CN113217915A

CN113217915A - Hazardous waste treatment method

Info

Publication number: CN113217915A
Application number: CN202110469885.XA
Authority: CN
Inventors: 洪月明
Original assignee: Lanxi Chuangli Energy Co ltd
Current assignee: Lanxi Chuangli Energy Co ltd
Priority date: 2021-04-28
Filing date: 2021-04-28
Publication date: 2021-08-06

Abstract

The invention provides a hazardous waste treatment method, and relates to the technical field of hazardous waste resource utilization. The hazardous waste treatment method comprises the following steps: preparing the hazardous waste into combustible slurry, cracking the combustible slurry in a gasifier at 1300-1500 ℃ in a weak reduction state to generate combustible gas and molten slag, combusting the combustible gas, and converting heat generated by combustion into steam energy, electric energy and/or heat energy of an industrial kiln. The method has the advantages that the traditional disposal mode of landfill and incineration is changed into the comprehensive utilization of the hazardous waste, a closed-loop economic mode of resources, waste products, wastes and renewable resources is formed, the domestic and industrial wastes are changed into valuable materials and recycled, so that the waste output is effectively reduced, the waste recycling is increased, and the economic benefit and the social benefit are further improved.

Description

Hazardous waste treatment method

Technical Field

The invention relates to the technical field of hazardous waste resource utilization, in particular to a hazardous waste treatment method.

Background

Along with the rapid development of social economy in China, the harm of hazardous waste brought by industrial production to the ecological environment is more obvious. At present, domestic related documents highlight the harmless bottom line requirements of solid waste pollution prevention and control, and simultaneously propose to establish a hazardous waste classification management system, further improve the legal regulations in the aspects of hazardous waste treatment planning, transfer transportation, operation permission and the like, and bring huge market opportunities for hazardous waste treatment industries. Therefore, the potential market space for the treatment of industrial hazardous waste in China is huge.

However, the current industrial hazardous waste disposal capacity is obviously insufficient. Statistical data show that annual production of hazardous waste in our country is rapidly increasing from 3976 million tons in 2015 to 6937 million tons in 2017, and is increasing at a rate of 30% annually. The production amount of industrial hazardous waste is large, the existing disposal capability is weak, and a large gap provides a wide space for the development of the industry. The approved treatment capacity of the whole national hazardous waste in 2018 is 10212 ten thousand tons, the actual treatment capacity is 2697 ten thousand tons, the actual comprehensive capacity utilization rate is only 30 percent, and the effective capacity is seriously insufficient. On the demand side, along with the dangerous waste disposal market supervision is more and more strict, especially after the enterprises that produce waste break the rules and regulations and store the dangerous waste accident and take place many times, each local government requires to continuously promote to dangerous waste disposal. The industrial hazardous waste disposal industry currently presents the industrial characteristics of small, scattered and weak. The average treatment scale of enterprises with the treatment quality of hazardous wastes is small, the average treatment capacity of each enterprise is less than 3 ten thousand tons per year, and the enterprises with the treatment capacity below 1 ten thousand tons per year account for more than 80 percent of the whole industry; the industry concentration is extremely low, and the sum of the processing capacities of the first ten enterprises in China only accounts for 6 percent; the capital capacity of part of industrial hazardous waste treatment enterprises is weak, the treatment technology and the quality are single, more than 90% of enterprises can treat no more than 5 types of hazardous waste, and the treatment scale of most of enterprises hazardous waste is less than 50 tons/day.

In addition to the above problems, the current hazardous waste treatment has certain problems: if the existing dangerous waste treatment thinking takes dangerous waste combustion as a main idea, a large amount of coal is needed to be matched with the dangerous waste combustion, so that not only is the coal resource wasted, but also the problem of high cost exists, meanwhile, the existing dangerous waste combustion treatment mode has the problem of generating toxic gases such as dioxin, the furnace slag is not completely combusted, meanwhile, waste water, waste gas, waste residues and the like are also generated, the method belongs to the economic mode of resource-waste product-resource + waste, and the huge cost can be consumed for treating the secondary waste gas, waste residues. In the present dangerous waste treatment environment, due to the limitation of the thought, a new dangerous waste treatment thought is difficult to develop. Therefore, there is an urgent need to develop a method for treating hazardous waste that can solve the above technical problems.

