CN211914939U - Incineration fly ash triboelectric separation treatment equipment - Google Patents

Abstract

The utility model discloses an incineration fly ash triboelectricity selects treatment facility, burn through the fluidized bed, the semidry process absorption tower, the active carbon sprayer, equipment such as sack cleaner carries out incineration disposal and gas cleaning to domestic waste, through the vibration friction ware, drum electricity selects the machine to burn the fly ash and carries out the separation of triboelectricity, obtain two kinds of products of smart ash and tail ash after the electricity selects the separation, the tail ash carries out the electrodialysis again and handles, remove and retrieve the heavy metal, the residual ash directly sends into landfill and handles after the electrodialysis, smart ash product sends into burning furnace combustion-supporting as combustion-supporting thing, decompose dioxin when utilizing active carbon fuel ization, this equipment can be simple fast, energy-conserving high efficiency, the environmental friendly realizes fly ash innocent treatment and high added value utilization, reduce simultaneously and burn factory running cost.

Description

Incineration fly ash triboelectric separation treatment equipment

Technical Field

The utility model belongs to the technical field of waste incineration flying ash treatment, in particular to incineration flying ash triboelectric separation treatment equipment.

Background

The incineration method for treating the household garbage has become a mainstream mode for domestic garbage treatment in China due to the advantages of short treatment time, small occupied area, capacity reduction, harmlessness, heat recovery and the like. In the domestic garbage incineration power plant, about 400 seats are provided at the end of 2018, and the total garbage incineration amount exceeds 38 ten thousand tons/day. Most (70-90%) of dioxin generated by garbage incineration is transferred into incineration fly ash, and the incineration fly ash is listed in national hazardous waste records of China due to the enrichment of highly toxic dioxin and toxic heavy metals. Calculated according to the fly ash production amount of 3-5% of the waste incineration amount, about 1.6 ten thousand tons of fly ash are produced every day in China, and the fly ash becomes a huge hidden danger of urban environmental safety. In 2014, in order to strictly control the emission of toxic and harmful substances in the incineration process, the emission standard of dioxin in waste incineration flue gas is from 1.0ng I-TEQ/m³Increased to 0.1ng I-TEQ/m³In order to reach the standard of flue gas emission, a large amount of activated carbon is sprayed into a flue of an incineration plant to adsorb dioxin in flue gas, and the spraying amount of the activated carbon is 150-200 mg/Nm³Flue gas, activated carbon that adsorbs dioxin, is mostly transferred to cloth bag fly ash, so fly ash contains considerable amounts of carbon components (activated carbon and unburned carbon). In addition, a small amount of unburned carbon residue carried out from the incinerator also enters the cloth bag fly ash, so that the content of carbon components (activated carbon and unburned carbon residue) in the incineration fly ash is high, and the unburned carbon residue is an enrichment source of organic pollutants such as dioxin. Heavy metals such as Cd, Zn, Pb and the like in the fly ash are mainly in exchangeable state (F1) and carbonate (F2) states, and the fly ash has strong mobility. At present, domestic waste incineration fly ash is mainly sent to a domestic waste landfill site for landfill disposal after cement solidification treatment, the method aims at solidifying heavy metals, potential hazards of dioxin cannot be eliminated, and the cement consumption is high due to high carbon components, so that a proper treatment method aiming at high carbon characteristics needs to be developed urgently.

Since the carbon component in the incineration fly ash exists mainly in the form of monomer particles, this allows the high carbon component in the fly ash to be removed using a physical separation method. Possible physical separation methods include a wet method represented by flotation and a dry method represented by electro-flotation. The former is based on the difference of the surface characteristics (wettability) of carbon elements and ash elements in the fly ash, namely the carbon elements have better hydrophobicity than the ash elements, and are easy to adhere to bubbles in a flotation machine and float upwards along with the bubbles under the action of an oil collecting agent. Patents 201410034832.5 and 201510705257.1 disclose a treatment method for recovering heavy metals by combining decarburization and flotation of fly ash from incineration of medical wastes with sulfidization precipitation or ion flotation, which solves the problems of fly ash decarburization and heavy metal recovery. In addition, the fly ash is directly returned to the incinerator for reburning, which proves that the method is a method for decomposing dioxin at high temperature, and the decomposition rate of the dioxin can reach more than 99 percent. The flotation method has good carbon removal effect, but the flotation is a wet process, and the carbon-rich refined ash after flotation needs expensive dehydration and drying steps before being sent into an incinerator for combustion supporting, so that the investment and operation cost are very high, and the popularization and application of the flotation technology are limited to a certain extent.

