TW202419145A - Fly ash treatment method - Google Patents

Abstract

The invention relates to a fly ash treatment method, which mixes fly ash in aqueous solution in a fixed ratio by pre-treatment, dehydrates it to obtain a solid, which is solidified by plasticizing treatment and fed into a melt furnace by high temperature melting, and obtains harmless recycled pellets by water quenching treatment. In addition, the dewatered liquid of the pre-treatment can be desalinated (e.g. dialysis treatment) to obtain a highly concentrated filtrate and reused water, which is subjected to crystallization or evaporation treatment (post-desalination) to finally obtain a salt, and the reused water can be channeled back to the pre-treatment as an aqueous solution for mixing with the fly ash. Accordingly, through the treatment mechanism of this invention, the fly ash containing pollutants can be properly purified and treated so as to achieve the effect of recycling.

Description

Fly ash treatment methods

The present invention relates to a fly ash treatment method, and more particularly to an application invention for properly purifying fly ash containing pollutants.

In today's era of vigorous development of various industries and significant improvement in people's living needs, the most serious problem arising from this is the substantial growth in the amount of various wastes (including general household waste, industrial waste and various business wastes), which has made environmental protection increasingly difficult. Among the waste generated in Taiwan each year, household waste only accounts for 28% of the total amount, and the remaining 72% is business waste. In the early days, landfill was the main treatment method for waste. As environmental awareness gradually rises, the land available for landfilling is gradually decreasing, and incineration is gradually being used to treat combustible waste. The treatment process of incineration waste includes: incineration step, fume washing step, dust collection step and solidification step, as explained below:

First, the incineration step is to transfer the combustible waste to be treated to the incinerator and burn it into bottom ash. During the incineration process, fly ash and incineration waste gas will be generated. In the fume scrubbing step, the acid gas in the incineration waste gas will be neutralized with slaked lime or sodium hydroxide to produce reaction ash and neutralized waste gas. Then activated carbon is applied to adsorb heavy metals or dioxins in the incineration waste gas. The final dust collection step is to collect particulate matter, activated carbon and other dust ash with a bag filter dust collector. Therefore, the fly ash of the garbage incineration plant is mostly reaction ash and dust ash.

The exhaust gas scrubbing and dust collection steps make the concentration of sulfur oxides, nitrogen oxides, hydrochloric acid, dioxins, heavy metals and other gases in the exhaust gas meet the domestic environmental protection regulations and standards, and then discharge them into the environment through the chimney. Finally, the fly ash collected by the bag filter dust collector is hazardous waste because it contains high chloride salts, dioxins and heavy metals. At present, most of the incineration fly ash from domestic waste incineration plants is treated by solidification and stabilization steps and then sent to landfills in various counties and cities for disposal.

Taiwan produces an average of about 200,000 tons of incineration fly ash each year, and about 300,000 tons of stabilized products are produced, almost all of which are landfilled. After being buried, the stabilized fly ash still has the risk of leaching harmful substances and polluting the land for a long time. In addition, the landfill capacity will be exhausted, and the harmful fly ash stabilized products will face the problem of having nowhere to bury them.

The high-temperature melting technology of incineration fly ash is to treat the incineration fly ash at high temperature (above 1350℃), which can destroy and decompose harmful organic matter (such as dioxin) in the fly ash; the main components of fly ash such as calcium, silicon, aluminum, magnesium and alkali metals will form vitrified substances, among which heavy metal oxides will be combined in the glass network structure to form insoluble and stable harmless slag, which can be reused as a substitute for aggregate in construction projects to extend the life of landfills.

However, the combustible waste of the garbage incinerator comes from various household garbage. The incineration fly ash from the incineration of kitchen waste and plastic products contains 20-30% chlorine salts. If the incineration fly ash is directly subjected to a high-temperature melting process, it has the following disadvantages:

1. When fly ash containing high chlorine salts melts at high temperatures, it not only produces harmful incineration exhaust gas, but also easily damages the incinerator, reducing the service life of the furnace body.

2. Chloride ions and metal ions melt at high temperature and are discharged with the exhaust gas. Due to the cooling process of the exhaust gas treatment, metal chlorides are formed, which may block the exhaust pipe.

3. The subsequent neutralization step of waste gas treatment will use a large amount of slaked lime or sodium hydroxide, resulting in high chemical cost expenditure.

