, then filter, wash with deionized water 2-3 times, and dry to obtain nano-sized barium carbonate; The first regulator is a 50% (w / w) ethanol solution, and the volume ratio of the ethanol solution to the first reaction solution is 1:

1. The second regulator is sodium alginate, and the weight ratio of sodium alginate to sodium carbonate is 1:

40.

2. The method for preparing nano-sized barium carbonate according to claim 1, characterized in that: The concentration of nanobubbles in the nanobubble reaction solution is 2.8–3.0 × 10⁻⁶. 8 per mL.

3. The method for preparing nano-sized barium carbonate according to claim 1, characterized in that: The sodium carbonate solution has a mass fraction of 28.4%.

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