CN110878942A

CN110878942A - Desulfurization method in rotary kiln of hazardous waste incineration system

Info

Publication number: CN110878942A
Application number: CN201911111382.4A
Authority: CN
Inventors: 邱金成; 张卫东; 杨兆标
Original assignee: Yunnan Dadi Fengyuan Environmental Protection Co Ltd
Current assignee: Yunnan Dadi Fengyuan Environmental Protection Co Ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-03-13

Abstract

The invention discloses a desulfurization method in a rotary kiln of a hazardous waste incineration system, which comprises the following steps: adding a certain proportion of desulfurizer into the hazardous waste to be incinerated in the kiln, uniformly mixing, burning in a rotary kiln, controlling the kiln temperature of the rotary kiln and the retention time of the waste, discharging the desulfurization reaction product out of the system along with the slag after complete reaction, and discharging the flue gas up to the standard. The invention has the advantages that: the used desulfurizer is cheap and easily available, an additional desulphurization device is not required to be added, the hazardous waste with the sulfur content higher than the feeding limit value of the incineration system can be treated, and the standard emission of the flue gas is ensured.

Description

Desulfurization method in rotary kiln of hazardous waste incineration system

Technical Field

The invention belongs to the technical field of harmless treatment of hazardous wastes, and particularly relates to a desulfurization method in a rotary kiln of a hazardous waste incineration system.

Background

The high-temperature incineration disposal of hazardous wastes is an important process for disposing hazardous wastes, and is mature and applied in China. Because of the limits of process equipment and flue gas emission indexes, the hazardous waste incineration system has strict requirements on S, Cl content of treated hazardous waste, generally, the S content is not more than 2%, the Cl content is not more than 1%, and if the content exceeds the standard, a matched rear-end flue gas treatment system cannot meet the requirements, so that the equipment corrosion is aggravated, and the flue gas is excessively discharged. However, as a centralized comprehensive hazardous waste disposal center, the collected wastes are various in types, the waste components are also different, the compatibility difficulty is high, especially for large amounts of high-S-content wastes, the mixed compatibility of the pretreatment stage at the front end of the system and the flue gas treatment at the rear end of the system cannot be coped with at all, and the in-kiln desulfurization is designed at the incineration disposal stage for solving the problems of similar wastes with slightly high S content.

Disclosure of Invention

The invention aims to provide a desulfurization method in a rotary kiln of a hazardous waste incineration system, which can remove part of S in waste in the rotary kiln of the incineration system and reduce the pressure of rear-end flue gas treatment.

The technical scheme of the invention is realized as follows:

a desulfurization method in a rotary kiln of a hazardous waste incineration system comprises the following steps: adding a certain proportion of desulfurizer into the dangerous waste with the sulfur content higher than the incineration feeding limit value, uniformly mixing, burning in a rotary kiln, controlling the temperature of the rotary kiln and the retention time of the waste, discharging the desulfurization reaction product out of the system along with the slag after the reaction is completed, and discharging the flue gas up to the standard.

Preferably, the hazardous waste with a sulfur content above the incineration feed limit is a hazardous waste with a sulfur content between 2% and 5%.

Preferably, the desulfurizing agent is limestone seed material; the particle size of the desulfurizer is 5-15 mm; the content of CaCO3 in the desulfurizer is more than 80 percent; the addition amount of the desulfurizer accounts for 10% -15% of the amount of the hazardous waste.

Preferably, the kiln temperature of the rotary kiln is 830-850 ℃.

Preferably, the waste residence time is from 55 to 65 minutes.

Preferably, the discharging system is discharged through a kiln tail slag remover and a boiler bottom ash discharger.

The standard emission of the flue gas meets the emission standard of hazardous waste incineration pollution control standard.

The principle of the invention is as follows:

after high-temperature incineration at about 850 ℃, S in the waste reacts to generate SO2, limestone doped in the materials is heated and decomposed in the rotary kiln to generate CaO, the CaO and the SO2 react in the rotary kiln in a contact manner to generate CaSO4, and the generated CaSO4 is discharged out of the system along with the slag.

The invention has the beneficial effects that:

(1) the source is desulfurized, the corrosion of equipment is reduced, and the flue gas is discharged after reaching standards.