Disclosure of Invention

The invention aims to provide a hazardous waste treatment method, which changes the traditional disposal modes of hazardous waste treatment and landfill, incineration and the like into the comprehensive utilization of hazardous waste, further combusts combustible gas to collect heat and converts the heat into steam energy, electric energy and/or heat energy of an industrial kiln, and is a closed-loop economic mode of resources, waste products, wastes and renewable resources.

The technical problem to be solved by the invention is realized by adopting the following technical scheme.

The embodiment of the application provides a hazardous waste treatment method, which comprises the following steps: preparing the hazardous waste into combustible slurry, cracking the combustible slurry in a gasifier at 1300-1500 ℃ in a weak reduction state to generate combustible gas and molten slag, combusting the combustible gas, and converting heat generated by combustion into steam energy, electric energy and/or heat energy of an industrial kiln.

Compared with the prior art, the embodiment of the invention has at least the following advantages or beneficial effects:

the method for treating the dangerous waste changes the traditional disposal modes of treating the dangerous waste, such as landfill and incineration, into comprehensive utilization of the dangerous waste, further combusts combustible gas to collect heat and convert the heat into steam energy, electric energy and/or heat energy of an industrial kiln, is a closed-loop economic mode of resources, waste products, wastes and renewable resources, and is completely different from the conventional dangerous waste treatment idea. The invention provides a novel method for treating hazardous waste, which comprises the steps of cracking the hazardous waste into combustible gas by using high temperature, and converting heat generated by combustion of the combustible gas into steam energy, electric energy and/or heat energy of an industrial kiln, so that the domestic and industrial wastes are changed into valuable things and recycled, thereby more effectively reducing the output of the wastes and increasing the reutilization of the wastes; meanwhile, the small particles formed by bonding the solid powder in the slurry of the gasification furnace and the hazardous waste water can be cracked into combustible gases (CO and H) at the high temperature of more than 1300 DEG C₂Etc.) and slag in a molten state, because the slag is cracked at a high temperature of more than 1300 ℃, the generation of toxic gas dioxin in the traditional environment of 700-800 ℃ is avoided, and meanwhile, the small particles are completely molten into slag in a molten state at a high temperature, so that the slag is fully moltenCracking to the inside of the small particles, and avoiding the incomplete cracking inside the small particles from generating toxic gas. The molten slag and the combustible gas are chilled by water at the bottom of the gasification furnace, so that the combustible gas can not be synthesized into dioxin again, and meanwhile, the molten slag is rapidly cooled in the process of being converted into solid slag, and the solid slag can not generate dioxin and is discharged out of the furnace.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a plant-wide process flow diagram of the present invention;

FIG. 2 is a process flow diagram of a gasification unit of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to specific examples.

The embodiment of the application provides a hazardous waste treatment method, which comprises the following steps: preparing the hazardous waste into combustible slurry, cracking the combustible slurry in a gasifier at 1300-1500 ℃ in a weak reduction state to generate combustible gas and molten slag, combusting the combustible gas, and converting heat generated by combustion into steam energy, electric energy and/or heat energy of an industrial kiln. The hazardous waste is cracked into combustible gas by using high temperature, and then the heat generated by the combustion of the combustible gasThe energy is converted into steam energy, electric energy and heat energy of an industrial kiln, and the method is a closed-loop economic mode of resources, waste products, wastes and renewable resources, so that the domestic and industrial wastes are changed into valuable things and recycled, the waste output is more effectively reduced, and the waste recycling is increased; meanwhile, the small particles formed by bonding the solid powder in the slurry of the gasification furnace and the hazardous waste water can be fully cracked into combustible gases (CO and H) at the high temperature of more than 1300 DEG C₂Etc.) and slag under the molten state, because the pyrolysis of 1300 ℃ above has avoided the production of poisonous gaseous dioxin under the traditional 700 ~ 800 ℃ environment, high temperature makes aforementioned tiny particle complete melting be molten state slag simultaneously, fully cracks to inside the tiny particle, has avoided the inside pyrolysis of tiny particle incompletely to produce poisonous gas. The molten slag and the combustible gas are chilled by water at the bottom of the gasification furnace, and meanwhile, the process of converting the molten slag into solid slag is rapid cooling, and dioxin is not generated and is discharged out of the furnace.

