阅读说明：本技术 一种垃圾焚烧飞灰的处理方法及其固化物 (Method for treating waste incineration fly ash and condensate thereof ) 是由 陈宏衍 郑世恩 于 2021-08-26 设计创作，主要内容包括：本发明提供了一种垃圾焚烧飞灰的处理方法及其固化物,涉及固废环保技术领域。垃圾焚烧飞灰的处理方法包括以下步骤：S100：对垃圾焚烧飞灰进行脱氯处理,获得脱氯飞灰；S200：对所述脱氯飞灰进行固化处理,获得固化物。本发明解决了垃圾焚烧飞灰时获得的固化飞灰耐久性和抗蚀性很差的技术问题,使获得的固化飞灰耐久脱危,且具有抗腐蚀、抗风化、耐高温、抗压强度高的技术效果。(The invention provides a method for treating waste incineration fly ash and a condensate thereof, and relates to the technical field of solid waste environment protection. The treatment method of the waste incineration fly ash comprises the following steps: s100: dechlorinating the waste incineration fly ash to obtain dechlorinated fly ash; s200: and curing the dechlorinated fly ash to obtain a cured substance. The invention solves the technical problem that the durability and corrosion resistance of the solidified fly ash obtained by burning the fly ash of the garbage are poor, so that the obtained solidified fly ash is durable and safe, and has the technical effects of corrosion resistance, weathering resistance, high temperature resistance and high compressive strength.)

1. A method for treating waste incineration fly ash is characterized by comprising the following steps:

s100: dechlorinating the waste incineration fly ash to obtain dechlorinated fly ash;

s200: and curing the dechlorinated fly ash to obtain a cured substance.

2. The processing method according to claim 1, wherein said S100 comprises the steps of:

s110: mixing and stirring the waste incineration fly ash and a solvent to obtain a fly ash-solvent mixture;

s120: and carrying out solid-liquid separation on the fly ash-solvent mixture to obtain the dechlorinated fly ash subjected to dechlorination treatment.

3. The processing method according to claim 2, wherein, after the S120, the S100 further comprises the steps of:

s130: drying the dechlorinated fly ash obtained through the S120 so that a water content of the dechlorinated fly ash is less than or equal to 10%.

4. The processing method according to claim 1, characterized in that before the S200, the processing method further comprises the steps of:

s300: adjusting the proportion of the dechlorinated fly ash obtained by the S100 so that the mass ratio of silicon oxide to aluminum oxide in the dechlorinated fly ash is (27-35): (17-25);

wherein the S200 comprises: and (3) performing solidification treatment on the dechlorinated fly ash obtained in the S300 to obtain the solidified substance.

5. The processing method according to any one of claims 1 to 4, wherein the S200 comprises the steps of:

s210: mixing and stirring the dechlorinated fly ash and an additive to obtain a fly ash-additive mixture; the additive comprises an alkaline catalyst and an additive;

s220: and carrying out compression molding on the fly ash-additive mixture to obtain the cured object subjected to curing treatment.

6. The treatment method according to claim 5, wherein the alkaline catalyst comprises one or more of sodium silicate, sodium hydroxide and potassium hydroxide, and the addition amount of the alkaline catalyst is 2-7% of the total mass of the silicon oxide and the aluminum oxide in the dechlorinated fly ash adopted in the S200.

7. The treatment method of claim 5, wherein the admixture comprises:

sodium silicate, the addition amount of which is 3% -5% of the total mass of silicon oxide and aluminum oxide in the dechlorination fly ash adopted in the S200; and/or the presence of a gas in the gas,

urea, wherein the addition amount of the urea is 1-3% of the total mass of silicon oxide and aluminum oxide in the dechlorination fly ash adopted in the S200; and or (b) a,

the permeable crystallization type waterproof material comprises a silicon-based permeable crystallization type water aqua, and the addition amount of the silicon-based permeable crystallization type water aqua is 0.1-0.7% of the total mass of silicon oxide and aluminum oxide in dechlorinated fly ash adopted by S200; the silicon-based permeable crystallization type water aqua is diluted by water for use.

8. The process according to claim 5, wherein the fly ash-additive mixture is compacted by mechanical pressing under a pressure of 25MPa for 8 s.

