阅读说明：本技术 一种利用垃圾焚烧飞灰制备免烧砖的方法 (Method for preparing baking-free bricks by using waste incineration fly ash ) 是由 马兵 焦少俊 胡佳慧 严小飞 赵泽华 于 2019-11-15 设计创作，主要内容包括：本发明涉及利用垃圾焚烧飞灰制备免烧砖的方法,包括以下步骤：将垃圾焚烧飞灰筛选,3mm以下的留下备用；将上述筛选后的垃圾焚烧飞灰使用球磨机粉磨,粉磨至粒径为200微米以下；水洗后干燥后与添加剂混合均匀成粉料；加水使用胶砂搅拌机搅拌,浇至成型模具中；在温度20～40℃、湿度70～90％条件下,养护28d以上,制成砖体。实现了对焚烧飞灰的资源化再利用,制备成可以作为建筑材料的免烧砖,制备出的免烧砖重金属浸出完全低于国家标准,同时制备的过程简单高效,不但处理了生活危废,同时将其再利用,具有显著的社会和经济价值。(The invention relates to a method for preparing baking-free bricks by utilizing waste incineration fly ash, which comprises the following steps: screening the waste incineration fly ash, and reserving the waste incineration fly ash with the particle size of less than 3mm for later use; grinding the screened waste incineration fly ash by using a ball mill until the particle size is below 200 microns; after being washed and dried, the mixture is evenly mixed with the additive to form powder; adding water, stirring by using a mortar stirrer, and pouring into a forming die; and maintaining for more than 28 days at the temperature of 20-40 ℃ and the humidity of 70-90% to prepare the brick body. The resource recycling of the incineration fly ash is realized, the baking-free brick which can be used as a building material is prepared, the leaching of the heavy metal of the prepared baking-free brick is completely lower than the national standard, the preparation process is simple and efficient, the life hazardous waste is treated, and the baking-free brick is recycled and has remarkable social and economic values.)

1. A method for preparing baking-free bricks by utilizing waste incineration fly ash is characterized by comprising the following steps: the method comprises the following steps:

(1) screening the waste incineration fly ash, and reserving the waste incineration fly ash with the particle size of less than 3mm for later use;

(2) grinding the screened waste incineration fly ash by using a ball mill until the particle size is below 200 microns;

(3) washing the waste incineration fly ash in the step (2) with water and then drying;

(4) uniformly mixing the waste incineration fly ash in the step (3) with an additive to form powder; adding water, stirring for 3-5 min by using a mortar stirrer, and pouring into a forming mold;

(5) and maintaining for more than 28 days at the temperature of 20-40 ℃ and the humidity of 70-90% to prepare the brick body.

2. The method for preparing baking-free bricks by using waste incineration fly ash according to claim 1, wherein the method comprises the following steps: the ratio of the waste incineration fly ash to the additive in the step (4) is 1.8-2: 1 by mass.

3. The method for preparing baking-free bricks by using waste incineration fly ash according to claim 1, wherein the method comprises the following steps: the additive in the step (4) is cement, quicklime, mirabilite and CaCl₂A mixture of gypsum, a water reducing agent, ferrous sulfate and sodium sulfate.

4. The method for preparing baking-free bricks by using waste incineration fly ash according to claim 3, wherein the method comprises the following steps: the additive comprises, by mass, 10-15% of cement, 30-45% of quicklime, 1-2% of mirabilite and CaCl₂2-4% of gypsum, 16-18% of water reducing agent, 2-3% of ferrous sulfate and the balance of sodium sulfate.

5. The method for preparing baking-free bricks by using waste incineration fly ash according to claim 1, wherein the method comprises the following steps: and (3) carrying out secondary washing in the washing process in the step (3), wherein the first washing condition is that the liquid-solid ratio of water to the household garbage incineration fly ash is 5-6, the frequency oscillation of 220-230 rpm is adopted during washing, the washing time is 30-90 min, the second washing condition is that the liquid-solid ratio of water to the household garbage incineration fly ash is 3-4, the frequency oscillation of 260-280 rpm is adopted during washing, and the washing time is 30-60 min.

