阅读说明：本技术 一种球状空心纳米硫酸钡的制备方法 (Preparation method of spherical hollow nano barium sulfate ) 是由 方畅 方利浮 于 2021-05-28 设计创作，主要内容包括：本发明公开了一种球状空心纳米硫酸钡的制备方法,其步骤是：1)将纳米碳酸钡浆液中,加入盐酸及反应助剂充分混匀,得到预反应混合物A；2)将六偏磷酸钠溶液加入盐酸,制备成预反应混合物B；3)将步骤1)得到的预反应混合物A、预反应混合物B同时加入到硫酸溶液中,加入时稳定pH值于2.0～6.0之间；待全部混匀后,pH值为1.5～1.8之间；4)充分搅拌步骤3)所得混合物30min以上,调节pH至7.0～9.0终止反应；5)压滤水洗后、干燥-得到空心球型纳米硫酸钡。该方法制备的空心硫酸钡,从而使得硫酸钡在作为添加剂时,能够增大其与主体材料解除的表面积和体积,从而极大提高硫酸钡作为添加剂的应用范围。(The invention discloses a preparation method of spherical hollow nano barium sulfate, which comprises the following steps: 1) adding hydrochloric acid and a reaction auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; 2) adding hydrochloric acid into a sodium hexametaphosphate solution to prepare a pre-reaction mixture B; 3) simultaneously adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution, and stabilizing the pH value between 2.0 and 6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) filtering, washing and drying to obtain the hollow spherical nano barium sulfate. The hollow barium sulfate prepared by the method can increase the surface area and volume of the barium sulfate which is removed from the main material when the barium sulfate is used as an additive, thereby greatly improving the application range of the barium sulfate as the additive.)

1. A method for preparing spherical hollow nano barium sulfate comprises the following steps: 1) adding hydrochloric acid and a reaction auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; 2) adding hydrochloric acid into a sodium hexametaphosphate solution to prepare a pre-reaction mixture B; 3) adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution at the same time, wherein the pH value is stabilized between 2.0 and 6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) filtering, washing and drying to obtain the hollow spherical nano barium sulfate.

2. The method for preparing spherical hollow nano barium sulfate according to claim 1, wherein the reaction auxiliary agent in step 1) is at least one of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate.

3. The method for preparing spherical hollow nano barium sulfate according to claim 1, wherein the reaction assistant in step 1) is prepared by mixing 5-8 parts by mass of sodium hexametaphosphate, 1-3 parts by mass of sodium pyrophosphate and 2-5 parts by mass of potassium tripolyphosphate.

4. The method for preparing spherical hollow nano barium sulfate according to claim 1, wherein the nano barium carbonate slurry in the step 1) is prepared by uniformly stirring barium carbonate with an average particle size of 1.0-8.0 μm, deionized water and pentaerythritol or sodium polyacrylate, wherein the mass ratio of barium carbonate to water to pentaerythritol or sodium polyacrylate is 50-100: 50-100: 1-5, sequentially pumping the barium carbonate slurry to a No. 1-4 ceramic horizontal sand mill arranged in a series connection mode by using a metering pump, performing primary grinding on the barium carbonate slurry by using a No. 1 sand mill, performing secondary grinding on the barium carbonate slurry by using a No. 2 sand mill, performing tertiary grinding on the barium carbonate slurry by using a No. 3 sand mill, performing four-stage grinding on the barium carbonate slurry by using a No. 4 sand mill, adding zirconia beads with the bead particle size of 100-2000 mu m into the sand mill, wherein the particle size of the zirconia beads added into the No. 1-2 sand mill is 600-2000 mu m, the particle size of the zirconia beads added into the No. 3-4 sand mill is 100-800 mu m, controlling the flow rate of the metering pump at 2-5L/min, controlling the rotation speed of the sand mill at 500-2000 r/min, and performing four-stage grinding to obtain the nano-grade barium carbonate slurry.

5. The method for preparing spherical hollow nano barium sulfate according to claim 1, wherein in the step 1), 1-2 parts by mass of 31% hydrochloric acid and 1-10 parts by mass of an auxiliary agent are added into 300-600 parts by mass of nano barium carbonate slurry, and after the mixture is fully mixed, a pre-reaction mixture A is obtained; the auxiliary agent is composed of at least one of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate.