9. The process of claim 1, wherein the dechlorinated fly ash further comprises: sodium oxide, the sodium oxide content being 2-10% of the dechlorinated fly ash; potassium oxide, the potassium oxide content is 1% -5% of the dechlorinated fly ash; calcium oxide, the content of the calcium oxide is 30% -40% of the dechlorinated fly ash; magnesium oxide, wherein the content of the magnesium oxide is 1% -5% of the dechlorinated fly ash; iron oxide, the iron oxide content being 2-10% of the dechlorinated fly ash.

10. A cured product obtained by the treatment method according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of solid waste environment protection, in particular to a method for treating waste incineration fly ash.

Background

The waste incineration fly ash refers to the trapped matters of a flue gas purification system and the bottom ash settled at the bottom of a flue and a chimney, contains harmful substances such as dioxin, heavy metal and the like, and endangers the environmental ecology and the human health if the harmful substances are not scientifically treated. Therefore, the waste incineration fly ash must be subjected to a necessary stabilization and solidification treatment in the place where the waste incineration fly ash is produced, and the waste incineration fly ash can be transported after the stabilization and solidification treatment, and a special transport means must be used for transportation.

At present, two methods of safe landfill and cement kiln synergy are mainly used for treating the fly ash, but the methods are not satisfactory. The former occupies the land and has the disadvantages of secondary environmental pollution; the latter is limited by seasons, the consumption rate is low, and the quality of cement is reduced. In addition, a method for solidifying the fly ash by adopting cement is also provided, the cement solidification technology is to seal the toxic factors in the fly ash by using the cement so as to prevent the pollution to the external environment, the treatment cost is low, and the cement solidification technology has good stabilizing effect on heavy metals in the fly ash. However, since the cement is cured to generate pores, when the environment is humid, moisture is merged into the cured material through the pores, excessive water-soluble chloride ions in the cured material are combined with free water to corrode the cured material from the inside, the physical strength of the cured material is reduced, the durability and corrosion resistance of the cured material are poor, a risk factor can break cocoons to cause pollution to the ecological environment, and the cement curing technology cannot achieve a good curing effect on fly ash.

Therefore, how to treat the waste incineration fly ash needs to be solved urgently, and the development of a curing technology for durably removing the danger of the waste incineration fly ash is particularly important.

Disclosure of Invention

The invention solves the technical problem that the durability and corrosion resistance of the solidified fly ash obtained by solidifying the waste incineration fly ash by using cement are poor, realizes cement-free solidification by carrying out dechlorination on the fly ash in advance and then solidifying the dechlorinated fly ash by using the additive, ensures that the obtained solidified fly ash is durable and dangerous, and has the technical effects of corrosion resistance, weathering resistance, high temperature resistance and high compressive strength.

In order to solve the above problems, the present invention provides a method for treating fly ash from waste incineration, comprising the following steps:

s100: dechlorinating the waste incineration fly ash to obtain dechlorinated fly ash;

s200: and (3) carrying out solidification treatment on the dechlorinated fly ash to obtain a solidified substance.

Compared with the prior art, the technical scheme of the invention can achieve the following effects: because the fly ash contains excessive water-soluble chloride ions, when the environment is humid, water and the solidified fly ash can form soluble chloride salt, the soluble chloride salt has corrosiveness, the physical strength of a solidified substance can be reduced, the solidified substance can generate a cavity phenomenon, the solidified substance is finally disintegrated under the natural action of dry-wet circulation and freeze-thaw of the environment, and the existence of the water-soluble chloride ions in the fly ash can not achieve a good solidification effect in a solidification treatment technology. The invention carries out dechlorination treatment on chloride ions contained in the waste incineration fly ash in advance, thereby avoiding that the chloride ions are combined with free water in the later period to form a solidified body from the inside to affect the solidification effect, ensuring that the obtained solidified body has good corrosion resistance effect, and improving the durability of the solidified body.

In one example of the present invention, S100 comprises the steps of:

s110: mixing and stirring the waste incineration fly ash and a solvent to obtain a fly ash-solvent mixture;

s120: and carrying out solid-liquid separation on the fly ash-solvent mixture to obtain dechlorinated fly ash subjected to dechlorination treatment.

