White carbon black taking waste diatomite as raw material and preparation method of white carbon black

Abstract

The invention relates to white carbon black taking waste diatomite as a raw material and a preparation method thereof, and the preparation method comprises the following steps: crushing and screening: crushing large particles in the waste diatomite, and sieving to remove large particle impurities; heat treatment: putting the waste diatomite from which the large-particle impurities are removed into a drying oven, and keeping for a first preset time at a first preset temperature; pickling: soaking the waste diatomite subjected to heat treatment in a soaking solution with an acidic pH value at a second preset temperature for a second preset time, and then washing with water; preparing a water glass solution: mixing the acid-washed waste diatomite with alkali liquor for reaction, and filtering out an undissolved part to obtain the water glass solution; and preparing the white carbon black: taking the water glass solution, introducing carbon dioxide gas to carry out precipitation reaction, standing and aging a precipitation system after the reaction is completed, then filtering, retaining a filter cake, and drying to obtain a white carbon black finished product. The method can help a winery to treat waste, and the additional value of the waste diatomite is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a white carbon black, in particular to a white carbon black using waste diatomite as raw material and a preparation method thereof. BACKGROUND

[0002] White carbon black is a general term for fine powder or particle of anhydrous and hydrous silicon dioxide or silicate. White carbon black is mainly used to reinforce rubber and improve the physical properties of rubber. Because white carbon black has similar uses as carbon black and is white, it is also commonly known as "white carbon black". In addition, white carbon black is often used as a carrier in medicine, and is used as a carrier or a flow agent in the pesticide, feed and other industries, and is used as a friction agent and thickening agent in toothpaste, and has a wide range of applications in the paint, papermaking, food and other industries.

[0003] Diatomite is a siliceous rock, the main chemical component of which is silicon dioxide (SiO2), which is generally formed by the deposition of silicate remains of single-cell algae collectively known as diatoms after death. Diatomite is soft, porous and light, and has the characteristics of adsorption, ion exchange capacity and porosity, and is often used as a filter material, thermal insulation material, abrasive material, filter aid, catalyst carrier and the like. White carbon black is usually produced using quartz sand as raw material, and the production process is very energy-consuming. Moreover, quartz sand, as a mineral resource, will face the risk of exhaustion in the future. At present, the sustainable source of white carbon black mainly comes from rice husk ash. However, the production of rice is mainly in the Asian region, while the rice husk resources in Europe and North America are relatively scarce. In the process of beer and baijiu (Chinese liquor) manufacturing, a large amount of waste diatomite is produced, and the surface of the waste diatomite is adsorbed with organic matter such as yeast and enzymes, which is very troublesome to handle. At present, the treatment of waste diatomite generally adopts solidification, landfill and recycling methods. Solidification refers to mixing waste diatomite with a solidifying agent to form a solid with certain hardness and strength for building materials or filling materials; landfill refers to filling waste diatomite in the soil of a designated area or using it as a roadbed filler; recycling refers to recycling and purifying waste diatomite for reuse or for preparing composite materials. The above methods have low added value and may cause environmental pollution.

[0004] Chinese patent CN100534934C reports a building material composition obtained from waste diatomite, which uses waste diatomite with quicklime to remove water, uses alkali for sterilization and harmless treatment, adds clay and pigment to obtain a diatomite building composite. However, the added value of this method is not high; Chinese patent CN103566913A reports a method for regenerating and utilizing waste diatomite filter residues produced in seaweed glue production, which mainly includes the processes of scrubbing and gel dissolution, screening and water selection, drying and roasting, and crushing and air classification, but this method is relatively complex, and the activated regenerated waste diatomite can be used for about 5 times, and finally still generates solid waste, causing secondary pollution. SUMMARY

[0005] The main purpose of the present application is to provide a preparation method of white carbon black with stable performance and high added value, using waste diatomite as raw material.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A preparation method of white carbon black using waste diatomite as raw material, comprising the following steps:

[0008] S1. Crushing and screening:

