A method for treating fly ash

Abstract

This invention discloses a method for treating fly ash, comprising the following steps: mixing fly ash with one or more metal oxides selected from ZnO and MgO to obtain a mixture, and then subjecting the mixture to high-temperature melting treatment; the amount of metal oxide added accounts for 15% to 25% of the mass of the mixture; the temperature of the high-temperature melting treatment is 1000 ℃ to 1400 ℃; the time of the high-temperature melting treatment is 2 h to 6 h; and the heating rate of the high-temperature melting treatment process is 5 ℃ / min to 20 ℃ / min. The addition of metal oxides can promote the removal of heavy metals or chlorine from the fly ash and obtain a stable solid-phase product with a compact structure and high strength, which is conducive to the harmless utilization of fly ash; furthermore, this treatment method is simple, environmentally friendly, and safe.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection, and in particular to a fly ash treatment method, and further to a fly ash treatment method for domestic waste incineration. Background Art

[0002] The incineration process of domestic waste will produce incineration ash, which includes bottom ash and fly ash. The properties of the two are quite different. Bottom ash generally contains Si and high heavy metal content; fly ash contains higher levels of heavy metals, dioxins and homologues, and is more harmful, so it needs to be stabilized and rendered harmless.

[0003] At present, the main treatment methods for fly ash include separation treatment and solidification and stabilization treatment. Among them, separation treatment includes acid extraction and alkali extraction, but this type of treatment method will produce a large amount of waste acid and waste alkali, increasing the treatment cost; solidification and stabilization treatment includes cement solidification, solidification landfill, high-temperature melting solidification, etc. Among them, cement solidification and solidification landfill generally occupy a large area, and high-temperature melting solidification can greatly reduce the hazard of fly ash, and has good volume reduction and weight reduction effects. The solid solution produced can also be used at a high value, so it is currently a more commonly used fly ash treatment method. However, the current high-temperature melting treatment method for fly ash still has the problem of high chlorine residue or low heavy metal volatilization rate. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a fly ash treatment method, which aims to solve the problem of high chlorine residue or low heavy metal volatilization rate in the current high-temperature melting method for treating fly ash.

[0005] The present invention proposes a fly ash treatment method, comprising the following steps:

[0006] S1. Mixing fly ash with metal oxides to obtain a mixture; the metal oxides are selected from one or more of ZnO and MgO;

[0007] S2, subjecting the mixed material to high temperature melting treatment;

[0008] The amount of the metal oxide added accounts for 15% to 25% of the mass of the mixture;

[0009] The temperature of the high temperature melting treatment is 1000°C to 1400°C;

[0010] The high temperature melting treatment time is 2h to 6h;

[0011] The heating rate of the high temperature melting treatment process is 5°C / min to 20°C / min.

[0012] The fly ash treatment method according to the embodiment of the present invention has at least the following beneficial effects: the fly ash treatment method mixes fly ash with specific metal oxides and performs high-temperature melting treatment. The addition of metal oxides can promote the removal of heavy metals or chlorine in the fly ash, and the volume reduction effect is obvious and the efficiency is high. A stable solid phase product can be obtained. The solid phase product has a compact structure and high strength, which is conducive to the harmless utilization of fly ash. In addition, the method has a simple process and is environmentally friendly and safe.

[0013] Among them, the role of metal oxides in promoting the removal of heavy metals and chlorine from fly ash during high-temperature melting treatment is partly due to the fact that, during the high-temperature melting treatment, metal oxides can form a network structure with the calcium-containing phase in the fly ash, which can make unstable chlorides more easily destroyed and thus promote the removal of chlorine; and some metal oxides can occupy the metal position in the molecular structure of the original metal chlorides and other compounds, thereby promoting the removal of heavy metals from fly ash.

[0014] In some embodiments of the present invention, the metal oxide specifically uses ZnO. After adding ZnO, the removal effect of chlorine in fly ash can be greatly improved, and the obtained product has a dense structure and a ceramic luster on the surface.

[0015] In some embodiments of the present invention, the added amount of the metal oxide may account for 15% to 20%, 14% to 22%, 16% to 18%, 17% to 22%, 18% to 24%, 20% to 25% or 22% to 24% of the mass of the mixture.