Compared with the prior art, the technical scheme has the following technical effects: the solvent can dissolve water-soluble chloride ions in the waste incineration fly ash, the mixing speed of the waste incineration fly ash and the solvent can be increased by stirring the waste incineration fly ash and the solvent, the chloride ions are dissolved in the solvent more quickly, and the dechlorination efficiency is improved. The solidified fly ash finally obtained has no chloride ions by transferring the destructive water-soluble chloride ions in the fly ash, thereby improving the corrosion resistance of the solidified fly ash. After the solid-liquid separation is carried out on the fly ash-solvent mixture, the solid is dechlorinated fly ash, the operation is simple and convenient, and the realization is easy. The chlorine-containing waste liquid obtained after solid-liquid separation is separately recycled, and the treated solution can be further used for dissolving waste incineration fly ash, so that the resource recycling is realized, and the environment is protected.

In one example of the present invention, after S120, S100 further includes the steps of:

s130: the dechlorinated fly ash obtained through S120 is subjected to a drying process so that the moisture content of the dechlorinated fly ash is less than or equal to 10%.

Compared with the prior art, the technical scheme has the following technical effects: because the water required by the subsequent curing treatment is only less than 10 percent of the cured body, the oxyhydrogen element of the water is converted into one component of the macromolecular salt in a hydroxyl form and is not separated out any more, so that the cured fly ash obtained by the curing treatment has high density and volume weight per M³And the compressive strength is high when the temperature is higher than 2T. And the invention providesThe embodiment adopts dry processing, the water content of the material is less than or equal to 10 percent, the initial setting and final setting time of the solidified fly ash is short, the solidification time is shortened, and the solidification efficiency is improved.

In one example of the present invention, before S200, the processing method further includes the steps of:

s300: the proportion of the dechlorinated fly ash obtained by S100 is adjusted, so that the mass ratio of silicon oxide to aluminum oxide in the dechlorinated fly ash is (27-35): (17-25);

wherein, S200 includes: the dechlorinated fly ash obtained in S300 is subjected to a curing treatment to obtain a cured product.

Compared with the prior art, the technical scheme has the following technical effects: dechlorinated fly ash contains various types of metal substances, wherein the silicon-aluminum oxide can improve the mechanical strength and compressive strength of a condensate. As the solidification treatment of the invention is carried out by the chemical reaction of dechlorination fly ash and additive, the mass ratio of silicon oxide to aluminum oxide is adjusted to (27-35) to (17-25), so that the heavy metal substances and the additive can react more fully, the effect of the solidification treatment on the fly ash can be optimal, and the obtained solidified substance is more stable.

In one example of the present invention, S200 comprises the steps of:

s210: mixing and stirring dechlorinated fly ash and an additive to obtain a fly ash-additive mixture; the additive comprises an alkaline catalyst and an additive;

s220: and (3) performing compression molding on the fly ash-additive mixture to obtain a cured object subjected to curing treatment.

Compared with the prior art, the technical scheme has the following technical effects: the fly ash is treated by a cement curing technology, the consumption of cement for curing is not less than 10 percent of that of cured materials, the capacity of the cured materials is increased, and the subsequent disposal cost is increased. The invention adopts cement-free solidification to the dechlorination fly ash solidification treatment, and realizes the durable danger elimination of the fly ash by a method of early dechlorination and cement-free solidification. Because no cement is used, the carbon emission generated by cement production is reduced for the society, the pollution to the environment is reduced, and the environment is more environment-friendly. And the addition of the additive can not lead to the capacity increase of a solidified body, and the subsequent treatment is convenient. Through the chemical reaction of the alkaline catalyst, the additive and dechlorinated fly ash, the heavy metal in the fly ash can be converted into a stable component of a high molecular compound, wherein chemical bonds of silicon and aluminum oxides are firstly decomposed and then recombined to form tetrahedral structural units of the non-metal high molecular compound to form a three-dimensional network structure. The recombination of the crystalline phase ensures that the solidified fly ash has excellent mechanical characteristics and has the advantages of acid and alkali resistance, weather resistance, high temperature resistance, high freezing and thawing property and high compressive strength. Therefore, the waste incineration fly ash is solidified through chemical reaction, the purpose of cement-free solidification is achieved, the solidification speed is high, the solidification effect is good, dechlorination fly ash and additives can be fully mixed by stirring the dechlorination fly ash and the additives, the reaction is full, the reaction speed is accelerated, the reaction time is shortened, and the working efficiency is improved.

