CN112642838B

CN112642838B - A kind of high-quality utilization method of waste incineration fly ash

Info

Publication number: CN112642838B
Application number: CN202011490422.3A
Authority: CN
Inventors: 马小玲; 谭宏斌; 杨飞华; 董发勤; 李玉香; 张吉秀; 王钧; 曲瑞雪; 吴涛; 范晓玲; 王进; 贺小春; 王进明; 邓秋林; 李芳�
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology
Priority date: 2020-12-17
Filing date: 2020-12-17
Publication date: 2022-03-29
Anticipated expiration: 2040-12-17
Also published as: CN112642838A

Abstract

本专利公开了一种垃圾焚烧飞灰高质化利用方法，将飞灰在悬浮器中低温还原处理，得到低毒灰；再逐步从低毒灰中分别得到硅铝钙渣、有色渣、含氯沉淀、含钠沉淀、含钾沉淀，实现飞灰中的不同物质分离，有利于其高质利用，最终滤液循环利用。本方法生产成本低，效率高。This patent discloses a high-quality utilization method of waste incineration fly ash. The fly ash is subjected to low-temperature reduction treatment in a suspender to obtain low-toxic ash; Chlorine precipitation, sodium-containing precipitation and potassium-containing precipitation can realize the separation of different substances in fly ash, which is conducive to its high-quality utilization, and the final filtrate is recycled. The method has low production cost and high efficiency.

Description

High-quality utilization method of waste incineration fly ash

Technical Field

The invention relates to the field of resource utilization of household garbage incineration fly ash, in particular to high-quality application of incineration fly ash.

Background

With the rapid increase of the quantity of urban domestic garbage, simple direct landfill can not meet the urban development requirement, and the garbage incineration technology is more mature in recent years. Waste incineration fly ash (hereinafter referred to as fly ash) generated in the waste incineration process is listed as HW18 dangerous waste by the nation because of containing heavy metals such as Zn, Cd, Pb, Hg, Cu and the like and organic pollutants such as dioxin and the like. According to the data of the national statistical bureau, about 400 seats of the operated waste incineration power plants are built nationwide by 2018, the annual generation amount of fly ash reaches 700 kilotons, and the fly ash is increased at the speed of 8-10% per year. The main treatment mode of the household garbage incineration fly ash is to enter a garbage landfill plant for landfill treatment after the household garbage incineration fly ash reaches the sanitary landfill standard through cement or medicament solidification and stabilization, but the method can occupy a large amount of land resources, so that the capacity of a landfill yard is seriously insufficient, the investment cost is high, and secondary pollution to the environment is easily caused; in addition, the fly ash is adopted to prepare cement, so that the problems of high content of chloride ions, standard exceeding of the total amount of heavy metals in cement clinker and the like easily occur, the doping amount of the fly ash is not more than 10 percent generally, and the problems can cause that a large amount of fly ash can not be treated and the environment is polluted. Therefore, how to economically, safely and effectively treat and utilize the waste incineration fly ash becomes a key of environmental management in China at present [ lujia, zhangsi, nivini, etc.. the research progress of solidification and comprehensive utilization of the waste incineration fly ash [ J ]. metal mine, 2019, (12): 182-187].

Aiming at the problems that the fly ash from the waste incineration cannot be effectively recycled, the environmental pollution and the like, the patent provides a fly ash high-value utilization method to promote the recycling utilization of the fly ash.

Disclosure of Invention

Compared with the prior art, the method can improve the added value of products, improve the production efficiency, realize the cyclic utilization of resources and have obvious economic and social benefits.

A method for high-quality utilization of waste incineration fly ash comprises the following steps:

reducing the fly ash in a suspension at low temperature to obtain low-toxicity ash; adding low-toxicity ash, water and a chelating agent into a field generator, uniformly stirring and filtering to obtain calcium silicoaluminate slag and primary filtrate; adding a vulcanizing agent into the primary filtrate, uniformly stirring, and filtering to obtain colored slag and secondary filtrate; adding a dechlorinating agent into the secondary filtrate, uniformly stirring, and filtering to obtain chlorine-containing precipitates and a tertiary filtrate; adding a sodium removing agent into the third filtrate, uniformly stirring, and filtering to obtain a sodium-containing precipitate and a fourth filtrate; adding a potassium removing agent into the four filtrates, uniformly stirring, and filtering to obtain potassium-containing precipitates and five filtrates.

The reducing agent used in the low-temperature reduction treatment is one of ethanol, kerosene and acetone, and the addition amount of the reducing agent is 1-10% of the mass of the fly ash.

The field used by the field generator is one of an acoustic field and an electromagnetic field.