In some embodiments of the present invention, the hazardous waste treatment method includes an organic hazardous waste solid and/or an inorganic hazardous waste solid. The hazardous waste treatment method provided by the invention has no limit on the types of hazardous wastes, has a wider application range, and can effectively treat various types of hazardous wastes.

In some embodiments of the present invention, the hazardous waste treatment method includes solid hazardous waste and/or liquid hazardous waste. When only dangerous solid waste exists, the slurry can be prepared by receiving waste water from other working sections, or the recovered and treated water of other working sections can be used, and clean water can be introduced to prepare the slurry in extreme cases.

In some embodiments of the present invention, in the method for treating hazardous waste, the organic hazardous waste further includes organic hazardous waste water. The organic hazardous waste water is used as the water for preparing the slurry, so that the aim of treating the organic hazardous waste water can be fulfilled, the consumption of water resources can be reduced, and the production cost is reduced.

In some embodiments of the present invention, the above-mentioned method for treating hazardous waste comprises a step of mixing the hazardous waste with coal to prepare a combustible slurry on the premise that the thermal value of the hazardous waste slurry is insufficient for gasification in the gasification furnace. When the used hazardous waste prepared slurry cannot reach a certain heat value for gasification, a certain amount of coal can be added during the preparation of the slurry, so that the heat value of the slurry is improved, and the slurry is cracked and gasified at 1300-1500 ℃ in a weak reduction state.

In some embodiments of the present invention, the amount of oxygen used in the cracking process under the weak reduction condition is 400-500 cubic meters per ton of slurry. By controlling the oxygen consumption, the organic matters in the organic hazardous waste can be gasified into CO and H to the maximum extent₂Reduction of CO₂The yield of (2).

In some embodiments of the invention, in the method for treating hazardous waste, the temperature of the cracking in the weak reduction state is 1300-1350 ℃, and the pressure of the cracking is 1.1-1.5 MPa. The cracking temperature can crack all kinds of organic hazardous wastes basically, and simultaneously, all slag is changed into a molten state.

In some embodiments of the present invention, in the method for treating hazardous waste, the molten slag is chilled by water to form solid slag. Thereby solidifying the metal ions of the slag.

In some embodiments of the invention, in the hazardous waste treatment mode, the combustible gas generated by cracking is quenched by water and then combusted, so that dioxin generated by the combustible gas in the cooling process is avoided.

In some embodiments of the present invention, in the hazardous waste treatment method, the quenched combustible gas is introduced into a steam boiler for combustion, and the generated steam is introduced into a power generation and/or heat supply system.

In some embodiments of the present invention, in the hazardous waste treatment method, the quenched combustible gas is introduced into an industrial kiln to be directly combusted to provide heat energy.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

Referring to fig. 1 and 2, the present embodiment provides a hazardous waste treatment system, which includes four sections of air separation, pulping, gasification and power generation, and is specifically configured as follows:

1. air separation:

the air separation mainly comprises liquid nitrogen and liquid oxygen prepared by an air separation device. The air separation device comprises an absorption tower, a bag type air filter, a centrifugal air compressor, a molecular sieve, a main heat exchanger, an expansion machine and a fractionating tower which are sequentially communicated.

The main principle of the air separation section is as follows: the raw material air is sucked in from the suction tower, dust and other mechanical impurities are removed by a bag type air filter, the raw material air is compressed to about 0.56Mpa by a centrifugal air compressor and sent to a molecular sieve adsorber to remove moisture and CO in the air₂The compressed air is cooled to the temperature close to the liquefaction temperature through the main heat exchanger, the expansion is carried out in an adiabatic way in the expansion machine to prepare cold energy, then the compressed air is liquefied in the fractionating tower according to the basic principle of air separation, and the rectification is carried out to obtain oxygen with the purity of 99.5 percent and nitrogen and argon with the purity of 99.99 percent. The oxygen is sent to an oxygen cabinet for gasification, and pure nitrogen and argon gas coming out from the top of the upper tower of the fractionating tower are converged and enter a liquefaction system to prepare high-purity liquid nitrogen and liquid argon to be sold as products.

