A preparation process of barium hydroxide octahydrate

Abstract

The present invention relates to the technical field of preparation of barium hydroxide, and specifically to a process for preparing barium hydroxide octahydrate, comprising the following steps: (1) crushing a raw material of witherite, uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, calcining and keeping warm to obtain crude barium oxide; (2) dispersing the crude barium oxide in water, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizer, filtering and washing to obtain a barium hydroxide solution, and concentrating, cooling, crystallizing, centrifuging and drying to obtain the barium hydroxide solution. The purpose of the present invention is to provide a process for preparing barium hydroxide octahydrate, aiming to improve the total leaching rate of barium and the purity of the product.

Description

Technical Field

[0001] The invention relates to the technical field of barium hydroxide preparation, and in particular to a preparation process of barium hydroxide octahydrate. Background Art

[0002] As an important inorganic chemical raw material, barium hydroxide octahydrate (Ba(OH)2·8H2O) is widely used in chemical, pharmaceutical, electronic and other fields. With the increasing global demand for environmentally friendly materials and technological progress, the application areas of barium hydroxide octahydrate are constantly expanding and the market demand is growing steadily.

[0003] At present, the preparation process of barium hydroxide octahydrate mainly includes a variety of methods such as barium sulfide method, barium carbonate method, and barium hydroxide method. These methods have their own advantages and disadvantages, but there is still a problem that the total leaching rate of barium is not high. Based on this, the present invention proposes a preparation process of barium hydroxide octahydrate. Summary of the invention

[0004] The invention aims to provide a process for preparing barium hydroxide octahydrate, aiming to improve the total leaching rate of barium and the purity of the product.

[0005] The present invention provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0006] (1) crushing the witherite raw material, uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, calcining and keeping warm to obtain crude barium oxide;

[0007] (2) Dispersing the crude barium oxide in water, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizer, filtering and washing to obtain a barium hydroxide solution, which is then concentrated, cooled, crystallized, centrifuged and dried to obtain the product.

[0008] Furthermore, the average particle size of the crushed witherite is 80-100 meshes.

[0009] Furthermore, the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100: (4-6): (16-18): (3-5).

[0010] Furthermore, the calcination temperature is 1250-1350° C., and the holding time is 3-4 hours.

[0011] Furthermore, the dispersion method is to stir at 400-500 r / min for 40-60 min, and the dispersion temperature is 60-70°C.

[0012] Furthermore, the ratio of the crude barium oxide to water is 140-160 g / L.

[0013] Furthermore, the desulfurizing agent comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of (5-6):(1-2):(1-2).

[0014] Furthermore, the desulfurizing agent is 8-10% by weight of the crude barium oxide.

[0015] Furthermore, the washing liquid used in the filtration washing is deionized water at a temperature of 40-50°C.

[0016] The beneficial effects of the present invention are:

[0017] The present invention crushes the witherite raw material to an average particle size of 80-100 meshes, with the purpose of increasing the surface area of ​​the raw material, so that in the subsequent calcination process, the contact area between the raw material and the reducing agent such as coal powder and charcoal is increased, the reaction is more complete, and thus the total leaching rate of barium is improved.

[0018] The present invention mixes the crushed witherite with coal powder, charcoal and silicon dioxide uniformly. The coal powder and charcoal act as reducing agents, which can reduce the barium sulfate in the witherite to barium sulfide at high temperature, while the silicon dioxide acts as a flux, which can reduce the calcination temperature and promote the reaction. The weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is limited to 100: (4-6): (16-18): (3-5), which can further improve the total leaching rate of barium.

[0019] In the present invention, zinc oxide, calcium oxide and copper oxide are used as compound desulfurizers, which can react with sulfur ions in the solution to generate insoluble sulfide precipitates, thereby removing sulfur ions in the solution and improving the purity of the product. At the same time, zinc oxide has a strong sulfur adsorption capacity and can preferentially combine with sulfur ions in the solution; calcium oxide can adjust the pH value of the solution and promote the dissolution and leaching of barium ions; copper oxide may participate in redox reactions under certain conditions, further promoting the decomposition of sulfides and the release of barium. This synergistic effect enables the compound desulfurizer to promote the leaching of barium ions while removing sulfur ions, thereby improving the total leaching rate of barium. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1

[0022] This embodiment provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0023] (1) crushing the witherite raw material to an average particle size of 90 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100:5:17:4; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1300°C, and the heat preservation time is 3.5 hours;

[0024] Among them, the total leaching rate of barium in step (1) is 63.4%;

[0025] (2) Dispersing the crude barium oxide in water at 65°C under stirring at 450 r / min for 50 min, wherein the ratio of crude barium oxide to water is 150 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizer, wherein the desulfurizer comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of 5.5:1.5:1.5; the desulfurizer is 9% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 45°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged and dried to obtain the obtained solution.

