Methods for calculating alkaline substances and pH pre-adjustment system before stabilization of waste incineration fly ash

Abstract

This invention discloses a method for calculating the alkaline content of fly ash before stabilization and a pH pre-adjustment system. The calculation method calculates the molar amounts of alkaline substances (n1+n2) in lime and the alkaline substances (n3, n4) consumed by the deacidification tower to remove SO2 and HCl based on relevant data. It also calculates the alkaline content of fly ash before stabilization for different acidic substances: for acidic substances with pH < 4.5, the amount of alkaline substances is calculated using n1+n2-n4; for acidic substances with pH ≥ 4.5, the amount of alkaline substances is calculated using n1+n2-n3-n4. This calculation method can accurately calculate the amount of alkaline substances in incineration fly ash before stabilization for different acidic substances, facilitating rapid pH pre-adjustment to a preset range and avoiding repeated adjustments, thus shortening the adjustment cycle. The pre-adjustment system provided by this invention allows operators to quickly pre-adjust the pH of fly ash to a preset range, and stabilization can meet landfill requirements in a single step, further shortening the stabilization cycle.

Description

Technical Field

[0001] This invention belongs to the field of waste incineration, and more specifically, relates to a method for calculating alkaline substances before stabilization of fly ash from waste incineration and a pH pre-adjustment system. Background Technology

[0002] Currently, the main method of treating municipal solid waste is incineration. During the incineration process, byproducts such as flue gas and fly ash are generated. Among them, the fly ash generated during incineration accounts for 3%-10% of the total amount of waste.

[0003] According to the "Standard for Pollution Control of Municipal Solid Waste Incineration" (GB 18485-2014), incineration fly ash refers to the material collected by the flue gas purification system. Because it contains soluble heavy metals, dioxins and soluble salts, it is clearly listed as hazardous waste (number HW18) in the "National Hazardous Waste List" (2016 edition). The proper treatment of incineration fly ash is a key and difficult point in the field of waste incineration. The current treatment of incineration fly ash mainly involves long-term and effective stabilization treatment.

[0004] Currently, the most widely used stabilization process for incineration fly ash is chemical solidification. However, practice has shown that the biggest problem with chemical solidification stabilization is that the moisture content and heavy metal leaching toxicity of the fly ash after a single stabilization treatment are difficult to meet the relevant requirements of the "Pollution Control Standard for Municipal Solid Waste Landfills" (GB 16889-2008). To meet these requirements, multiple stabilization treatments are necessary, resulting in high consumption of organic acids and metal chelating agents, high overall treatment costs, and long treatment cycles. Therefore, calculating the alkaline content of the fly ash and pre-adjusting its pH before stabilization treatment is beneficial for saving chelating agent usage and shortening the stabilization treatment cycle. However, currently, incineration fly ash is not subject to such calculations and pre-treatment before stabilization. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a method for calculating alkaline substances in waste incineration fly ash before stabilization and a pH pre-adjustment system. The purpose is to calculate the alkaline substances in fly ash before stabilization treatment, and to pre-adjust the pH of the fly ash based on the calculation results, precisely adjusting the alkalinity of the fly ash to a preset range. This achieves stabilization compliance in a single step, shortening the stabilization cycle. This solves the technical problem that existing incineration fly ash, without pre-treatment before stabilization, often fails to meet standards in a single stabilization attempt, requiring multiple stabilization treatments and resulting in long treatment cycles.

[0006] To achieve the above objectives, according to one aspect of the present invention, a method for calculating alkaline substances in waste incineration fly ash before stabilization is provided, comprising the following steps:

[0007] Obtain the amount of lime injected into the deacidification tower, and calculate the molar amount of Ca(OH)2 n1 and CaO n2 in the lime based on the proportion of Ca(OH)2 and CaO in the injected lime. Then the total molar amount of alkaline substances in the lime is n1+n2.

[0008] Obtain the amount of waste material added (M), the content of S and Cl elements in the waste material (k1 and k2), and the removal rates of S and Cl by the deacidification tower (μ1 and μ2). Calculate the molar amount of alkaline substance consumed by the deacidification tower to remove SO2 (n3) and the molar amount of alkaline substance consumed to remove HCl (n4); where k1 is 0.06%-0.18% and k2 is 0.08%-0.24%.

