Method for resource utilization of de-zincing rotary kiln and benzopyrene sludge

Abstract

The present application belongs to the technical field of harmless disposal of benzopyrene hazardous waste sludge, and particularly relates to a method for resource utilization of benzopyrene sludge in a rotary kiln for zinc removal. The method comprises: mixing benzopyrene-containing sludge and zinc removal production ingredients to obtain a mixture, wherein the mass of the benzopyrene-containing sludge is less than or equal to 40% based on the total mass of the mixture; and feeding the mixture into a rotary kiln at a temperature of 600-1300 DEG C for treatment, wherein the total residence time of the mixture in the rotary kiln is greater than or equal to 60 min, and the zinc removal production ingredients contain zinc-containing dust and sludge. The method can remove more than 95% of benzopyrene from the benzopyrene-containing sludge without generating secondary pollutants, and the emitted flue gas does not contain benzopyrene, SO2, NO x , dioxin, etc., all of which are within the standard range. The method is highly operable and can be used for industrial treatment.

Description

Technical Field

[0001] This invention belongs to the technical field of harmless treatment of benzo[a]pyrene hazardous waste sludge, specifically involving a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. Background Technology

[0002] With the vigorous promotion of ecological civilization construction in my country, river water management has become a hot topic in recent years. The difficulty of river water management lies in the need to implement harmless treatment of the large amount of sludge containing organic or aromatic pollutants generated by dredging projects. The existing technology "A method for remediating organic polluted soil" discloses that the method uses a rotary kiln to separate organic matter from the soil, thereby remediating soil contaminated by organic matter. The specific method is as follows: the rotary kiln is used for indirect heating desorption, the hot air and the soil do not come into direct contact, the heating temperature exceeds 550℃, and the organic pollutants in the polluted soil are completely separated to achieve the purpose of soil remediation. However, the composition of organic pollutants is relatively complex, and the efficiency of single high-temperature heating treatment in removing organic pollutants from soil still needs to be studied.

[0003] Benzo[a]pyrene is a substance classified as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC) of the World Health Organization. If hazardous waste sludge containing benzo[a]pyrene is discharged or piled up without proper treatment, it will pollute the soil, water and air, and eventually enter the human body through circulation, posing a significant threat to human health. Therefore, how to harmlessly dispose of hazardous waste sludge containing benzo[a]pyrene is a very important issue. The existing technology "A treatment agent for benzo[a]pyrene-contaminated sludge and its preparation method" discloses a treatment agent for benzo[a]pyrene-contaminated sludge. The preparation method of the treatment agent includes: (1) mixing flue ash, moss powder, moringa leaf powder, potassium nitrate, snakeberry leaf powder, Chinese medicine residue and sodium fumarate, ball milling and stirring for 15-30 min, calcining at 180-200℃ for 1-2 h, taking it out and cooling it in an environment below -5 degrees Celsius, and grinding it into (2) Mix the product obtained in the previous step with earthworm powder, silkworm pupa powder, dried mangosteen peel powder, lithium feldspar, soda ash and L-carnitine, ball mill and stir for 25-40 min, calcine at 100-120℃ for 20-50 min, take it out and cool it in an environment below 0 degrees Celsius, and grind it into powder; (3) Mix the above product with calcium hydrogen phosphate, avermectin, hexamethyldisilazane, rutin and water, ball mill and stir at 10-20℃ for 1-1.5 h; (4) Let the product obtained in the previous step stand for 10-24 h, then stir and mix evenly, spray dry at 2-5℃ to obtain the finished product. This sludge treatment agent has a significant treatment effect on benzo[a]pyrene polluted sludge, and the benzo[a]pyrene fixation rate exceeds 93%. However, this sludge treatment agent has many components and the preparation process is complicated, which has certain limitations on the industrial treatment of benzo[a]pyrene polluted sludge. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies in treating sludge contaminated with organic or aromatic hydrocarbons, which lack clear efficacy and are limited in industrial-scale processing. Therefore, this invention proposes a method for the co-processing of benzo[a]pyrene-containing sludge in a zinc removal rotary kiln for resource utilization. The method involves co-processing a certain proportion of benzo[a]pyrene-containing sludge with zinc-containing dust-laden sludge in a rotary kiln for harmless treatment. During the treatment process, the temperature and residence time of all materials within the rotary kiln are simultaneously controlled. Using this method, the removal rate of benzo[a]pyrene-containing sludge can reach over 95%. Simultaneously, benzo[a]pyrene is completely decomposed into carbon dioxide and water during the treatment process, without generating secondary pollutants. This method is environmentally friendly, as the emitted flue gas does not contain benzo[a]pyrene, and the emissions only contain SO2 and NO. x The content of dioxins and other substances is within the standard range. At the same time, the method of the present invention is highly operable and can be industrialized.