2. Preparing slurry:

the multielement slurry preparation system comprises a belt scale, a rod mill and a wastewater storage tank; the dangerous waste solids are also conveyed to a storage bin, are metered by a belt weigher together with the raw coal and then enter a rod mill; mixing the dangerous waste solids with the pretreated wastewater, introducing the mixture into a wastewater storage tank, adding a slurry additive into the wastewater storage tank, introducing the mixture into a rod mill after mixing, grinding the mixture into a slurry mixture with certain particle size distribution by the rod mill, and finally sending the mixture into a multi-component slurry gasification system by a slurry pump;

it should be noted that if the organic waste solid cannot be burned after being pulped by adding water or after being mixed with organic waste liquid for pulping, certain high-quality coal needs to be added. At this time, high-quality coal needs to be conveyed to a screening and crushing device through a belt conveyor, and the high-quality coal enters a storage bin after being crushed and is treated together with organic waste solids and the like.

3. Gasification of

The system comprises a gasification unit, a gasification furnace burner cooling water unit and a gasification furnace slag treatment unit, wherein the multi-element slurry gasification system is provided with five gasification furnaces (four burners and one spare), and four sets of nozzle cooling water systems are shared by four gasification furnaces. The method comprises the following specific steps:

(1) the gasification unit is mainly a gasification furnace, a combustion chamber and a condensation chamber are arranged in the gasification furnace, a burner for spraying oxygen from an air separation section into the combustion chamber is arranged on the combustion chamber, a slurry inlet, a combustible gas outlet and a molten-state slag outlet are also arranged on the combustion chamber, the slurry inlet is communicated with the rod mill through a slurry pump, and the molten-state slag outlet of the combustion chamber is connected through a down pipe chilling chamber; a combustible gas outlet of the combustion chamber is communicated with a secondary combustion system; the chilling chamber is provided with a solid slag outlet;

the slurry, the waste liquid and the oxygen are subjected to gasification reaction in a combustion chamber of the gasification furnace, and the gasification reaction comprises the following reaction processes:

after the slurry and oxygen from the air separation stage are sprayed into the gasification furnace, the slurry and the oxygen are rapidly heated to high temperature, moisture in the slurry is rapidly changed into steam, and organic dangerous solid powder in the slurry is directly subjected to cracking reaction at the high temperature of 1300-1500 ℃.

The overall reaction formula can be written as: CnHm + (n/2) O₂—→nCO+(m/2)H₂+ Q, carbon conversion is generally above 95%.

The gasification reaction process comprises the following steps: o is₂Contact with organic hazardous solid powder, O₂Reaction of internal diffusion with contact with carbon atoms, O₂And gasifying reaction is carried out with carbon, and reaction products are diffused outwards.

Combustion reaction between carbon and oxygen: mC + O₂＝2(m-1)CO+(2-m)CO₂

It comprises the following steps: c and CO₂The reaction of (1): c + CO₂＝2CO

For the reaction between C and water vapor: c + H₂O＝CO+H₂

The gasifier produces combustible gases and small amounts of other materials (including chlorides, sulfides, nitrogen, argon, methane, etc.), molten slag and fine ash particles. The gas and a small amount of ash content carried in the gas enter a secondary combustion system through a combustible gas outlet of the gasification furnace, molten slag and fine ash particles enter a chilling chamber along a descending pipe, and are rapidly quenched at about 200 ℃ and directly changed into solid, so that toxic gases such as dioxin and the like are prevented from being generated at 700-800 ℃.

(2) Cooling water unit for burner of gasification furnace

The burner cooling water continuously and circularly flows through a water jacket at the end part of the process burner so as to protect the process burner in the high-temperature environment of the combustion chamber of the gasification furnace. The burner cooling water system comprises a set of burner cooling water tank, a burner cooling water pump and a burner cooling water heat exchanger which are used for burners of the gasifier. The burner cooling water standby pump can be automatically started under the condition that the burner cooling water pump fails and is connected with an accident power supply. Returning the burner cooling water to enter a burner cooling water-gas-liquid separator arranged in the gasification furnace. The carbon monoxide analyzer arranged on the air vent of the separator can continuously detect the coal gas leaked into the burner cooling water system and send out early warning.

During the furnace drying before starting and feeding, an electric heating rod or a preheating burner is used for heating until the temperature in the gasification furnace reaches the required ignition temperature. The electric heating rod or the preheating burner has an independent adjusting system. And (4) pumping out and evacuating the oven drying waste gas in the gasification furnace by using an induced draft fan.

