Production process of medical activated carbon taking coal as matrix

Abstract

The invention belongs to the technical field of activated carbon production, and relates to a process for producing medical activated carbon by taking coal as a matrix. The method comprises the following steps: S1, raw material pretreatment: selecting high-quality coal of which the ash content is lower than 10% and the fixed carbon content is higher than 70%, crushing the high-quality coal into particles of 1-5mm, then cleaning the particles with deionized water for 2-3 times, and drying the particles until the water content is lower than 5%; s2, carbonization treatment: putting the pretreated coal particles into a carbonization furnace, heating to 600-700 DEG C at a heating rate of 5-10 DEG C / min in a nitrogen atmosphere, and keeping the temperature for 30-60 minutes to obtain a carbonized product. By optimizing each production step and parameter, the purity, the specific surface area, the pore structure, the antibacterial performance and other key indexes of the activated carbon are improved, so that the activated carbon meets the strict requirements of medical standards, and an efficient and environment-friendly production process capable of producing the high-quality medical activated carbon is formed.

Description

Technical Field

[0001] The invention belongs to the technical field of activated carbon production, and relates to a production process of medical activated carbon using coal as a matrix. Background Art

[0002] Activated carbon has rich pore structure and large specific surface area, and is widely used in the medical field, such as blood purification, drug carrier, wound dressing, etc. At present, the production process of medical activated carbon has some shortcomings, such as insufficient product purity, unsatisfactory pore structure, and difficult to control impurity content. These problems limit the improvement of the performance of medical activated carbon and its application in the field of high-end medical care. The present invention aims to provide an improved production process of medical activated carbon based on coal to overcome the defects of the prior art.

[0003] In order to overcome the shortcomings of the existing technology, people have proposed various solutions through continuous exploration. For example, a Chinese patent discloses a water-resistant soil-based honeycomb activated carbon and its production process [application number: 201010248345.0]. This water-resistant soil-based honeycomb activated carbon is made by mixing one of the soil matrix kaolin, clay, and natural silica sand with activated carbon or activated carbon carbon raw materials to make mud, and then placing it in a high temperature environment for heating treatment, so that the soil matrix particles are hot-melted and bonded to each other. However, in the production process, this solution is still prone to defects such as insufficient product purity, unsatisfactory pore structure, and difficult to control impurity content, and still cannot meet the strict requirements of medical standards. Summary of the invention

[0004] The purpose of the present invention is to provide a production process that is efficient, environmentally friendly and can produce high-quality medical activated carbon. By optimizing the various production steps and parameters, the key indicators such as the purity, specific surface area, pore structure and antibacterial performance of the activated carbon are improved so that it meets the strict requirements of medical standards.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A production process of medical activated carbon using coal as a matrix comprises the following steps:

[0007] S1: Raw material pretreatment: Select high-quality coal with an ash content of less than 10% and a fixed carbon content of more than 70%, crush it into particles of 1-5 mm, then wash it with deionized water 2-3 times, and dry it to a moisture content of less than 5%;

[0008] S2: Carbonization treatment: The pretreated coal particles are placed in a carbonization furnace, and the temperature is increased to 600-700°C at a heating rate of 5-10°C / min under a nitrogen atmosphere, and maintained for 30-60 minutes to obtain a carbonized product;

[0009] S3: Activation treatment:

[0010] - Physical activation: Mix the carbonized product with water vapor in a mass ratio of 1:2-1:5 and activate it in an activation furnace at 800-900°C for 60-120 minutes; or

[0011] -Chemical activation: the carbonized product is mixed evenly with a potassium hydroxide solution with a mass concentration of 30%-50% in a mass ratio of 1:1-1:3, activated at 400-600°C for 90-180 minutes, and then pickled with a hydrochloric acid solution with a mass concentration of 5%-10%, and then rinsed with deionized water until neutral;

[0012] S4: Post-treatment: The activated carbon is washed with water at a temperature of 80-100°C for 3-5 times, and then dried in a vacuum drying oven at 100-120°C for 2-4 hours to obtain a medical activated carbon product.

[0013] In the above-mentioned production process of medical activated carbon based on coal, in the step S1, the drying method is vacuum drying, and the vacuum degree is -0.08--0.1MPa.

[0014] In the above-mentioned production process of medical activated carbon based on coal, in the step S2, the temperature rise rate of the carbonization furnace is controlled with an accuracy within the range of ±1°C / minute.

[0015] In the above-mentioned production process of medical activated carbon based on coal, in the S3 physical activation step, the water vapor flow rate in the activation furnace is controlled at 0.5-1.5 kg / h.