In the incineration fly ash, the carbon component has good electrical conductivity relative to non-conductor inorganic substances, and the electrical property difference provides a precondition for the electrical separation of the incineration fly ash. The difference in electrical properties of the carbon component and the inorganic substance can be enhanced by triboelectric charging, and then the simultaneous separation of the carbon component and dioxin in the fly ash can be realized in an electrostatic field. Compared with a flotation method, the dry method operation and the simple process of the electric separation method do not need a huge wastewater treatment and product dehydration system, and the triboelectric separation technology is used for dry separation, so that the high cost of dehydration and a product drying system is saved, and the environmental pollution and the water resource waste caused in the separation process are effectively avoided.

Electrodialysis is a physical-chemical process in which ions are transferred from one part of a solution to another part of the solution by the selective permeability of an ion exchange membrane under the action of an external direct current electric field. The electrodialysis device is manufactured on the principle that cations can permeate through the positive membrane and anions can permeate through the negative membrane based on the fact that the ionic membrane has selective permeability to the anions and the positive ions of electrolyte in a solution under the action of a direct current electric field, and the anions and the positive ions respectively move directionally through an anion and cation exchange membrane and enter a concentration chamber of the anions and the positive ions. Electrodialysis technology has been widely used in the treatment of wastewater and the removal of heavy metals from contaminated soil. Patent 201310681066.7 discloses a method for removing heavy metals in waste incineration fly ash by electrodialysis, the hydrophobic characteristic of dioxin is considered, the dioxin is almost insoluble in the electrodialysis process, and activated carbon in the fly ash has strong adsorption characteristic to dioxin, the dioxin can be concentrated in residual ash after the electrodialysis, the dioxin content in the residual ash after the electrodialysis treatment exceeds the original ash, and the residual ash still can not directly enter the landfill site for landfill. Therefore, electrodialysis is more suitable for treating the fly ash after removing dioxin.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome prior art not enough, for eliminating dioxin harm in the waste incineration flying ash, solve the influence of high content active carbon to flying ash follow-up treatment, a fly ash triboelectric selection treatment facility and method of burning is provided, it can make the carbon component carry electric charge in the flying ash through the friction, then select through the electricity, carbon component and dioxin separate in the flying ash in step with the dry process, obtain two kinds of products of essence ash and tail ash, the essence ash is sent into to burn again and is solved dioxin decomposition and fuel and recycle the problem, the tail ash adopts the electrodialysis method to retrieve heavy metal and removes, dechlorination simultaneously, carry out high added value utilization when realizing flying ash innocent treatment safely effectively.

The utility model discloses a realize through following technical scheme:

the utility model provides an incineration fly ash triboelectric selects treatment facility which characterized in that: comprises a fluidized bed incinerator, a semi-dry absorption tower, an active carbon injector, a bag-type dust remover, a vibration friction device and a drum electric separator,

the gas outlet of the fluidized bed incinerator is connected with the inlet of the semidry absorption tower, the outlet of the semidry absorption tower is connected with the gas inlet of the bag-type dust remover through an activated carbon injector, the gas outlet of the bag-type dust remover is connected with a chimney through an induced draft fan, the discharge port at the bottom end of the bag-type dust remover is connected with the fly ash inlet of the vibration friction device, the fly ash outlet of the vibration friction device is connected with the feed inlet of the drum electric separator, and the carbon-rich fine ash discharge port of the drum electric separator.