In one embodiment of the present invention, the alkaline catalyst comprises one or more of sodium silicate, sodium hydroxide and potassium hydroxide, and the amount of the alkaline catalyst added is 2-7% of the total mass of the silicon oxide and the aluminum oxide in the dechlorinated fly ash used in S200.

Compared with the prior art, the technical scheme has the following technical effects: the alkaline catalyst can promote the chemical reaction between the silicon-aluminum oxide in the dechlorination fly ash and the additive, improve the reaction rate, shorten the fly ash solidification treatment time and reduce the time cost, and when the addition amount of the alkaline catalyst is 2-7% of the mass of the waste incineration fly ash, the catalytic effect of the alkaline catalyst is optimal.

In one embodiment of the invention, the admixture comprises:

the addition amount of the sodium silicate is 3 to 5 percent of the total mass of silicon oxide and aluminum oxide in the dechlorination fly ash adopted in the S200; and/or the presence of a gas in the gas,

urea, wherein the addition amount of the urea is 1-3% of the total mass of silicon oxide and aluminum oxide in the dechlorination fly ash adopted in the S200; and or (b) a,

the permeable crystallization type waterproof material comprises a silicon-based permeable crystallization type water agent, and the addition amount of the silicon-based permeable crystallization type water agent is 0.1-0.7% of the total mass of silicon oxide and aluminum oxide in dechlorination fly ash adopted in S200; the silicon-based permeable crystallization type water aqua is diluted by water for use.

Compared with the prior art, the technical scheme has the following technical effects: the sodium silicate can be dissolved in water, the dissolving speed is high, the aqueous solution is alkaline, and the sodium silicate has strong adhesiveness, can improve the adhesiveness inside a cured product, and can improve the strength of the cured product. Under the natural action of environmental dry-wet cycle and freeze-thaw, the cured product has stable structure and is not easy to disintegrate. Urea can generate urea-formaldehyde resin under the condition of polymerization in an alkaline environment, and the generated urea-formaldehyde resin is fused in a condensate structure, so that the durability of the condensate can be improved. The material molecules of the silicon-based permeable crystallization type water aqua are retained in the alkaline building material, and when the building material permeates into the capillary pores when meeting water, the material can generate chemical reaction with the alkaline aggregate when meeting free water to generate new crystals to block the capillary pores, thereby achieving the aim of water prevention. The silicon-based permeable crystallization type water aqua is diluted by water and then is uniformly sprayed on dechlorinated fly ash, so that cured materials after curing treatment have good waterproof performance and are not easy to be corroded by water.

In one embodiment of the present invention, the fly ash-additive mixture is pressed by mechanical pressing under a static pressure of 25MPa for 8 s.

Compared with the prior art, the technical scheme has the following technical effects: the heavy metal precipitation in the condensate can be reduced by using the chelating agent to solidify the fly ash, but the strength of the fly ash cannot be improved, the fly ash cannot be recycled, and the condensate can only be stacked in a concentrated manner and occupies the land. The fly ash-additive mixture obtained in the embodiment of the invention is the original material of the cured substance, and after reprocessing, various construction materials with safety, environmental protection and good physicochemical properties can be manufactured, so that resource utilization is realized, economic benefits can be generated, and the fly ash curing process has more sustainable development property because the fly ash-additive mixture does not occupy land in a centralized manner.

In one example of the present invention, dechlorinated fly ash further comprises: sodium oxide with a content of 2-10% of dechlorinated fly ash; potassium oxide with a content of 1-5% of dechlorinated fly ash; calcium oxide with a content of 30-40% of dechlorinated fly ash; magnesium oxide with a content of 1-5% of dechlorinated fly ash; the content of the iron oxide is 2-10% of dechlorinated fly ash.

Compared with the prior art, the technical scheme has the following technical effects: dechlorinated fly ash contains abundant metal substances, and can enhance the physical strength and stability of cured materials.

In another aspect, embodiments of the present invention also provide a cured product obtained by the treatment method according to any one of the embodiments of the present invention.

Compared with the prior art, the technical scheme has the following technical effects: the condensate is obtained by a cement-free curing method, the waste incineration fly ash is dechlorinated in advance, the corrosion action of chloride ions on the condensate is avoided, the waste incineration fly ash is cured by a chemical additive, and the silicon-aluminum oxide in the fly ash becomes a stable component of a high molecular compound through the chemical reaction, so that the condensate has excellent mechanical properties and the advantages of corrosion resistance, weathering resistance, high temperature resistance and high compressive strength.

