Low-sulfur barium carbonate and preparation method thereof

Abstract

The invention belongs to the technical field of inorganic chemical industry, and particularly relates to low-sulfur barium carbonate and a preparation method thereof. The preparation method of the low-sulfur barium carbonate comprises the following steps: (1) adding an auxiliary agent into yellow water, heating and stirring; (2) when the solution becomes colorless from yellow, carrying out suction filtration to obtain white water; (3) adding the heated sodium carbonate solution into the white water, and performing suction filtration after the reaction is completed to obtain a filter cake; and (4) pulping, washing and drying the filter cake to obtain the low-sulfur barium carbonate. The preparation method of the low-sulfur barium carbonate is simple to operate and short in technological process, and the sulfur content in the barium carbonate can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic chemical industry, and particularly relates to low-sulfur barium carbonate and a preparation method thereof. Background Art

[0002] Low sulfur barium carbonate is a high purity barium carbonate product with a low sulfur content. This material has important applications in many industries due to its high purity and specific chemical properties. It can be used to produce optical glass, ceramics and magnets to improve the physical properties of these products; it can be used in the manufacture of electronic ceramics, PTC (positive temperature coefficient) thermistors and capacitors and other electronic components; it can be used to manufacture optical glass and cathode ray tube glass, as well as barium magnetic materials; it can be used to prepare fireworks and flares, because barium carbonate can produce unique colors and effects when burning; it can be used to synthesize barium manganese carbonate single crystals. This type of material has the characteristics of high purity, good chemical stability and low water absorption, and is suitable for applications in special environments.

[0003] The traditional carbonization preparation process causes the oxidation of sulfur to form polysulfides and sulfur to be entrained into the barium carbonate product due to the influence of oxygen in the barium sulfide clinker leaching process and the carbonization process of carbon dioxide, resulting in an increase in the total sulfur content of the barium carbonate product, affecting the use of downstream customers. Summary of the invention

[0004] In view of the defects of the prior art, the present invention provides a low-sulfur barium carbonate and a preparation method thereof.

[0005] Specifically, the present invention is achieved through the following technical solutions:

[0006] A method for preparing low-sulfur barium carbonate comprises:

[0007] (1) Add additives to yellow water, heat and stir;

[0008] (2) When the solution changes from yellow to colorless, filter it to obtain white water;

[0009] (3) adding the heated sodium carbonate solution to the white water, and filtering after the reaction is completed to obtain a filter cake;

[0010] (4) The filter cake is pulped, washed and dried to obtain low-sulfur barium carbonate.

[0011] In the above-mentioned method for preparing low-sulfur barium carbonate, the concentration of barium sulfide in the yellow water is 120-130 g / L; and the mass concentration of the sodium carbonate solution is 26%-30%.

[0012] In the above-mentioned method for preparing low-sulfur barium carbonate, the auxiliary agent is sodium hydroxide; the mass volume ratio of the auxiliary agent to the yellow water is 1: (800-1200).

[0013] In the above-mentioned method for preparing low-sulfur barium carbonate, the excess amount of sodium carbonate after the reaction in step (3) is less than 5%.

[0014] In the above-mentioned method for preparing low-sulfur barium carbonate, the heating temperature of the yellow water in step (1) is 60-70° C.; and the heating temperature of the sodium carbonate solution in step (3) is 44-70° C.

[0015] In the above-mentioned method for preparing low-sulfur barium carbonate, in step (3), the sodium carbonate solution is added to the white water at a flow rate of 0.3 to 0.4 m / s. 3 / h.

[0016] In the above-mentioned method for preparing low-sulfur barium carbonate, the sodium carbonate solution is a refined sodium carbonate solution treated with barium sulfide or high-activity barium carbonate or directly filtered.

[0017] In the above-mentioned method for preparing low-sulfur barium carbonate, the temperature of the pulping and washing is room temperature, and the solid-liquid ratio is 1:(5-15).

[0018] A low-sulfur barium carbonate is prepared by the above-mentioned preparation method.

[0019] The total sulfur content of the above-mentioned low-sulfur barium carbonate is ≤0.06wt%.