The operation method of the incineration fly ash triboelectric separation treatment equipment comprises the following steps:

the household garbage is firstly burnt in a fluidized bed furnace, the burnt bottom ash is discharged from a discharge port at the bottom of a grate furnace, flue gas generated by burning is deacidified by a semidry absorption tower, an activated carbon injector sprays activated carbon powder to adsorb dioxin in the flue gas, the activated carbon powder adsorbing the dioxin is mixed with fly ash and enters a bag-type dust remover to become bag-type fly ash, and the flue gas passing through the bag-type dust remover is discharged from a chimney through a draught fan;

the incineration fly ash collected by the bag-type dust collector is sent into a mixer, is fully mixed with a modifier and a regulator in the mixer, and is sent into a vibration friction device through a fly ash inlet, the charged fly ash after friction charge is discharged from a fly ash outlet and then enters a drum electric separator for electric separation, carbon-rich refined ash, an intermediate product and tail ash obtained after separation are respectively discharged from a tail ash discharge port, an intermediate product discharge port and a refined ash discharge port, the intermediate product is sent back to the electric separator for electric separation again, and finally carbon-rich refined ash and tail ash products are obtained;

the enriched fine ash is directly sent into an incinerator to be used as combustion-supporting substances for fuel utilization, and dioxin is decomposed while activated carbon is subjected to fuel utilization;

the tail ash product is prepared into mortar with an assistant and water to be subjected to electrodialysis treatment in an electrodialysis tank, 3 products such as heavy metal concentrated solution, residual ash and waste liquid are obtained after treatment, heavy metals such as Pb and Zn can be recovered from the heavy metal concentrated solution through hydrometallurgy, the residual ash is directly sent to a refuse landfill to be subjected to landfill treatment, and the waste liquid is directly sent to a sewage system to be treated and then is safely discharged.

The vibration friction device consists of vibration equipment, a vibration charging device, a negative electrode and a positive electrode.

The utility model discloses an advantage and beneficial effect do:

the utility model discloses at first add the charge difference of carbon component and inorganic matter in the modifier reinforcing flying dust in the flying dust, add the regulator simultaneously and promote flying dust friction charge in-process dioxin adsorb in the carbon component. According to the method, the incineration fly ash is subjected to frictional charge to enable inorganic substances and activated carbon in the incineration fly ash to have opposite charges, synchronous separation of carbon components and dioxin is realized in a high-voltage electrostatic field, and electric separation is performed to obtain two products, namely refined ash and tail ash, wherein the refined ash product is dry, the content of the carbon components is about 4 times of that of the original fly ash, the heat value exceeds 3000 kilocalories, the refined ash product can be used as a combustion supporter to be directly mixed with garbage raw materials and sent into an incinerator for reburning, high-temperature decomposition of the dioxin and fuel utilization of the carbon components are realized, and the addition amount of fire coal in the incinerator is effectively reduced; and (3) performing electrodialysis treatment on the tail ash product, wherein the residual ash has very low content of chlorine salt and heavy metal, the volume of the residual ash is greatly reduced, the residual ash can be directly sent to a domestic garbage landfill for landfill to realize final safe disposal, the heavy metal concentrated solution can be used as a raw material of a smelting plant to recover heavy metals such as Pb, Zn and the like, and the residual wastewater can be discharged after being treated. The method can perform on-line electric separation at the bottom of a bag-type dust collector of the incinerator, reduce the toxicity of dioxin in the fly ash and the landfill disposal amount, greatly solve the defect of high cement consumption caused by high content of carbon components in the fly ash in the current domestic cement curing method, and effectively reduce the environmental risk of the dioxin in the landfill. The utility model discloses can realize innocent treatment and the high added value utilization of waste incineration flying dust under the low-cost condition, the utility model discloses a plurality of problems are solved to technology, kill many birds with one stone, have easy operation, with low costs, treatment effect good and do not have advantages such as secondary pollution.

Drawings

Fig. 1 is a schematic view of the overall connection structure of the present invention.

FIG. 2 is a schematic view of the structure of the vibration friction device of the present invention

Fig. 3 is a process flow chart of the electrodialysis treatment of the tail ash of the utility model.