[0016] In step S2, the high temperature melting treatment is generally to heat the material to a predetermined temperature at a predetermined heating rate and then keep the temperature at a predetermined temperature for a predetermined time. In some embodiments of the present invention, the temperature of the high temperature melting treatment (i.e., the holding temperature) is 1100°C to 1400°C, 1200°C to 1400°C, 1250°C to 1350°C, or 1300°C to 1400°C.

[0017] In some embodiments of the present invention, the time of the high temperature melting treatment (ie, the holding time) is 2.5 h to 5.5 h, 3 h to 6 h, 3.5 h to 5.5 h, 4 h to 6 h, 4.5 h to 5.5 h or 5 h to 6 h.

[0018] In some embodiments of the present invention, the heating rate of the high temperature melt treatment process is 5°C / min to 10°C / min, 8°C / min to 12°C / min, 10°C / min to 15°C / min, 12°C / min to 16°C / min, 14°C / min to 18°C / min, 15°C / min to 20°C / min or 16°C / min to 18°C / min.

[0019] In some embodiments of the present invention, the fly ash is dried before being mixed with the additive, wherein the fly ash may be cooled and weighed every half an hour during the drying process, and specifically dried until there is no obvious mass difference between two consecutive weighings.

[0020] In some embodiments of the present invention, after the fly ash is mixed with the metal oxide, it is further ground and sieved to obtain a mixture. Specifically, since agglomeration may occur during the drying process of the fly ash, after the dried fly ash is mixed with the metal oxide, it is further ground and sieved to ensure that the material is completely sieved, thereby controlling the particle size of the material to be within a particle size range suitable for melting.

[0021] In some embodiments of the present invention, the fly ash is selected from one or more of fly ash from the incineration of domestic waste, fly ash from the incineration of medical waste, and fly ash from the incineration of industrial hazardous waste.

[0022] In some embodiments of the present invention, the fly ash treatment method further comprises: cooling and collecting the flue gas generated during the high temperature melting treatment to obtain secondary ash. Specifically, the flue gas generated during the high temperature melting treatment can be passed through a circulating condensation device for condensation and collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0024] Figure 1 This is a test result diagram of the effect of fly ash sample processing volume on the volatilization rate of heavy metals after high-temperature melting treatment;

[0025] Figure 2 This is a test result diagram of the effect of high temperature melting treatment time on the volatilization rate of heavy metals;

[0026] Figure 3 This is a test result diagram of the effect of high temperature melting treatment temperature on the volatilization rate of heavy metals;

[0027] Figure 4 This is a graph showing the total toxic equivalent ratio and emission reduction rate test results of dioxin homologues in the fly ash from incineration of domestic waste before treatment and the solid solution of fly ash obtained after treatment in Comparative Example 6;

[0028] Figure 5 This is the XRD spectrum of the additive ZnO and the product fly ash solid solution in Example 1. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0030] The embodiments and comparative examples of the present invention are described by taking waste incineration fly ash as an example. In the experimental process, the inventor first conducted an experiment using waste incineration fly ash as the treatment object, and conducted a single factor experiment on the effects of sample treatment volume, high-temperature melting treatment time and temperature on the volatilization rate of heavy metals to determine more suitable treatment conditions.

[0031] Specifically, the waste incineration fly ash is first subjected to a high-temperature melting treatment, and the solid product obtained by the treatment is leached, crushed, and ground, and then the heavy metal and chlorine removal effect test is carried out according to the chlorine content test standard and the heavy metal digestion step to examine the treatment effect of the above fly ash treatment method. According to this method, a single-factor experiment is carried out by adjusting the sample processing volume, as well as the time and temperature of the high-temperature melting treatment, and the treatment conditions are determined in combination with the actual production. Furthermore, on the basis of the single-factor experimental treatment method, metal oxides are added to the waste incineration fly ash and mixed, and then a high-temperature melting treatment is carried out, and then the heavy metal and chlorine removal effect test is carried out to explore and verify the scheme of the present invention.

[0032] Some experiments and results conducted by the inventors in the actual research process are listed below to further illustrate the scheme of the present invention in detail.

[0033] The fly ash used was from a domestic waste incineration treatment plant in Guizhou, and the specific composition is shown in Table 1.