[0009] The molar amount of alkaline substances in fly ash before stabilization shall be calculated according to the following principles:

[0010] (1) If the pH of the added acidic substance is <4.5, the molar amount of alkaline substance in the fly ash before stabilization shall be calculated according to n1+n2-n4.

[0011] (2) If the added acidic substance has a pH ≥ 4.5, the molar amount of alkaline substance in the fly ash before stabilization shall be calculated according to n1 + n2 - n3 - n4.

[0012] Preferably, in the method for calculating alkaline substances before stabilization of waste incineration fly ash, the proportions of Ca(OH)2 and CaO in the lime are 90% and 10%, respectively.

[0013] Preferably, in the method for calculating alkaline substances before stabilization of waste incineration fly ash, μ1 and μ2 are both 80-90%.

[0014] Preferably, in the method for calculating alkaline substances before stabilization of waste incineration fly ash, k1 is 0.12% and k2 is 0.16%.

[0015] According to another aspect of the present invention, a pH pre-adjustment system for stabilizing fly ash from waste incineration is also provided, which includes a data acquisition module, a data calculation module and a data output module;

[0016] The data acquisition module is used to acquire the amount of waste raw material added M, the amount of lime sprayed m, the proportions of calcium hydroxide and calcium oxide in the lime α1 and α2, the proportions of S and Cl elements in the waste raw material k1 and k2, and the removal rates of S and Cl in the deacidification tower μ1 and μ2, and submit the acquired data to the data accounting module.

[0017] The data calculation module, based on the acquired data and according to the alkaline substance calculation method for pre-stabilization of waste incineration fly ash as described in the invention, calculates the molar amount of alkaline substances in the fly ash, and calculates the amount of acidic substances required to pre-adjust the fly ash to a preset range based on the alkaline substance calculation results, specifically according to the following principles:

[0018] (1) If the pH of the added acidic substance is <4.5, the amount of acidic substance to be added shall be calculated according to the molar amount of alkaline substance in fly ash as n1+n2-n4, and submitted to the data output module.

[0019] (2) If the added acidic substance has a pH ≥ 4.5, the amount of acidic substance added shall be calculated according to the molar amount of alkaline substance in fly ash as n1 + n2 - n3 - n4, and submitted to the data output module.

[0020] The data output module outputs the amount of acidic substance required to pre-adjust the pH of fly ash to a preset range before stabilization, based on the acidic substance calculation results.

[0021] Preferably, in the pH pre-adjustment system for stabilizing fly ash from waste incineration, k1 is set at 0.06%-0.18% and k2 is set at 0.08%-0.24%.

[0022] Preferably, in the pH pre-adjustment system for stabilizing fly ash from waste incineration, the proportions α1 and α2 of calcium hydroxide and calcium oxide in the lime are 90% and 10%, respectively.

[0023] Preferably, in the pH pre-adjustment system for stabilizing fly ash from waste incineration, the removal rates μ1 and μ2 of S and Cl in the deacidification tower are both 80%-90%.

[0024] Preferably, in the pH pre-adjustment system for stabilizing waste incineration fly ash, k1 is 0.12% and k2 is 0.16%.

[0025] Preferably, in the pH pre-adjustment system for stabilizing fly ash from waste incineration, the removal rates μ1 and μ2 of S and Cl in the deacidification tower are both 85%.

[0026] Overall, compared with the prior art, the above-described technical solutions conceived in this invention, by providing a method for calculating alkaline substances before stabilization of waste incineration fly ash, can achieve the following beneficial effects:

[0027] The present invention provides a method for calculating the alkaline content of incineration fly ash before stabilization. Based on representative key data obtained from extensive experiments and practice, it calculates the total molar amount (n1+n2) of alkaline substances in the lime sprayed in the deacidification tower, the molar amount (n3) of alkaline substances consumed in removing SO2, and the molar amount (n4) of alkaline substances consumed in removing HCl. Furthermore, it calculates the amount of alkaline substances in the fly ash before stabilization for different pH ranges of acidic substances. For acidic substances with pH < 4.5, the molar amount of alkaline substances in the fly ash before stabilization is calculated using n1+n2-n4; for acidic substances with pH ≥ 4.5, the molar amount of alkaline substances in the fly ash before stabilization is calculated using n1+n2-n3-n4. The calculation method provided by this invention can accurately calculate the amount of alkaline substances in incineration fly ash before stabilization for different acidic substances, facilitating rapid pre-adjustment of the fly ash pH to a preset range, avoiding repeated adjustments, and shortening the adjustment cycle.