[0009] After crushing and screening the large particles in the waste diatomite, remove the large particle impurities;

[0010] S2. Heat treatment:

[0011] Put the waste diatomite after removing large particle impurities into an oven, and keep it at a first preset temperature for a first preset time;

[0012] S3. Acid washing:

[0013] After heat treatment, immerse the waste diatomite in a soaking solution with a second preset temperature and a pH of acid for a second preset time, and then wash it with water;

[0014] S4. Preparation of water glass solution:

[0015] Mix the waste diatomite after acid washing with lye and react, filter out the undissolved part, and obtain the water glass solution;

[0016] S5. Preparation of white carbon black:

[0017] Take the water glass solution, pass carbon dioxide gas for precipitation reaction, after the reaction is completed, let the precipitation system stand for aging, then filter to obtain filter cake, grind and dry the filter cake to obtain white carbon black product.

[0018] The waste diatomite is at least one of waste diatomite from a brewery and waste diatomite from a liquor factory.

[0019] The screen for screening is 16-200 mesh.

[0020] The first preset temperature is 200-400 DEG C, and the first preset time is 10-120 minutes;

[0021] The second preset temperature is 50-80 DEG C, and the second preset time is 1-4 hours.

[0022] The pH of the soaking solution is less than 4, and hydrochloric acid or sulfuric acid is used to adjust the pH of the soaking solution, and the washing-out liquid after washing is neutral; the soaking solution is stirred, the stirring speed is 300-600 rpm, and the stirring time is the second preset time.

[0023] The alkali liquor is sodium hydroxide or potassium hydroxide solution, the concentration of the alkali liquor is 1-5 mol / L, the ratio of the waste diatomite and the alkali liquor is 100g:0.5-2L, the mixing reaction time of the waste diatomite and the alkali liquor is 1-5 hours, and the reaction temperature is 60-100℃.

[0024] In the preparation of the white carbon black, the volume percentage concentration of the carbon dioxide is 10-100%, the gas pressure is 0.05-0.30 MPa, and the aging time is 0.5-3 hours.

[0025] The drying is selected from spray drying or oven hot air drying; the spray drying inlet air temperature is 160-200℃, and the outlet air temperature is 70-90℃; the oven hot air drying temperature is 80-200℃; and the oven hot air drying time is 1-5 hours.

[0026] The application also provides a white carbon black prepared by the method.

[0027] By the above technical solution, the application has at least the following advantages:

[0028] The application adds a heat treatment step. Since the waste diatomite of the winery contains a certain amount of organic matter such as yeast and enzymes, it may affect the subsequent reaction. After adding the heat treatment step, the organic matter can be decomposed and removed at high temperature.

[0029] The application adds an acid pickling step to remove metal oxides in the waste diatomite, thereby improving the purity of the product.

[0030] The application provides a relatively sustainable production method of white carbon black. The raw material used in the application is waste diatomite of the winery, which is low in price and more widely and sustainably sourced.

[0031] The application also provides a relatively carbon-reduced white carbon black product. Traditional white carbon black production processes usually use sulfuric acid for precipitation reaction. In the application, carbon dioxide (CO2) is used instead of sulfuric acid in the precipitation reaction step, further consuming carbon dioxide. According to the evaluation, the carbon emission of the white carbon black prepared by the method of the application is half of that of the traditional process.

[0032] The application can help the winery to dispose of waste and greatly improve the added value of the waste diatomite. The waste diatomite is usually disposed of by landfill or brick burning, and has limited added value and may pollute the environment. The application converts it into white carbon black by the simplest and most economical process, which has little pollution to the environment and costs close to traditional white carbon black, and thus can develop its application in products such as tires, shoe materials, and toothpaste.