[0005] This invention proposes a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing benzo[a]pyrene sludge with zinc removal production feedstock to obtain a mixture, wherein the benzo[a]pyrene sludge accounts for ≤40% of the total mass of the mixture (100%); conveying the mixture to a rotary kiln at 600-1300℃ for processing; wherein the total residence time of the mixture in the rotary kiln is ≥60 min; and wherein the zinc removal production feedstock contains zinc-containing dust and sludge.

[0006] Preferably, the benzo[a]pyrene-containing sludge accounts for 5-10% of the total mass of the mixture, which is 100% of the total mass of the mixture.

[0007] Preferably, the benzo[a]pyrene content in the benzo[a]pyrene-containing sludge is 5-10 mg / kg.

[0008] Preferably, the zinc removal production ingredients contain 70-85% zinc-containing dust and sludge by mass.

[0009] Preferably, the kiln tail temperature of the rotary kiln is 600-1000℃, the kiln middle temperature is 1000-1300℃, the kiln head temperature is 650-1000℃, and the rotary kiln temperature is maintained at 1000-1300℃ for ≥10 minutes.

[0010] Preferably, the total residence time of the mixture in the rotary kiln is 70-90 minutes.

[0011] Preferably, the temperature of the rotary kiln is maintained at 1000-1300℃ for 20-30 minutes.

[0012] Preferably, the zinc removal production batch contains 80% zinc-containing dust and 20% coke oven dust by mass percentage.

[0013] Preferably, the zinc removal production batch contains 80% zinc-containing dust and 20% coal powder by mass percentage.

[0014] Preferably, the kiln slag obtained after rotary kiln treatment is used as cement clinker for cement production.

[0015] The method for the resource utilization of benzo[a]pyrene sludge in a dezincification rotary kiln as described in this invention has the following beneficial effects:

[0016] In this invention, a certain mass ratio of benzo[a]pyrene-containing sludge and zinc-containing dust sludge from a zinc removal production batch are synergistically and harmlessly treated together in a rotary kiln. The zinc removal rotary kiln is a high-zinc, high-iron combustion environment, and the combustion flue gas contains a large amount of fine-particle zinc oxide. Zinc oxide is a photocatalyst that can accelerate the oxidative thermal decomposition of organic pollutants such as benzo[a]pyrene, promoting the synergistic effect of benzo[a]pyrene-containing sludge and zinc-containing dust sludge. Simultaneously, the temperature in the rotary kiln and the movement of all materials within the kiln are controlled during the treatment process. The residence time effectively degrades the benzo[a]pyrene content in sludge containing benzo[a]pyrene. Using the method described in this invention to treat sludge containing benzo[a]pyrene, the removal rate of benzo[a]pyrene can reach over 95%. Simultaneously, during the treatment process, benzo[a]pyrene is completely decomposed into carbon dioxide and water, without generating secondary pollutants, exhibiting the advantages of being green and environmentally friendly. The resulting kiln slag can be used as clinker for cement production, and the quality of the zinc oxide product recovered from the rotary kiln remains unchanged. Furthermore, the emitted flue gas does not contain benzo[a]pyrene, and the SO2 and NO in the flue gas are minimal. x The content of dioxins and other substances is within the standard range. At the same time, the method of the present invention is highly operable and can realize the low-cost, large-scale harmless industrial treatment and full resource utilization of hazardous waste sludge containing benzo[a]pyrene. Detailed Implementation

[0017] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0018] Benzo[a]pyrene is a hydrocarbon-containing organic compound that decomposes into carbon dioxide and water vapor at temperatures above 1000℃. The chemical formula for the decomposition reaction of benzo[a]pyrene in a rotary kiln is: C 20 H 12 +23O2=20CO2+6H2O.

