Harmless treatment system and method for resource utilization of garbage fly ash
Technical Field
The invention relates to the technical field of waste incineration fly ash treatment, in particular to a harmless treatment system and a harmless treatment method for resource utilization of waste fly ash.
Background
The yield of household garbage increases year by year, and at present, the garbage is generally treated by incineration. The fly ash is the inevitable product of waste incineration, and accounts for about 3-5% of the amount of the incinerated waste. The fly ash generated by burning the garbage causes serious environmental pollution, and harmful substances such as dioxin, heavy metals and the like contained in the fly ash can also harm animals, plants and human health, so that the fly ash generated by burning the garbage needs to be treated again.
The current treatment methods for waste incineration fly ash mainly include three methods:
chemical agent stabilizing technology, namely chemical agents and heavy metals are used for carrying out chemical reaction so as to convert heavy metal elements into a form with inactive chemical properties, but the generated complex has high leaching concentration when the garbage fly ash is treated by the method, and cannot meet the requirement of environmental protection;
the cement solidification technology is used for solidifying heavy metals, and the heavy metals form stable compounds on the surfaces of hydrated silicate colloids of cement through chemical reaction, but the method for treating the garbage fly ash can increase the capacity of the fly ash, further increase the landfill volume and increase the landfill cost;
the melting and solidifying technology is that the waste incineration fly ash and the vitreous powder are mixed and melted at the high temperature of 1000-1600 ℃, but the waste incineration fly ash treated by the method has high energy consumption.
Disclosure of Invention
In order to overcome the technical problems, the invention aims to provide a harmless treatment system and a treatment method for resource utilization of garbage fly ash, the system can effectively decompose dioxin and recycle heavy metals, greatly reduces environmental pollution, realizes secondary utilization of resources, meets the requirements of energy conservation and environmental protection, and has the characteristics of simple process, high reaction efficiency, environmental protection, reliability and low production cost.
In order to achieve the purpose, the invention adopts the technical scheme that:
a harmless treatment system for resource utilization of garbage fly ash comprises a mixing device 1, a feeding belt conveyor 2, a forming device 3, a preheating furnace 4, a novel hot melting furnace 9, a waste heat boiler electric closed loop system 11 and a flue gas treatment system 14 which are connected in sequence; the feeding belt machine 2 comprises a feeding belt machine I2 a and a feeding belt machine II 2b, raw materials in the mixing device 1 are uniformly mixed according to a certain proportion, the raw materials are conveyed to a forming device 3 through the feeding belt machine I2 a to be solidified and formed, and the forming raw materials are continuously conveyed to a low-temperature preheating furnace 4 through the feeding belt machine II 2b to be heated and preheated and then fall into a novel hot melting furnace 9; the flue gas generated in the novel hot melting furnace 9 is introduced into a flue gas treatment system 14 from the top outlet of the preheating furnace 4 through a waste heat boiler electric closed loop system 11.
Including exhaust-heat boiler 13 among the exhaust-heat boiler electric closed loop system 11, exhaust-heat boiler 13 utilizes the waste heat power generation in the flue gas, and exhaust-heat boiler 13 links to each other with system oxygen station 12, system oxygen station 12 export provides oxygen for the chemical physics reaction in novel hot melting furnace 9 through pipe connection pure oxygen nozzle 7 and burn out wind spout 6.
The preheating furnace 4 is provided with a labyrinth arrangement baffle 5.
The novel hot melting furnace 9 is provided with a pure oxygen nozzle 7, the pure oxygen nozzle 7 sprays pure oxygen to react with the mixture in the high-temperature melting pool at the bottom of the novel hot melting furnace 9, the heavy metal is reduced to form a metal simple substance in the dioxin decomposition and flying ash, and the bottom of the novel hot melting furnace 9 is provided with a slag outlet 8 and a metal outlet 10.
The flue gas treatment system 14 comprises a heavy metal catcher 15, a dust remover 16, a desulphurization device 17 and an induced draft fan 18 which are arranged in sequence.
A harmless treatment method for resource utilization of garbage fly ash comprises the following steps;
firstly, raw materials are uniformly mixed according to a certain proportion through a mixing device 1, the raw materials are conveyed to a forming device 3 through a feeding belt conveyor I2 a for curing and forming, and the forming raw materials are continuously conveyed to a low-temperature preheating furnace 4 through a feeding belt conveyor II 2 b; the forming raw material is directly sent into a novel hot melting furnace 9 after being preliminarily heated in a preheating furnace 4; pure oxygen is sprayed into the novel hot melting furnace 9 through the pure oxygen nozzle 6 and reacts with a reducing agent in a high-temperature melting tank at the bottom of the novel hot melting furnace 9, clean combustion of reducing atmosphere is realized, dioxin is decomposed at high temperature, harmless products generated by decomposition enter slag liquid, a small amount of heavy metal is reduced, fly ash slag and reduced heavy metal are respectively recovered through a slag outlet 8 and a metal outlet 10, and resource utilization can be realized after cooling; the high-temperature flue gas rich in the volatile heavy metals firstly enters a waste heat boiler 13 for power generation, wherein part of the power is supplied to an oxygen generation station 12 for oxygen generation, and the outlet of the oxygen generation station 12 is connected with a pure oxygen nozzle 6 through a pipeline; the flue gas then loops through heavy metal catcher 15, dust remover 16, desulphurization unit 17, draught fan 18 to the heavy metal particulate matter in the entrapment flue gas realizes high-efficient flue gas purification treatment.