6. The method for preparing spherical hollow nano barium sulfate according to claim 1, wherein in the step 2), 1 to 3 parts by mass of sodium hexametaphosphate is added to 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and 1 to 5 parts by mass of 31% hydrochloric acid is added to obtain a pre-reaction mixture B.

7. The method for preparing spherical hollow nano barium sulfate according to claim 1, wherein in the step 3), the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water.

8. A method for preparing spherical hollow nano barium sulfate comprises the following steps: 1) adding 1-2 parts by mass of 31% hydrochloric acid and 1-10 parts by mass of an auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; the auxiliary agent consists of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate, wherein the mass ratio of the sodium hexametaphosphate: sodium pyrophosphate: potassium tripolyphosphate (5-8): (1-3): (2-5); 2) adding 1-3 parts by mass of sodium hexametaphosphate into 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and adding 1-5 parts by mass of 31% hydrochloric acid to obtain a pre-reaction mixture B; 3) adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution at the same time, wherein the pH value is stabilized between 2.0 and 6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) washing the filter by pressure filtration, and drying to obtain hollow spherical nano barium sulfate; the preparation method of the nano barium carbonate comprises the following steps: uniformly stirring barium carbonate with the average particle size of 1.0-8.0 micrometers, deionized water and pentaerythritol or sodium polyacrylate, wherein the mass ratio of barium carbonate to water to pentaerythritol or sodium polyacrylate is 50-100: 50-100: 1-5, sequentially pumping the barium carbonate slurry to a No. 1-4 ceramic horizontal sand mill arranged in a series connection mode by using a metering pump, performing primary grinding on the barium carbonate slurry by using a No. 1 sand mill, performing secondary grinding on the barium carbonate slurry by using a No. 2 sand mill, performing tertiary grinding on the barium carbonate slurry by using a No. 3 sand mill, performing four-stage grinding on the barium carbonate slurry by using a No. 4 sand mill, adding zirconia beads with the bead particle size of 100-2000 mu m into the sand mill, wherein the particle size of the zirconia beads added into the No. 1-2 sand mill is 600-2000 mu m, the particle size of the zirconia beads added into the No. 3-4 sand mill is 100-800 mu m, controlling the flow rate of the metering pump at 2-5L/min, controlling the rotation speed of the sand mill at 500-2000 r/min, and performing four-stage grinding to obtain the nano-grade barium carbonate slurry.

Technical Field

The invention relates to the field of inorganic nano material synthesis, in particular to a preparation method of hollow sphere type nano barium sulfate.

Background

Barium sulfate is one of the most important inorganic chemical products nowadays, is widely applied to industries such as rubber, plastics, coatings, medicines and the like, and is also used as a weighting agent for drilling mud of petroleum and natural gas. The barium sulfate has the characteristics of acid-base resistance and good corrosion resistance, so that the barium sulfate is added into rubber and plastic products as a filler, plays the roles of increasing the volume, increasing the volume and reducing the cost, and can improve the mechanical strength, the thermodynamic property and the corrosion and aging resistance of the products. However, the density of barium sulfate is relatively high, and when the common barium sulfate powder is used as an additive, the density of the product is often greatly improved, the advantage of light weight of plastic and rubber products is weakened and reduced, the production cost is increased, and the product is greatly limited in the use range. Therefore, under the condition of the same mass, the volume and the surface area of the barium sulfate can be increased as much as possible, the density of rubber and plastic products can be effectively reduced, the advantage of light weight is kept, and the production cost is reduced.

At present, the production process of nano precipitated barium sulfate mainly comprises a method of carrying out a displacement reaction or a neutralization reaction on compounds containing barium ions, such as barium carbonate, barium hydroxide, barium chloride, barium sulfide and the like and compounds containing sulfate ions, such as sulfuric acid, sodium sulfate, ammonium sulfate and the like, so as to generate nano precipitated barium sulfate. The modified barium sulfate obviously improves the mechanical properties such as tear strength, impact strength and the like of products such as films and the like; however, the hollow sphere type nano barium sulfate is not reported at present.