[0019] This invention proposes a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing benzo[a]pyrene sludge with zinc removal production feedstock to obtain a mixture, wherein the benzo[a]pyrene sludge accounts for ≤40% of the total mass of the mixture (100%); conveying the mixture to a rotary kiln at 600-1300℃ for processing; wherein the total residence time of the mixture in the rotary kiln is ≥60 min; and wherein the zinc removal production feedstock contains zinc-containing dust and sludge.

[0020] In a specific embodiment of the method described in this invention, the mass of the benzo[a]pyrene-containing sludge can be 5%, 10%, 20%, 30%, or 40% of the total mass of the mixture, calculated as 100%. When the mass of the benzo[a]pyrene-containing sludge is >40% of the total mass of the mixture, there is a risk of excessive residual benzo[a]pyrene content in the kiln slag (GB 36600-2018 requires benzo[a]pyrene in soil ≤1.5 mg / kg). In this document, both the benzo[a]pyrene-containing sludge and the zinc removal production ingredients are measured on a dry basis. In a preferred embodiment of the method described in this invention, the mass of the benzo[a]pyrene-containing sludge is 5-10% of the total mass of the mixture, calculated as 100%.

[0021] In a specific embodiment of the method described in this invention, the rotary kiln can be divided into a kiln tail, a kiln middle, and a kiln head. The highest temperature inside the rotary kiln is in the kiln middle section. Specifically, the kiln tail temperature is 600-1000℃, the kiln middle temperature is 1000-1300℃, and the kiln head temperature is 650-1000℃. In a preferred embodiment of the method described in this invention, the rotary kiln temperature is maintained at 1000-1300℃ for ≥10 minutes. In a more preferred embodiment, the rotary kiln temperature is maintained at 1000-1300℃ for 20-30 minutes, for example, 20 minutes, 25 minutes, or 30 minutes.

[0022] In a specific embodiment of the method described in this invention, the total residence time of the mixture in the rotary kiln is ≥60 min. When the total residence time of the mixture in the rotary kiln is <60 min, there is a risk of high residual benzo[a]pyrene content in the kiln slag after adding hazardous waste sludge containing benzo[a]pyrene in a certain proportion with the zinc dezincification production feedstock into the rotary kiln. Specifically, the total residence time of the mixture in the rotary kiln can be 60 min, 70 min, 80 min, 90 min, 120 min, 180 min, 240 min, 300 min, or 360 min. In a preferred embodiment, the total residence time of the mixture in the rotary kiln is 70-90 min.

[0023] In a specific embodiment of the method described in this invention, the benzo[a]pyrene content in the benzo[a]pyrene-containing sludge is >1.5 mg / kg, specifically, for example, it can be 2 mg / kg, 3 mg / kg, 4 mg / kg, 5.60 mg / kg, 7.99 mg / kg, 8.42 mg / kg, 10 mg / kg, 20 mg / kg, 30 mg / kg, 50 mg / kg, or 100 mg / kg. In a preferred embodiment of the method described in this invention, the benzo[a]pyrene content in the benzo[a]pyrene-containing sludge is 5-10 mg / kg. When the benzo[a]pyrene content is 5-10 mg / kg, after treatment in a rotary kiln, the removal rate of benzo[a]pyrene can reach over 99%, and the benzo[a]pyrene content in the treated kiln slag is <0.1 mg / kg. The kiln slag can be used as clinker for cement production, and the emitted flue gas does not contain benzo[a]pyrene.

[0024] In a specific embodiment of the method described in this invention, the zinc removal production feed contains 70-85% zinc-containing dust and sludge by mass percentage, specifically, for example, 70%, 75%, 80% or 85%.

[0025] In a preferred embodiment of the method described in this invention, the dezincification production feed contains 80% zinc-containing dust and 20% coke oven dust by mass percentage.

[0026] In a preferred embodiment of the method described in this invention, the zinc removal production feed contains 80% zinc-containing dust and 20% coal powder by mass percentage.

[0027] In a specific embodiment of the method described in this invention, the kiln slag obtained after rotary kiln treatment is used as cement clinker for cement production.

[0028] Unless otherwise specified, the test methods or experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are obtained from conventional commercial sources or prepared by conventional methods.

[0029] The main chemical components of zinc-containing dust sludge are: 26.85% TFe by mass, 6.49% Zn by mass, and the remainder being impurities; the main chemical components of coke oven dust are: 86.93% C by mass, and the remainder being impurities.