[0034] Table 1: Main metal and chlorine content in fly ash from municipal solid waste incineration

[0035]

[0036] 1. Determination of the treatment volume of fly ash from incineration of domestic waste

[0037] Comparative Example 1

[0038] A fly ash treatment method, the fly ash treatment method comprising the following steps:

[0039] S1. Take 40 g of fly ash from the incineration of domestic waste and dry it in a constant temperature box, then grind it and pass it through a 60-mesh sieve, and ensure that the fly ash is completely sieved;

[0040] S2. Add the material after the treatment in step S1 into a 100 mL corundum crucible, use a high-temperature melting furnace as a reactor, and raise the temperature to 1400°C at a heating rate of 10°C / min through program temperature control, and then keep it at 1400°C for 2 h; after cooling, take out the product fly ash solid solution.

[0041] The fly ash from the incineration of domestic waste before treatment and the solid solution of the fly ash obtained after treatment were completely digested, and the ion concentration in the solution of the digestion solution was determined by ICP-OES, and the chlorine removal effect in the solid solution was determined by HPIC. It was calculated that the total chlorine removal efficiency was 84.33%, the soluble chlorine removal rate was 92.57%, and the heavy metal volatilization rates were 94.41% for Cu, 93.47% for Pb, 100% for Cd, and 64.14% for Zn.

[0042] Comparative Examples 2 to 5

[0043] Based on Comparative Example 1, the inventor conducted a single factor experiment on the effect of the treatment amount of domestic waste incineration fly ash on the volatilization rate of heavy metals. Specifically, Comparative Examples 2 to 5 took 10 g, 20 g, 30 g, and 50 g of domestic waste incineration fly ash, respectively, and treated the domestic waste incineration fly ash according to the treatment method in Comparative Example 1 to obtain the product fly ash solid solution.

[0044] The chlorine removal effect in the fly ash solid solution of the product in Comparative Example 2 was determined by HPIC, and the domestic waste incineration fly ash before treatment and the fly ash solid solution obtained after treatment of Comparative Examples 2 to 5 were completely digested, and the ion concentration in the solution of the digestion solution was determined by ICP-OES. It was calculated that the total chlorine removal efficiency of Comparative Example 2 was 96.74%, the soluble chlorine removal rate was 98.29%, the heavy metal volatilization rate of Cu was 97.06%, Zn was 78.95%, Pb was 93.59%, and Cd was 94.60%; the volatilization rates of heavy metals Cu, Zn, Pb and Cd in Comparative Examples 2 to 5 and the heavy metal volatilization rate test results of Comparative Example 1 are as shown in FIG. Figure 1 shown.

[0045] Experiments have shown that when the amount of fly ash added to the crucible is too low, the material loses weight after melting, leaving very little solid solution. Since the fly ash adheres tightly to the crucible wall after melting at high temperature, it is difficult to separate.

[0046] Considering that a small amount of fly ash sample can reduce its initial thickness, during high-temperature melting treatment, the fly ash melts and diffuses from the surface to the inside, and the fly ash sample at the bottom melts last. However, melting represents an increase in fluidity, and the solid phase sample gradually becomes a liquid phase component. The heavy metals and chlorine in the bottom material are hindered from volatilizing and escaping through the liquid phase layer. Therefore, the smaller the treatment amount, the better the removal effect of heavy metals and chlorine in the fly ash. However, considering the treatment efficiency of actual production, for the determination of the treatment amount, it will be chosen to treat a larger amount without significantly affecting the removal effect. Furthermore, based on the above, it is determined that the treatment amount of 40g of the fly ash sample from the incineration of domestic waste in Comparative Example 1 is a more suitable treatment amount in the above treatment method.

[0047] (II) Determination of the time for high temperature melting treatment

[0048] Based on the above-determined processing volume of the municipal solid waste incineration fly ash sample, on the basis of the processing method of comparative example 1, the time of the high-temperature melting treatment is further adjusted to examine the effect of the processing time on the volatilization rate of heavy metals, and then determine the processing time of the high-temperature melting treatment.

[0049] Comparative Example 6

[0050] A fly ash treatment method, the difference between this comparative example and comparative example 1 is that: in step S2, the insulation time of 2h in the high-temperature melting treatment in comparative example 1 is adjusted to 6h, and other operations are the same as comparative example 1.

[0051] Specifically, the fly ash treatment method comprises the following steps:

[0052] S1. Take 40 g of fly ash from the incineration of domestic waste and dry it in a constant temperature box, then grind it and pass it through a 60-mesh sieve, and ensure that the fly ash is completely sieved;

[0053] S2. Add the material after the treatment in step S1 into a corundum crucible, use a high-temperature melting furnace as a reactor, and raise the temperature to 1400°C at a heating rate of 10°C / min through program temperature control, and then keep it at 1400°C for 6 hours; after cooling, take out the product fly ash solid solution.

