Method for preparing high-activity activated carbon from lead smelting water-quenched slag and application of high-activity activated carbon

Abstract

The invention belongs to the technical field of activated carbon preparation, and particularly relates to a method for preparing high-activity activated carbon from lead smelting water quenching slag and application. The preparation method of the high-activity activated carbon comprises the following steps: (1) respectively sampling the lead smelting water-quenched slag and the raw coal, and detecting respective chemical compositions and contents of the lead smelting water-quenched slag and the raw coal; (2) the lead smelting water-quenched slag and raw coal are compounded according to a certain proportion based on the content of Fe and Ca active substances; and (3) adding a binder into the mixed sample obtained by compounding, and carrying out hot press molding, carbonization and activation treatment to obtain the high-activity activated carbon. The activated carbon is prepared by regulating and controlling the addition amount of the lead smelting water-quenched slag and is used for flue gas purification, waste is turned into wealth, high-value utilization of the lead smelting water-quenched slag is achieved, the preparation cost of the activated carbon is reduced, and the obtained activated carbon has high activity and is suitable for industrial production. The industrial application of the activated carbon dry method integrated flue gas purification technology in the non-electric industry is promoted.

Description

Technical Field

[0001] The invention belongs to the technical field of activated carbon preparation, and specifically relates to a method and application of preparing high-activity activated carbon by utilizing lead smelting water-quenched slag. Background Art

[0002] Nitrogen oxides (NO x ) and CO 2 It will cause environmental problems such as acid rain, which seriously threatens the safety of human living environment. Regarding denitrification, the current denitrification technology of thermal power plants is relatively mature, and the ultra-low emission transformation has been basically completed. However, the non-electric industry (coking, sintering, etc.) has a lower flue gas temperature, usually below 250°C, and the mature denitrification technology of thermal power plants cannot be further promoted. At the same time, the adsorption method is still an important measure to achieve carbon peak and carbon neutrality. In recent years, activated carbon has been widely used in flue gas treatment / purification in non-electric industries due to its advantages such as good adsorption performance, no water consumption, and basically no secondary pollution.

[0003] At present, activated carbon has problems such as high cost and low performance. The patent document (patent number ZL202211239364.6) discloses a method for preparing highly active activated carbon by blending coal with active minerals such as iron and calcium in coal. The patent document (patent number ZL202110954786.0) discloses that iron and calcium minerals in coal will regulate the physical and chemical structure of activated carbon and thus enhance its ability to remove pollutants.

[0004] my country is a major producer of lead smelting, and the output of lead has maintained an upward trend year by year. At the same time, for every ton of metallic lead produced, about 0.96 tons of lead smelting water-quenched slag is produced at the same time. According to the development trend of rapid growth in lead production, a large amount of lead smelting water-quenched slag will be produced in the future. A large amount of disorderly stockpiled lead smelting water-quenched slag will not only occupy a large area of ​​land, but also seriously threaten the ecological environment. Lead smelting water-quenched slag contains rich iron and calcium minerals. Using it for the preparation of activated carbon will inevitably regulate and optimize the physical and chemical structure of activated carbon and thus enhance its ability to remove pollutants.

[0005] In view of the shortcomings of the above-mentioned activated carbon, such as high cost and low performance, and the good application potential of lead smelting water-quenched slag in the preparation of high-activity activated carbon, it is urgent to find a reasonable, scientific and precise method to guide the preparation of high-activity activated carbon using lead smelting water-quenched slag. Summary of the invention

[0006] In view of this, the purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a method and application of preparing high-activity activated carbon using lead smelting water-quenched slag.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] In a first aspect, the present invention provides a method for preparing highly active activated carbon using lead smelting water-quenched slag, comprising the following steps:

[0009] Step 1: Take samples of lead smelting water-quenched slag and raw coal respectively, and detect their chemical composition and content;

[0010] Step 2: Compounding the lead smelting water-quenched slag and raw coal in a certain proportion based on the Fe and Ca active material contents;

[0011] Step 3: Add a binder to the compounded mixed sample, and obtain the highly active activated carbon through hot pressing, carbonization and activation treatment.