[0033] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and can be implemented according to the content of the specification, as follows. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A process flow chart for preparing white carbon black from waste diatomite is provided in the present application;

[0035] Figure 2 The thermogravimetric analysis curve of waste diatomite is provided in the present application. DETAILED DESCRIPTION

[0036] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined object of the application, the specific embodiments, structures, features and effects of the present application are described in detail below in combination with the drawings and preferred embodiments. In the following description, different "an embodiment" or "embodiments" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0037] As shown in Figure 1 The method of the present application uses waste diatomite from a winery as raw material, and the waste diatomite is subjected to crushing, screening, heat treatment and acid washing, then reacted with an alkali solution of a certain concentration, filtered to obtain a water glass solution, then carbon dioxide is introduced for precipitation reaction, then aged and adjusted in pH, and finally filtered and dried to obtain finished white carbon black.

[0038] The white carbon black prepared by the present application has the advantages of environmentally friendly and carbon reduction, low price, and is conducive to the recycling of waste from wineries, and the process characteristics of the present application are suitable for large-scale industrial production. The white carbon black obtained has stable performance and high added value, and has good application prospects in products such as tires, shoe materials and toothpaste.

[0039] The present application will be further described below through specific embodiments:

[0040] Example 1

[0041] The large waste diatomite particles from a brewery are crushed and passed through a 100-mesh sieve to remove large-particle impurities. The waste diatomite from which the large-particle impurities have been removed is placed in an oven and heat-treated at 300°C for 2 hours. 100 g of the heat-treated waste diatomite is added to water, and stirred at 60°C at a speed of 450 rpm. Sulfuric acid is used to adjust the solution to pH = 1 during the stirring. The waste diatomite is soaked in the acidic soaking solution for 2 h while stirring for 2 h. After the stirring and soaking are stopped, the waste diatomite is washed with water until the washing effluent is neutral. The neutral waste diatomite after the acid washing is added to 1000 ml of a sodium hydroxide solution with a concentration of 2 mol / L. Boiling is performed to 100°C, and the reaction is performed for 4 hours. The undissolved part is filtered off to obtain a water glass solution. Pure carbon dioxide gas with a volume percentage concentration of 100% is introduced into the water glass solution at a gas pressure of 0.2 MPa to perform a precipitation reaction. After the reaction is completed, the precipitation system is left to stand for 2 hours. Filtration is performed again, and the filter cake is reserved. The filter cake is ground and dried in an oven at 150°C for 2 hours to obtain a white carbon black product.

[0042] Example 2

[0043] The large waste diatomite particles from a brewery are crushed and passed through a 16-mesh sieve to remove large-particle impurities. The waste diatomite from which the large-particle impurities have been removed is placed in an oven and heat-treated at 400°C for 10 minutes. 100 g of the heat-treated waste diatomite is added to water, and stirred at 50°C at a speed of 300 rpm. Sulfuric acid is used to adjust the solution to pH = 3 during the stirring. The waste diatomite is soaked in the acidic soaking solution for 4 h while stirring for 4 h. After the stirring and soaking are stopped, the waste diatomite is washed with water until the washing effluent is neutral. The neutral waste diatomite after the acid washing is added to 500 ml of a potassium hydroxide solution with a concentration of 5 mol / L. After the reaction is performed at 60°C for 5 hours, the undissolved part is filtered off to obtain a water glass solution. Carbon dioxide gas with a volume percentage concentration of 50% is introduced into the water glass solution at a gas pressure of 0.05 MPa to perform a precipitation reaction. After the reaction is completed, the precipitation system is left to stand for 0.5 hours. Filtration is performed again to obtain a filter cake. The filter cake is ground and spray-dried. The inlet air temperature for the spray drying is 180°C, and the outlet air temperature is 80°C. A white carbon black product is obtained.