[0020] The technical solution of the present invention has the following beneficial effects:

[0021] The preparation method of low-sulfur barium carbonate of the present invention has simple operation and short process flow, and can effectively reduce the sulfur content in the barium carbonate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the following detailed description of the preferred embodiment.The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting the invention.

[0023] Figure 1 This is a scanning electron micrograph of the barium carbonate prepared in Example 1;

[0024] Figure 2 This is a particle size distribution diagram of barium carbonate prepared in Example 1;

[0025] Figure 3 This is a scanning electron micrograph of the barium carbonate prepared in Example 2;

[0026] Figure 4 This is a particle size distribution diagram of barium carbonate prepared in Example 2;

[0027] Figure 5 This is a scanning electron micrograph of the barium carbonate prepared in Example 3;

[0028] Figure 6 This is the particle size distribution diagram of the barium carbonate prepared in Example 3. DETAILED DESCRIPTION

[0029] In order to fully understand the purpose, features and effects of the present invention, the present invention is described in detail through the following specific embodiments. Except for the following contents, the process method of the present invention adopts conventional methods or devices in the art. Unless otherwise specified, the following terms have the meanings commonly understood by those skilled in the art.

[0030] When a numerical range is disclosed herein, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0031] Specifically, the method for preparing low-sulfur barium carbonate provided by the present invention comprises:

[0032] (1) Add additives to yellow water, heat and stir;

[0033] (2) When the solution changes from yellow to colorless, filter it to obtain white water;

[0034] (3) adding the heated sodium carbonate solution to the white water, and filtering after the reaction is completed to obtain a filter cake;

[0035] (4) The filter cake is pulped, washed, dried, and crushed to obtain low-sulfur barium carbonate.

[0036] The present invention adds an auxiliary agent to the yellow water to convert the elemental sulfur therein into negative divalent sulfur and sulfite, thereby avoiding the generation of barium polysulfide and turning the yellow water into a colorless clear solution. Elemental sulfur is insoluble in water, resulting in washing being meaningless to reduce total sulfur, while negative divalent sulfur and sulfite are easily soluble in water and can be removed by washing, which is a guarantee of low sulfur. In some preferred embodiments, the yellow water comes from a barium sulfide workshop, and its main component is barium sulfide, and the barium sulfide concentration in the yellow water is 120-130 g / L, and the temperature is 60-70°C.

[0037] Optionally, the concentration of the barium sulfide solution is 120 g / L, 121 g / L, 122 g / L, 123 g / L, 124 g / L, 125 g / L, 126 g / L, 127 g / L, 128 g / L, 129 g / L or 130 g / L; the temperature of the barium sulfide solution is 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C.

[0038] Further preferably, the concentration of barium sulfide in the yellow water is 123-127 g / L, and the temperature is 60-67°C.

[0039] Among them, the auxiliary agent is a chemical substance with strong alkalinity.

[0040] In some preferred embodiments, the auxiliary agent is sodium hydroxide; the mass volume ratio of the auxiliary agent to the yellow water is 1g:(800-1200ml), and more preferably 1g:1000ml.

[0041] In step (1), after the auxiliary agent is added to the yellow water, the chemical reaction that occurs is:

[0042] 3S+6NaOH=2Na 2 S+Na 2 SO 3 +3H 2 O

[0043] In some preferred embodiments, the mass concentration of the sodium carbonate solution is 26% to 30%, and the temperature is 44 to 70°C.

[0044] Optionally, the mass concentration of the sodium carbonate solution is 26%, 26.5%, 27%, 27.5%, 28%, 28.5%, 29%, 29.5% or 30%; the temperature of the sodium carbonate solution is 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, 62°C, 64°C, 66°C, 68°C or 70°C.

[0045] Further preferably, the mass concentration of the sodium carbonate solution is 27% to 29%, and the temperature is 50 to 60°C.

[0046] In some preferred embodiments, the sodium carbonate solution is added to the white water at a flow rate of 0.3-0.4 m / s. 3 / h.