Disclosure of Invention

In order to solve the technical problems, the invention aims to invent a preparation method of spherical hollow nano barium sulfate.

In order to achieve the purpose, the technical scheme of the invention is as follows: a method for preparing spherical hollow nano barium sulfate comprises the following steps: 1) adding hydrochloric acid and a reaction auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; 2) adding hydrochloric acid into a sodium hexametaphosphate solution to prepare a pre-reaction mixture B; 3) adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution at the same time, wherein the pH value is stabilized between 2.0 and 6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) filtering, washing and drying to obtain the hollow spherical nano barium sulfate.

Preferably, the reaction assistant in step 1) is at least one of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate.

Preferably, the reaction auxiliary agent in the step 1) is formed by mixing 5-8 parts by mass of sodium hexametaphosphate, 1-3 parts by mass of sodium pyrophosphate and 2-5 parts by mass of potassium tripolyphosphate.

Preferably, the preparation method of the nano barium carbonate slurry in the step 1) is that barium carbonate with an average particle size of 1.0-8.0 μm, deionized water and pentaerythritol or sodium polyacrylate are uniformly stirred, and the mass ratio of barium carbonate to water to pentaerythritol or sodium polyacrylate is 50-100: 50-100: 1-5, sequentially pumping the barium carbonate slurry to a No. 1-4 ceramic horizontal sand mill arranged in a series connection mode by using a metering pump, performing primary grinding on the barium carbonate slurry by using a No. 1 sand mill, performing secondary grinding on the barium carbonate slurry by using a No. 2 sand mill, performing tertiary grinding on the barium carbonate slurry by using a No. 3 sand mill, performing four-stage grinding on the barium carbonate slurry by using a No. 4 sand mill, adding zirconia beads with the bead particle size of 100-2000 mu m into the sand mill, wherein the particle size of the zirconia beads added into the No. 1-2 sand mill is 600-2000 mu m, the particle size of the zirconia beads added into the No. 3-4 sand mill is 100-800 mu m, controlling the flow rate of the metering pump at 2-5L/min, controlling the rotation speed of the sand mill at 500-2000 r/min, and performing four-stage grinding to obtain the nano-grade barium carbonate slurry.

Preferably, in the step 1), 300-600 parts by mass of nano barium carbonate slurry is added with 1-2 parts by mass of 31% hydrochloric acid and 1-10 parts by mass of an auxiliary agent, and the mixture is fully mixed to obtain a pre-reaction mixture A; the auxiliary agent is composed of at least one of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate.

Preferably, in the step 2), 1 to 3 parts by mass of sodium hexametaphosphate is added to 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and then 1 to 5 parts by mass of 31% hydrochloric acid is added to obtain a pre-reaction mixture B.

Preferably, in step 3), the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water.

A method for preparing spherical hollow nano barium sulfate comprises the following steps: 1) adding 1-2 parts by mass of 31% hydrochloric acid and 1-10 parts by mass of an auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; the auxiliary agent consists of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate, wherein the mass ratio of the sodium hexametaphosphate: sodium pyrophosphate: potassium tripolyphosphate = (5-8): (1-3): (2-5); 2) adding 1-3 parts by mass of sodium hexametaphosphate into 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and adding 1-5 parts by mass of 31% hydrochloric acid to obtain a pre-reaction mixture B; 3) adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution at the same time, wherein the pH value is stabilized between 2.0 and 6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) washing the filter by pressure filtration, and drying to obtain hollow spherical nano barium sulfate; the preparation method of the nano barium carbonate comprises the following steps: uniformly stirring barium carbonate with the average particle size of 1.0-8.0 micrometers, deionized water and pentaerythritol or sodium polyacrylate, wherein the mass ratio of barium carbonate to water to pentaerythritol or sodium polyacrylate is 50-100: 50-100: 1-5, sequentially pumping the barium carbonate slurry to a No. 1-4 ceramic horizontal sand mill arranged in a series connection mode by using a metering pump, performing primary grinding on the barium carbonate slurry by using a No. 1 sand mill, performing secondary grinding on the barium carbonate slurry by using a No. 2 sand mill, performing tertiary grinding on the barium carbonate slurry by using a No. 3 sand mill, performing four-stage grinding on the barium carbonate slurry by using a No. 4 sand mill, adding zirconia beads with the bead particle size of 100-2000 mu m into the sand mill, wherein the particle size of the zirconia beads added into the No. 1-2 sand mill is 600-2000 mu m, the particle size of the zirconia beads added into the No. 3-4 sand mill is 100-800 mu m, controlling the flow rate of the metering pump at 2-5L/min, controlling the rotation speed of the sand mill at 500-2000 r/min, and performing four-stage grinding to obtain the nano-grade barium carbonate slurry.