[0028] The pH pre-adjustment system for stabilizing waste incineration fly ash provided by this invention can automatically output the amount of acidic substances to be added based on the relevant data obtained, making it convenient for operators to quickly pre-adjust the pH of fly ash to a preset range. Moreover, if the incineration fly ash is pre-adjusted to neutral, it can meet the landfill requirements in one stabilization, which can significantly shorten the stabilization cycle. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0030] The flue gas produced after waste incineration contains acidic gases such as SO2 and HCl. Current deacidification methods typically involve spraying lime slurry to generate CaSO3 and CaCl2 to remove these gases. Extensive practice has shown that the amount of lime sprayed based on experience is often excessive, resulting in high and complex alkaline content in the collected fly ash, making it difficult to meet landfill requirements after a single stabilization treatment. Existing literature reports that lowering the pH of fly ash before stabilization treatment improves the stabilization effect. However, the content of alkaline substances in fly ash is unknown, and the amount of alkaline substances cannot be simply determined by measuring its pH value. This is because the alkaline substances in fly ash mainly include CaSO3 generated after deacidification, Ca(OH)2 and CaO from residual lime, etc. These substances have low solubility, and measuring pH value cannot accurately calculate the amount of alkaline substances in fly ash, affecting the subsequent chelation effect. In practice, it is difficult to quickly adjust the pH of fly ash to a suitable range, mainly because the composition of waste raw materials is complex, and the processes of different waste incineration plants are not entirely the same. The production of SO2 and HCl acidic gases after waste combustion is difficult to accurately calculate, and the amount of these acidic gases removed after passing through the deacidification tower is also difficult to estimate. Furthermore, the lime sprayed in the deacidification tower generally contains two alkaline substances, Ca(OH)2 and CaO, and the specific proportions of these two alkaline substances generally vary slightly depending on the supplier. Due to the difficulty in accurately obtaining various key data, current incineration fly ash generally does not undergo pH pre-adjustment treatment, but instead undergoes multiple stabilization treatments until it meets the requirements, resulting in a long stabilization treatment cycle.

[0031] This study obtained the above-mentioned representative relevant data through extensive practice and statistical analysis. Among them, the reference value for the proportion of sulfur (S) in each ton of municipal solid waste is generally 0.12%, and its fluctuation range in practice is 0.06%-0.18%; the reference value for the proportion of chloride (Cl) is generally 0.16%, and its fluctuation range in practice is 0.08%-0.24%; according to the statistical analysis of existing lime data, the average proportion of Ca(OH)2 in lime is 90%, and the average proportion of CaO is 10%; the removal rate of acidic gases by the deacidification tower on the existing waste incineration plant production line is generally 80-90%.

[0032] Based on this, the present invention provides a method for calculating alkaline substances in waste incineration fly ash before stabilization, which includes the following steps:

[0033] Obtain the following data: the amount of waste material added (M), the content of S and Cl elements in the waste material (k1 and k2), the amount of lime injected into the deacidification tower (m), and the removal rates of S and Cl by the deacidification tower (μ1 and μ2).

[0034] The content of alkaline substances in incineration fly ash was calculated, and the alkaline substances were Ca(OH)2 and CaO.

[0035] (1) Calculate the total molar amount of alkaline substances in the sprayed lime, specifically as follows:

[0036] ① Molar amount of calcium hydroxide:

[0037] ② Molar amount of calcium oxide:

[0038] ③ Total molar amount of alkaline substances in lime: n 总 =n1+n2

[0039] In the formula, m is the amount of lime sprayed; α1 is the proportion of calcium hydroxide in the lime, preferably an average proportion of 90%; M1 is the relative molecular mass of Ca(OH)2; α2 is the proportion of calcium oxide in the lime, preferably an average proportion of 10%; and M2 is the relative molecular mass of CaO.