4. After combustion and incineration, the gas (smoke) will enter the liquid phase through screening and water washing, forming harmful heavy metal waste liquid. If harmful waste containing heavy metals is produced after general wastewater treatment, it is not economically efficient to recover the extracted heavy metals, and the technology is not yet mature. Therefore, these waste liquids will have secondary pollution problems. Therefore, from the perspective of overall waste treatment, since heavy metal substances are not destroyed, if heavy metals in fly ash are extracted, it will only allow heavy metal pollution to migrate to the liquid phase, causing many water quality and environmental pollution incidents.

The inventor has accumulated rich experience in design, development and actual manufacturing in the relevant industry for many years, and has developed and researched the above-mentioned problems to provide a fly ash treatment method, which can subsequently treat the fly ash produced by waste incineration to obtain non-toxic substances and achieve the purpose of having better practical value.

The main purpose of the present invention is to provide a fly ash treatment method, especially a method for properly purifying fly ash containing pollutants.

The main purpose and effect of the fly ash treatment method of the present invention are achieved by the following specific technical means:

The main method is to mix the fly ash with an aqueous solution according to a fixed ratio in a pre-treatment, and then dehydrate the fly ash to obtain a solid. The solid is solidified by shaping and fed into a melting furnace for high-temperature smelting, and then quenched with water to obtain harmless recycled pellets. In addition, the dehydrated liquid of the pre-treatment can be desalinated by a desalination technology (such as dialysis) to obtain a high-concentration filter liquid and recycled water. The filter liquid is subjected to crystallization or evaporation (post-desalination) to obtain a salt, and the recycled water can be led back to the pre-treatment as an aqueous solution for mixing with the fly ash. In this way, through the treatment mechanism of the present invention, the fly ash containing pollutants can be properly purified to achieve the effect of recycling and reuse.

In a preferred embodiment of the fly ash treatment method of the present invention, the desalination technology can adopt one of distillation treatment, reverse osmosis treatment, electrodialysis treatment, crystallization treatment, dialysis treatment and evaporation treatment or a combination thereof.

In a preferred embodiment of the fly ash treatment method of the present invention, the heat source of the flue gas generated during the smelting process of the smelting furnace can be recovered through a heat exchange process and reused by the smelting furnace.

In a preferred embodiment of the fly ash treatment method of the present invention, the flue gas heat source generated by the smelting process of the smelting furnace can be treated through a condensation system and desulfurization and denitrification procedures.

In a preferred embodiment of the fly ash treatment method of the present invention, the light liquid precipitated from the high-concentration filter crystal is a high-Ph value solution (alkaline) that can be introduced into the condensation system as a water source for the condensation system to wash the flue gas. Since the flue gas contains chlorine and sulfur, which are acidic gases, washing the flue gas with an aqueous solution has the effect of neutralizing the flue gas. The light liquid after use in the condensation system is then introduced back into the previous treatment step.

In a preferred embodiment of the fly ash treatment method of the present invention, the ratio of fly ash to aqueous solution in the pre-treatment step is 1:2-9 of fly ash: aqueous solution; and the best ratio is 1:3-5 of fly ash: aqueous solution.

In a preferred embodiment of the fly ash treatment method of the present invention, the melting furnace melts the solids at a high temperature of 2000-3500°C.

In order to make the technical content, purpose of the invention and the effects achieved by the present invention more complete and clear, they are described in detail below, and please refer to the disclosed drawings and figure numbers:

First, the practical application technology and means of the present invention are shown in the first and second figures, which are schematic diagrams of the fly ash treatment method of the present invention. The fly ash is mainly mixed with an aqueous solution in a fixed ratio to form a mixture, and then the mixture is dehydrated (1) to obtain a solid (11) and a dehydrated liquid (12). The dehydrated liquid (12) is subjected to a desalination technology (A) to obtain salts and recycled water (22); and the solid (11) is solidified into a semi-finished product through a shaping treatment, and then the semi-finished product is fed into a melting furnace (4) and smelted at a high temperature into a liquid slurry; the liquid slurry is subjected to a water quenching treatment (5) to rapidly cool it to obtain a solid slag, and the solid slag is the harmless recycled granular material (6).

The desalination technology (A) can adopt one of distillation treatment (A01), reverse osmosis treatment (A02), electrodialysis treatment (A03), crystallization treatment (3), dialysis treatment (2) and evaporation treatment (9) or a combination thereof. In the fly ash treatment method, the desalination technology (A) includes pre-desalination (A1) for front-end treatment and post-desalination (A2) for back-end treatment. The pre-desalination (A1) is mainly used to receive the dehydrated liquid (12) and desalinate the dehydrated liquid (12) to obtain a high-concentration filtered liquid (21) and recycled water (22). The recycled water (22) can be used as a water solution for mixing with the fly ash; and the post-desalination (A2) is used to receive the high-concentration filtered liquid (21) generated in the pre-desalination (A1) treatment process and desalinate (evaporate) the high-concentration filtered liquid (21) to obtain a salt.

