Method for preparing high-purity carbon from rice husk carbon

Abstract

The invention discloses a method for preparing high-purity carbon from rice husk charcoal, and aims to solve the problems that the rice husk charcoal cannot be comprehensively utilized and resources are wasted due to the fact that high-purity activity cannot be obtained when the rice husk charcoal is treated by an existing method, the following scheme is provided: S1, grinding: grinding the rice husk charcoal into powder; s2, mixing and filtering: mixing the ground rice husk charcoal with diluted hydrochloric acid, and filtering after full reaction; s3, drying: drying the extract; s4, mixing, filtering and drying: mixing the dried extract with a sodium hydroxide solution, filtering after full reaction, and drying the extract. S5, mixing and drying: adding a dilute hydrofluoric acid solution into the dried extract after the sodium hydroxide reaction, fully reacting, and washing and drying the extract; according to the method, the sodium silicate solution can be obtained while the high-purity rice husk charcoal is prepared, so that the environment pollution caused by agricultural waste rice husks is avoided, the resource waste is avoided, and the comprehensive utilization value of the rice husks is improved.

Description

Technical Field

[0001] The invention relates to the technical field of preparing high-purity carbon from rice husk, and in particular to a method for preparing high-purity carbon from rice husk carbon. Background Art

[0002] Activated carbon has rich internal pore structure and high specific surface area, and is an excellent adsorption material. It is formed by the accumulation of six rings formed by carbon, and its main chemical component is carbon, containing a small amount of hydrogen, nitrogen, oxygen and ash. It has stable physical and chemical properties, is resistant to acid and alkali, can withstand water, high temperature and high pressure, is insoluble in water and organic solvents, can be easily regenerated after failure, and is a circular economy material.

[0003] At present, there are about a dozen methods for producing carbon black and white carbon black from rice husk charcoal at home and abroad, but these methods basically prepare sodium silicate solution and carbon black by heating and pressurizing the mixture of rice husk charcoal and alkali, and then add the sodium silicate solution to white carbon black. However, the extract carbon black still contains a small amount of silicon dioxide that is not dissolved by the alkali, and the carbon black cannot be used to produce high-grade activated carbon.

[0004] Currently, there is no method in the prior art to remove a small amount of silicon dioxide from carbon black, resulting in a waste of resources. Therefore, we propose a method for preparing high-purity carbon from rice husk charcoal to solve the above problem. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing high-purity carbon from rice husk carbon.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A method for preparing high-purity carbon from rice husk carbon comprises the following steps:

[0008] S1: Grinding: Grinding rice husk charcoal;

[0009] S2: Acid washing: Add the ground rice husk charcoal into dilute hydrochloric acid and mix them for full reaction;

[0010] S3: Filtration: Filter the fully reacted solid-liquid mixture obtained in S2 to obtain an extract; S4: Washing and drying: Wash the extract obtained in S3 with water for several times and dry it;

[0011] S5: alkaline hydrolysis: heating and pressurizing the dried extract in S4 and dilute alkali to obtain alkaline hydrolysis, filtering the obtained solution to obtain a filtrate and an extract;

[0012] S6: Drying: drying the extract obtained in S5;

[0013] S7: pickling: adding dilute hydrofluoric acid to the dried extract in S6, reacting sufficiently, filtering, and obtaining a filtrate and an extract;

[0014] S8: washing: the extract obtained in S7 is washed two to three times with distilled water and dried to obtain rice husk charcoal.

[0015] Preferably, in S1, the rice husk charcoal is ground and then screened with a 200-mesh sieve, and the screened large-particle rice husk charcoal is ground again until there are no large-particle rice husk charcoal.

[0016] Preferably, in S2, the mass of rice husk charcoal and dilute hydrochloric acid is 100g:40ml, and the concentration of hydrochloric acid is 1M.

[0017] Preferably, in S5, sodium hydroxide is used as the alkali, the concentration of the alkali solution is 1 M, the ratio of rice husk charcoal to the alkali solution is 100 g:40 ml, the reaction conditions are 2 standard atmospheric pressures and 200° C., and the reaction time is 80 min.

[0018] Preferably, in S7, the concentration of hydrofluoric acid is 0.5 M, the ratio of rice husk charcoal to hydrofluoric acid is 100 g:30 ml, and the reaction time is 20 min.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. The present invention can improve the efficiency of the reaction by grinding the rice husk charcoal, and can prepare a sodium silicate solution from the rice husk charcoal through mixing, leaching and filtering, thus laying a foundation for the preparation of white carbon black.

[0021] 2. After the extract of the present invention is dissolved in alkali and washed with acid, a hydrofluoric acid solution is added to extract the residual silicon dioxide in the extract to prepare high-purity rice husk charcoal.

[0022] 3. The present invention can prepare high-purity rice husk charcoal and sodium silicate solution, which not only avoids the environmental pollution of agricultural waste rice husks, but also avoids the waste of resources and improves the comprehensive utilization value of rice husks. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a flow chart of a method for preparing high-purity carbon from rice husk carbon. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings, and the technical solutions in the embodiments of the present invention are clearly and completely described. 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.