[0026] The total leaching rate of barium in step (2) is 75.7%; the purity of the final product prepared is 99.2%.

[0027] Example 2

[0028] This embodiment provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0029] (1) crushing the witherite raw material to an average particle size of 80 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100:4:16:3; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1250°C, and the heat preservation time is 3 hours;

[0030] Among them, the total leaching rate of barium in step (1) is 62.8%;

[0031] (2) Dispersing the crude barium oxide in water at 60°C under stirring at 400 r / min for 40 min, wherein the ratio of crude barium oxide to water is 140 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizing agent, wherein the desulfurizing agent comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of 5:1:1; the desulfurizing agent is 8% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 40°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged and dried to obtain the obtained solution.

[0032] The total leaching rate of barium in step (2) is 75.6%, and the purity of the final product prepared is 99.1%.

[0033] Example 3

[0034] This embodiment provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0035] (1) crushing the witherite raw material to an average particle size of 100 mesh, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100:6:18:5; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1350°C, and the heat preservation time is 4 hours;

[0036] Among them, the total leaching rate of barium in step (1) is 62.2%;

[0037] (2) Dispersing the crude barium oxide in water at 70°C with stirring at 500 r / min for 60 min, wherein the ratio of the crude barium oxide to water is 160 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizing agent, wherein the desulfurizing agent comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of 3:1:1; the desulfurizing agent is 10% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 50°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged and dried to obtain the obtained solution.

[0038] The total leaching rate of barium in step (2) is 75.2%, and the purity of the final product prepared is 98.9%.

[0039] Example 4

[0040] This embodiment provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0041] (1) crushing the witherite raw material to an average particle size of 80 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100:6:16:5; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1250°C, and the heat preservation time is 4 hours;

[0042] Among them, the total leaching rate of barium in step (1) is 63.1%;

[0043] (2) Dispersing the crude barium oxide in water at 70°C with stirring at 500 r / min for 40 min, wherein the ratio of the crude barium oxide to water is 140 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizing agent, wherein the desulfurizing agent comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of 6:1:2; the desulfurizing agent is 8% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 50°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged and dried to obtain the obtained solution.

[0044] The total leaching rate of barium in step (2) is 75.4%, and the purity of the final product prepared is 99.1%.

[0045] Comparative Example 1

[0046] This comparative example provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0047] (1) crushing the witherite raw material to an average particle size of 90 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100:5:17:4; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1300°C, and the heat preservation time is 3.5 hours;

[0048] Among them, the total leaching rate of barium in step (1) is 63.4%;

[0049] (2) The crude barium oxide is dispersed in water at 65°C by stirring at 450 r / min for 50 min, wherein the ratio of the crude barium oxide to water is 150 g / L. The residue is filtered to obtain a secondary treated residue, which is then washed with deionized water. The two filtrates obtained are collected and desulfurized with a desulfurizer, wherein the desulfurizer comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of 5.5:1.5:1.5; the desulfurizer is 9% of the weight of the crude barium oxide; the barium hydroxide solution is obtained after filtering and washing with deionized water at a temperature of 45°C, and the barium hydroxide solution is obtained after concentration, cooling, crystallization, centrifugation and drying.

[0050] The total leaching rate of barium in step (2) is 75.7%; the purity of the final product prepared is 99.1%.

[0051] Comparative Example 2

[0052] This comparative example provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0053] (1) crushing the witherite raw material to an average particle size of 90 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, charcoal and silicon dioxide is 100:17:4; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1300°C, and the heat preservation time is 3.5 hours;

[0054] Among them, the total leaching rate of barium in step (1) is 60.4%;

[0055] (2) Dispersing the crude barium oxide in water at 65°C under stirring at 450 r / min for 50 min, wherein the ratio of crude barium oxide to water is 150 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizer, wherein the desulfurizer comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of 5.5:1.5:1.5; the desulfurizer is 9% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 45°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged and dried to obtain the obtained solution.