[0044] Example 3

[0045] The large waste diatomite particles from a liquor factory were crushed and passed through a 200-mesh sieve to remove large-particle impurities. The waste diatomite from which the large-particle impurities had been removed was placed in an oven and heat-treated at 200°C for 100 minutes. 100 g of the waste diatomite after heat treatment was added to water, and the solution was stirred at 80°C at a speed of 600 rpm for 1 hour. During the stirring, hydrochloric acid was used to adjust the solution to pH = 6. The waste diatomite was soaked in the acid solution under stirring for 1 h, and then washed with water until the washing liquid was neutral. The waste diatomite after acid washing and neutralization was added to 2000 ml of a sodium hydroxide solution with a concentration of 1 mol / L. After reaction at 80°C for 1 hour, the undissolved part was filtered out to obtain a water glass solution. Carbon dioxide gas with a volume percentage concentration of 10% was introduced into the water glass solution to perform a precipitation reaction at a gas pressure of 0.3 MPa. After the reaction was completed, the precipitation system was allowed to stand for aging for 3 hours, and then was filtered to obtain a filter cake. The filter cake was ground and dried in an oven at 200°C for 1 hour to obtain a white carbon black product.

[0046] Comparative Example 1 (without a heat treatment step)

[0047] The large waste diatomite particles from a beer factory were crushed and passed through a 100-mesh sieve to remove large-particle impurities. 100 g of the waste diatomite after heat treatment was added to water, and the solution was stirred at 60°C at a speed of 450 rpm. During the stirring, sulfuric acid was used to adjust the solution to pH = 1. The waste diatomite was soaked in the acid solution for 2 h, and stirring was performed for 2 h during the soaking. After the stirring and soaking were stopped, the waste diatomite was washed with water until the washing liquid was neutral. The waste diatomite after acid washing and neutralization was added to 1000 ml of a sodium hydroxide solution with a concentration of 2 mol / L. Boiling was performed to 100°C, and after reaction for 4 hours, the undissolved part was filtered out to obtain a water glass solution. Pure carbon dioxide gas with a volume percentage concentration of 100% was introduced into the water glass solution to perform a precipitation reaction at a gas pressure of 0.2 MPa. After the reaction was completed, the precipitation system was allowed to stand for aging for 2 hours, and then was filtered. The filter cake was reserved, and the filter cake was ground and dried in an oven at 150°C for 2 hours to obtain a white carbon black product.

[0048] Comparative Example 2 (without an acid washing step)

[0049] The large waste diatomite particles from a beer factory were crushed and passed through a 100-mesh sieve to remove large-particle impurities. The waste diatomite from which the large-particle impurities had been removed was placed in an oven and heat-treated at 300°C for 2 hours. 100 g of the waste diatomite after heat treatment was added to 1000 ml of a sodium hydroxide solution with a concentration of 2 mol / L. After reaction at 100°C for 4 hours, the undissolved part was filtered out to obtain a water glass solution. Carbon dioxide gas with a volume percentage concentration of 100% was introduced into the water glass solution to perform a precipitation reaction at a gas pressure of 0.2 MPa. After the reaction was completed, the precipitation system was allowed to stand for aging for 2 hours, and then was filtered. The filter cake was reserved, and the filter cake was ground and dried in an oven at 150°C for 2 hours to obtain a white carbon black product.

[0050] The products of the above examples were subjected to performance testing, and the results are shown in Table 1.

[0051] Table 1. Performance testing results

[0052] Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Purity (dry basis) (%) 95.83 94.78 95.96 94.61 91.35 Heating loss (%) 4.8 4.9 4.7 5.4 5.7 Ignition loss (%) 5.1 5.0 5.3 5.2 5.5 pH 7.7 7.9 8.0 7.9 8.2 Sodium (mg / kg) 412 433 426 446 589 Aluminium (mg / kg) 57 60 55 64 2138 Iron (mg / kg) 28 26 30 31 281 Magnesium (mg / kg) 26 28 25 27 277

[0053] As can be seen from Table 1, the purity of the white carbon black obtained in Examples 1, 2 and 3 is higher than that of Comparative Examples 1 and 2, and the metal content is lower, because the preparation process of the examples of the present application includes a heat treatment step and an acid washing step at the same time, the heat treatment step can effectively remove the organic matter in the raw material, avoiding the influence of organic matter on the subsequent steps; the acid washing step can effectively remove the oxides (such as iron oxide) that are not soluble in water in the raw material, as well as the metal oxides (such as aluminum oxide, magnesium oxide, etc.) that can react with lye / water at high temperature. In Comparative Example 1, the purity of the product is slightly reduced because the heat treatment step is omitted; in Comparative Example 2, the metal ion residue in the product is more than that in other examples because the acid washing step is omitted.

