阅读说明：本技术 免烧砖及其制备方法 (Baking-free brick and preparation method thereof ) 是由 宋军 孔德勇 刘光聪 于 2019-09-30 设计创作，主要内容包括：本发明公开一种免烧砖及制备方法,所述免烧砖包括生活垃圾焚烧飞灰30-45份、碱性物质10-15份、工业废渣5-10份、水玻璃30-45份和溶剂0-25份；其中,所述工业废渣为废碳酸钙、铸件废砂、铁矿尾矿渣中的两种或三种；所述制备方法是将生活垃圾焚烧飞灰、碱性物质、工业废渣、水玻璃及溶剂经碱激发、搅拌制得制砖浆料后,将浆料排至模具中,经震荡、压制、养护后制成免烧砖。本发明工艺简单、成本低廉,本制成的免烧砖还具有良好的环境友好性和强度,可作为建筑用砖进行应用,实用性强,有效解决了当前生活垃圾焚烧飞灰处置难的问题。(The invention discloses a baking-free brick and a preparation method thereof, wherein the baking-free brick comprises 30-45 parts of domestic garbage incineration fly ash, 10-15 parts of alkaline substances, 5-10 parts of industrial waste residues, 30-45 parts of water glass and 0-25 parts of a solvent; wherein the industrial waste residue is two or three of waste calcium carbonate, casting waste sand and iron ore tailing slag; the preparation method comprises the steps of carrying out alkali excitation on the household garbage incineration fly ash, alkaline substances, industrial waste residues, water glass and a solvent, stirring to prepare brick making slurry, discharging the slurry into a mold, and carrying out vibration, pressing and curing to prepare the baking-free brick. The invention has simple process and low cost, and the prepared baking-free brick has good environmental friendliness and strength, can be applied as a building brick, has strong practicability, and effectively solves the problem of difficult disposal of the current domestic garbage incineration fly ash.)

1. The baking-free brick is characterized by comprising the following raw materials in parts by weight:

30-45 parts of domestic waste incineration fly ash, 10-15 parts of alkaline substances, 5-10 parts of industrial waste residues, 30-45 parts of water glass and 0-25 parts of solvent;

wherein, the industrial waste residue is two or three of waste calcium carbonate, casting waste sand and iron ore tailing slag.

2. The baking-free brick as claimed in claim 1, wherein the fly ash from incineration of household garbage is mixed with residue, and the residue is fly ash and/or incineration ash.

3. The baking-free brick as claimed in claim 2, wherein the residue is a mixture of fly ash and incineration ash, and the weight ratio of the household garbage incineration fly ash, the fly ash and the incineration ash is 8-10: 0-3: 0-2.

4. The baking-free brick as claimed in claim 1, wherein the alkaline substance is one or more of waste sodium hydroxide, waste caustic sludge, waste lye and red mud.

5. The baking-free brick as claimed in claim 4, wherein the alkaline substance comprises, by weight, 5-15: 0-1: 0-10: 0-3 parts of waste sodium hydroxide, waste caustic sludge, waste alkali liquor and red mud.

6. The baking-free brick as claimed in claim 1, wherein the industrial waste residue comprises 3-5 weight percent of: 1-2: 0-1 of waste calcium carbonate, casting waste sand and iron ore tailing slag; the water glass is 3.1-3.4mol/L sodium silicate solution.

7. The baking-free brick according to claim 1, wherein the solvent is clear water, and/or landfill leachate concentrate.

8. A method of preparing a baking-free brick as claimed in any one of claims 1 to 7, comprising the steps of:

alkali excitation is carried out on the water glass under the action of the alkaline substance to obtain a mixture A;

dissolving and mixing the household garbage incineration fly ash and the industrial waste residue in the solvent to obtain a mixture B;

mixing the mixture A and the mixture B to obtain brick making slurry;

and pressing and forming the brick making slurry and curing to obtain the baking-free brick.

9. The method as claimed in claim 8, wherein the brick-making slurry is placed in a mold before the press-molding, vibrated for 3-5 minutes, press-molded again, and cured at a temperature of 20-70 ℃ for 3-7 days.