(3) Gasification slag treatment unit

The lock hopper is communicated with a solid slag outlet of the chilling chamber, a discharge hole of the lock hopper is communicated with the slag tank, and the lock hopper is connected with the chilling chamber through a water pump.

The solid slag and other solid particles deposited at the bottom of the chilling chamber of the gasification furnace are brought into the lock hopper through the circulation effect of the circulating water flow. Most of ash slag discharged from the gasification furnace settles at the bottom of the lock hopper and is automatically discharged by the lock hopper system at regular intervals. And drawing out relatively clear water from the top of the lock hopper, and circularly entering the water bath of the chilling chamber of the gasification furnace through the lock hopper circulating pump. The ash slag in the slag pool is fished out by the slag dragging machine and sent to the outside of the battery limits.

The slag discharge cycle time of the interlocking slag discharge system of the gasification furnace is preset, the slag discharge cycle is generally about 30 minutes, the part of the slag pool provided with the slag salvaging machine is temporarily separated from the other part of the slag pool by closing the partition plate valve, so that slag is settled on the slag salvaging machine and is sent out of the slag pool by the slag salvaging machine.

4. Power generation

The power generation system comprises a combustion furnace, wherein the combustion furnace is provided with a combustible gas inlet and an air inlet and is also provided with an exhaust port, the combustible gas coming out of the combustion chamber of the gasification furnace enters the combustion furnace through the combustible gas inlet and is mixed with the air entering through the air inlet, and the combustible gas is rapidly combusted in the combustion furnace₂And water vapor, releasing a large amount of heat energy. High temperature CO₂And H₂And the O carries a large amount of heat energy to enter a heat recoverer, and the heat energy is collected and converted into electric energy.

The useless processing system of danger that this embodiment provided has:

1. the hazardous waste treatment system provided by the embodiment meets the requirements of the spirit of the current energy-saving emission-reduction comprehensive working scheme and the planning of the environmental protection industry. The construction danger is useless resource processing power generation facility, through dangerous useless centralization, innoxious and reduction processing, to the pressure that alleviates the useless total amount control of discharging of danger, promotes the development of local economy and has very important realistic meaning.

2. The hazardous waste treatment system provided by the embodiment is built according to the five gasification furnaces (quarto-backup) standard, the total investment is 60000 ten thousand yuan, the annual resource utilization hazardous waste capacity is 35 ten thousand tons, and the annual income is 70000 ten thousand yuan calculated according to the average 2000 yuan/ton of hazardous waste in Zhejiang province at present. Meanwhile, the heat value of each ton of hazardous waste is equivalent to 0.5 ton of electric coal, 17.5 ten thousand tons of electric coal are saved annually, 12250 ten thousand yuan can be saved, and the production cost can be compensated by the produced byproducts of liquid nitrogen and liquid argon. The estimated annual profit total (after tax) is 35000 ten thousand yuan, the investment profit rate is 58%, and all the investments (after tax) can be completely recovered in 1.7 years, so that the hazardous waste treatment system provided by the embodiment has obvious economic benefit, realizes environmental protection, governance and benefit promotion, and can play a demonstration role in the national thermoelectric industry.

3. The hazardous waste treatment system provided by the invention has great significance for demonstrating the national power generation industry from structural adjustment and transformation into environment-friendly enterprises. Meanwhile, a good foundation is laid for the next step of research and development work of treatment of various dangerous waste and solid wastes. The power generation technology is comprehensively utilized by utilizing hazardous waste resources, so that the whole production system is optimized and reasonable, the raw material structure is improved, the resource utilization rate is improved, the product cost is reduced, the market competitiveness and the economic effect are improved, the benefit promotion of environmental protection and treatment is realized, and the development of enterprises to green and circular economy is facilitated.

Example 2

Referring to fig. 1 and 2, the present embodiment provides a method for processing hazardous waste using the aforementioned hazardous waste processing system, including the following steps:

1. preparation of the slurry

Conveying the hazardous wastes into a rod mill, grinding the hazardous wastes into a solid mixture, adding a certain amount of water into the solid mixture during grinding to prepare slurry, wherein the water content in the slurry is about 50%.

It should be noted that the water may be organic hazardous wastewater, or other industrial wastewater, or the wastewater treated by the system used in the method, preferably organic hazardous wastewater, which can save water resources and further treat the hazardous organic substances in the wastewater to prevent environmental damage or eutrophication of the water body.