Drawings

Fig. 1 is a flow chart of a method for treating fly ash from waste incineration according to an embodiment of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

The first embodiment is as follows:

referring to fig. 1, the present embodiment provides a method for treating fly ash from waste incineration, including the following steps:

s10: and (4) dechlorinating treatment. Taking 20kg of waste incineration fly ash, mixing with water and stirring to obtain a fly ash-water mixture;

s20: and (4) solid-liquid separation. Performing solid-liquid separation on the fly ash-water mixture to obtain dechlorinated fly ash subjected to dechlorination, and recycling and treating chlorine-containing wastewater;

s30: and (5) drying. Drying the dechlorinated fly ash by using a dryer until the moisture content is 9%;

s40: and (4) adjusting the mixture ratio. And (3) analyzing the components of the dried dechlorinated fly ash, and analyzing to obtain that the mass ratio of silicon oxide to aluminum oxide is 23.3:7.25, and the aluminum element is added by 10% to enable the dechlorinated fly ash to meet the requirement of a curing ratio when the mass ratio of the silicon oxide to the aluminum oxide is not met and the dechlorinated fly ash can fully react with the additive when the mass ratio of the silicon oxide to the aluminum oxide is (27-35): 17-25). After the aluminum element is supplemented, the mass ratio of the silicon oxide to the aluminum oxide is 23.3: 17.25.

S50: and (5) curing treatment. The dechlorination fly ash after the proportion adjustment is mixed and stirred with additives, wherein the additives are an alkali catalyst and an additive. The alkali catalyst is sodium hydroxide with an addition amount of 3.5% of the total amount of silicon oxide and aluminum oxide, and is pulverized to μm level with specific surface area greater than 350m²(ii) in terms of/g. The additive is silicon-based permeable crystallization type water agent, the addition amount of the silicon-based permeable crystallization type water agent is 0.1 percent of the total amount of silicon oxide and aluminum oxide, the silicon-based permeable crystallization type water agent is diluted by 15 times by adding water, and the silicon-based permeable crystallization type water agent is uniformly sprayed on dechlorination fly ash. Stirring the additive and dechlorinated fly ash, mixing and stirring for 15 minutes at the rotating speed of 450 revolutions per minute, mechanically pressurizing the fly ash-additive mixture, and carrying out static pressure maintaining for 8 seconds under the pressure condition of 25Mpa to carry out compression molding to obtain a cured substance.

It is worth to be noted that the fly ash contains a large amount of water-soluble chloride ions, so that water is selected as a solvent in the dechlorination treatment, and the chloride ions can be well dissolved in the water to achieve a good dechlorination effect. The chlorine ions contained in the waste incineration fly ash are dechlorinated in advance, so that the phenomenon that the solidification body is combined with free water in the later stage and is silkworm-transformed from the inside to influence the solidification effect is avoided, and the obtained solidified fly ash has good corrosion resistance.

The chlorine-containing wastewater is subjected to reclaimed water reuse treatment, and the purified water obtained after treatment can be reused for dechlorination, so that the waste of water resources is reduced, and the method is more environment-friendly.

The dechlorination fly ash is dried until the water content is 9 percent, so that the initial setting and final setting time of the solidified fly ash are short, the solidification time is shortened, and the solidification efficiency is improved.

Sodium hydroxide and a silicon-based permeable crystallization type water aqua are selected as additives to solidify the dechlorinated fly ash, so that chemical bonds of silicon and aluminum oxides are decomposed and then recombined to form a three-dimensional network structure consisting of tetrahedral structural units of a non-metal high molecular compound. The obtained solidified fly ash has excellent mechanical characteristics, acid and alkali resistance and weather resistance due to the recombination of the crystalline phase. Meanwhile, the obtained solidified fly ash has high compressive strength, high freeze-thaw performance, corrosion resistance and high temperature resistance.

The dried dechlorinated fly ash was subjected to composition analysis to obtain a mixture containing 23.3% silica, 7.25% alumina, 2.55% ferric oxide, 32.6% calcium oxide, and 2.03% magnesium oxide.