[0054] Referring to Figure 2 , the ordinate is the percentage of body weight, and the abscissa is the temperature. As can be seen from the results of Figure 2 , the organic impurities in diatomite begin to decompose at about 260℃, and the decomposition is basically completed at about 420℃. The content of organic matter is about 4%.

[0055] The thermal gravimetric analysis experiment of the present application was performed on a Mettler TGA-1100, preheated at 25℃ for 2 minutes, then heated to 600℃ at 10℃ / min, and then kept for 5 minutes.

[0056] Chemical component analysis was performed by wavelength dispersive X-ray fluorescence spectroscopy (XRF), using a Bruker S8 Tiger II, grinding and calcining the sample, and then testing after embedding and pressing the sample with boric acid. Test method: Best Detection (Vac 28mm).

[0057] The above is only a preferred embodiment of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, and equivalent embodiments with equivalent changes are equivalent. Any simple modification, equivalent change and modification made to the above examples according to the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A method for producing white carbon black from waste diatomite, characterized by, The method comprises the following steps: S1. Crushing and screening: Crushing and screening the large particles in the waste diatomite to remove large particle impurities; S2. Heat treatment: Placing the waste diatomite after removing large particle impurities into an oven, and keeping it at a first preset temperature for a first preset time; S3. Acid washing: Soaking the waste diatomite after heat treatment in a soaking solution with a second preset temperature and an acid pH for a second preset time, and then washing it with water; S4. Preparing a water glass solution: Mixing the waste diatomite after acid washing with a lye solution, filtering out the undissolved part, and obtaining a water glass solution; S5. Preparing white carbon black: Taking the water glass solution, passing carbon dioxide gas to perform a precipitation reaction, and after the reaction is completed, placing the precipitation system to stand for aging, then filtering to obtain a filter cake, grinding and drying the filter cake to obtain white carbon black products.

2. The production method according to claim 1, characterized by, The waste diatomite is at least one of waste diatomite from a brewery and waste diatomite from a liquor factory.

3. The preparation method according to claim 1, characterized in that, The screen for the screening is 16-200 mesh.

4. The production method according to any one of claims 1 to 3, characterized by, The first preset temperature is 200-400℃, and the first preset time is 10-120 minutes.

5. The preparation method according to claim 4, characterized in that, The second preset temperature is 50-80℃, and the second preset time is 1-4 hours.

6. The production method according to claim 5, characterized by, The pH of the soaking solution is less than 4, and hydrochloric acid or sulfuric acid is used to adjust the pH of the soaking solution, and the washing liquid after the water washing is neutral; The soaking solution is stirred at a speed of 300-600 rpm for the second preset time.

7. The preparation method according to claim 6, characterized in that, The lye solution is a sodium hydroxide or potassium hydroxide solution, the concentration of the lye solution is 1-5 mol / L, the ratio of the waste diatomite to the lye solution is 100 g:0.5-2 L, the mixing reaction time of the waste diatomite and the lye solution is 1-5 hours, and the reaction temperature is 60-100℃.

8. The preparation method according to claim 7, characterized in that, In the preparation of white carbon black, the volume percentage concentration of carbon dioxide is 10-100%, the gas pressure is 0.05-0.30 MPa, and the aging time is 0.5-3 hours.

9. The preparation method according to claim 8, characterized in that, The drying is selected from spray drying or oven hot air drying; the inlet air temperature of the spray drying is 160-200℃, and the outlet air temperature is 70-90℃; the temperature of the oven hot air drying is 80-200℃; and the oven hot air drying time is 1-5 hours.

10. A white carbon black characterized by, Prepared by the method according to any one of claims 1-9.

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