2. Cracking

And (2) feeding the slurry prepared in the step (1) into a gasification furnace for cracking, mixing the slurry with oxygen with the purity of 99.5% or more, wherein the consumption of the oxygen is 400-500 cubic meters per ton of the slurry, the gasification temperature is 1300-1350 ℃, the gasification pressure is about 1.3MPa, a firebrick and a heat insulation brick are lined in a combustion chamber, the temperature of the outer furnace wall of the gasification furnace can be kept at about 170-260 ℃, and after the reaction is finished, combustible gas and molten slag are obtained.

3. Burning of

The combustible gas generated by cracking is led into a combustion system to be mixed with oxygen, the oxygen is sufficient, the combustible gas is fully combusted, and a large amount of heat energy and CO are generated₂And H₂O。

4. Power generation

High temperature CO₂And H₂And the O carries a large amount of heat energy to enter a heat recoverer, and the heat energy is collected and converted into electric energy.

Examples of effects

The purpose of the effect example is to verify the effect of the hazardous waste treatment method provided by the embodiment of the invention on treating hazardous waste.

1. Collecting hazardous waste

Organic dangerous waste solid and organic dangerous waste liquid produced by Risheng pharmaceutical Co Ltd of Jiangxi province in 2021 year 1 are collected, and the total amount is 200 tons.

Organic dangerous waste solid and organic dangerous waste liquid produced by Jiangxi Koran pharmaceutical Co Ltd in 2020 and 12 months are collected, and the total amount is 120 tons.

The organic dangerous waste solid and the organic dangerous waste liquid produced by the Boya biopharmaceutical group of the limited company in 12 months of 2020 are collected, and the total amount is 300 tons.

2. Treatment of

The collected hazardous organic waste solids and hazardous organic waste liquids were processed as in example 2, and heat was collected and converted to electrical energy.

3. Results

TABLE 1

In summary, the method for processing hazardous waste provided by this embodiment includes the following advantages:

the method for treating the hazardous waste provided by the invention prepares the hazardous waste into combustible slurry, can add a certain amount of coal if necessary, and generates CO and H by cracking reaction of the slurry at high temperature and medium pressure₂The combustible gas is the combustible gas with effective components, can generate a large amount of heat energy after being combusted, replaces part of coal resources, and changes the whole dangerous waste treatment mode into a closed-loop economic mode of resources, waste products, wastes and renewable resources.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hazardous waste treatment method is characterized by comprising the following steps: preparing the hazardous waste into combustible slurry, cracking the combustible slurry in a gasifier at 1300-1500 ℃ in a weak reduction state to generate combustible gas and molten slag, combusting the combustible gas, and converting heat generated by combustion into steam energy, electric energy and/or heat energy of an industrial kiln.

2. The method for treating hazardous waste of claim 1, wherein the hazardous waste comprises organic type solids and/or inorganic type hazardous solids.

3. The hazardous waste treatment method according to claim 2, wherein the hazardous waste comprises solid hazardous waste and/or liquid hazardous waste.

4. The hazardous waste treatment method according to claim 2 or 3, wherein the preparation of the hazardous waste into the combustible slurry comprises a process of mixing the hazardous waste with coal to prepare the combustible slurry on the premise that the hazardous waste slurry has insufficient calorific value and is gasified in the gasification furnace.

5. The method for treating hazardous waste according to claim 1, wherein the amount of oxygen used in the pyrolysis of the combustible slurry in the gasifier under the weakly reducing condition is 400-500 cubic/ton slurry.

6. The method for treating hazardous waste according to claim 5, wherein the temperature of cracking in the weakly reducing state is 1300-1350 ℃, and the pressure is 1.1-1.5 MPa.

7. The method for treating hazardous waste of claim 6, wherein the molten slag is chilled in water to become solid slag.

8. The method for treating the hazardous waste according to claim 6, wherein the combustible gas generated by cracking is quenched by water and then combusted.

9. The hazardous waste treatment method according to claim 8, wherein the quenched combustible gas is introduced into a steam boiler for combustion, and the generated steam is introduced into a power generation and/or heating system.

10. The method for treating hazardous waste of claim 8, wherein the quenched combustible gas is introduced into an industrial kiln and directly burned to provide heat energy.