Wherein:

the device comprises a fluidized bed incinerator 1, a fan 2, a semidry absorption tower 3, an activated carbon injector 4, a bag-type dust remover 5, an induced draft fan 6, a chimney 7, a mixer 8, a vibration friction device 9, a drum electric separator 10, a tail ash discharge port 11, an intermediate product discharge port 12, a fine ash discharge port 13, a fly ash inlet 14, a vibration charging device 15, a vibration device 16, a negative electrode 17, a positive electrode 18 and a fly ash outlet 19.

For a person skilled in the art, other relevant figures can be obtained from the above figures without inventive effort.

Detailed Description

The technical solution of the present invention will be further described with reference to the following specific examples.

An incineration fly ash triboelectric separation treatment device comprises

A fluidized bed incinerator 1, a fan 2, a semidry method absorption tower 3, an activated carbon ejector 4, bag-type dust collectors 5 and 6, an induced draft fan, a chimney 7, a mixer 8, a vibration friction device 9, a drum electric separator 10,

the household garbage is firstly burnt in a fluidized bed furnace, the burnt bottom ash is discharged from a discharge port at the bottom of the fluidized bed furnace, smoke generated by burning is discharged from the tail of the burning furnace, a smoke outlet at the tail of the burning furnace is connected with a semi-dry absorption tower, so that the smoke discharged from the burning furnace is deacidified by the semi-dry absorption tower, an outlet of the semi-dry absorption tower is connected with an air inlet of a bag-type dust collector through an active carbon ejector, the active carbon ejector sprays active carbon powder to adsorb dioxin in the smoke, the active carbon powder adsorbing the dioxin is mixed with fly ash, the active carbon powder adsorbing the dioxin is filtered and transferred into bag-type fly ash through the bag-type dust collector, and gas passing through the bag-type dust collector is discharged from a chimney through a draught fan.

The gas outlet of the fluidized bed incinerator is connected with the inlet of a semi-dry absorption tower, the outlet of the semi-dry absorption tower is connected with the gas inlet of a bag-type dust remover through an active carbon injector, the gas outlet of the bag-type dust remover is connected with a chimney through an induced draft fan, the discharge outlet at the bottom end of the bag-type dust remover is connected with the fly ash inlet of a vibration friction device, the fly ash is fully mixed and charged with a modifier and a regulator in the friction device, the fly ash outlet of the vibration friction device is connected with the inlet of a drum electric separator, charged fly ash from a filter bag enters the drum electric separator for electric separation, and carbon-rich refined ash, intermediate products and tail ash obtained after separation are discharged from a tail ash discharge port 11, an intermediate;

the intermediate product is sent back to the electric separator for secondary electric separation, and finally carbon-rich refined ash and tail ash products are obtained; the enriched refined ash is sent into the garbage raw material of the incinerator to be used as combustion-supporting material for fuel utilization. Referring to the attached figure 3, tail ash products are prepared into mortar with an auxiliary agent and water to be subjected to electrodialysis treatment in an electrodialysis tank, 3 products such as heavy metal concentrated solution, residual ash and waste liquid are obtained after treatment, heavy metals such as Pb and Zn can be recovered from the heavy metal concentrated solution through hydrometallurgy, the residual ash is directly sent to a refuse landfill for landfill treatment, and the waste liquid is directly sent to a sewage system for safe discharge after treatment;

the vibration friction device is composed of a fly ash inlet 14, a vibration charging device 15, vibration equipment 16, a negative electrode 17, a positive electrode 18 and a fly ash outlet 19, the fly ash inlet and the fly ash outlet are respectively arranged on two sides of the vibration charging device, the fly ash inlet is arranged on the higher side of the vibration charging device, the fly ash outlet is arranged on the lower side of the vibration charging device, the negative electrode is connected to the upper side of the vibration charging device, and the positive electrode is connected to the lower side of the vibration charging device.

The following describes a specific method for electrically beneficiation of fly ash with reference to specific examples.