The chelating agent is one of citric acid, ethylene diamine tetraacetic acid and triethanolamine, and the addition amount of the chelating agent is 1-10% of the mass of the fly ash.

The vulcanizing agent is one of ammonium dithiocarbamate, thiourea and thioamide, and the addition amount is 1-10% of the mass of the fly ash.

The dechlorinating agent is one of bismuth nitrate, water slag and copper slag, and the addition amount of the dechlorinating agent is 1-10% of the mass of the fly ash.

The sodium removing agent is one of kaolin, palygorsgolite and montmorillonite, and the adding amount is 1-10% of the mass of the fly ash.

The potassium removing agent is one of tetraphenyl boric acid, fluosilicic acid and pyroantimonic acid, and the adding amount of the potassium removing agent is 1-10% of the mass of the fly ash.

Compared with the prior art, the invention has the following advantages:

and (3) carrying out low-temperature reduction treatment on the fly ash in a suspension device to eliminate dioxin in the fly ash, wherein the removal rate of the dioxin is 100%, so that low-toxicity ash is obtained. The suspension device consists of a preheater and a decomposing furnace. The number of the preheater stages is 1-3, and the preheater is designed according to the principle of a preheater commonly used in a pre-decomposition cement kiln. The decomposing furnace is a columnar spouting turbulent bed in principle and is formed by connecting 1-5 column units with necking in series, the ratio of the inner diameter of each column unit to the inner diameter of each necking is 1.1:1-1.8:1, and the ratio of the inner height of each column unit to the inner diameter of each column is 1:1-4: 1. Each cylinder unit has a reducing agent and an air inlet so that the atmosphere of each cylinder unit can be adjusted separately. The temperature in the decomposition furnace in the suspension device is 500-700 ℃, and the decomposition time of the dioxin in the suspension device is 0.5-2 seconds. In addition, the heat source of the decomposing furnace in the suspension device in the patent is high-temperature flue gas introduced into the waste incinerator, and the temperature of the flue gas is 900-. And the flue gas containing reducing atmosphere discharged by the suspension device enters a waste incinerator for combustion, and the heat of the reducing gas in the flue gas is recovered. The reducing agent is one of ethanol, kerosene and acetone, and the reducing agent can easily decompose dioxin into nontoxic gas, thereby being beneficial to detoxification of fly ash.

The field generator is a container capable of generating a physical field, the field of the field generator is one of a sound field and an electromagnetic field, the sound field is ultrasonic waves, the electromagnetic field is microwaves, and the physical field can promote heavy metals in the fly ash to react with the chelating agent to obtain soluble chelate to enter the solution. The adding amount of the water in the field generator is 400-1000% of the mass of the fly ash, and the water can be tap water or five times of filtrate. The chelating agent is one of citric acid, ethylenediamine tetraacetic acid and triethanolamine, and is easy to chelate with heavy metals in fly ash, so that the heavy metals in the calcium alumino-silicate slag can be eliminated, and the resource utilization of the calcium alumino-silicate slag can be facilitated. The contents of heavy metals and harmful impurities in the calcium silico-aluminum slag are lower than the relevant standard requirements issued by the national, environmental or building material departments, and the calcium silico-aluminum slag can be used as a production raw material of cement and can also be used as an admixture of the cement.

The vulcanizing agent is one of ammonium dithiocarbamate, thiourea and thioamide, and the vulcanizing agent reacts with heavy metal ions in the filtrate to obtain colored slag precipitate, so that the heavy metal ions in the solution are eliminated, and the content of the residual heavy metal ions in the solution is lower than 0.005 mg/L. The vulcanizing agents are organic matters, and do not generate hydrogen sulfide and pollute the environment in the using process. The vulcanizing agents have strong action capability with heavy metals, and the produced sulfides have low solubility, thereby being beneficial to the recovery of the heavy metals in the solution. The recovered heavy metal slag (non-ferrous slag) is used as a raw material of a lead-zinc smelting plant, and is beneficial to resource utilization of heavy metal.

The dechlorinating agent is one of bismuth nitrate, water slag and copper slag, and reacts with chloride ions in the filtrate to generate chlorine-containing precipitates, and the chlorine is removed from the filtrate, wherein the removal rate of the chloride ions is more than 95%. Bismuth nitrate reacts with chloride ions in the filtrate to obtain bismuth oxychloride, which is a novel high-grade environment-friendly pearlescent material and is used in the fields of plastics, automobile interior decoration materials, printing ink and the like. The water granulated slag is waste slag generated in a steel mill, and reacts with chloride ions in the filtrate to obtain calcium chloroaluminate, wherein the calcium chloroaluminate is a nanoscale intercalation compound and is mainly applied to water treatment, soil remediation, slow release agents of fertilizers and the like. The copper slag is metal copper scraps generated in the copper processing process, and the metal copper scraps react with chloride ions in the filtrate to obtain cuprous chloride, and the cuprous chloride can be used as a catalyst, a bactericide, a mordant and the like.