[0047] Optionally, the sodium carbonate solution is added to the white water at a flow rate of 0.30 m 3 / h, 0.31m 3 / h, 0.32m 3 / h、0.33m 3 / h, 0.34m 3 / h, 0.35m 3 / h, 0.36m 3 / h, 0.37m 3 / h, 0.38m 3 / h, 0.39m 3 / h or 0.40m 3 / h.

[0048] Further preferably, the sodium carbonate solution is added to the white water at a flow rate of 0.35 m / s. 3 / h.

[0049] In step (3), sodium carbonate solution is added to white water, and the chemical reaction that occurs is:

[0050] BaS+Na 2 CO 3 =BaCO 3 ↓+Na 2 S

[0051] In some preferred embodiments, the amount of sodium carbonate added is slightly excessive (mass ratio excess <5%), thereby converting all free barium ions in the system into barium carbonate.

[0052] In some preferred embodiments, in order to further reduce the total sulfur content in the barium carbonate, the present invention refines the purchased sodium carbonate.

[0053] Optionally, the refining is to add a small amount of barium sulfide treated with an auxiliary agent to the sodium carbonate solution, and filter after the reaction is completed. Due to the difference in ion level constants, part of the sulfate in the sodium carbonate is converted into barium sulfate precipitation, and the corresponding part of the sulfate in the sodium carbonate is removed after filter pressing.

[0054] Optionally, the refining is to add highly active barium carbonate to the sodium carbonate solution, so that part of the sulfate in the sodium carbonate is converted into barium sulfate precipitate due to the difference in ion order constants, and the corresponding part of the sulfate in the sodium carbonate is removed after filter pressing.

[0055] Optionally, the refining is to directly filter the sodium carbonate solution, thereby removing mechanical impurities and some metal ions (such as magnesium, zinc, etc.) in the solution.

[0056] In some preferred embodiments, the temperature of the pulping and washing is room temperature, and the solid-liquid ratio is 1:(5-15).

[0057] In some other preferred embodiments, the pulping and washing includes primary pulping and washing and secondary pulping and washing. The primary pulping and washing is performed at room temperature with a solid-liquid ratio of 1:(5-15); the secondary pulping and washing is performed at 70-80°C with a solid-liquid ratio of 1:(5-15).

[0058] In some preferred embodiments, solid-liquid separation is performed after the pulping and washing, and the pH of the filtrate is controlled at 7 to 9, more preferably 7.

[0059] On the other hand, the present invention also provides a low-sulfur barium carbonate, which is prepared by the above-mentioned preparation method.

[0060] The total sulfur content of the low-sulfur barium carbonate prepared according to the method of the present invention is ≤0.06wt%, meeting the use requirements of downstream customers.

[0061] Example

[0062] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods without specific conditions in the following examples are based on conventional methods and conditions.

[0063] Example 1

[0064] (1) Take 1600 mL of yellow water, heat it to 62°C, add 1.6 g of an auxiliary agent, stir for 10 min, and then filter it. The color changes from yellow to a milky white turbid liquid. Press filter to obtain the white water mother liquor.

[0065] (2) Take 100g of sodium carbonate and add it to a 1L beaker containing 250mL of pure water. Heat to dissolve, maintain the temperature at 69°C, add 5g of highly active carbonic acid and stir for 10min. After filtration, take the clarified mother liquor and maintain the temperature at 0.3m 3 / h flow rate into 1000mL white water mother liquor to react, after adding the materials, continue stirring for 10min, detect the end point, and filter. Wash once at a solid-liquid ratio of 1:10, wash at room temperature (10℃) for 30min under stirring, then filter, and detect barium carbonate after drying.

[0066] According to the test, the total sulfur in barium carbonate is 0.06% and the Fe is 2.7ppm. Figure 1 , particle size distribution see Figure 2 .

[0067] Example 2

[0068] (1) Take 2000 mL of yellow water with a concentration of 123.12 g / L, heat it to 60°C, add 2 g of auxiliary agent under stirring, stir for 10 minutes, filter and obtain the white water mother liquor, and control the temperature at 55-70°C.