Example 1:

the chemical composition, the thermal ignition loss and the dioxin content of certain waste incineration fly ash (namely, cloth bag fly ash) are shown in table 1. 0.5 percent (mass ratio) of kerosene is used as a modifier, 2 percent of normal hexane is used as a regulator and added into waste incineration fly ash, the mixture is uniformly mixed and then sent into a vibration friction device for friction charge, the charged fly ash is sent into a drum electric separator for electric separation, the voltage of the drum electric separator is 45kV, the rotating speed of a drum is 200r/min, the intermediate product is subjected to electric separation for 2 times, and two products of carbon-rich refined ash and tail ash are finally obtained after electric separation, the carbon content of the two products is respectively 39.46 percent and 4.27 percent, the dioxin content is respectively 8.35 and 2.65ng I-TEQ/g, the heat value of the carbon-rich refined ash reaches 2985 kilocalories, the carbon-rich refined ash is used as combustion-supporting material of a waste incinerator and is mixed into waste for incineration, so that the fuel utilization of the carbon components and the decomposition of the dioxin are realized. The content of dioxin in tail ash meets the dioxin limit value (less than 3ng TEQ/g) required by GB16889-2008

Referring to the attached figure 2, the tail ash product is subjected to electrodialysis treatment, sodium citrate and water are prepared into a solution according to the ratio of 1: 10, the tail ash and the solution are prepared into mortar according to the solid-to-liquid ratio of 150g/l, the mortar is subjected to electrodialysis treatment in an electrodialysis tank at the current density of 15A/m2, and after the electrodialysis treatment is carried out for 12 days, the recovery rates of heavy metals such as Pb, Zn, Cd and the like after the electrodialysis treatment reach 17.5%, 24.3% and 50.5% respectively; 63.4 percent of chlorine in the tail ash is removed, and the waste liquid is directly sent to a sewage system for treatment and then is safely discharged; the heavy metal concentrated solution can further recover heavy metals such as Pb, Zn and the like through hydrometallurgy; the leaching concentrations of heavy metals such as Cu, Pb, Zn, Cd and the like in the residual ash are respectively 0.09mg/L, 1.14mg/L, 2.32mg/L and 0.05mg/L, which are all lower than the pollution control standard of a domestic garbage landfill (GB16889-2008), and meet the standard of directly entering the domestic garbage landfill for landfill.

Table 1: main chemical component (%) -of incineration fly ash in example 1

Table 2: thermal ignition loss rate, heavy metal and dioxin content (%)

Example 2:

the same incineration fly ash in example 1 is adopted, 1.5 percent (mass ratio) of acetic acid as a modifier, 1.0 percent of acetone and 0.4 percent of surfactant (Tween80) as a regulator are added into the incineration fly ash of the garbage, the mixture is uniformly mixed and then sent into a vibration friction device for friction charge, the charged fly ash is sent into a drum electric separator for electric separation, the voltage of the drum electric separator is 38kV, the drum rotating speed is 220r/min, the intermediate product is subjected to electric separation for 2 times, two products of carbon-rich refined ash and tail ash are finally obtained after the electric separation, the carbon content in the two products is respectively 38.77 percent and 4.97 percent, the dioxin content is respectively 8.16 and 2.78ng of I-TEQ/g, the tail ash can be added with a small amount of cement and solidified heavy metal and then sent into the domestic garbage for landfill disposal, the heat value of the carbon-rich refined ash reaches 3108 kilocalories, the carbon-rich refined ash is used as a combustion supporter of the garbage incinerator for incineration, the fuel utilization of the carbon component and the decomposition of the dioxin are realized. The content of dioxin in tail ash meets the dioxin limit value (less than 3ng TEQ/g) required by GB16889-2008

Referring to the attached figure 2, the tail ash product is subjected to electrodialysis treatment, sodium citrate and water are prepared into a solution according to the ratio of 1: 9, the tail ash and the solution are prepared into mortar according to the solid-to-liquid ratio of 150g/l, the mortar is subjected to electrodialysis treatment in an electrodialysis tank at the current density of 16.5A/m2, and after 14 days of electrodialysis treatment, the recovery rates of heavy metals such as Pb, Zn, Cd and the like after the electrodialysis treatment reach 18.2%, 23.8% and 51.2% respectively; the chlorine in the tail ash is removed by 61.4 percent, and the waste liquid is directly sent to a sewage system for treatment and then is safely discharged; the heavy metal concentrated solution can further recover heavy metals such as Pb, Zn and the like through hydrometallurgy; the leaching concentrations of heavy metals such as Cu, Pb, Zn, Cd and the like in the residual ash are respectively 0.09mg/L, 1.02mg/L, 2.31mg/L and 0.03mg/L, which are all lower than the pollution control standard of a domestic garbage landfill (GB16889-2008), and meet the standard of directly entering the domestic garbage landfill for landfill.