[0054] The fly ash from the incineration of domestic waste before treatment and the solid solution of the fly ash obtained after treatment were completely digested, and the ion concentration in the solution of the digestion solution was determined by ICP-OES, and the removal effect of chlorine in the solid solution was determined by HPIC. It was calculated that the total chlorine removal efficiency was 90.11%, the soluble chlorine removal rate was 96.68%, and the heavy metal volatilization rates were 100% for Cu, 77.93% for Zn, 99.36% for Pb, and 98.23% for Cd.

[0055] Comparative Examples 7 to 9

[0056] The fly ash treatment methods of Comparative Examples 7 to 9 differ from those of Comparative Examples 6 and 1 in that in step S2, the high-temperature melting treatment time is 3 h, 4 h, and 5 h, respectively, and the other operations are the same as those of Comparative Examples 6 and 1, and the product fly ash solid solution is obtained by treatment.

[0057] The domestic waste incineration fly ash before treatment and the product fly ash solid solution obtained after treatment were completely digested, and the ion concentration in the solution of the digestion solution was determined by ICP-OES. The volatility of heavy metals Cu, Zn, Pb and Cd was calculated. The results obtained were similar to the heavy metal volatility test results of Comparative Example 1 and Comparative Example 6. Figure 2 shown.

[0058] According to the test results, as the time of high-temperature melting treatment increases, energy consumption increases, and the volatilization rate of heavy metals increases over time. However, if the insulation time is too long, the energy consumption will be too high, which is not conducive to actual production applications. Therefore, when scaling up and industrializing fly ash treatment, reasonable adjustments can be made according to the fly ash treatment volume.

[0059] (III) Determination of temperature for high temperature melting treatment

[0060] Based on the above, on the basis of the treatment method of comparative example 1, the temperature of high-temperature melting is further adjusted to examine the effect of the treatment temperature on the volatilization rate of heavy metals, and then determine the temperature of high-temperature melting treatment.

[0061] Comparative Examples 10 to 13

[0062] The fly ash treatment methods of Comparative Examples 10 to 13 differ from those of Comparative Example 1 in that, in step S2, the insulation temperature of 1400°C in the high-temperature melting treatment in Comparative Example 1 is adjusted to 1000°C, 1100°C, 1200°C and 1300°C respectively, and the other operations are the same as those in Comparative Example 1, and the product fly ash solid solution is obtained by treatment.

[0063] The domestic waste incineration fly ash before treatment and the product fly ash solid solution obtained after treatment were completely digested, and the ion concentration in the solution of the digestion solution was determined by ICP-OES. The volatility of heavy metals Cu, Zn, Pb and Cd was calculated. The results obtained were similar to the heavy metal volatility test results of Comparative Example 1. Figure 3 shown.

[0064] The test shows that the insulation temperature of the high-temperature melting treatment is too low, which is not conducive to the melting and volatilization of the substances in the fly ash. Since the main phases in the fly ash are CaCO3, CaSO4, CaClOH, NaCl, KCl, etc., the melting and boiling points of the substances are different, and the critical temperatures of thermal decomposition vary greatly. However, when the insulation temperature is around 1300℃, the XRD results show that the removal effect of NaCl and KCl is good, CaCO3 and CaSO4 are completely decomposed, and the characteristic peak of CaO appears.

[0065] Based on the above, it can be seen that when 10g of municipal solid waste incineration fly ash is subjected to high-temperature melting treatment at a holding temperature of 1400℃ and a holding time of 6h, the chlorine removal efficiency in the fly ash can reach more than 90%, or even more than 95%, the volatilization rates of heavy metals Cu, Pb, and Cd are higher than 90%, and the removal rate of heavy metal Zn is higher than 60%, or even close to 80%; and compared with the original fly ash, the product after high-temperature melting treatment is a dense solid solution, and the volume reduction effect (manifested in weight loss and volume collapse) is good, reaching more than 50%.

[0066] In addition, the total toxic equivalent ratio and emission reduction rate of dioxin homologues in the fly ash from incineration of domestic waste before treatment (i.e., original fly ash) and the solid solution of fly ash obtained after treatment (i.e., treated sample) in Comparative Example 6 were tested, and the results were as follows: Figure 4 And as shown in Table 2. Figure 4 (a) is the total toxic equivalent ratio of dioxin homologues in the fly ash from incineration of domestic waste before treatment and in the solid solution of fly ash obtained after treatment; (b) is the emission reduction rate of dioxin-like substances.