[0012] Preferably, in step 1, the lead smelting water-quenched slag and the raw coal are sampled and ground to below 200 meshes respectively to release the solid solution in the lead smelting water-quenched slag and enhance its activity; further, the raw coal and the lead smelting water-quenched slag are fully mixed.

[0013] Preferably, in step 2, the mass ratio of the lead smelting water-quenched slag to the raw coal is 2% to 10% to ensure effective catalysis of the lead smelting water-quenched slag.

[0014] Preferably, the binder in step 3 includes coal tar and asphalt. Since the main body of coal is a non-polar hydrocarbon, a binder needs to be added during the preparation process to improve the molding performance of the coal sample. Coal tar and asphalt can increase the viscosity and surface tension of the coal sample exponentially, greatly enhance the interaction between particles, and greatly enhance the plasticity of the mixed sample.

[0015] Preferably, in step 3, the mass percentage of the binder is 20% to 30% based on the mass of the mixed sample, so as to ensure the molding performance of the activated carbon and the economy of preparing the activated carbon.

[0016] Preferably, the hot pressing conditions in step 3 are: pressure of 25-35 MPa, temperature of 50-85° C., and time of 4-10 min, so that the prepared activated carbon has better wear resistance.

[0017] Preferably, the carbonization conditions in step 3 are: carbonization temperature of 450-750° C., and carbonization time of 40-100 min, so as to better realize the catalytic effect of iron-containing and calcium-containing minerals in lead smelting water-quenched slag on coal pyrolysis, thereby obtaining a precursor with initial developed structural pores.

[0018] Preferably, the activation conditions in step 3 are as follows: the activation medium is water vapor, the activation temperature is 800-950°C, the flow rate of water vapor is 0.03-0.08 mL / min·g, and the introduction time of water vapor is 20-90 min, so as to utilize the heavy iron-containing and calcium-containing minerals in the lead smelting water-quenched slag to catalyze the activation process, thereby obtaining activated carbon with a developed pore structure and a higher yield.

[0019] In a second aspect, the present invention provides an application of highly active activated carbon prepared by the method described above in flue gas purification, wherein the application includes use for flue gas denitrification and flue gas carbon dioxide adsorption.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention uses lead smelting water-quenched slag to prepare high-activity activated carbon, provides a scientific and reasonable compounding basis, realizes the high-value utilization of lead smelting water-quenched slag, reduces the preparation cost of activated carbon, and the obtained activated carbon has high activity;

[0022] (2) The present invention can provide scientific, reasonable and accurate guidance for the preparation of low-cost, high-performance activated carbon using water-quenched slag from lead smelting, and further promote the industrial application of activated carbon dry integrated flue gas purification technology in non-electricity industries, with extremely high market prospects and practical utilization value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flow chart of a method for preparing highly active activated carbon using lead smelting water-quenched slag;

[0024] Figure 2 This is the trend chart of denitrification rate of activated carbon with different contents of lead smelting water quenching slag at 120℃;

[0025] Figure 3 The activated carbon with different contents of lead smelting water quenching slag at 25℃CO 2 Removal capacity change trend chart. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0027] Example 1

[0028] A method for preparing highly active activated carbon using lead smelting water-quenched slag, specifically comprising the following steps:

[0029] (1) Taixi coal (TX) was selected as raw coal and lead smelting water-quenched slag (LSWS) of Qinghai Western Mining Group was selected as additives, and they were ground to less than 200 mesh respectively. The chemical composition and content of raw coal ash and lead smelting water-quenched slag were obtained by X-ray fluorescence spectrometer (XRF), as shown in Table 1;

[0030] Table 1

[0031]

[0032] (2) compounding Taixi coal and lead smelting water-quenched slag in mass ratios of 1:0, 1:3%, 1:6%, 1:9%, and 1:12%, respectively, and mixing them evenly to obtain a mixed sample;