Example 3:

the same incineration fly ash as in example 1 is adopted, 0.7 percent (mass ratio) of acetic acid as a modifier, 0.9 percent of toluene and 0.8 percent of surfactant (SDS) as a regulator are added into the waste incineration fly ash, the mixture is evenly mixed and then sent into a vibration friction device for friction charge, the charged fly ash is sent into a drum electric separator for electric separation, the voltage of the drum electric separator is 25kV, the drum rotating speed is 160r/min, the intermediate product is subjected to electric separation for 2 times, two products of carbon-rich refined ash and tail ash are finally obtained after the electric separation, the carbon content of the two products is respectively 38.75 percent and 4.72 percent, the dioxin content is respectively 8.42 and 2.55ng I-TEQ/g, the tail ash can be sent into household garbage for landfill disposal after a small amount of cement is added to solidify heavy metal, the calorific value of the carbon-rich refined ash reaches 3108 kilocalories, the carbon-rich refined ash is used as combustion supporter of the waste incinerator and is mixed into the waste incineration fly ash of the waste incinerator, the fuel utilization of the carbon component and the decomposition of the dioxin are realized. The content of dioxin in tail ash meets the dioxin limit value (less than 3ng TEQ/g) required by GB16889-2008

Referring to the attached figure 2, the tail ash product is subjected to electrodialysis treatment, sodium citrate and water are prepared into a solution according to the ratio of 1: 12, the tail ash and the solution are prepared into mortar according to the solid-to-liquid ratio of 150g/l, the mortar is subjected to electrodialysis treatment in an electrodialysis tank at the current density of 14A/m2, and after the electrodialysis treatment is carried out for 13 days, the recovery rates of heavy metals such as Pb, Zn, Cd and the like after the electrodialysis treatment reach 17.5%, 24.2% and 52.2% respectively; chlorine in the tail ash is removed by 62.6 percent, and the waste liquid is directly sent to a sewage system for treatment and then is safely discharged; the heavy metal concentrated solution can further recover heavy metals such as Pb, Zn and the like through hydrometallurgy; the leaching concentrations of heavy metals such as Cu, Pb, Zn, Cd and the like in the residual ash are respectively 0.08mg/L, 1.11mg/L, 2.25mg/L and 0.05mg/L, which are all lower than the pollution control standard of a domestic garbage landfill (GB16889-2008), and meet the standard of directly entering the domestic garbage landfill for landfill.

The above embodiment illustrates a new process for harmless treatment and resource utilization of fly ash from incineration of garbage, and the utility model is suitable for fly ash from incineration of household garbage and fly ash from incineration of medical garbage. The frictionizer is not limited to a vibrating frictionizer, and the electric separator is not limited to a drum electric separator, but can also be other triboelectric separation equipment used for coal and fly ash.

Although the preferred embodiments of the present invention have been described with reference to the accompanying drawings, the present invention is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the spirit and scope of the present invention, which is within the protection scope of the present invention.

Claims (1)

1. The utility model provides an incineration fly ash triboelectric selects treatment facility which characterized in that: the device comprises a fluidized bed incinerator, a semi-dry absorption tower, an activated carbon ejector, a bag-type dust remover, a vibration friction device and a drum electric separator, wherein:

the air outlet of the fluidized bed incinerator is connected with the inlet of the semidry absorption tower, the outlet of the semidry absorption tower is connected with the air inlet of the bag-type dust remover through an activated carbon injector, the air outlet of the bag-type dust remover is connected with a chimney through an induced draft fan, the discharge port at the bottom end of the bag-type dust remover is connected with the fly ash inlet of the vibration friction device through a mixer, the fly ash outlet of the vibration friction device is connected with the feed inlet of the drum electric separator, and the carbon-rich refined ash discharge port of the drum electric separator.

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