[0040] (2) Calculate the molar amount of alkaline substances consumed by the SO2 and HCl reactions in the deacidification tower, specifically as follows:

[0041] ④ The molar amount of alkaline substance consumed by SO2, n3:

[0042] In the formula, M is the amount of waste raw material added; k1 is the proportion of S element in the waste, which is between 0.06% and 0.18%, preferably 0.12%; μ1 is the removal rate of S in the deacidification tower, which is between 80% and 90%; M3 is the relative atomic mass of S element.

[0043] ⑤ The molar amount of alkaline substance consumed by HCl, n4:

[0044] In the formula, M is the amount of waste raw material added; k2 is the proportion of Cl element in the waste, which is between 0.08% and 0.24%, preferably 0.16%; μ2 is the removal rate of Cl in the deacidification tower, which is between 80% and 90%; M4 is the relative atomic mass of Cl element.

[0045] (3) Calculate the molar amount of alkaline substances in the incineration fly ash before stabilization. The specific calculation principles are as follows:

[0046] (1) If the added acidic substance pH < 4.5, CaSO3 can be decomposed into CaO and SO2. Therefore, the molar amount that can be reduced to CaO is n3. Then, the calculation is based on the molar amount of alkaline substances in fly ash as n1 + n2 - n4.

[0047] (2) If the added acidic substance has a pH ≥ 4.5, the calculation shall be based on the molar amount of alkaline substance in fly ash as n1 + n2 - n3 - n4.

[0048] Because different incineration plants add different acidic substances, the CaSO3 generated during the deacidification process in the deacidification tower may be decomposed again into CaO and SO2. The CaO produced during decomposition consumes the acidic substances. Therefore, the mass of alkaline substances in fly ash before stabilization cannot be simply calculated by subtracting the total molar amount of alkaline substances from the amount consumed. This calculation method easily leads to repeated adjustments and a long cycle. This invention calculates the alkaline substances in fly ash before stabilization by adding acidic substances of different pH values, thus avoiding the need for repeated adjustments and a long cycle caused by adding too much or too little acidic substances.

[0049] In addition, the present invention also provides a pH pre-adjustment system for stabilizing fly ash from waste incineration, which includes a data acquisition module, a data calculation module, and a data output module.

[0050] The data acquisition module is used to acquire the amount of waste raw material added M, the amount of lime sprayed m, the proportions of calcium hydroxide and calcium oxide in the lime α1 and α2, the proportions of S and Cl elements in the waste raw material k1 and k2, and the removal rates of S and Cl in the deacidification tower μ1 and μ2, and submit the acquired data to the data accounting module.

[0051] Furthermore, the calcium hydroxide and calcium oxide in the lime are preferably calculated as follows: calcium hydroxide accounts for 90% and calcium oxide accounts for 10%.

[0052] The proportions of S and Cl elements in the waste material are k1 and k2, respectively, wherein k1 is preferably 0.06%-0.18% and k2 is preferably 0.08%-0.24%.

[0053] The removal rates μ1 and μ2 of S and Cl in the deacidification tower are both between 80% and 90%.

[0054] The data calculation module calculates the molar amounts of calcium hydroxide and calcium oxide in the sprayed lime, n1 and n2, based on the obtained amounts of waste material added, lime sprayed, and the proportions of calcium hydroxide and calcium oxide in the lime. The sum of these two amounts is the total molar amount n of alkaline substances in the sprayed lime. 总 ;

[0055] Based on the amount of waste material added, the proportion of sulfur in the waste material and its removal rate in the deacidification tower, the molar amount n3 of alkaline substances consumed by SO2 is calculated according to the molar coefficient of alkaline substances and SO2.

[0056] Based on the amount of waste material added, the proportion of Cl element in the waste material, and its removal rate in the deacidification tower, the molar amount n4 of alkaline substance consumed by HCl is calculated according to the molar coefficient of alkaline substance to HCl. The amount of acidic substance required to pre-adjust the incineration fly ash to the preset range is calculated according to the following principles:

[0057] (1) If the pH of the added acidic substance is <4.5, the amount of acidic substance is calculated according to the molar amount of alkaline substance in fly ash as n1+n2-n4, and submitted to the data output module.

[0058] (2) If the added acidic substance has a pH ≥ 4.5, the amount of acidic substance used shall be calculated according to the molar amount of alkaline substance in fly ash as n1 + n2 - n3 - n4, and submitted to the data output module.