When the desalination technology (A) of the present invention is actually implemented, there are several ways that can be combined, such as distillation treatment (A01), reverse osmosis treatment (A02), electrodialysis treatment (A03), crystallization treatment (3), dialysis treatment (2) and evaporation treatment (9). The following is a preferred implementation method and a detailed description. Please refer to the third and fourth figures, which are a block diagram of an embodiment of the fly ash treatment method of the present invention, and the structure diagram mainly includes:

a) providing a pre-treatment step of mixing fly ash with an aqueous solution in a predetermined ratio to form a mixture, and then subjecting the mixture to a dehydration treatment (1) to obtain a solid (11) and a dehydrated liquid (121), wherein the dehydrated liquid (12) is subjected to a dialysis treatment (2) to obtain a high-concentration filtered liquid (21) and recycled water (22), wherein the recycled water (22) can be introduced back into the pre-treatment as an aqueous solution for mixing with the fly ash, and the solid (11) is solidified into a semi-finished product through a shaping treatment (13);

b) subjecting the high-concentration filtered liquid (21) to a crystallization treatment (3) to precipitate a dilute liquid (31) and a salt (32), wherein the dilute liquid (31) can be returned to the previous treatment step as an aqueous solution for mixing with the fly ash;

c) feeding the semi-finished product into a melting furnace (4) and melting it at high temperature into liquid slurry;

d) The liquid slurry is subjected to a water quenching treatment (5) to allow the high-temperature slurry to be rapidly cooled by water quenching to form solid slag, and then subjected to a solid-liquid separation process to obtain the solid slag, which is the harmless recycled granular material (6).

Please refer to the first and second figures. When used in actual operation, fly ash containing harmful substances can be obtained from waste, incinerator incineration process, etc. [For example, sodium fly ash (salt content is about 60%)], and in the pre-treatment step (a), the obtained fly ash is mixed with a water solution according to a fixed ratio. The water solution here refers to water, and the ratio of fly ash to water can range from 1:2-9; however, a better appropriate ratio is listed here, which is to wash and stir the fly ash with water in a ratio of 1:3-5 of aqueous solution to form a mixed liquid, and then the mixture is subjected to a dehydration treatment (1). The dehydration treatment (1) can be adding a dehydrating agent or using a plate and frame dehydrator or any other treatment mechanism that can perform dehydration, and the mixed liquid is dehydrated to obtain a solid (11). and a dehydrated liquid (12), and then the dehydrated liquid (12) is subjected to a desalination technology. First, pre-desalination is performed, and dialysis treatment (2) is selected here. The dehydrated liquid (12) is subjected to dialysis treatment (2) to obtain a high-concentration filtered liquid (21) and recycled water (22). The recycled water (22) can be returned to the pre-treatment as an aqueous solution for mixing with the fly ash. The high-concentration filtered liquid (21) contains high-concentration chlorine (chemical formula: Cl) and sodium chloride (chemical formula: NaCl), and the chlorine content is about 30% and the sodium chloride content is about 50%. The solid matter (11) of the dehydrated mixture is subjected to a shaping treatment (13) to become a semi-finished product in a solidified state. The solidified semi-finished products are further stored in a semi-finished product warehouse (14) to wait for the next processing procedure.

Next, step (b) and step (c) are two parallel processes, and the order of the two processes can be determined by the operator or they can be operated simultaneously. The semi-finished product in step (a) can be first fed into a melting furnace (4) to perform step (c). The melting furnace (4) is defined as a melting furnace that can stretch the temperature to a high temperature of 3500°C. The high temperature is generated by burning gas, heavy oil, etc. The semi-finished products are melted at a high temperature of about 2000-3500°C, so that the solidified semi-finished products are melted into a liquid molten state; however, in order to save energy, the flue gas heat source of the high-temperature melting process of the melting furnace (4) can be recovered through a heat exchange treatment (7) process, and the heat source is guided back to the melting furnace (4) for reuse, thereby achieving the effect of saving energy.