[0030] Example 1

[0031] This embodiment provides a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing river dredging sludge with a benzo[a]pyrene content of 8.42 mg / kg with zinc removal production feedstock at a dry basis mass ratio of 0.3:1; conveying the resulting mixture to a rotary kiln with a processing capacity of 800 tons / day for processing; the kiln tail temperature of the rotary kiln is 850℃, the kiln middle temperature is 1220℃, and the kiln head temperature is 800℃; the time for each part of the rotary kiln to be maintained above 1000℃ is 25 minutes; the total residence time of the mixture in the rotary kiln is 75 minutes; and the zinc removal production feedstock contains 80% zinc-containing dust and 20% coke oven dust.

[0032] The benzo[a]pyrene content in the kiln slag obtained from the rotary kiln was 0.01 mg / kg, with a benzo[a]pyrene removal rate of 99%. The kiln slag was comprehensively utilized as a cement raw material. The benzo[a]pyrene content in the rotary kiln exhaust gas was 0, and the dioxin content in the exhaust gas was 0.018 ng TEQ / Nm³. 3 (GB18484-2020 emission standard requires less than 0.5 ng TEQ / Nm³) 3 The SO2 content is 12 mg / Nm³. 3 (Emission standard is below 35mg / Nm) 3 NO x The content is 21 mg / Nm 3 (Emission standard is below 50mg / Nm) 3 ).

[0033] Example 2

[0034] This embodiment provides a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing river dredging sludge with a benzo[a]pyrene content of 7.99 mg / kg with zinc removal production feedstock at a dry basis mass ratio of 0.3:1; conveying the resulting mixture to a rotary kiln with a processing capacity of 800 tons / day for processing; the kiln tail temperature of the rotary kiln is 600℃, the kiln middle temperature is 1150℃, and the kiln head temperature is 650℃; the time for each part of the rotary kiln to be maintained above 1000℃ is 30 minutes; the total residence time of the mixture in the rotary kiln is 80 minutes; and the zinc removal production feedstock contains 80% zinc-containing dust and 20% coke oven dust.

[0035] The benzo[a]pyrene content in the kiln slag obtained from the rotary kiln was 0.012 mg / kg, with a benzo[a]pyrene removal rate of 99%. The kiln slag was comprehensively utilized as a cement raw material. The benzo[a]pyrene content in the rotary kiln exhaust gas was 0, and the dioxin content in the exhaust gas was 0.017 ng TEQ / Nm³. 3 (Emission standard is less than 0.5 ng TEQ / Nm) 3The SO2 content was 12.5 mg / Nm³. 3 (Emission standard is below 35mg / Nm) 3 NO x The content is 19.8 mg / Nm 3 (Emission standard is below 50mg / Nm) 3 ).

[0036] Example 3

[0037] This embodiment provides a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing river dredging sludge with a benzo[a]pyrene content of 5.60 mg / kg with zinc removal production feedstock at a dry basis mass ratio of 0.4:1; conveying the resulting mixture to a rotary kiln with a processing capacity of 800 tons / day for processing; the kiln tail temperature of the rotary kiln is 700℃, the kiln middle temperature is 1200℃, and the kiln head temperature is 650℃; the time for each part of the rotary kiln to be maintained above 1000℃ is 30 minutes; the total residence time of the mixture in the rotary kiln is 85 minutes; and the zinc removal production feedstock contains 80% zinc-containing dust and 20% coke oven dust.

[0038] The benzo[a]pyrene content in the kiln slag obtained from the rotary kiln was 0.007 mg / kg, with a benzo[a]pyrene removal rate of 99%. The kiln slag was comprehensively utilized as a cement raw material. The benzo[a]pyrene content in the rotary kiln exhaust gas was 0, and the dioxin content in the exhaust gas was 0.016 ng TEQ / Nm³. 3 (Emission standard is less than 0.5 ng TEQ / Nm) 3 The SO2 content is 13 mg / Nm³. 3 (Emission standard is below 35mg / Nm) 3 NO x The content is 20.6 mg / Nm 3 (Emission standard is below 50mg / Nm) 3 ).