[0016] In the above-mentioned production process of medical activated carbon based on coal, in the S3 chemical activation step, the mixing process of the potassium hydroxide solution and the carbonized product is carried out for 30-60 minutes under the condition of a stirring speed of 200-500 r / min.

[0017] In the above-mentioned production process of medical activated carbon based on coal, in the step S4, the vacuum degree of the vacuum drying oven is between -0.05 and -0.09 MPa.

[0018] In the above-mentioned production process of medical activated carbon using coal as a matrix, in the step S1, vacuum drying is performed in a vacuum dryer.

[0019] In the above-mentioned production process of medical activated carbon based on coal, in the step S4, the activated activated carbon is washed four times with deionized water at a temperature of 80-100°C.

[0020] In the above-mentioned production process of medical activated carbon based on coal, the entire production process is carried out in a clean workshop in accordance with GMP standards.

[0021] In the above-mentioned production process of medical activated carbon based on coal, in the S2 carbonization treatment step and the S3 activation treatment step, the waste gas generated is purified by an alkali solution spray tower and an activated carbon adsorption device before being discharged.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] 1. The present invention optimizes various production steps and parameters to improve key indicators such as the purity, specific surface area, pore structure and antibacterial performance of activated carbon, so that it meets the strict requirements of medical standards and forms an efficient, environmentally friendly production process that can produce high-quality medical activated carbon.

[0024] 2. The medical activated carbon prepared by the process of the present invention has the following excellent properties: iodine adsorption value greater than 1000 mg / g, specific surface area greater than 1500 m 2 / g, which makes it have strong adsorption capacity and can effectively adsorb toxins, impurities, etc. in the body. The ash content is less than 3%, and the iron content is less than 0.05%, which ensures the purity of the product and reduces the potential harm to the human body. The antibacterial rate of Escherichia coli and Staphylococcus aureus is greater than 90%, with good antibacterial properties, which can prevent wound infection, etc. The pore volume with a pore size distribution in the range of 0.5-5nm accounts for more than 70% of the total pore volume. This suitable pore size distribution is conducive to the adsorption of molecules of different sizes and improves the effect of medical activated carbon in medical applications.

[0025] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings.

[0028] Example 1

[0029] like Figure 1 As shown, a production process of medical activated carbon using coal as a matrix comprises the following steps:

[0030] S1: Raw material pretreatment: Select high-quality coal with an ash content of less than 10% and a fixed carbon content of more than 70%, crush it into particles of 1-5 mm, then wash it with deionized water 2-3 times, and dry it to a moisture content of less than 5%;

[0031] S2: Carbonization treatment: The pretreated coal particles are placed in a carbonization furnace, and the temperature is increased to 600-700°C at a heating rate of 5-10°C / min under a nitrogen atmosphere, and maintained for 30-60 minutes to obtain a carbonized product;

[0032] S3: Activation treatment:

[0033] - Physical activation: Mix the carbonized product with water vapor in a mass ratio of 1:2-1:5 and activate it in an activation furnace at 800-900°C for 60-120 minutes; or

[0034] -Chemical activation: the carbonized product is mixed evenly with a potassium hydroxide solution with a mass concentration of 30%-50% in a mass ratio of 1:1-1:3, activated at 400-600°C for 90-180 minutes, and then pickled with a hydrochloric acid solution with a mass concentration of 5%-10%, and then rinsed with deionized water until neutral;

[0035] S4: Post-treatment: The activated carbon is washed with water at a temperature of 80-100°C for 3-5 times, and then dried in a vacuum drying oven at 100-120°C for 2-4 hours to obtain a medical activated carbon product.

[0036] In the step S1, the drying method is vacuum drying, and the vacuum degree is -0.08--0.1 MPa.

[0037] In the step S2, the temperature rise rate of the carbonization furnace is controlled with an accuracy within the range of ±1°C / minute.

[0038] In the S3 physical activation step, the steam flow rate in the activation furnace is controlled at 0.5-1.5 kg / h.

[0039] In the S3 chemical activation step, the mixing process of the potassium hydroxide solution and the carbonized product is carried out for 30-60 minutes at a stirring speed of 200-500 r / min.

[0040] In the step S4, the vacuum degree of the vacuum drying oven is between -0.05 and 0.09 MPa.

[0041] In the step S1, vacuum drying is performed in a vacuum dryer.

[0042] In the step S4, the activated activated carbon is washed four times with deionized water at a temperature of 80-100°C.

[0043] The entire production process is carried out in a clean workshop that meets GMP standards, and the air cleanliness in the workshop reaches Class 100,000.

[0044] In the S2 carbonization treatment step and the S3 activation treatment step, the waste gas generated is purified by an alkali solution spray tower and an activated carbon adsorption device before being discharged, and the purification efficiency reaches more than 95%.