After the semi-finished product is melted by the melting furnace (4), the liquid slurry is subjected to water quenching treatment (5). Water quenching mainly refers to a cooling step to cool the high-temperature liquid slurry. Here, the water quenching treatment (5) is performed by cooling water with a temperature lower than that of the slurry to reduce the temperature of the liquid slurry, so that the liquid slurry is broken into irregular solid slag after water quenching. The solid slag is then subjected to a solid-liquid separation process to separate the solid slag from the cooling water to obtain harmless recycled pellets (6) [i.e., the solid slags]. The harmless recycled pellets (6) are stored in a warehouse for reuse. Furthermore, in the solid-liquid separation process after water quenching, the cooling water used for water quenching can be returned to step (a) for use and reused as an aqueous solution to be mixed with fly ash for washing and stirring, thereby achieving the effect of saving water resources.

In addition, the flue gas heat source generated by the melting furnace (4) during the melting process can be recycled and also introduced into the subsequent air pollution treatment process [i.e., air pollution control facilities (8)]. The air pollution control facilities include a condensation system (81) and a desulfurization and denitrification process. The flue gas is introduced into the condensation system (81) to wash and remove harmful substances in the flue gas, and then the flue gas is discharged after the desulfurization and denitrification process. The condensation system (81) adopts a scrubbing tower to use water to wash the steam and smoke generated by the melting furnace, and the harmful substances contained in the smoke can be removed by washing. The gas (high temperature) after the treatment of the condensation system (81) can be discharged after the desulfurization and denitrification process, thereby achieving energy saving effect.

Next, the high-concentration filtered liquid (21) in step (a) contains high-concentration chlorine (chemical formula: Cl) and sodium chloride (chemical formula: NaCl). The high-concentration filtered liquid (21) is subjected to step (b), i.e., post-desalination, in which a crystallization treatment (3) is applied to the high-concentration filtered liquid (12) to precipitate a desalted liquid (21) and a salt (22). The salt (22) can be used for other purposes. The dilute liquid (31) obtained by crystallization treatment (3) of the high-concentration filtered liquid (12) is a high-Ph value solution (alkaline). The dilute liquid (31) can be introduced back to the pre-treatment step in step (a) to be used as an aqueous solution for mixing with the fly ash, or the dilute liquid (31) can be introduced into a condensation system (81) to serve as a water source for the condensation system (81) to wash the flue gas. Since the flue gas contains chlorine and sulfur, which are acidic gases, washing the flue gas with an aqueous solution has the effect of neutralizing the flue gas, such as the condensation system (81) in the subsequent process of the melting furnace (4) mentioned above.

In summary, the purpose of the crystallization treatment (3) of the present invention is not to obtain refined salt. When the water-soluble salt compound (i.e., high-salt sodium fly ash) is washed with hot water, the washing efficiency can be improved. When the concentration of the waste liquid after washing and dehydration reaches the saturation critical value [i.e., the chlorine content is about 30%, and the sodium chloride content is about 50%], the water after the crystals are precipitated by cooling in a freezer is recycled. This process can first separate harmful heavy metals by electrolysis ionization to achieve a harmless effect.

Please refer to the fifth and sixth figures, which are block and structure diagrams of the second embodiment of the fly ash treatment method of the present invention, which mainly include:

a1) providing a pre-treatment step of mixing fly ash with an aqueous solution in a predetermined ratio to form a mixture, and then subjecting the mixture to a dehydration treatment (1) to obtain a solid (11) and a dehydrated liquid (12). The dehydrated liquid (12) is subjected to a dialysis treatment (2) [pre-desalination] to obtain a high-concentration filtered liquid (21) and recycled water (22). The recycled water (22) can be introduced back into the pre-treatment as an aqueous solution for mixing with the fly ash, and the solid (11) is solidified into a semi-finished product through a shaping treatment (13);

b1) subjecting the high-concentration filtered liquid (21) to evaporation treatment (9) [and then desalination] to obtain salts (91);

c1) feeding the semi-finished product into a melting furnace (4) and melting it at high temperature into liquid slurry;

d1) The liquid slurry is subjected to a water quenching treatment (5) to allow the high-temperature slurry to be rapidly cooled by water quenching to form solid slag, and then a solid-liquid separation process is performed to obtain the solid slag, and the solid slag is the harmless recycled granular material (6).