[0056] The total leaching rate of barium in step (2) is 75.7%; the purity of the final product prepared is 98.2%.

[0057] Comparative Example 3

[0058] This comparative example provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0059] (1) crushing the witherite raw material to an average particle size of 90 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder and silicon dioxide is 100:5:4; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1300°C, and the heat preservation time is 3.5 hours;

[0060] Among them, the total leaching rate of barium in step (1) is 55.6%;

[0061] (2) Dispersing the crude barium oxide in water at 65°C under stirring at 450 r / min for 50 min, wherein the ratio of crude barium oxide to water is 150 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizer, wherein the desulfurizer comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of 5.5:1.5:1.5; the desulfurizer is 9% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 45°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged and dried to obtain the obtained solution.

[0062] The total leaching rate of barium in step (2) is 75.7%; the purity of the final product prepared is 97.7%.

[0063] Comparative Example 4

[0064] This comparative example provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0065] (1) crushing the witherite raw material to an average particle size of 90 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder and charcoal is 100:5:17; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1300°C, and the heat preservation time is 3.5 hours;

[0066] Among them, the total leaching rate of barium in step (1) is 58.2%;

[0067] (2) Dispersing the crude barium oxide in water at 65°C under stirring at 450 r / min for 50 min, wherein the ratio of crude barium oxide to water is 150 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizer, wherein the desulfurizer comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of 5.5:1.5:1.5; the desulfurizer is 9% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 45°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged and dried to obtain the obtained solution.

[0068] The total leaching rate of barium in step (2) is 75.7%; the purity of the final product prepared is 98.0%.

[0069] Comparative Example 5

[0070] This comparative example provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0071] (1) crushing the witherite raw material to an average particle size of 90 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100:5:17:4; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1300°C, and the heat preservation time is 3.5 hours;

[0072] Among them, the total leaching rate of barium in step (1) is 63.4%;

[0073] (2) Dispersing the crude barium oxide in water at 65°C under stirring at 450 r / min for 50 min, wherein the ratio of crude barium oxide to water is 150 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizing agent, wherein the desulfurizing agent comprises calcium oxide and copper oxide in a weight ratio of 1.5:1.5; the desulfurizing agent is 9% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 45°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged, and dried to obtain the obtained solution.

[0074] The total leaching rate of barium in step (2) is 70.3%; the purity of the final product prepared is 97.5%.

[0075] Comparative Example 6

[0076] This comparative example provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0077] (1) crushing the witherite raw material to an average particle size of 90 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100:5:17:4; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1300°C, and the heat preservation time is 3.5 hours;

[0078] Among them, the total leaching rate of barium in step (1) is 63.4%;

[0079] (2) Dispersing the crude barium oxide in water at 65°C under stirring at 450 r / min for 50 min, wherein the ratio of crude barium oxide to water is 150 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizing agent, wherein the desulfurizing agent comprises zinc oxide and copper oxide in a weight ratio of 5.5:1.5; the desulfurizing agent is 9% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 45°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged, and dried to obtain the obtained solution.

[0080] The total leaching rate of barium in step (2) is 71.8%; the purity of the final product prepared is 98.1%.

[0081] Comparative Example 7

[0082] This comparative example provides a process for preparing barium hydroxide octahydrate, the steps comprising:

[0083] (1) crushing the witherite raw material to an average particle size of 90 meshes, and uniformly mixing the crushed witherite with coal powder, charcoal and silicon dioxide, wherein the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100:5:17:4; calcining and heat preservation to obtain crude barium oxide; the calcination temperature is 1300°C, and the heat preservation time is 3.5 hours;

[0084] Among them, the total leaching rate of barium in step (1) is 63.4%;

[0085] (2) Dispersing the crude barium oxide in water at 65°C under stirring at 450 r / min for 50 min, wherein the ratio of crude barium oxide to water is 150 g / L, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizing agent, wherein the desulfurizing agent comprises zinc oxide and calcium oxide in a weight ratio of 5.5:1.5; the desulfurizing agent is 9% of the weight of the crude barium oxide; filtering and washing with deionized water at a temperature of 45°C to obtain a barium hydroxide solution, which is concentrated, cooled, crystallized, centrifuged, and dried to obtain the obtained solution.

[0086] The total leaching rate of barium in step (2) is 70.6%, and the purity of the final product prepared is 98.5%.