[0067] Table 2: Dioxin content in fly ash original sample and treated sample (ng / kg)

[0068]

[0069] Depend on Figure 4 The results show that after the fly ash from the incineration of domestic waste in Comparative Example 6 was treated by high-temperature melting, the PCDFs / PCDDs ratio decreased, and the dioxin toxicity equivalent decreased from 232.73 ng I-TEQ / kg in the original fly ash to 23.17 ng I-TEQ / kg in the solid solution of the product, which is much lower than the 100 ng I-TEQ / kg specified in the national standard. The total removal efficiency exceeded 90%, achieving the maximum detoxification. Among them, the emission reduction rates of T4CDF, P5CDF, H6CDF, H7CDF, and O8CDF were 1.27%, 92.28%, 92.87%, 91.06%, and 93.93%, respectively; the emission reduction rates of P5CDD, H6CDD, H7CDD, and O8CDD were 79.73%, 91.26%, 94.85%, and 98.03%, respectively.

[0070] The results in Table 2 show that the total dioxin toxicity equivalent of the fly ash solid solution after high-temperature melting treatment is 23.179 ng I-TEQ / kg, of which the toxicity equivalent of PCDFs is 12.039 ng I-TEQ / kg, accounting for 51.94% of the total toxicity equivalent, and the toxicity equivalent of PCDDs is 11.14 ng I-TEQ / kg, accounting for 48.06% of the total toxicity equivalent.

[0071] Based on the above experimental research on the treatment process and condition parameters, further additives were added to the fly ash for treatment and effect testing experiments, including the following:

[0072] Example 1

[0073] A fly ash treatment method, the difference between this embodiment and comparative example 1 is that: in step S1, the amount of fly ash from the incineration of domestic waste is adjusted from 40g in comparative example 1 to 32g, and after drying the moisture of the fly ash from the incineration of domestic waste, 8g of ZnO sample is added, and the mixture is obtained after grinding and passing through a 60-mesh sieve, and the other operations are the same as those in comparative example 1.

[0074] Specifically, the fly ash treatment method comprises the following steps:

[0075] S1. Take 32 g of fly ash from the incineration of domestic waste, dry the water in a constant temperature box, add 8 g of ZnO sample, and then grind and pass through a 60-mesh sieve, and ensure that the material is completely sieved to obtain a mixed material;

[0076] S2. Add the mixture into a corundum crucible, use a high-temperature melting furnace as a reactor, and control the temperature through a program. Raise the temperature to 1400°C at a heating rate of 10°C / min, and then keep it at 1400°C for 2 h. After cooling, take out the product fly ash solid solution, which has a ceramic luster and a dense structure.

[0077] The X-ray diffractometer was used to scan ZnO and the product fly ash solid solution respectively, and the results are as follows: Figure 5 shown.

[0078] The product fly ash solid solution was completely digested, and the ion concentration in the solution of the digestion solution was determined by ICP-OES, and the chlorine removal effect in the solid solution was determined by HPIC. It was calculated that the total chlorine removal efficiency was 95.71%, the soluble chlorine removal rate was 97.76%, the heavy metal volatilization rate was 95.57% for Cu, 54.78% for Zn, 93.30% for Pb, and 98.52% for Cd. Compared with Comparative Example 1, the removal effect of chlorine in fly ash can be greatly promoted, and the removal effect of heavy metal Cu can be improved at the same time.

[0079] Example 2

[0080] A fly ash treatment method. The difference between this embodiment and embodiment 1 is mainly that MgO is used in this embodiment to replace ZnO in embodiment 1, and the amounts of the two and other operations are the same as those in embodiment 1.

[0081] Specifically, the fly ash treatment method comprises the following steps:

[0082] S1. Take 32 g of fly ash from the incineration of domestic waste, dry the water in a constant temperature box, add 8 g of MgO sample, and then grind and pass through a 60-mesh sieve, and ensure that the fly ash is completely sieved to obtain a mixture;

[0083] S2. Add the mixed material into a corundum crucible, use a high-temperature melting furnace as a reactor, and raise the temperature to 1400°C at a heating rate of 10°C / min through program temperature control, and then keep it at 1400°C for 2 h; cool and collect the flue gas generated during the high-temperature melting process, and take out the melt obtained by the high-temperature melting treatment after cooling to obtain a product fly ash solid solution.