[0059] The data output module outputs the results based on the amount of acidic substance used. The staff weighs the acidic substance according to the output results and adds it to the fly ash to react fully, which can quickly adjust the pH of the fly ash to the preset range.

[0060] Blindly adding acid to adjust pH can easily lead to over- or under-addition of acid and a long adjustment period. If the added acidic substance has a pH < 4.5, CaSO3 in the fly ash can decompose into CaO and SO2 at pH < 4.5. The CaO generated from the decomposition will further increase the consumption of organic or inorganic acids, and the lime remaining in the fly ash will also react with the acid, increasing acid consumption. Repeated adjustments are necessary, making it difficult to quickly adjust the fly ash pH to the preset range, and the adjustment period is long.

[0061] The following is an example:

[0062] Example 1

[0063] (1) Obtain the amount of waste raw materials added for waste incineration: calculated based on a ton of waste added;

[0064] (2) Calculation of the total molar amount of alkaline substances: Based on the fact that 8-12 kg of lime is sprayed per ton of garbage; and that the lime contains 90% Ca(OH)2 and 10% CaO, the calculation of the alkaline substances containing Ca is as follows:

[0065] ① Calculate the molar amount of Ca(OH)2

[0066] Mass: 8 × 90% = 7.2 kg, 12 × 90% = 10.8 kg; that is, the mass range is 7.2-10.8 kg; the molar mass range is 97.3-145.9 mol.

[0067] ② Calculate the molar amount of CaO

[0068] Mass: 8 × 10% = 0.8 kg, 12 × 10% = 1.2 kg; that is, the mass range is 0.8-1.2 kg; the molar mass range is 14.3-21.4 mol, so the molar mass range of Ca element is 111.6-167.3 mol, that is, the molar mass range of Ca-containing alkaline substances is 111.6-167.3 mol.

[0069] (2) The amount of alkaline substances consumed by the deacidification tower is specifically calculated as follows:

[0070] The reactions that occur during deacidification:

[0071] Ca(OH)₂ + SO₂ = CaSO₃↓ + H₂O

[0072] CaO + SO2 = CaSO3

[0073] Ca(OH)₂ + 2HCl = CaCl₂ + 2H₂O

[0074] CaO + 2HCl = CaCl₂ + H₂O

[0075] The combustion of waste produces SO2 and HCl gases. The sulfur (S) and chlorine (Cl) in these gases all originate from the sulfur (S) and chlorine (Cl) in the waste raw materials.

[0076] The sulfur (S) content in each ton of waste material is 0.12% (empirical reference value), and the chloride (Cl) content is 0.16% (empirical reference value). The S and Cl contents fluctuate within a range of 0.5-1.5 times the empirical values. The removal rate of S and Cl in the desulfurization tower is 80%-90%. That is, the amount of SO2 used to consume Ca in each ton of waste material ranges from 0.48-1.62 kg, and the amount of HCl used to consume Ca ranges from 0.64-2.16 kg.

[0077] Therefore, the amount of calcium (S) consumed in 1 ton of waste is 15-50.6 mol, and the amount of calcium (Cl) consumed is 18-60.8 mol. Assuming a molar ratio of alkaline substance to SO2 of 1:1 and a molar ratio of alkaline substance to HCl of 1:2, the amount of alkaline substance consumed by SO2 and HCl ranges from 24-81 mol. Therefore, the remaining amount of alkaline substance ranges from 30.6-143.3 mol.

[0078] (3) Calculate the amount of acidic substance added to adjust the pH before fly ash stabilization.

[0079] Take acetic acid as an example

[0080] Acetic acid typically has a pH of 2.9, meaning pH < 4.5. CaSO3 will decompose into CaO and SO2, therefore the amount of Ca that can be reduced to alkaline substances ranges from 15 to 50.6 mol. The total molar amount of Ca-containing alkaline substances consumed during leaching ranges from 45.6 to 193.9 mol.

[0081] Each ton of waste produces 30-50 kg of fly ash. This translates to 0.912-6.463 mol of alkaline substances (Ca) per kilogram of fly ash. The reaction of acetic acid with CaO is as follows:

[0082] 2CH3COOH+CaO=Ca(CH3COO)2+H2O

[0083] Therefore, during the reaction, 1.824-12.926 mol of acetic acid is required to neutralize 1 kg of fly ash, which translates to a volume of 104.4-740.1 ml of acetic acid.