[0087] The barium leaching rate and product purity of the above-mentioned embodiments and comparative examples are compared in Table 1.

[0088] Table 1: Barium leaching rate and product purity

[0089] Total leaching rate of barium in step (1) / % Total leaching rate of barium in step (2) / % Product purity / % Example 1 63.4 75.7 99.2 Example 2 62.8 75.6 99.1 Example 3 62.2 75.2 98.9 Example 4 63.1 75.4 99.1 Comparative Example 1 63.4 75.7 99.1 Comparative Example 2 60.4 75.7 98.2 Comparative Example 3 55.6 75.7 97.7 Comparative Example 4 58.2 75.7 98.0 Comparative Example 5 63.4 70.3 97.5 Comparative Example 6 63.4 71.8 98.1 Comparative Example 7 63.4 70.6 98.5

[0090] By comparing the above-mentioned embodiments and comparative examples, it can be seen that comparative examples 1-7 are all based on the embodiments as comparisons, and the specific preparation methods are adjusted, wherein the residue in step (2) in comparative example 1 is processed step by step; coal powder is not used as a raw material in comparative example 2; charcoal is not used as a raw material in comparative example 3; silicon dioxide is not used as a raw material in comparative example 4; the desulfurizer in comparative example 5 does not contain zinc oxide; the desulfurizer in comparative example 6 does not contain calcium oxide; and the desulfurizer in comparative example 7 does not contain copper oxide.

[0091] Based on this, the step-by-step treatment of the residue in Comparative Example 1 has no significant effect on the total leaching rate of barium and the purity of the product. Therefore, the residue treatment method provided in the present invention can reduce production costs and improve production efficiency.

[0092] For comparative examples 2-4, different raw materials will lead to a lower total leaching rate of barium and poor product purity; therefore, the weight ratio of crushed witherite, coal powder, charcoal and silica is 100: (4-6): (16-18): (3-5), which improves the total leaching rate of barium.

[0093] For comparative examples 5-7, the difference in the raw materials of the desulfurizing agent further affects the total leaching rate of barium and the purity of the product. Therefore, when zinc oxide, calcium oxide and copper oxide with a weight ratio of (5-6): (1-2): (1-2) are used as a composite desulfurizing agent, the total leaching rate of barium and the purity of the product can be effectively improved.

[0094] Finally, it should be noted that: the applicant declares that the present invention uses the above-mentioned embodiments to illustrate the products and detailed preparation methods of the present invention, but the present invention is not limited to the above-mentioned products and detailed preparation methods, that is, it does not mean that the present invention must rely on the above-mentioned products and detailed preparation methods to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials of the products of the present invention and the addition of auxiliary materials, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0095] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the specific details in the above embodiments, and the technical solution of the present invention can be subjected to a variety of simple modifications within the technical concept of the present invention. These simple modifications all belong to the protection scope of the present invention.

[0096] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0097] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A process for preparing barium hydroxide octahydrate, characterized in that the steps include: (1) crushing the witherite raw material, mixing the crushed witherite with coal powder, charcoal and silicon dioxide, calcining and keeping warm to obtain crude barium oxide; the weight ratio of the crushed witherite, coal powder, charcoal and silicon dioxide is 100: (4-6): (16-18): (3-5); (2) dispersing crude barium oxide in water, filtering and washing the residue with deionized water, desulfurizing the obtained filtrate with a desulfurizing agent, filtering and washing to obtain a barium hydroxide solution, and concentrating, cooling, crystallizing, centrifuging and drying the solution; the desulfurizing agent comprises zinc oxide, calcium oxide and copper oxide in a weight ratio of (5-6): (1-2): (1-2); The calcination temperature is 1250-1350°C and the holding time is 3-4h; The desulfurizing agent is 8-10% of the weight of the crude barium oxide; The average particle size of the crushed witherite is 80-100 meshes.

2. The process for preparing barium hydroxide octahydrate according to claim 1, characterized in that: The dispersion method comprises stirring at 400-500 r / min for 40-60 min, and the dispersion temperature is 60-70° C.

3. The process for preparing barium hydroxide octahydrate according to claim 1, characterized in that: The ratio of the crude barium oxide to water is 140-160 g / L.

4. The process for preparing barium hydroxide octahydrate according to claim 1, characterized in that: The washing liquid used in the filtration washing is deionized water with a temperature of 40-50°C.