Technical Field

The invention relates to the technical field of environmental protection and circular economy, in particular to a baking-free brick prepared from domestic garbage incineration fly ash and industrial waste residues and a preparation method thereof.

Background

The household garbage incineration fly ash refers to the bottom ash settled at the bottom of a flue and a chimney and a smoke purification system in the household garbage incineration equipment. Because the fly ash generated by burning the household garbage contains heavy metals such as lead, mercury, chromium and the like and substances such as dioxin and the like which are high in carcinogenic substances, the fly ash generated by burning the household garbage is listed in a waste category HW18 (waste code 772) 002-18 of national hazardous waste records of China. Although the pollution control standard of the domestic garbage landfill (GB16889-2008) stipulates that the fly ash from the incineration of the domestic garbage can enjoy the exemption management right of hazardous wastes in the landfill process under certain conditions, the standard disposal method of the fly ash from the incineration of the domestic garbage, namely cement and a chemical chelating agent are used for manufacturing a solidified body and then are subjected to centralized landfill, so that the standard reaching stability is poor, and the potential safety hazard of the environment exists; and the disposal method consumes a large amount of cement and chelating agent, resulting in high disposal cost. Due to the prominent reasons of difficult site selection of landfill sites, limited landfill disposal capacity and the like, domestic waste incineration plants are currently being built all over the country. Therefore, the amount of fly ash generated by burning domestic garbage in China can be predicted to increase in a geometric form in the coming years. In conclusion, the problems of difficult fly ash disposal and high cost are urgently needed to be solved. In addition, the main treatment mode of removing the concentrated solution of the leachate in the garbage incineration plants in China is incinerator back-spraying treatment, but the treatment mode can reduce the incinerator temperature, so that the carcinogens such as tail gas dioxin and the like exceed the standard, and the health and the environmental safety of surrounding residents are seriously threatened. With the perfection of environmental protection monitoring work and the improvement of environmental protection appeal of the surrounding people, the back spraying of the concentrated solution becomes an important bottleneck for restricting the stable operation of the waste incineration plant.

At present, the process for the synergistic treatment of the household garbage incineration fly ash and the industrial waste residue is less, or the whole process only focuses on the building garbage or the municipal sludge in the treatment process, but does not follow the solidification effect of pollutants in the fly ash, and the whole process for the synergistic treatment is complex, for example, the steps of drying, sintering, ceramization and the like are also needed, and the operation is complex.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, so that the baking-free brick and the preparation method thereof are provided, the method has high environmental safety and strong economic feasibility, and the problem that the fly ash generated by burning the household garbage is difficult to dispose at present is effectively solved; the prepared large baking-free brick has good environmental friendliness and strength, can be applied as a building brick, and has strong practicability.

In order to achieve the above purpose, the invention provides the following technical scheme:

a baking-free brick comprises the following raw materials in parts by weight:

30-45 parts of domestic waste incineration fly ash, 10-15 parts of alkaline substances, 5-10 parts of industrial waste residues, 30-45 parts of water glass and 0-25 parts of solvent;

wherein, the industrial waste residue is two or three of waste calcium carbonate, casting waste sand and iron ore tailing slag.

In one embodiment, the household garbage incineration fly ash is also mixed with residues, and the residues are fly ash and/or incineration ash.

In one embodiment, the residue is a mixture of fly ash and incineration ash, and the weight ratio of the household garbage incineration fly ash to the fly ash and the incineration ash is 8-10: 0-3: 0-2.

In one embodiment, the alkaline substance is one or more of waste sodium hydroxide, waste caustic sludge, waste lye and red mud.

In one embodiment, the alkaline substance comprises, in order by weight, 5 to 15: 0-1: 0-10: 0-3 parts of waste sodium hydroxide, waste caustic sludge, waste alkali liquor and red mud.

In one embodiment, the industrial waste residue comprises 3-5 parts by weight: 1-2: 0-1 of waste calcium carbonate, casting waste sand and iron ore tailing slag.

In one embodiment, the water glass is 3.1-3.4mol/L sodium silicate solution.