When used in actual operation, step (a1) is the same as step (a) above and will not be described in detail. The semi-finished product in step (a1) is fed into a melting furnace (4) to perform the smelting operation in step (b1), and the high-concentration filtered liquid (21) in step (a1) is evaporated (9) [post-diluted] in step (b1). Before the evaporation (9), the high-concentration filtered liquid (21) can be neutralized and deacidified. The liquid (21) is introduced into a first cooling and deacidification tower (10), and the first cooling and deacidification tower (10) is connected to the melting furnace (4). The melting furnace (4) introduces the flue gas generated in the smelting process into the first cooling and deacidification tower (10), and the high-concentration filtered liquid (21) and the flue gas are neutralized and removed by reaction to obtain concentrated salt water. The concentrated salt water is then evaporated (9) to remove water, thereby obtaining salts (91).

Next, in step (d1), the liquid slurry melted in the melting furnace (4) is subjected to water quenching treatment (5). The water quenching treatment (5) is a cooling step, which is the same as the above-mentioned step and will not be described in detail. The solid slag after cooling is then subjected to a solid-liquid separation process to obtain solid slag, which is the harmless recycled pellets (6).

However, the aforementioned embodiments or drawings do not limit the product structure or usage of the present invention. Any appropriate changes or modifications by a person having ordinary knowledge in the relevant technical field should be deemed to be within the patent scope of the present invention.

In summary, the embodiments of the present invention can achieve the expected effects, and the specific structure disclosed therein has not been seen in similar products, nor has it been disclosed before the application. It fully complies with the provisions and requirements of the Patent Law. Therefore, an application for an invention patent is filed in accordance with the law, and we sincerely request your review and grant of the patent. We would be grateful for your kindness.

A: Desalination technology

A1:Front Fade

A2: Post-fade

A01: Distillation

A02: Reverse Osmosis Treatment

A03: Electrodialysis

1: Dehydration treatment

11: Solids

12: Dehydration fluid

13: Shaping

14: Semi-finished product storage

2: Dialysis treatment

21: High concentration filter liquid

22: Reuse water

3: Crystallization treatment

31: Light liquid

32: Salt

4: Melting furnace

5: Water quenching

6: Recycled granules

7: Heat exchange treatment

8: Air pollution control facilities

81:Condensation system

9: Evaporation treatment

91: Salt

10: Cooling and deacidification tower

Figure 1: Schematic diagram of the structure of the present invention.

Figure 2: Block diagram of the desalination technology types of the present invention.

Figure 3: A block diagram of an embodiment of the present invention

Figure 4: Schematic diagram of the overall structure of the first embodiment of the present invention.

Figure 5: Block diagram of the second embodiment of the present invention

Figure 6: Schematic diagram of the overall structure of the second embodiment of the present invention.

A: Desalination technology

A1:Front fade

A2: Post-fade

1: Dehydration treatment

11: Solids

12: Dehydration liquid

22: Reuse water

4: Melting furnace

5: Water quenching treatment

6: Recycled granules

Claims (16)