(2) The hazardous waste with the S content higher than the feeding limit value can be treated by the incineration system, and the adaptability of the hazardous waste incineration system is improved.

(3) The used materials are easy to take and cheap, the operation is simple, and the operation is safe and reliable.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiment is only one embodiment of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The cyanide-containing waste residues to be treated in a certain hazardous waste treatment center are taken as treatment objects, the incineration treatment capacity is designed to be 30t/d, and the waste residue components are as follows: total cyanogen =831mg/kg, total sulphur =4.303mg/kg, total chlorine =0.122mg/kg, calorific value =2338 cal/g.

The cyanogen-containing waste residue is treated by the method of the invention: adding limestone seeds with the waste amount of 14 percent into the cyanogen-containing waste residues, uniformly mixing, burning in a rotary kiln, controlling the temperature of the rotary kiln to be 830-850 ℃, controlling the retention time of the wastes to be 65min, and discharging the desulfurization reaction products out of a system along with the waste residues after the reaction is completed.

Measuring the flue gas emission index: SO2=200mg/m3, HCl =8mg/m3

Example 2

The mixture to be treated in a certain hazardous waste treatment center is taken as a treatment object, the designed incineration disposal capacity is 30t/d, and the content of waste residues is as follows: total sulfur =3.633mg/kg, total chlorine =0.249mg/kg, calorific value =4650 cal/g.

The cyanogen-containing waste residue is treated by the method of the invention: adding 12% of limestone seeds into the cyanogen-containing waste residues, uniformly mixing, burning in a rotary kiln, controlling the kiln temperature of the rotary kiln to be 830-850 ℃, controlling the retention time of wastes to be 60min, and discharging the desulfurization reaction products out of a system along with the slag after the reaction is completed.

Measuring the flue gas emission index: SO2=125mg/m3, HCl =12mg/m3

Example 3

The method is characterized in that oil sludge to be treated in a certain hazardous waste treatment center is taken as a treatment object, the designed incineration treatment capacity is 30t/d, and the content of waste residues is as follows: total sulfur =2.528mg/kg, total chlorine =0.378mg/kg, and calorific value =4812 cal/g.

The cyanogen-containing waste residue is treated by the method of the invention: adding 10% of limestone seed materials into the cyanogen-containing waste residues, uniformly mixing, burning in a rotary kiln, controlling the kiln temperature of the rotary kiln to be 830-850 ℃, controlling the retention time of wastes to be 60min, and discharging desulfurization reaction products out of a system along with the slag after the reaction is completed.

Measuring the flue gas emission index: SO2=78mg/m3, HCl =23mg/m3

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A desulfurization method in a rotary kiln of a hazardous waste incineration system is characterized by comprising the following steps: the method comprises the following steps: adding a desulfurizing agent into the dangerous waste with the sulfur content higher than the incineration feeding limit value, uniformly mixing, burning in a rotary kiln, controlling the temperature of the rotary kiln and the retention time of the waste, discharging the desulfurization reaction product out of the system along with the slag after the reaction is completed, and discharging the flue gas up to the standard.

2. The method for desulfurizing a hazardous waste incineration system rotary kiln according to claim 1, wherein the hazardous waste having a sulfur content higher than the incineration feed limit is a hazardous waste having a sulfur content of 2% to 5%.

3. The desulfurization method in a rotary kiln of a hazardous waste incineration system according to claim 1, wherein the desulfurizing agent is limestone seed material; the particle size of the desulfurizer is 5-15 mm; the content of CaCO3 in the desulfurizer is more than 80 percent; the addition amount of the desulfurizer accounts for 10% -15% of the amount of the hazardous waste.

4. The desulfurization method in a rotary kiln of a hazardous waste incineration system according to claim 1, wherein the temperature of the rotary kiln is 830 to 850 ℃.

5. The method for desulfurizing a hazardous waste incineration system in a rotary kiln according to claim 1, wherein the waste retention time is 55 to 65 minutes.

6. The method for desulfurization in a rotary kiln for a hazardous waste incineration system according to claim 1, wherein the exhaust system is exhausted through a kiln tail slag remover and a boiler bottom ash discharger.