In one embodiment, the solvent is clear water, and/or landfill leachate concentrate. Under the condition of permission, the landfill leachate or the landfill leachate concentrated solution can be adopted as much as possible, so that the problem of concentrated solution disposal of a waste incineration plant after the concentrated solution is abandoned and sprayed back can be solved to a certain extent.

A method for preparing the baking-free brick comprises the following steps:

alkali excitation is carried out on the water glass under the action of the alkaline substance to obtain a mixture A;

dissolving and mixing the household garbage incineration fly ash and the industrial waste residue in the solvent to obtain a mixture B;

mixing the mixture A and the mixture B to obtain brick making slurry;

and pressing and forming the brick making slurry and curing to obtain the baking-free brick.

In one embodiment, the brick making slurry is placed into a mold to be vibrated for 3-5 minutes before the compression molding so as to remove bubbles and increase compactness by vibration, and then the brick making slurry is subjected to compression molding and cured for 3-7 days at the temperature of 20-70 ℃ to obtain the brick making slurry.

Compared with the prior art, the invention has the following beneficial effects:

(1) firstly, the baking-free brick mainly comprises domestic garbage incineration fly ash, water glass, industrial waste residue, alkaline substances and the like, wherein elements such as silicon, aluminum and the like in the domestic garbage incineration fly ash can chemically react with the alkaline substances and the water glass to form an inorganic polymer (geopolymer) with a three-dimensional mesh structure, and the geopolymer can stably solidify pollutants such as heavy metals with higher environmental pollution risk by virtue of the mesh structure, so that the environmental friendliness of the baking-free brick is ensured; meanwhile, the polymer of the network structure crystal has extremely high strength, and the service life of the polymer is far longer than that of a portland cement solidified body;

secondly, compared with the defects of limited storage capacity, difficult site selection of a newly-built landfill site, overhigh treatment economic cost, unstable pollutant curing efficiency and the like of the household garbage incineration fly ash treated by adopting a landfill mode in the prior art, on one hand, the invention takes ecological civilization construction as a starting point, utilizes a geopolymer reaction principle and takes the household garbage incineration fly ash as a main raw material to manufacture the baking-free brick for the building material, realizes the comprehensive utilization of the fly ash, greatly saves the storage capacity of the landfill site and solves the comprehensive utilization problems of various dangerous wastes and large solid wastes from the aspect of circular economy;

on the other hand, the alkaline substance in the invention can provide a necessary alkaline environment for geopolymer reaction by waste alkaline substances such as waste sodium hydroxide, waste alkaline residues, waste alkali liquor, red mud and the like, thereby indirectly saving the disposal resources of the substances. A small amount of waste calcium carbonate in the industrial waste residue can obviously improve the strength of the baking-free brick; the casting waste sand and the iron ore tailing slag not only can play a role of an inorganic dispersant, but also can be used as a framework of a baking-free brick to increase the strength of the baking-free brick; the use of these bulk solid wastes greatly alleviates the disposal difficulties of these bulk solid wastes, enables recycling economy, and reduces the disposal cost of the fly ash.

(2) The method for making the bricks by using the geopolymer reaction principle has the advantages of simple operation, less condition requirements, suitability for most regions, wide applicability, better strength, lower raw material cost and strong popularization compared with baking-free bricks prepared by other technologies. The service life of the product prepared by the method is far longer than that of a silicate cement building material; the baking-free brick prepared by the method has high strength, and the compressive strength can reach 9-14MPa after being maintained for 14 days at normal temperature; the compression strength of the high-temperature cured baking-free brick can reach 15-20Mpa, the three-dimensional network structure of the baking-free brick can stably solidify the pollutants in fly ash and other raw materials, the pollutants in the baking-free brick are rarely separated out under natural conditions, the environment friendliness is strong, the storage capacity pressure of a landfill site is greatly relieved, and the circular economy is realized.

Detailed Description

The technical solutions of the present invention are described clearly and completely below, and it is obvious that the described embodiments are some, not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

It should be noted that the water glass used in the following examples is a commercially available sodium silicate solution of 3.1-3.4 mol/L; unless otherwise specified, 1 part described in the following examples each represents 1 g.