A fly ash treatment method mainly comprises the following steps: mixing fly ash with an aqueous solution in a fixed ratio to form a mixture, and then subjecting the mixture to a dehydration treatment to obtain a solid and a dehydrated liquid. The dehydrated liquid is subjected to a desalination technology to obtain salts and recycled water; the solid is solidified into a semi-finished product through a shaping treatment, and then the semi-finished product is fed into a melting furnace and smelted at a high temperature to form a liquid slurry; the liquid slurry is subjected to a water quenching treatment to rapidly cool it to obtain a solid slag, and the solid slag is harmless recycled granular material. The fly ash treatment method as described in item 1 of the patent application scope, wherein the desalination technology is one of distillation treatment, reverse osmosis treatment, electrodialysis treatment, crystallization treatment, dialysis treatment and evaporation treatment or a combination thereof. As described in the fly ash treatment method of item 2 of the patent application scope, the desalination technology includes pre-desalination and post-desalination, the pre-desalination is to receive the dehydrated liquid and desalinate the dehydrated liquid to obtain a high-concentration filtered liquid and recycled water, and the recycled water can be used as a water solution for mixing with the fly ash; and the post-desalination is to receive the high-concentration filtered liquid and subject the high-concentration filtered liquid to crystallization treatment to obtain a salt. As described in the fly ash treatment method of item 2 of the patent application scope, the desalination technology includes pre-desalination and post-desalination. The pre-desalination is to receive the dehydrated liquid and subject the dehydrated liquid to crystallization treatment to obtain high-concentration filtered liquid and recycled water, and the recycled water can be used as a water solution for mixing with the fly ash; and the post-desalination is to receive the high-concentration filtered liquid and subject the high-concentration filtered liquid to evaporation treatment to obtain a salt. As described in the fly ash treatment method of item 3 of the patent application scope, the pre-desalination adopts dialysis treatment and crystallization treatment, the dialysis treatment is corresponding to receiving the dehydrated liquid, and dialyzing the dehydrated liquid into a high-concentration filtered liquid and recycled water, and then the high-concentration filtered liquid is subjected to the crystallization treatment to precipitate a dilute liquid and salts, and the dilute liquid can be used as a water solution for mixing with the fly ash. A fly ash treatment method, the steps of which are as follows: a) providing a pre-treatment step of mixing fly ash with an aqueous solution in a fixed ratio to form a mixture, and then dehydrating the mixture to obtain a solid and a dehydrated liquid, the dehydrated liquid is dialyzed to obtain a high-concentration filter liquid and recycled water, and the solid is solidified into a semi-finished product by shaping; b) subjecting the aforementioned high-concentration filter liquid to crystallization treatment to precipitate a dilute liquid and a salt, and the dilute liquid can be led back to the pre-treatment step as an aqueous solution for mixing with the fly ash; c) the semi-finished product is fed into a melting furnace and smelted at high temperature into a liquid slurry; d) The liquid slurry is subjected to a water quenching treatment, so that the high-temperature slurry is rapidly cooled by water quenching to become a solid slag, and then a solid-liquid separation process is performed to obtain the solid slag, which is the harmless recycled granular material. The fly ash treatment method as described in Item 6 of the patent application scope, wherein the recycled water in step (a) can be returned to the previous treatment step as an aqueous solution for mixing with the fly ash. As described in the fly ash treatment method of item 6 of the patent application scope, the heat source of the flue gas generated by the smelting process of the smelting furnace in the step (c) can be recovered through a heat exchange process and reused by the smelting furnace. As described in item 8 of the patent application scope, the fly ash treatment method, wherein the flue gas heat source generated by the smelting process of the molten furnace can be introduced into the subsequent air pollution control facility for treatment, wherein the air pollution control facility includes a condensation system and a desulfurization and denitrification process treatment. As described in item 9 of the patent application scope, the fly ash treatment method, wherein the light liquid precipitated by the high-concentration filtered liquid precipitation treatment in step (b) is a high-Ph value solution that can be introduced into the condensation system in the air pollution control facility as a water source for providing the condensation system with flue gas washing. The light liquid washes the acidic flue gas and has the effect of neutralizing the flue gas. The light liquid after use in the condensation system is then introduced back to the previous treatment step. As described in item 6 of the patent application, the fly ash treatment method, wherein the ratio of fly ash to aqueous solution in step (a) is in the range of 1:2 to 9 of fly ash: aqueous solution. The fly ash treatment method as described in item 11 of the patent application, wherein the ratio of fly ash to aqueous solution in step (a) is in the range of 1:3-5 of fly ash: aqueous solution. The fly ash treatment method as described in Item 6 of the patent application, wherein the melting furnace in step (c) performs melting at a temperature of 2000-3500°C. A fly ash treatment method, the steps of which are as follows: a1) providing a pre-treatment step of mixing fly ash with an aqueous solution in a fixed ratio to form a mixture, and then dehydrating the mixture to obtain a solid and a dehydrated liquid, the dehydrated liquid is dialyzed to obtain a high-concentration filter liquid and recycled water, and the solid is solidified into a semi-finished product by shaping; b1) evaporating the high-concentration filter liquid to obtain salts; c1) feeding the semi-finished product into a melting furnace and smelting it at high temperature into a liquid slurry; d1) The liquid slurry is subjected to a water quenching treatment, so that the high-temperature slurry is rapidly cooled by water quenching to become a solid slag, and then a solid-liquid separation process is performed to obtain the solid slag, and the solid slag is the harmless recycled granular material. The fly ash treatment method as described in Item 14 of the patent application, wherein the recycled water in step (a1) can be returned to the previous treatment step as an aqueous solution for mixing with the fly ash. The fly ash treatment method as described in item 14 or 15 of the patent application scope, wherein the high-concentration filtered liquid in step (b1) is input into a first-stage cooling and deacidification tower, and the first-stage cooling and deacidification tower is connected to the melting furnace. The melting furnace introduces the flue gas generated by the smelting process into the first-stage cooling and deacidification tower, and the high-concentration filtered liquid and the flue gas are neutralized and deacidified to obtain concentrated salt water after the reaction, and the concentrated salt water is then evaporated to remove water to obtain salts.

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