And (3) reprocessing the fly ash-additive mixture obtained in the step, wherein the water content of the fly ash-additive mixture is 11.8% during processing, and detecting the compressive strength of the fly ash-additive mixture after pressure forming.

In addition, a control group 1 is set, the control group 1 is solidified by cement, the addition amount of the cement is 15% of the waste incineration fly ash, the solidified fly ash obtained by solidifying 15% of the cement is reprocessed, and the compressive strength of the solidified fly ash is detected after compression molding.

The results of the measurements of the compressive strength of the solidified fly ash obtained by the present invention and the solidified fly ash obtained by using 15% cement are shown in table 1.

TABLE 1

As can be seen from table 1, the compression strength of the solidified fly ash obtained by the method for treating waste incineration fly ash provided in this example after being subjected to pressure molding is higher than that of the solidified fly ash obtained by curing with 15% cement, and the compression strength of the solidified fly ash of control group 1 after being molded is lower, and thus the solidified fly ash cannot be recycled well. Therefore, the fly ash solidification treatment method provided by the embodiment is superior to the cement solidification treatment technology. The solidified fly ash obtained in the embodiment can be stacked and maintained after being maintained for 24 hours at normal temperature, can be loaded and transported after 72 hours, and has the compressive strength of 20MPa after 7 days, so that the construction material prepared from the solidified fly ash can be normally constructed. On the other hand, the present example provides a solidified fly ash exhibiting a tendency to increase in compressive strength over time.

In addition, the solidified fly ash obtained in the embodiment is tested for anti-freezing performance, and the testing method refers to JGJ/T70-2009.

After 200 times of freeze thawing detection, the obtained fixed fly ash has no damage phenomena such as layering, cracking, through seams and the like, so the fixed fly ash has high freeze thawing performance and strong weather resistance.

Example two:

referring to fig. 1, the present embodiment provides a method for treating fly ash from waste incineration, including the following steps:

s10: and (4) dechlorinating treatment. Taking 25kg of waste incineration fly ash, mixing with water and stirring to obtain a fly ash-water mixture;

s20: and (4) solid-liquid separation. Performing solid-liquid separation on the fly ash-water mixture to obtain dechlorinated fly ash subjected to dechlorination, and recycling and treating chlorine-containing wastewater;

s30: and (5) drying. Drying the dechlorinated fly ash by using a dryer until the moisture content is 10%;

s40: and (4) adjusting the mixture ratio. The components of the dechlorinated fly ash after drying are analyzed, the main components are shown in Table 2, the mass ratio of silicon oxide to aluminum oxide is 20.5:5.8, and the silicon oxide to aluminum oxide does not meet the requirement of curing ratio of (27-35): (17-25), 5% of silicon element and 12% of aluminum element are required to be added, so that the silicon oxide and aluminum oxide meet the requirement of curing ratio and can fully react with additives. After the silicon element and the aluminum element are supplemented, the mass ratio of the silicon oxide to the aluminum oxide is 25.5: 17.8.

S50: and (5) curing treatment. The dechlorination fly ash after the proportion adjustment is mixed and stirred with additives, wherein the additives are an alkali catalyst and an additive. The additive is alkali catalyst and additive. The alkali catalyst is selected from sodium silicate powder, and the addition amount of the sodium silicate powder is 5 percent of the total amount of silicon oxide and aluminum oxide; and sodium hydroxide in an amount of 0.5% based on the total amount of silicon oxide and aluminum oxide, and pulverizing them into a size of μmThe surface area is more than 350m²(ii) in terms of/g. The additive is silicon-based permeable crystallization type water agent, the addition amount of the silicon-based permeable crystallization type water agent is 0.1 percent of the total amount of silicon oxide and aluminum oxide, the silicon-based permeable crystallization type water agent is diluted by 15 times by adding water, and the silicon-based permeable crystallization type water agent is uniformly sprayed on dechlorination fly ash. Stirring the additive and dechlorinated fly ash, mixing and stirring for 15 minutes at the rotating speed of 450 revolutions per minute, mechanically pressurizing the fly ash-additive mixture, and carrying out static pressure maintaining for 8 seconds under the pressure condition of 25Mpa to carry out compression molding to obtain a cured substance.

It is worth to say that the dechlorinated fly ash is dried until the water content is 10%, so that the initial setting time and the final setting time of the solidified fly ash are short, the solidification time is shortened, and the solidification efficiency is improved.