[0045] In this embodiment, the raw material is pretreated: high-quality coal with an ash content of less than 10% and a fixed carbon content of more than 70% is selected. This is because coal with low ash content and high fixed carbon content is conducive to the subsequent production of high-quality activated carbon. It is crushed into particles of 1-5 mm. This particle size facilitates the subsequent carbonization and activation reactions to proceed uniformly. Then it is washed with deionized water 2-3 times to remove impurities and soluble minerals on the surface of the coal, and then dried to a water content of less than 5%. The drying method adopts vacuum drying with a vacuum degree of -0.08--0.1MPa. This drying method can quickly remove moisture at a lower temperature to avoid oxidation and structural damage of the coal;

[0046] Carbonization treatment: Place the pretreated coal particles in a carbonization furnace and carbonize them under a nitrogen atmosphere. Heat up to 600-700°C at a heating rate of 5-10°C / minute and maintain for 30-60 minutes. Controlling the heating rate, carbonization temperature and time is key. Too fast a heating rate will lead to uneven pyrolysis of the coal and produce too much tar and other impurities. Improper carbonization temperature and time will affect the structure and properties of the carbonized product and will not provide a good foundation for subsequent activation. The role of the nitrogen atmosphere is to isolate the air, prevent the coal from oxidizing and burning during the carbonization process, ensure the stability of the carbonization reaction, and obtain a carbonized product.

[0047] Activation treatment:

[0048] Physical activation: The carbonization product is mixed with water vapor in a mass ratio of 1:2-1:5, and activated in an activation furnace at 800-900°C for 60-120 minutes. During this process, water vapor reacts with carbon, such as C+H2O→H2+CO, and the generated gas continuously escapes, thereby creating a rich pore structure inside the carbon and increasing the specific surface area of ​​the activated carbon. At the same time, the water vapor flow rate in the activation furnace is controlled at 0.5-1.5kg / h to ensure the stability and uniformity of the activation reaction;

[0049] Chemical activation: Mix the carbonized product with a potassium hydroxide solution with a mass concentration of 30%-50% in a mass ratio of 1:1-1:3, and activate it at 400-600℃ for 90-180 minutes. Potassium hydroxide solution reacts chemically with carbon at high temperature, which can effectively corrode the surface of carbon and form a developed pore structure. The mixing process is carried out for 30-60 minutes under the condition of a stirring speed of 200-500r / min to ensure that the potassium hydroxide solution and the carbonized product are fully in contact and react. After activation, pickling is carried out with a hydrochloric acid solution with a mass concentration of 5%-10% to remove metal impurities in the activated carbon, and then rinsed with deionized water until neutral;

[0050] Post-treatment: Wash the activated carbon with deionized water at 80-100℃ for 3-5 times to completely remove the acid, alkali and other impurities remaining on the surface of the activated carbon. Then dry it in a vacuum drying oven at 100-120℃ for 2-4 hours with a vacuum degree between -0.05--0.09MPa to obtain a medical activated carbon product.

[0051] Medical activated carbon prepared by a production process of medical activated carbon based on coal, wherein the iodine adsorption value of the medical activated carbon is greater than 1000 mg / g and the specific surface area is greater than 1500 m 2 / g, the ash content is less than 3%, the iron content is less than 0.05%, and the antibacterial rates against Escherichia coli and Staphylococcus aureus are both greater than 90%, and the pore volume of the medical activated carbon with a pore size distribution in the range of 0.5-5nm accounts for more than 70% of the total pore volume.

[0052] The medical activated carbon prepared by the above process has the following excellent properties: iodine adsorption value greater than 1000 mg / g, specific surface area greater than 1500 m 2 / g, which makes it have strong adsorption capacity and can effectively adsorb toxins, impurities, etc. in the body. The ash content is less than 3%, and the iron content is less than 0.05%, which ensures the purity of the product and reduces the potential harm to the human body. The antibacterial rate of Escherichia coli and Staphylococcus aureus is greater than 90%, with good antibacterial properties, which can prevent wound infection, etc. The pore volume with a pore size distribution in the range of 0.5-5nm accounts for more than 70% of the total pore volume. This suitable pore size distribution is conducive to the adsorption of molecules of different sizes and improves the effect of medical activated carbon in medical applications.

[0053] At the same time, the entire production process is carried out in a clean workshop that meets GMP standards. The air cleanliness in the workshop reaches 100,000 levels, ensuring that the production process is not polluted by the outside world and that the stability and reliability of product quality are guaranteed. During the carbonization and activation steps, the waste gas generated is purified by an alkali spray tower and an activated carbon adsorption device before being discharged. The purification efficiency reaches more than 95%, reducing pollution to the environment and meeting environmental protection requirements.