[0039] Example 4

[0040] This embodiment provides a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing river dredging sludge with a benzo[a]pyrene content of 20 mg / kg with zinc removal production feedstock at a dry basis mass ratio of 0.3:1; conveying the resulting mixture to a rotary kiln with a processing capacity of 800 tons / day for processing; the kiln tail temperature of the rotary kiln is 850℃, the kiln middle temperature is 1220℃, and the kiln head temperature is 800℃; the time for each part of the rotary kiln to be maintained above 1000℃ is 25 minutes; the total residence time of the mixture in the rotary kiln is 75 minutes; and the zinc removal production feedstock contains 80% zinc-containing dust and 20% coke oven dust.

[0041] The benzo[a]pyrene content in the kiln slag obtained from the rotary kiln was 1 mg / kg, with a benzo[a]pyrene removal rate of 95%. The kiln slag was comprehensively utilized as a cement raw material. The benzo[a]pyrene content in the rotary kiln exhaust gas was 0, and the dioxin content in the exhaust gas was 0.018 ng TEQ / Nm³. 3 (Emission standard is less than 0.5 ng TEQ / Nm) 3 The SO2 content is 12 mg / Nm³. 3 (Emission standard is below 35mg / Nm) 3 NO x The content is 21 mg / Nm 3 (Emission standard is below 50mg / Nm) 3 ).

[0042] Example 5

[0043] This embodiment provides a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing river dredging sludge with a benzo[a]pyrene content of 7.99 mg / kg with zinc removal production feedstock at a dry basis mass ratio of 0.05:1; conveying the resulting mixture to a rotary kiln with a processing capacity of 800 tons / day for processing; the kiln tail temperature of the rotary kiln is 600℃, the kiln middle temperature is 1150℃, and the kiln head temperature is 650℃; the time for each part of the rotary kiln to be maintained above 1000℃ is 30 minutes; the total residence time of the mixture in the rotary kiln is 80 minutes; and the zinc removal production feedstock contains 80% zinc-containing dust and 20% coke oven dust.

[0044] The benzo[a]pyrene content in the kiln slag obtained from the rotary kiln was 0.006 mg / kg, with a benzo[a]pyrene removal rate of 99.92%. The kiln slag was comprehensively utilized as a cement raw material. The benzo[a]pyrene content in the rotary kiln exhaust gas was 0, and the dioxin content in the exhaust gas was 0.015 ng TEQ / Nm³. 3 (Emission standard is less than 0.5 ng TEQ / Nm) 3 The SO2 content is 12 mg / Nm³.3 (Emission standard is below 35mg / Nm) 3 NO x The content is 20 mg / Nm 3 (Emission standard is below 50mg / Nm) 3 ).

[0045] Comparative Example 1

[0046] This embodiment provides a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing river dredging sludge with a benzo[a]pyrene content of 7.99 mg / kg with zinc removal production feedstock at a dry basis mass ratio of 0.5:1; conveying the resulting mixture to a rotary kiln with a processing capacity of 800 tons / day for processing; the kiln tail temperature of the rotary kiln is 600℃, the kiln middle temperature is 1150℃, and the kiln head temperature is 650℃; the time for each part of the rotary kiln to be maintained above 1000℃ is 30 minutes; the total residence time of the mixture in the rotary kiln is 80 minutes; and the zinc removal production feedstock contains 75% zinc-containing dust and 25% coke oven dust.

[0047] The benzo[a]pyrene content in the kiln slag obtained from the rotary kiln was 1.13 mg / kg, with a removal rate of 85.86%. The kiln slag was comprehensively utilized as a cement raw material. The benzo[a]pyrene content in the rotary kiln exhaust gas was 0, and the dioxin content in the exhaust gas was 0.02 ng TEQ / Nm³. 3 (Emission standard is less than 0.5 ng TEQ / Nm) 3 The SO2 content is 15 mg / Nm³. 3 (Emission standard is below 35mg / Nm) 3 NO x The content is 23.5 mg / Nm 3 (Emission standard is below 50mg / Nm) 3 ).

[0048] Comparative Example 2

[0049] This embodiment provides a method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln. The method includes: mixing river dredging sludge with a benzo[a]pyrene content of 8.42 mg / kg with zinc removal production feedstock at a dry basis mass ratio of 0.3:1; conveying the resulting mixture to a rotary kiln with a processing capacity of 800 tons / day for processing; the kiln tail temperature of the rotary kiln is 850℃, the kiln middle temperature is 1220℃, and the kiln head temperature is 800℃; the time for each part of the rotary kiln to be maintained above 1000℃ is 10 minutes; the total residence time of the mixture in the rotary kiln is 30 minutes; and the zinc removal production feedstock contains 80% zinc-containing dust and 20% coke oven dust.