The sodium removing agent is one of kaolin, palygorsgolite and montmorillonite, and the minerals can react with sodium to generate sodium-containing precipitates so as to remove sodium ions in the solution, wherein the removal rate of the sodium ions is more than 90%. The precipitate phase is zeolite, which can be used as ion exchanger, adsorptive separator, desiccant, catalyst, etc.

The potassium removing agent is one of tetraphenyl boric acid, fluosilicic acid and pyroantimonic acid, and the substances can react with potassium to generate potassium-containing precipitates, so that the potassium in the filtrate is removed, the removal rate of potassium ions is more than 90%, and the recovery of the potassium is realized. And (5) the five filtrates after potassium removal enter a field generator through a pump for recycling.

Filtration equipment is one of vacuum filter press, pile spiral shell machine, plate and frame filter press in this patent, and the filter residue moisture content all is less than 15% after the filtration, has the characteristics that the energy consumption is low, with low costs.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

Reducing the fly ash in a suspension at low temperature to obtain low-toxicity ash; adding low-toxicity ash, water and a chelating agent into a field generator, uniformly stirring and filtering to obtain calcium silicoaluminate slag and primary filtrate; adding a vulcanizing agent into the primary filtrate, uniformly stirring, and filtering to obtain colored slag and secondary filtrate; adding a dechlorinating agent into the secondary filtrate, uniformly stirring, and filtering to obtain chlorine-containing precipitates and a tertiary filtrate; adding a sodium removing agent into the third filtrate, uniformly stirring, and filtering to obtain a sodium-containing precipitate and a fourth filtrate; adding a potassium removing agent into the four filtrates, uniformly stirring, and filtering to obtain potassium-containing precipitates and five filtrates. The application of the hair-restorer, the formulation of the reducing agent, the chelating agent, are shown in Table 1. The formulas of the vulcanizing agent, the dechlorinating agent, the sodium removing agent and the potassium removing agent are shown in the table 2.

TABLE 1

TABLE 2

The embodiments of the present invention can be implemented and achieved, and the present invention is not limited to these embodiments.

Claims

1. A method for high-quality utilization of waste incineration fly ash is characterized by comprising the following steps: reducing the fly ash in a suspension at low temperature to obtain low-toxicity ash; adding low-toxicity ash, water and a chelating agent into a field generator, uniformly stirring and filtering to obtain calcium silicoaluminate slag and primary filtrate; adding a vulcanizing agent into the primary filtrate, uniformly stirring, and filtering to obtain colored slag and secondary filtrate; adding a dechlorinating agent into the secondary filtrate, uniformly stirring, and filtering to obtain chlorine-containing precipitates and a tertiary filtrate; adding a sodium removing agent into the third filtrate, uniformly stirring, and filtering to obtain a sodium-containing precipitate and a fourth filtrate; adding a potassium removing agent into the fourth filtrate, uniformly stirring, and filtering to obtain a potassium-containing precipitate and the fifth filtrate; wherein, the suspension device consists of a preheater and a decomposing furnace; the temperature in the decomposing furnace is 500-700 ℃ during the low-temperature reduction treatment; the reducing agent used in the low-temperature reduction treatment is one of ethanol, kerosene and acetone, and the addition amount is 1-10% of the mass of the fly ash; the field used by the field generator is one of a sound field and an electromagnetic field; the chelating agent is one of citric acid, ethylene diamine tetraacetic acid and triethanolamine, and the addition amount is 1-10% of the mass of the fly ash; the dechlorinating agent is one of bismuth nitrate, water slag and copper slag, and the addition amount of the dechlorinating agent is 1-10% of the mass of the fly ash; the sodium removing agent is one of kaolin, palygorsgolite and montmorillonite, and the adding amount is 1-10% of the mass of the fly ash; the potassium removing agent is one of tetraphenyl boric acid, fluosilicic acid and pyroantimonic acid, and the adding amount is 1-10% of the mass of the fly ash; the recycled non-ferrous slag is used as a raw material of a lead-zinc smelting plant.

2. The method for high-quality utilization of waste incineration fly ash according to claim 1, wherein the vulcanizing agent is one of ammonium dithiocarbamate, thiourea and thioamide, and the addition amount is 1-10% of the mass of the fly ash.