[0069] (2) Take 3L of pure water, add 1.2kg of sodium carbonate under heating and stirring, and after complete dissolution at 60°C, obtain 3335mL of solution, take a sample for analysis. Then add 15g of highly active barium carbonate, stir at 55-70°C for 20min, and filter to obtain a sodium carbonate solution.

[0070] (3) Take 472 mL of sodium carbonate solution and heat it at 57°C. 3 / h flow rate into the white water mother liquor for reaction. After the addition is completed, continue stirring for 20 minutes and filter.

[0071] (4) With a solid-liquid ratio of 1:10, the mixture was slurried and washed at room temperature for 30 min, filtered, and dried to obtain barium carbonate.

[0072] According to the test, the total sulfur in barium carbonate is 0.045% and the Fe is 3.9ppm. Figure 3 , particle size distribution see Figure 4 .

[0073] Scanning electron microscopy Figure 3 , particle size distribution see Figure 4 .

[0074] Example 3

[0075] (1) Take 2000 mL of yellow water with a concentration of 125.57 g / L, heat it to 67°C, add 2 g of an auxiliary agent, stir for 10 min, maintain the temperature at 55-70°C, and filter to obtain a white water mother liquor.

[0076] (2) Take 172 g of sodium carbonate and add it to a beaker containing 430 mL of pure water. Heat and stir until dissolved and filter.

[0077] (3) Sodium carbonate solution at 0.4 m 3 / h flow rate into the white water mother liquor for reaction. After the addition is completed, continue stirring for 10 minutes and filter.

[0078] (4) The filter cake was pulped and washed at 20°C for 30 min at a solid-liquid ratio of 1:10, filtered, and dried to obtain barium carbonate.

[0079] After testing, the total sulfur in barium carbonate is 0.054% and the Fe is 4.0ppm. Figure 5 , particle size distribution see Figure 6 .

[0080] Example 4

[0081] (1) Take 1000 ml of yellow water with a concentration of 124.57 g / L in a 5L beaker, heat it to 67°C, add 1 g of an additive, stir for 10 min, and then filter it. The color changes from yellow to a milky white turbid liquid. After filtering, the white water mother liquor is obtained.

[0082] (2) Take 88g of sodium carbonate and add it to a 1L beaker containing 220mL of pure water. Heat and dissolve it. Maintain the temperature at 62°C. Add 2.5mL of treated barium sulfide solution. The color changes from colorless to cyan. After filtration, take the mother liquor and keep it at the temperature for later use.

[0083] (3) Sodium carbonate solution at 0.3 m 3 / h flow rate into the white water mother liquor for reaction, the reaction temperature is 60℃, after the addition of materials, continue stirring for 10min, detect the end point, and filter.

[0084] (4) The first washing is carried out at a solid-liquid ratio of 1:10, and the mixture is washed at room temperature (10°C) for 30 minutes under stirring, and then filtered; the second washing is carried out at a solid-liquid ratio of 1:5, and the mixture is heated and stirred at 70-80°C for 30 minutes, and then filtered. The filter cake is heated and dried to obtain barium carbonate.

[0085] After testing, the total sulfur content in barium carbonate is 0.063% and the Fe content is 3 ppm.

[0086] Example 5

[0087] (1) Take 2000 mL of yellow water with a concentration of 125.57 g / L, heat it to 60°C, add 2 g of an auxiliary agent, stir for 10 min, maintain the temperature at 60-63°C, and filter to obtain a white water mother liquor.

[0088] (2) Take 170 g of sodium carbonate and add it to a beaker containing 425 mL of pure water. Heat and stir until dissolved and filter.

[0089] (3) Sodium carbonate solution at 0.4 m 3 / h flow rate to add to the white water mother liquor for reaction. After the addition is completed, continue stirring for 10 minutes and filter.

[0090] (4) The filter cake was pulped and washed at 19° C. for 30 min at a solid-liquid ratio of 1:10. The filtrate had a pH of 7-8. The filter cake was filtered and dried to obtain barium carbonate.