The alkali catalyst adopts dry powder sodium silicate and sodium hydroxide, wherein the dry powder sodium silicate is used as an activator, the strength of the solid fly ash can be ensured, the sodium hydroxide is used as a reinforcing agent, the porosity of the solidified fly ash is reduced, and the dry powder sodium silicate and the sodium hydroxide accelerate the chemical reaction; the additive is silicon-based permeable crystallization type water aqua to enhance the waterproof performance of the solidified fly ash. The alkali catalyst and the additive are used as additives to solidify the dechlorinated fly ash, so that chemical bonds of silicon and aluminum oxides are decomposed and then recombined to form tetrahedral structural units of the non-metal high molecular compound to form a three-dimensional network structure. The recombination of the crystalline phases ensures that the obtained condensate has excellent mechanical properties, and is acid-base resistant and weather resistant. Meanwhile, the obtained solidified fly ash has high compressive strength, high freezing and thawing performance, corrosion resistance, high temperature resistance and good waterproof performance.

TABLE 2

And (3) reprocessing the fly ash-additive mixture obtained in the step, wherein the water content of the fly ash-additive mixture is 12.5% during processing, and detecting the compressive strength of the fly ash-additive mixture after pressure forming.

In addition, a control group 2 is arranged, the control group 2 is solidified by cement, the addition amount of the cement is 10% of the waste incineration fly ash, the solidified fly ash obtained by solidifying 10% of the cement is reprocessed, and the compressive strength of the solidified fly ash is detected after compression molding.

The results of the measurements of the compressive strength of the solidified fly ash obtained by the present invention and the solidified fly ash obtained by using 10% cement are shown in table 2.1.

TABLE 2.1

As can be seen from table 2.1, the compression strength of the solidified fly ash obtained by the method for treating waste incineration fly ash provided in this example after pressure molding is higher than that of the solidified fly ash obtained by 10% cement curing, and the compression strength of the solidified fly ash of control group 2 after molding is lower, and thus it cannot be well reused. Therefore, the fly ash solidification treatment method provided by the embodiment is superior to the cement solidification treatment technology. The solidified fly ash obtained in the embodiment can be stacked and maintained after being maintained for 24 hours at normal temperature, and can be loaded and transported after 72 hours, and the compressive strength can reach 16MPa after 7 days. On the other hand, the present example provides a solidified fly ash exhibiting a tendency to increase in compressive strength over time.

In addition, the solidified fly ash obtained in the embodiment is tested for anti-freezing performance, and the testing method refers to JGJ/T70-2009.

After 200 times of freeze thawing detection, the obtained fixed fly ash has no damage phenomena such as layering, cracking, through seams and the like, so the fixed fly ash has high freeze thawing performance and strong weather resistance.

Example 3:

referring to fig. 1, the present embodiment provides a method for treating fly ash from waste incineration, including the following steps:

s10: and (4) dechlorinating treatment. Taking 25kg of waste incineration fly ash, mixing with water and stirring to obtain a fly ash-water mixture;

s20: and (4) solid-liquid separation. Performing solid-liquid separation on the fly ash-water mixture to obtain dechlorinated fly ash subjected to dechlorination, and recycling and treating chlorine-containing wastewater;

s30: and (5) drying. Drying the dechlorinated fly ash by using a dryer until the moisture content is 9%;

s40: and (4) adjusting the mixture ratio. The components of the dechlorinated fly ash after drying are analyzed, the main components are shown in Table 3, the mass ratio of silicon oxide to aluminum oxide is 22.3:9.6, and the silicon oxide to aluminum oxide does not meet the requirement of curing ratio of (27-35): (17-25), 5% of silicon element and 11% of aluminum element are required to be added, so that the silicon oxide and aluminum oxide meet the requirement of curing ratio and can fully react with additives. After the silicon element and the aluminum element are supplemented, the mass ratio of the silicon oxide to the aluminum oxide is 27.3: 20.6.