[0025] Reference Figure 1A method for preparing high-purity carbon from rice husk carbon comprises the following steps:

[0026] S1: Grinding: Grinding rice husk charcoal;

[0027] S2: Acid washing: Add the ground rice husk charcoal into dilute hydrochloric acid and mix them for full reaction;

[0028] S3: Filtration: Filter the fully reacted solid-liquid mixture obtained in S2 to obtain an extract; S4: Washing and drying: Wash the extract obtained in S3 with water for several times and dry it;

[0029] S5: alkaline hydrolysis: heating and pressurizing the dried extract in S4 and dilute alkali to obtain alkaline hydrolysis, filtering the obtained solution to obtain a filtrate and an extract;

[0030] S6: Drying: drying the extract obtained in S5;

[0031] S7: pickling: adding dilute hydrofluoric acid to the dried extract in S6, reacting sufficiently, filtering, and obtaining a filtrate and an extract;

[0032] S8: washing: the extract obtained in S7 is washed two to three times with distilled water and dried to obtain rice husk charcoal.

[0033] In this example, in S1, the rice husk charcoal is ground, and then screened with a sieve, and the screened large-particle rice charcoal is ground again until it reaches 200 meshes.

[0034] In this embodiment, in S2, the mass of rice husk charcoal and dilute hydrochloric acid is 100g:40ml, and the concentration of hydrochloric acid is 1M.

[0035] In this embodiment, in S3, the reaction time is 10 to 15 minutes, centrifugal filtration is used, and the filter cloth has a pore size of 300 meshes.

[0036] In this embodiment, in S4, the extract is washed with pure water two to three times, the thermostat is set at 200° C., and the washed extract is sealed and dried in the thermostat for 30 minutes.

[0037] In this embodiment, in S5, sodium hydroxide is used as the alkali, the concentration of the alkali solution is 1M, the ratio of rice husk charcoal to the alkali solution is 100g:40ml, the reaction conditions are 2 standard atmospheric pressures and 200°C, and the reaction time is 80min.

[0038] In this embodiment, in S6, the extract is washed with pure water two to three times, the thermostat is 200° C., and the washed extract is sealed and dried in the thermostat for 30 minutes.

[0039] In this embodiment, in S7, the concentration of hydrofluoric acid is 0.5 M, the ratio of rice husk charcoal to hydrofluoric acid is 100 g:30 ml, the reaction time is 20 min, and the reaction must be carried out in a fume hood.

[0040] In this embodiment, in S8, the extract is washed with pure water two to three times, the thermostat is set at 200° C., and the washed extract is sealed and dried in the thermostat for 30 minutes.

[0041] The present invention can improve the efficiency of the reaction by grinding the rice husk charcoal, and can prepare a sodium silicate solution from the rice husk charcoal by mixing, leaching and filtering, thereby laying a foundation for preparing white carbon black. After the leaching product is alkali-dissolved and acid-washed, a hydrofluoric acid solution is added to the leaching product to extract the residual silicon dioxide, thereby preparing high-purity rice husk charcoal. At the same time, when the present invention can prepare high-purity rice husk charcoal, a sodium silicate solution can also be obtained, which not only avoids the environmental pollution of agricultural waste rice husks, but also avoids the waste of resources and improves the comprehensive utilization value of rice husks.

[0042] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. After reading this specification, those skilled in the art can make non-creative modifications to this embodiment as needed, but they are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing high-purity carbon from rice husk carbon, characterized in that: The following steps are involved: S1: Grinding: Grinding rice husk charcoal; S2: Acid washing: Add the ground rice husk charcoal into dilute hydrochloric acid and mix them for full reaction; S3: Filtration: Filter the fully reacted solid-liquid mixture obtained in S2 to obtain an extract; S4: washing and drying: washing the extract obtained in S3 with water several times and drying; S5: alkaline hydrolysis: heating and pressurizing the dried extract in S4 and dilute alkali to obtain alkaline hydrolysis, filtering the obtained solution to obtain a filtrate and an extract; S6: Drying: drying the extract obtained in S5; S7: pickling: adding dilute hydrofluoric acid to the dried extract in S6, reacting sufficiently, filtering, and obtaining a filtrate and an extract; S8: washing: the extract obtained in S7 is washed two to three times with distilled water and dried to obtain rice husk charcoal.

2. The method for preparing high-purity carbon from rice husk carbon according to claim 1, characterized in that: In S1, the rice husk charcoal is ground and then screened with a 200-mesh sieve, and the screened large-particle rice husk charcoal is ground again until there are no large-particle rice husk charcoal.

3. The method for preparing high-purity carbon from rice husk carbon according to claim 1, characterized in that: In S2, the mass of rice husk charcoal and dilute hydrochloric acid is 100g:40ml, and the concentration of hydrochloric acid is 1M.

4. The method for preparing high-purity carbon from rice husk carbon according to claim 1, characterized in that: In S5, sodium hydroxide is used as the alkali, the concentration of the alkali solution is 1 M, the ratio of rice husk charcoal to the alkali solution is 100 g:40 ml, the reaction conditions are 2 standard atmospheric pressures and 200° C., and the reaction time is 80 min.

5. The method for preparing high-purity carbon from rice husk carbon according to claim 1, characterized in that: In S7, the concentration of hydrofluoric acid is 0.5 M, the ratio of rice husk charcoal to hydrofluoric acid is 100 g:30 ml, and the reaction time is 20 min.

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