[0091] After testing, the total sulfur content in barium carbonate is 0.058% and the Fe content is 2.6ppm.

[0092] Comparative Example 1

[0093] (1) Take 2000 mL of yellow water with a concentration of 125.57 g / L, maintain the temperature at 60°C, and filter to obtain white water mother liquor.

[0094] (2) Take 477 mL of the sodium carbonate solution prepared in step (2) of Example 2 and heat it to keep it warm. 3 / h flow rate into the white water mother liquor for reaction. After the addition is completed, continue stirring for 10 minutes and filter.

[0095] (4) The filter cake was slurried and washed at 16°C for 30 min at a solid-liquid ratio of 1:10, and then filtered and dried to obtain barium carbonate.

[0096] After testing, the total sulfur content in barium carbonate is 0.13% and the Fe content is 3.5 ppm.

[0097] Comparative Example 2

[0098] (1) Take 1000 mL of yellow water with a concentration of 126.06 g / L, heat it to 60°C, maintain the temperature, and filter it to obtain white water mother liquor.

[0099] (2) Take 243 mL of the sodium carbonate solution prepared in step (2) of Example 2, heat it to 57° C., keep it warm, and add 0.4 mL of sodium carbonate solution to the mixture. 3 / h flow rate into the white water mother liquor for reaction. After the addition is completed, continue stirring for 10 minutes and filter.

[0100] (3) The filter cake was pulped and washed at 17°C for 30 min at a solid-liquid ratio of 1:10. The filtrate had a pH of 7. The filter cake was filtered and dried to obtain barium carbonate.

[0101] After testing, the total sulfur content in barium carbonate is 0.1% and the Fe content is 2.4 ppm.

[0102] The present invention has been disclosed above with preferred embodiments, but those skilled in the art should understand that these embodiments are only used to describe the present invention and should not be understood as limiting the scope of the present invention. It should be noted that all changes and substitutions equivalent to these embodiments should be deemed to be included in the scope of the claims of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined in the claims.

Claims

1. A method for preparing low-sulfur barium carbonate, characterized in that: include: (1) Add additives to yellow water, heat and stir; (2) When the solution changes from yellow to colorless, filter it to obtain white water; (3) adding the heated sodium carbonate solution to the white water, and filtering after the reaction is completed to obtain a filter cake; (4) The filter cake is pulped, washed and dried to obtain low-sulfur barium carbonate.

2. The method for preparing low-sulfur barium carbonate according to claim 1, characterized in that: The concentration of barium sulfide in the yellow water is 120-130 g / L; the mass concentration of the sodium carbonate solution is 26%-30%.

3. The method for preparing low-sulfur barium carbonate according to claim 1, characterized in that: The auxiliary agent is sodium hydroxide; the mass volume ratio of the auxiliary agent to the yellow water is 1: (800-1200).

4. The method for preparing low-sulfur barium carbonate according to claim 1, characterized in that: After the reaction in step (3) is completed, the excess amount of sodium carbonate is less than 5%.

5. The method for preparing low-sulfur barium carbonate according to claim 1, characterized in that: The heating temperature of the yellow water in step (1) is 60-70° C.; the heating temperature of the sodium carbonate solution in step (3) is 44-70° C.

6. The method for preparing low-sulfur barium carbonate according to claim 1, characterized in that: In step (3), the sodium carbonate solution is added to the white water at a flow rate of 0.3 to 0.4 m / s. 3 / h.

7. The method for preparing low-sulfur barium carbonate according to claim 1, characterized in that: The sodium carbonate solution is a refined sodium carbonate solution treated with barium sulfide or high-activity barium carbonate or directly filtered.

8. The method for preparing low-sulfur barium carbonate according to claim 1, characterized in that: The temperature of the pulping and washing is room temperature, and the solid-liquid ratio is 1:(5-15).

9. A low-sulfur barium carbonate, characterized in that: The preparation method is described in any one of claims 1 to 8.

10. The low-sulfur barium carbonate according to claim 9, characterized in that: The total sulfur content of the low-sulfur barium carbonate is ≤0.06wt%.

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