The invention has the beneficial effects that:
the invention provides a harmless treatment system for resource utilization of garbage fly ash, wherein a reusable product can be formed mainly through two steps of material treatment preheating-reduction melting in a preheating furnace and a novel hot melting furnace, so that the system has a simple structure and high production efficiency;
the waste heat boiler is used for generating electricity and generating oxygen in the waste heat boiler electric closed loop system, so that the energy utilization efficiency is improved, and the fly ash treatment and operation cost is reduced;
in the reaction process, the forming raw material is preliminarily heated in the low-temperature preheating furnace, so that the energy consumption of the novel hot melting furnace is reduced, the aim of saving energy is fulfilled, and the production cost is effectively reduced;
in the reaction process, the garbage fly ash is treated and then undergoes a series of complex and violent chemical and physical reactions in a novel hot melting furnace, so that dioxin is thoroughly decomposed, and simultaneously reduction, separation, melting and solidification of heavy metals are realized, the environmental pollution is greatly reduced, the secondary utilization of resources is realized, and the requirements of energy-saving and environment-friendly policies are met.
Drawings
FIG. 1 is a schematic view of a harmless treatment system for recycling waste fly ash according to the present invention.
Wherein, 1 is mixing equipment; 2a is a feeding belt machine; 2b is a feeding belt machine; 3, forming equipment; 4, a preheating furnace; 5 is a baffle plate; 6 is an over-fire air nozzle; 7 is a pure oxygen nozzle; 8 is a slag outlet; 9 is a novel hot melting furnace; 10 is a metal outlet; 11 is an electric closed-loop system of the waste heat boiler; 12 is an oxygen generation station; 13 is a waste heat boiler; 14 is a flue gas treatment system; 15 is a heavy metal catcher; 16 is a dust remover; 17 is a desulfurizing device; 18 is a draught fan.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Referring to fig. 1, the invention comprises a mixing device 1, a feeding belt conveyor I2 a, a feeding belt conveyor II 2b, a forming device 3, a preheating furnace 4, a novel hot melting furnace 9, a waste heat boiler electric closed loop system 11 and a flue gas processing system 14. The outlet of the mixing device 1 is connected to the inlet of the forming device 3 through a feeding belt conveyor I2 a, the outlet of the forming device 3 is connected to the inlet of the preheating furnace 4 through a feeding belt conveyor II 2b, and after the formed raw materials are preliminarily heated up in the preheating furnace 4 to reduce energy consumption, the raw materials are directly fed into the novel hot melting furnace 9 to be subjected to melting treatment.
The raw materials formed by the forming device 3 are preliminarily preheated in the preheating furnace 4 and then sent into the novel hot melting furnace 9 for melting treatment so as to reduce the energy consumption of the melting furnace.
Pure oxygen is sprayed into the novel hot melting furnace 9 through a pure oxygen nozzle 6 and reacts with a reducing agent in a high-temperature melting tank at the bottom of the novel hot melting furnace to form a reducing atmosphere, and dioxin is decomposed and separated at the high temperature of 1000-1100 ℃ to form a few chloride ions and added calcium chloride synthesized by oxidative calcification to enter slag liquid; a small amount of oxides of manganese, copper, chromium and the like are reduced into elemental metals.
The fly ash slag and the reduced heavy metal are respectively recovered through a slag outlet 8 and a metal outlet 10, and can be recycled after being cooled.
High temperature flue gas gets into exhaust-heat boiler electric power closed loop system 11 through 4 top exports in preheater, uses exhaust-heat boiler 13 to utilize the waste heat power generation in the flue gas among the exhaust-heat boiler electric power closed loop system 11, and wherein partial power supplies to system oxygen station 12 and carries out oxygen manufacturing, and system oxygen station 12 export provides oxygen for the chemical physics reaction in novel hot melting furnace 9 through pipe connection pure oxygen nozzle 6.
The flue gas gets into flue gas processing system 14 afterwards, retrieves heavy metal zinc etc. through heavy metal catcher 15, further traps the fine particle thing through dust remover 16, carries out the desulfurization through desulphurization unit 17, realizes the full particle diameter entrapment of heavy metal particle thing in the flue gas, and the high-efficient seizure and the gas cleaning of heavy metal particle thing are handled in the flue gas.
The baffle 5 arranged in a labyrinth way is arranged in the preheating furnace 4, so that the retention time of the formed raw materials in the furnace is effectively increased, and the preheating effect is enhanced.
The working process of the invention is as follows:
firstly, raw materials are uniformly mixed according to a certain proportion through a mixing device 1, the raw materials are conveyed to a forming device 3 through a feeding belt conveyor I2 a for curing and forming, and the forming raw materials are continuously conveyed to a low-temperature preheating furnace 4 through a feeding belt conveyor II 2 b; the forming raw material is directly sent into a novel hot melting furnace 9 after being preliminarily heated in a preheating furnace 4; pure oxygen is sprayed into the novel hot melting furnace 9 through the pure oxygen nozzle 6 and reacts with a reducing agent in a high-temperature melting tank at the bottom of the novel hot melting furnace 9, clean combustion of reducing atmosphere is realized, dioxin is decomposed at high temperature, harmless products generated by decomposition enter slag liquid, a small amount of heavy metal is reduced, fly ash slag and reduced heavy metal are respectively recovered through a slag outlet 8 and a metal outlet 10, and resource utilization can be realized after cooling; the high-temperature flue gas rich in the volatile heavy metals firstly enters a waste heat boiler 13 for power generation, wherein part of the power is supplied to an oxygen generation station 12 for oxygen generation, and the outlet of the oxygen generation station 12 is connected with a pure oxygen nozzle 6 through a pipeline; the flue gas then loops through heavy metal catcher 15, dust remover 16, desulphurization unit 17, draught fan 18 to the heavy metal particulate matter in the entrapment flue gas realizes high-efficient flue gas purification treatment.
The above contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical solution according to the technical idea of the present invention, such as changing the atmosphere to air instead of oxygen, etc., fall within the protection scope of the claims of the present invention.