[0050] The benzo[a]pyrene content in the kiln slag obtained from the rotary kiln was 1.27 mg / kg, with a removal rate of 84.92%. The kiln slag was comprehensively utilized as a cement raw material. The benzo[a]pyrene content in the rotary kiln exhaust gas was 0, and the dioxin content in the exhaust gas was 0.019 ng TEQ / Nm³. 3 (Emission standard is less than 0.5 ng TEQ / Nm) 3 The SO2 content is 12 mg / Nm³. 3 (Emission standard is below 35mg / Nm) 3 NO x The content is 21 mg / Nm 3 (Emission standard is below 50mg / Nm) 3 ).

[0051] As can be seen from the results of Examples 1-5 and Comparative Examples 1-2, the present invention synergistically and harmlessly treats a certain mass of benzo[a]pyrene-containing sludge and zinc-containing dezincification production feedstock together in a rotary kiln. Since the dezincification rotary kiln is a high-zinc, high-iron combustion environment, the combustion flue gas contains a large amount of fine-particle zinc oxide. Zinc oxide is a photocatalyst that can accelerate the oxidative thermal decomposition of organic pollutants such as benzo[a]pyrene, promoting the synergistic effect of benzo[a]pyrene-containing sludge and zinc-containing dust. Simultaneously, the temperature in the rotary kiln is controlled... By controlling the temperature and residence time of all materials within the rotary kiln, the benzo[a]pyrene-containing sludge can be effectively degraded. Using the method described in this invention to treat benzo[a]pyrene-containing sludge can achieve a benzo[a]pyrene removal rate of over 95%. Simultaneously, benzo[a]pyrene is completely decomposed into carbon dioxide and water during the treatment process, without generating secondary pollutants, thus possessing the advantages of being green and environmentally friendly. The resulting kiln slag can be used as clinker for cement production, and the quality of the zinc oxide product recovered from the rotary kiln remains unchanged. Furthermore, the emitted flue gas does not contain benzo[a]pyrene, and the SO2 and NO2 in the flue gas are minimal. x The levels of dioxins and other substances were all within the standard range.

[0052] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln, characterized in that, The method includes: mixing benzo[a]pyrene-containing sludge with zinc desulfurization production feedstock to obtain a mixture, wherein the benzo[a]pyrene-containing sludge accounts for ≤40% of the total mass of the mixture (100%), and conveying the mixture to a rotary kiln at 600-1300℃ for processing, wherein the total residence time of the mixture in the rotary kiln is ≥60 min, and the zinc desulfurization production feedstock contains zinc-containing dust and sludge; The chemical formula for the decomposition reaction of benzo[a]pyrene in a rotary kiln is: C 20 H 12 +23O2=20CO2+6H2O; The rotary kiln has a tail temperature of 600-1000℃, a middle temperature of 1000-1300℃, and a head temperature of 650-1000℃. The rotary kiln maintains a temperature of 1000-1300℃ for ≥10 minutes.

2. The method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln according to claim 1, characterized in that, Based on the total mass of the mixture being 100%, the mass of the benzo[a]pyrene-containing sludge is 5-10%.

3. The method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln according to claim 1, characterized in that, The benzo[a]pyrene content in the benzo[a]pyrene-containing sludge is 5-10 mg / kg.

4. The method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln according to claim 1, characterized in that, The zinc removal production batch contains 70-85% zinc-containing dust and sludge by mass.

5. The method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln according to claim 1, characterized in that, The total residence time of the mixture in the rotary kiln is 70-90 minutes.

6. The method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln according to claim 1, characterized in that, The temperature of the rotary kiln is maintained at 1000-1300℃ for 20-30 minutes.

7. The method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln according to claim 4, characterized in that, The zinc removal production batch contains 80% zinc-containing dust and 20% coke oven dust by mass.

8. The method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln according to claim 4, characterized in that, The zinc removal production batch contains 80% zinc-containing dust and 20% coal powder by mass.

9. The method for the resource utilization of benzo[a]pyrene sludge in conjunction with zinc removal rotary kiln according to claim 1, characterized in that, The kiln slag obtained after being processed by a rotary kiln is used as cement clinker for making cement.