[0054] Example 2

[0055] Combination Figure 1As shown, coal with an ash content of 8% and a fixed carbon content of 75% was selected, crushed into 3 mm particles, washed with deionized water 3 times, and dried to a moisture content of 4% at a vacuum degree of -0.09 MPa. It was heated to 650°C at 8°C / min in a nitrogen atmosphere and kept for 45 minutes for carbonization. Then physical activation was adopted, and the carbonized product was mixed with water vapor in a mass ratio of 1:3, activated at 850°C for 90 minutes, and the water vapor flow rate was 1kg / h. Finally, it was washed with deionized water at 90°C 4 times, dried at a vacuum degree of -0.07MPa and 110°C for 3 hours, and a medical activated carbon product was obtained. After testing, various performance indicators achieved the expected results.

[0056] Example 3

[0057] Combination Figure 1 As shown, coal with 9% ash content and 72% fixed carbon was selected, and after treatment, it was mixed with 40% potassium hydroxide solution in a mass ratio of 1:2 by chemical activation method, mixed at a stirring speed of 300r / min for 40 minutes, activated at 500℃ for 120 minutes, and after acid washing, water washing and drying, medical activated carbon with excellent performance was obtained.

[0058] The verification of multiple examples shows that the production process of the present invention is stable and reliable, can produce high-quality medical activated carbon, meets the use needs in the medical field, and has broad application prospects.

[0059] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways without departing from the spirit of the present invention.

Claims

1. A process for producing medical activated carbon based on coal, characterized in that: The following steps are involved: S1: Raw material pretreatment: Select high-quality coal with an ash content of less than 10% and a fixed carbon content of more than 70%, crush it into particles of 1-5 mm, then wash it with deionized water 2-3 times, and dry it to a moisture content of less than 5%; S2: Carbonization treatment: The pretreated coal particles are placed in a carbonization furnace, and the temperature is increased to 600-700°C at a heating rate of 5-10°C / min under a nitrogen atmosphere, and maintained for 30-60 minutes to obtain a carbonized product; S3: Activation treatment: - Physical activation: Mix the carbonized product with water vapor in a mass ratio of 1:2-1:5 and activate it in an activation furnace at 800-900°C for 60-120 minutes; or -Chemical activation: the carbonized product is mixed evenly with a potassium hydroxide solution with a mass concentration of 30%-50% in a mass ratio of 1:1-1:3, activated at 400-600°C for 90-180 minutes, and then pickled with a hydrochloric acid solution with a mass concentration of 5%-10%, and then rinsed with deionized water until neutral; S4: Post-treatment: The activated carbon is washed with water at a temperature of 80-100°C for 3-5 times, and then dried in a vacuum drying oven at 100-120°C for 2-4 hours to obtain a medical activated carbon product.

2. The process for producing medical activated carbon based on coal according to claim 1, characterized in that: In the step S1, the drying method is vacuum drying, and the vacuum degree is -0.08--0.1 MPa.

3. The process for producing medical activated carbon based on coal according to claim 1, characterized in that: In the step S2, the temperature rise rate of the carbonization furnace is controlled with an accuracy within the range of ±1°C / minute.

4. The process for producing medical activated carbon based on coal according to claim 3, characterized in that: In the S3 physical activation step, the steam flow rate in the activation furnace is controlled at 0.5-1.5 kg / h.

5. The process for producing medical activated carbon based on coal according to claim 1, characterized in that: In the S3 chemical activation step, the mixing process of the potassium hydroxide solution and the carbonized product is carried out for 30-60 minutes at a stirring speed of 200-500 r / min.

6. The process for producing medical activated carbon based on coal according to claim 1, characterized in that: In the step S4, the vacuum degree of the vacuum drying oven is between -0.05 and 0.09 MPa.

7. The process for producing medical activated carbon based on coal according to claim 2, characterized in that: In the step S1, vacuum drying is performed in a vacuum dryer.

8. The process for producing medical activated carbon based on coal according to claim 6, characterized in that: In the step S4, the activated activated carbon is washed four times with deionized water at a temperature of 80-100°C.

9. The process for producing medical activated carbon based on coal according to claim 8, characterized in that: The entire production process is carried out in a clean workshop that meets GMP standards.

10. The process for producing medical activated carbon based on coal according to claim 1, characterized in that: In the S2 carbonization treatment step and the S3 activation treatment step, the waste gas generated is purified by an alkali solution spray tower and an activated carbon adsorption device before being discharged.

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