S50: and (5) curing treatment. The dechlorination fly ash after the proportion adjustment is mixed and stirred with additives, wherein the additives are an alkali catalyst and an additive. The additive is alkali catalyst and additive. The alkali catalyst is dry powder potassium hydroxide, and the addition amount of the alkali catalyst is 6 percent of the total amount of silicon oxide and aluminum oxide; and sodium hydroxide in an amount of 1% of the total amount of the silicon oxide and the aluminum oxide, and pulverizing them into a size of μm with a specific surface area of more than 400m²(ii) in terms of/g. The additive is sodium silicate dry powder, and the addition amount of the additive is 1 percent of the total amount of silicon oxide and aluminum oxide. Stirring the additive and dechlorinated fly ash, mixing and stirring for 15 minutes at the rotating speed of 450 revolutions per minute, mechanically pressurizing the fly ash-additive mixture, and carrying out static pressure maintaining for 8 seconds under the pressure condition of 25Mpa to carry out compression molding to obtain a cured substance.

It is worth to say that the dechlorinated fly ash is dried until the water content is 9%, so that the initial setting time and the final setting time of the solidified fly ash are short, the solidification time is shortened, and the solidification efficiency is improved.

The alkali catalyst adopts dry powder potassium hydroxide and sodium hydroxide, wherein the dry powder potassium hydroxide is used as an excitant and can ensure the strength of the solid fly ash, and the sodium hydroxide is used as a reinforcer and reduces the porosity of the solidified fly ash, so that the dry powder potassium hydroxide and the sodium hydroxide accelerate the chemical reaction; the additive adopts sodium silicate dry powder, so that the cohesiveness inside the solidified fly ash can be improved, and the solidified fly ash has a stable structure and is difficult to disintegrate under the natural action of environmental dry-wet circulation and freeze thawing. The alkali catalyst and the additive are used as additives to solidify the dechlorinated fly ash, so that chemical bonds of silicon and aluminum oxides are decomposed and then recombined to form tetrahedral structural units of the non-metal high molecular compound to form a three-dimensional network structure. The obtained solidified fly ash has excellent mechanical characteristics, acid and alkali resistance and weather resistance due to the recombination of the crystalline phase. Meanwhile, the obtained solidified fly ash has high compressive strength, high freezing and thawing performance, corrosion resistance, high temperature resistance and good waterproof performance.

TABLE 3

And (3) reprocessing the fly ash-additive mixture obtained in the step, wherein the water content of the fly ash-additive mixture is 13.5% during processing, and detecting the compressive strength of the fly ash-additive mixture after pressure forming.

In addition, a control group 3 is set, the control group 3 is solidified by cement, the addition amount of the cement is 10% of the waste incineration fly ash, the solidified fly ash obtained by solidifying 10% of the cement is reprocessed, and the compressive strength of the solidified fly ash is detected after compression molding.

The results of the measurements of the compressive strength of the solidified fly ash obtained by the present invention and the solidified fly ash obtained by using 10% cement are shown in table 3.1.

TABLE 3.1

As can be seen from table 3.1, the compression strength of the solidified fly ash obtained by the method for treating waste incineration fly ash provided in this example after being pressurized and molded is higher than that of the solidified fly ash obtained by curing with 10% cement, and the compression strength of the solidified fly ash of control group 3 after being molded is lower, and thus the solidified fly ash cannot be recycled well. Therefore, the fly ash solidification treatment method provided by the embodiment is superior to the cement solidification treatment technology. The solidified fly ash obtained in the embodiment can be stacked and maintained after being maintained for 24 hours at normal temperature, can be loaded and transported after 72 hours, and has the compressive strength of 20MPa after 7 days and 30MPa after 28 days. On the other hand, the present example provides a solidified fly ash exhibiting a tendency to increase in compressive strength over time. Therefore, the solidified fly ash obtained in the embodiment is pressurized, formed and cultured, so that various construction materials with safety, environmental protection and good physical and chemical properties can be prepared, and the construction materials have the advantages of the solidified fly ash, namely high compressive strength, acid and alkali resistance, weathering resistance, corrosion resistance, high temperature resistance and good waterproof performance, and can be well applied to actual production and life. Meanwhile, the fly ash is made into construction materials, so that waste is changed into valuable, danger elimination is durable, and pollution to the environment is avoided.

In addition, the solidified fly ash obtained in the embodiment is tested for anti-freezing performance, and the testing method refers to JGJ/T70-2009.

After 200 times of freeze thawing detection, the obtained fixed fly ash has no damage phenomena such as layering, cracking, through seams and the like, so the fixed fly ash has high freeze thawing performance and strong weather resistance.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.