[0033] (3) Add 23 wt.% (based on the mass of the mixed coal) of a binder (coal tar) to the mixed sample obtained by the above compounding and mix them thoroughly. After hot pressing (constant temperature and pressure at 75°C and 25 MPa for 5 min), carbonize at 600°C for 1 h to obtain a precursor. The precursor is crushed into 20-40 meshes, and 10 g of the precursor is activated in a water vapor (water inlet: 0.06 mL / min·g, 900°C) atmosphere for 80 min to obtain the activated carbon (AC-X LSWS, where X is the amount of lead smelting water-quenched slag added).

[0034] Example 2

[0035] The activated carbon prepared in Example 1 was tested for denitrification activity in the following simulated flue gas, the simulated flue gas composition of which was: 500 ppm NO, 500 ppm NH 3 、5Vol.%O 2 and nitrogen as the balance gas, the total gas flow rate is 200 mL / min, and the space velocity is 4000 h -1 , the temperature is 120℃. The denitrification rate (Re, %) is calculated by the following formula:

[0036]

[0037] Where Cin and Cout are the inlet and outlet concentrations of NO, respectively.

[0038] The results of the denitrification activity test are shown in Table 2 and Figure 2 .

[0039] Table 2

[0040]

[0041] Example 3

[0042] The activated carbon prepared in Example 1 was measured for CO on a Quantachrome ASiQwin instrument. 2Removal capacity. Test conditions: temperature 25°C; pressure 0–1.0 bar; CO 2 The concentration is 99.999%.

[0043] CO 2 The removal capacity results are shown in Table 3 and Figure 3 .

[0044] Table 3

[0045]

[0046] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing highly active activated carbon using lead smelting water-quenched slag, characterized in that: The following steps are involved: Step 1: Take samples of lead smelting water-quenched slag and raw coal respectively, and detect their chemical composition and content; Step 2: Compounding the lead smelting water-quenched slag and raw coal in a certain proportion based on the Fe and Ca active material contents; Step 3: Add a binder to the compounded mixed sample, and obtain the highly active activated carbon through hot pressing, carbonization and activation treatment.

2. The method for preparing high-activity activated carbon using lead smelting water-quenched slag according to claim 1, characterized in that: In the step 1, the lead smelting water-quenched slag and the raw coal are sampled and ground to less than 200 meshes.

3. The method for preparing high-activity activated carbon using lead smelting water-quenched slag according to claim 1, characterized in that: In step 2, the mass ratio of lead smelting water-quenched slag to raw coal is 2% to 10%.

4. The method for preparing high-activity activated carbon using lead smelting water-quenched slag according to claim 1, characterized in that: In step 3, the binder includes coal tar and asphalt.

5. The method for preparing high-activity activated carbon using lead smelting water-quenched slag according to claim 1, characterized in that: In step 3, the mass percentage of the binder is 20% to 30% based on the mass of the mixed sample.

6. The method for preparing high-activity activated carbon using lead smelting water-quenched slag according to claim 1, characterized in that: The conditions for hot pressing in step 3 are: pressure of 25-35 MPa, temperature of 50-85° C., and time of 4-10 min.

7. The method for preparing high-activity activated carbon using lead smelting water-quenched slag according to claim 1, characterized in that: The carbonization conditions in step 3 are: carbonization temperature is 450-750° C., and carbonization time is 40-100 min.

8. The method for preparing high-activity activated carbon using lead smelting water-quenched slag according to claim 1, characterized in that: The activation conditions in step 3 are as follows: the activation medium is water vapor, the activation temperature is 800-950° C., the flow rate of water vapor is 0.03-0.08 mL / min·g, and the introduction time of water vapor is 20-90 min.

9. Use of high-activity activated carbon obtained by the method according to any one of claims 1 to 8 in flue gas purification.

10. The use of high-activity activated carbon according to claim 9, characterized in that: Used for flue gas denitrification and flue gas carbon dioxide adsorption.

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