[0084] The fly ash pre-treated with acetic acid was stabilized, and the results showed that the standard could be met in one stabilization treatment.

[0085] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for calculating alkaline substances in waste incineration fly ash before stabilization, characterized in that, Includes the following steps: Obtain the amount of lime injected into the deacidification tower, and calculate the molar amount of Ca(OH)2 n1 and the molar amount of CaO n2 in the lime based on the proportion of Ca(OH)2 and CaO in the injected lime. Then the total molar amount of alkaline substances in the lime is n1+n2. Obtain the amount of waste material added (M), the S and Cl content (k1 and k2) in the waste material, and the removal rates (μ1 and μ2) of S and Cl by the desulfurization tower. Calculate the molar amount (n3) of alkaline substances consumed by the desulfurization tower to remove SO2. And the molar amount n4 of alkaline substance consumed to remove HCl; where k1 is 0.06%-0.18% and k2 is 0.08%-0.24%; The molar amount of alkaline substances in fly ash before stabilization shall be calculated according to the following principles: (1) If the pH of the added acidic substance is less than 4.5, the molar amount of alkaline substance in the fly ash before stabilization shall be calculated according to n1+n2-n4. (2) If the added acidic substance has a pH ≥ 4.5, the molar amount of alkaline substance in the fly ash before stabilization shall be calculated according to n1 + n2 - n3 - n4.

2. The method for calculating alkaline substances in waste incineration fly ash before stabilization as described in claim 1, characterized in that, The lime contains 90% Ca(OH)2 and 10% CaO.

3. The method for calculating alkaline substances in waste incineration fly ash before stabilization as described in claim 1, characterized in that, Both μ1 and μ2 are 80-90%.

4. The method for calculating alkaline substances in waste incineration fly ash before stabilization as described in claim 3, characterized in that, The value of k1 is 0.12%, and the value of k2 is 0.16%.

5. A pH pre-adjustment system for stabilizing fly ash from waste incineration, characterized in that, It includes a data acquisition module, a data calculation module, and a data output module; The data acquisition module is used to acquire the amount of waste raw material added M, the amount of lime sprayed m, the proportions of calcium hydroxide and calcium oxide in the lime α1 and α2, the proportions of S and Cl elements in the waste raw material k1 and k2, and the removal rates of S and Cl in the deacidification tower μ1 and μ2, and submit the acquired data to the data accounting module. The data calculation module, based on the acquired data and according to the method for calculating alkaline substances in fly ash before stabilization as described in any one of claims 1 to 4, calculates the molar amount of alkaline substances in the fly ash before stabilization, and calculates the amount of acidic substances required to adjust the fly ash to a preset range based on the alkaline substance calculation results, specifically according to the following principles: (1) If the pH of the added acidic substance is <4.5, the amount of acidic substance to be added shall be calculated according to the molar amount of alkaline substance in fly ash as n1+n2-n4, and submitted to the data output module. (2) If the added acidic substance has a pH ≥ 4.5, the amount of acidic substance added shall be calculated according to the molar amount of alkaline substance in fly ash as n1 + n2 - n3 - n4, and submitted to the data output module. The data output module outputs the amount of acidic substance required to pre-adjust the pH of fly ash to a preset range before stabilization, based on the acidic substance calculation results.

6. The pH pre-adjustment system for stabilizing fly ash from waste incineration as described in claim 5, characterized in that, The value of k1 is between 0.06% and 0.18%, and the value of k2 is between 0.08% and 0.24%.

7. The pH pre-adjustment system for stabilizing fly ash from waste incineration as described in claim 5, characterized in that, The proportions of calcium hydroxide and calcium oxide in the lime, α1 and α2, are 90% and 10%, respectively.

8. The pH pre-adjustment system for stabilizing fly ash from waste incineration as described in claim 5, characterized in that, The removal rates of S and Cl in the deacidification tower, μ1 and μ2, are both 80%-90%.

9. The pH pre-adjustment system for stabilizing fly ash from waste incineration as described in claim 6, characterized in that, k1 is set to 0.12%, and k2 is set to 0.16%.

10. The pH pre-adjustment system for stabilizing fly ash from waste incineration as described in claim 9, characterized in that, The removal rates of S and Cl in the deacidification tower, μ1 and μ2, are both 85%.