Drawings

FIG. 1 is a graph showing the results of particle size measurement of nano-sized hollow barium sulfate obtained in example 1

FIG. 2 is an SEM scanning electron micrograph of nano-sized hollow barium sulfate obtained in example 1

FIG. 3 is a graph showing the results of particle size measurement of nano-sized hollow barium sulfate obtained in example 2

FIG. 4 is an SEM scanning electron micrograph of nano-scale hollow barium sulfate obtained in example 2

FIG. 5 shows the results of particle size measurement of nano-sized hollow barium sulfate obtained in example 3

FIG. 6 is an SEM scanning electron micrograph of nano-sized hollow barium sulfate obtained in example 3

FIG. 7 shows the results of particle size measurement of nano-sized hollow barium sulfate obtained in example 4

FIG. 8 is an SEM scanning electron micrograph of nano-sized hollow barium sulfate obtained in example 4

FIG. 9 shows the results of particle size measurement of nano-sized hollow barium sulfate obtained in comparative example 2

FIG. 10 is an SEM scanning electron micrograph of nano-sized hollow barium sulfate obtained in comparative example 2.

Detailed Description

The following further illustrates embodiments of the invention:

the nano barium carbonate is prepared according to the following method: uniformly stirring barium carbonate with the average particle size of 1.0-8.0 micrometers, deionized water and pentaerythritol or sodium polyacrylate, wherein the mass ratio of barium carbonate to water to pentaerythritol or sodium polyacrylate is 50-100: 50-100: 1-5, sequentially pumping the barium carbonate slurry to a No. 1-4 ceramic horizontal sand mill arranged in a series connection mode by using a metering pump, performing primary grinding on the barium carbonate slurry by using a No. 1 sand mill, performing secondary grinding on the barium carbonate slurry by using a No. 2 sand mill, performing tertiary grinding on the barium carbonate slurry by using a No. 3 sand mill, performing four-stage grinding on the barium carbonate slurry by using a No. 4 sand mill, adding zirconia beads with the bead particle size of 100-2000 mu m into the sand mill, wherein the particle size of the zirconia beads added into the No. 1-2 sand mill is 600-2000 mu m, the particle size of the zirconia beads added into the No. 3-4 sand mill is 100-800 mu m, controlling the flow rate of the metering pump at 2-5L/min, controlling the rotation speed of the sand mill at 500-2000 r/min, and performing four-stage grinding to obtain the nano-grade barium carbonate slurry.

Example 1

The hollow nano barium sulfate is prepared according to the following method: 1) adding 1 part by mass of 31% hydrochloric acid and 2 parts by mass of an auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; the auxiliary agent consists of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate, wherein the mass ratio of the sodium hexametaphosphate: sodium pyrophosphate: potassium tripolyphosphate = 5: 1: 2; 2) adding 2 parts by mass of sodium hexametaphosphate into 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and adding 1 part by mass of 31% hydrochloric acid to obtain a pre-reaction mixture B; 3) simultaneously adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution, wherein the pH value is stabilized to be 2.0-6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) filtering, washing and drying to obtain the hollow spherical nano barium sulfate, wherein the median particle diameter of the particles is D50: about 98 nm.

Example 2

The hollow nano barium sulfate is prepared according to the following method: 1) adding 1 part by mass of 31% hydrochloric acid and 10 parts by mass of an auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; the auxiliary agent consists of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate, wherein the mass ratio of the sodium hexametaphosphate: sodium pyrophosphate: potassium tripolyphosphate = 8: 1: 5; 2) adding 3 parts by mass of sodium hexametaphosphate into 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and adding 1 part by mass of 31% hydrochloric acid to obtain a pre-reaction mixture B; 3) simultaneously adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution, wherein the pH value is stabilized to be 2.0-6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) washing with press filtration water, and drying to obtain nano barium sulfate with a particle median diameter D50: about 110 nm.