[0084] The cooled product fly ash solid solution was completely digested, and the ion concentration in the solution of the digestion solution was determined by ICP-OES, and the chlorine removal effect in the solid solution was determined by HPIC. It was calculated that the total chlorine removal efficiency was 75.98%, the soluble chlorine removal rate was 82.33%, the heavy metal volatilization rate was 74.79% for Cu, 93.27% for Zn, 97.00% for Pb, and 95.49% for Cd. Compared with Comparative Example 1, the removal effect of heavy metals Pb and Zn can be improved.

[0085] Example 3

[0086] A fly ash treatment method. The difference between this embodiment and embodiment 1 is mainly that: in this embodiment, 2g ZnO and 6g MgO are used to replace 8g ZnO in embodiment 1, and other operations are the same as those in embodiment 1.

[0087] Specifically, the fly ash treatment method comprises the following steps:

[0088] S1. Take 32 g of fly ash from the incineration of domestic waste, dry the water in a constant temperature box, add 2 g of ZnO and 6 g of MgO samples, and then grind and pass through a 60-mesh sieve, and ensure that the material is completely sieved to obtain a mixed material;

[0089] S2. Add the mixed material into a corundum crucible, use a high-temperature melting furnace as a reactor, and raise the temperature to 1400°C at a heating rate of 10°C / min through program temperature control, and then keep it at 1400°C for 2 h; cool and collect the flue gas generated during the high-temperature melting process, and take out the melt obtained by the high-temperature melting treatment after cooling to obtain a product fly ash solid solution.

[0090] The cooled product fly ash solid solution was completely digested, and the ion concentration in the solution of the digestion solution was determined by ICP-OES, and the chlorine removal effect in the solid solution was determined by HPIC. It was calculated that the total chlorine removal efficiency was 78.97%, the soluble chlorine removal rate was 87.58%, and the heavy metal volatilization rates were 97.31% for Cu, 82.12% for Zn, 91.31% for Pb, and 90.42% for Cd. Compared with Comparative Example 1, the removal effect of heavy metals Cu and Zn can be improved.

[0091] From the above, based on high-temperature melting treatment, fly ash undergoes pyrolysis and separation during the heat treatment process. The main chlorine-containing substances in fly ash are NaCl and KCl. During the high-temperature melting process, they melt and volatilize in the form of chlorides, which greatly reduces the proportion of chlorine. The heavy metals in fly ash are mainly Cu, Cd, Pb, and Zn, which are harmful to the environment. The melting method can remove heavy metals to the greatest extent, converting the solid solution of hazardous waste fly ash into general solid waste. The dioxin toxicity equivalent is reduced from 232.73 ng I-TEQ / kg in the original sample to 23.17 ng I-TEQ / kg in the solid solution, and the total removal efficiency exceeds 90%. After adding specific metal oxides (especially ZnO), the removal effect of chlorine or some heavy metals in fly ash is greatly improved, and the obtained product has a dense structure and a ceramic luster on the surface.

[0092] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A fly ash treatment method, characterized in that: The following steps are involved: S1. Mixing fly ash with metal oxide to obtain a mixture; the metal oxide is ZnO; S2, subjecting the mixed material to high temperature melting treatment; The added amount of the metal oxide accounts for 15% to 25% of the mass of the mixed material; The temperature of the high temperature melting treatment is 1000°C to 1400°C; The high temperature melting treatment time is 2h to 6h; The heating rate of the high temperature melting process is 5°C / min to 20°C / min; The fly ash is selected from fly ash from the incineration of domestic waste.

2. The fly ash treatment method according to claim 1, characterized in that: The temperature of the high temperature melting treatment is 1100°C to 1400°C.

3. The fly ash treatment method according to any one of claims 1 to 2, characterized in that: Before the fly ash is mixed with the metal oxide, the fly ash is first dried.

4. The fly ash treatment method according to claim 3, characterized in that: After the fly ash and the metal oxide are mixed, they are further ground and sieved to obtain a mixture.

5. The fly ash treatment method according to any one of claims 1 to 2, characterized in that: The fly ash treatment method further comprises: cooling and collecting the flue gas generated during the high-temperature melting treatment process.

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