Example 3

The hollow nano barium sulfate is prepared according to the following method: 1) adding 2 parts by mass of 31% hydrochloric acid and 8 parts by mass of an auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; the auxiliary agent is sodium hexametaphosphate; 2) adding 3 parts by mass of sodium hexametaphosphate into 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and adding 5 parts by mass of 31% hydrochloric acid to obtain a pre-reaction mixture B; 3) simultaneously adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution, wherein the pH value is stabilized to be 2.0-6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) filtering, washing and drying to obtain spherical nano barium sulfate, wherein the median particle size is D50: 89 nm.

Example 4

The hollow nano barium sulfate is prepared according to the following method: 1) adding 2 parts by mass of 31% hydrochloric acid and 6 parts by mass of an auxiliary agent into the nano barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; the auxiliary agent consists of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate, wherein the mass ratio of the sodium hexametaphosphate: sodium pyrophosphate: potassium tripolyphosphate = 5: 3: 2; 2) adding 1 part by mass of sodium hexametaphosphate into 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and adding 5 parts by mass of 31% hydrochloric acid to obtain a pre-reaction mixture B; 3) simultaneously adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution, wherein the pH value is stabilized to be 2.0-6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) washing with press filtration water, and drying to obtain olive-type nano barium sulfate, wherein the particle size is D50: 190 nm.

Comparative example 1

An ordinary precipitated barium sulfate was used as comparative example 1.

Comparative example 2

The hollow barium sulfate was prepared as follows: 1) adding 100 parts by mass of barium carbonate into 200 parts by mass of water, uniformly mixing to obtain barium carbonate slurry, adding 1 part by mass of 31% hydrochloric acid and 2 parts by mass of an auxiliary agent into the barium carbonate slurry, and fully and uniformly mixing to obtain a pre-reaction mixture A; the auxiliary agent consists of sodium hexametaphosphate, sodium pyrophosphate and potassium tripolyphosphate, wherein the mass ratio of the sodium hexametaphosphate: sodium pyrophosphate: potassium tripolyphosphate = 5: 1: 2; 2) adding 2 parts by mass of sodium hexametaphosphate into 100 parts by mass of water to prepare a sodium hexametaphosphate solution, and adding 1 part by mass of 31% hydrochloric acid to obtain a pre-reaction mixture B; 3) simultaneously adding the pre-reaction mixture A and the pre-reaction mixture B obtained in the step 1) into a sulfuric acid solution, wherein the pH value is stabilized to be 2.0-6.0 during adding; after all the components are uniformly mixed, the pH value is 1.5-1.8; the sulfuric acid solution is prepared from 50 parts by mass of 98% concentrated sulfuric acid and 300 parts by mass of water; 4) fully stirring the mixture obtained in the step 3) for more than 30min, adjusting the pH value to 7.0-9.0, and stopping the reaction; 5) washing by using press filtration water, and drying to obtain barium sulfate, wherein the median particle size D50: 789 nm.

The hollow spherical nano barium sulfate prepared in the examples 1 to 4 and the comparative examples 1 and 2 are tested, and the bulk density of the barium sulfate is detected, wherein the detection result is as follows:

performance of	Barite powder	Comparative example 1	Comparative example 2	Example 1	Example 2	Example 3	Example 4
								Bulk density of barium sulfate g/cm3	1.582	0.789	0.573	0.297	0.435	0.368	0.422

And (4) conclusion: when the ratio of phosphate to hydrochloric acid is 2: the barium sulfate particles obtained in the step 1 are of a nano hollow spherical shape, which is ideal; in addition, if the raw material is experimentally treated by using non-nano-grade barium carbonate, a satisfactory hollow sphere cannot be obtained, the generated barium sulfate particles are not obviously different from the common barium sulfate particles, the particle size is large, and the generation of hollow barium sulfate is not found.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.