6. The method for preparing baking-free bricks by using waste incineration fly ash according to claim 1, wherein the method comprises the following steps: the pH is controlled to be above 10 during the washing process.

Technical Field

The invention relates to a method for preparing baking-free bricks by utilizing waste incineration fly ash, belonging to the field of reduction, harmlessness and resource utilization of hazardous wastes.

Background

With the advance of urbanization and the increasing development of human production and living, the generated garbage brings great threat to human living and ecological environment, and the garbage problem becomes an important social problem. According to statistics, the annual yield increasing speed of the municipal solid waste is up to 8-10%, the annual yield of the municipal solid waste in 2010 is about 3 hundred million tons, and the annual yield of the municipal solid waste is estimated to reach 7.1 hundred million tons in 2020. The municipal solid waste treatment rate of China is only about 50%, and the harmless treatment rate is lower and less than 2%. The long-term open-air stacking of the garbage causes serious pollution to the environment and brings serious threat to human health, so that how to treat the domestic garbage economically, effectively and powerfully is one of the problems which are commonly concerned and urgently needed to be solved by the whole society. The waste incineration comes from the end of the 19 th century, and after the 70 th century, due to the improvement and perfection of the industrial technology level and the great increase of the amount of combustible materials in the waste, the waste incineration treatment technology is mature day by day. In particular, in the last thirty years, waste incineration plants bloomed all the time, almost all developed countries have built waste incineration plants of different quantities and scales one after the other, and developing countries have also started investing in creating waste incineration plants.

The widespread use of waste incineration technology inevitably causes a series of problems, and secondary pollutants (mainly gas emissions and incineration ash) generated in the waste incineration process are attracting more and more attention. As the amount of household garbage burned increases year by year, a large amount of solid waste, i.e., incineration slag, is generated, the waste incineration slag generally comprises residual incineration residues on a grate and fine ash falling from the space between the grates, and waste heat boiler ash and slag are mixed, collected and disposed in some incineration plants. The slag accounts for about 80 percent of the weight of the incineration ash and mainly comprises slag, black and nonferrous metals, ceramic fragments, glass and other non-combustible inorganic matters and incompletely combusted organic matters. The fly ash is residue collected in a flue gas purification system and a heat recovery system such as an economizer, a boiler and the like, and accounts for about 20% of the total amount of ash. Such a large amount of slag is generated, which makes disposal difficult. In order to save increasingly tense landfill sites and reduce the disposal cost of the slag, the resource utilization of the slag is a feasible method which is more in line with the actual situation of China.

Disclosure of Invention

In order to solve the problems, the invention provides a method for preparing a baking-free brick by using waste incineration fly ash, which is used for preparing the household waste incineration fly ash into the baking-free brick so as to realize the reutilization of hazardous waste.

In order to achieve the above purpose, the specific scheme of the invention is as follows:

a method for preparing baking-free bricks by utilizing waste incineration fly ash comprises the following steps:

(1) screening the waste incineration fly ash, and reserving the waste incineration fly ash with the particle size of less than 3mm for later use;

(2) grinding the screened waste incineration fly ash by using a ball mill until the particle size is below 200 microns;

(3) washing the waste incineration fly ash in the step (2) with water and then drying;

(4) uniformly mixing the waste incineration fly ash in the step (3) with an additive to form powder; adding water, stirring for 3-5 min by using a mortar stirrer, and pouring into a forming mold;

(5) and maintaining for more than 28 days at the temperature of 20-40 ℃ and the humidity of 70-90% to prepare the brick body.

Further, the ratio of the waste incineration fly ash to the additive in the step (4) is 1.8-2: 1 by mass.

Further, the additive in the step (4) is a mixture of cement, quicklime, mirabilite, CaCl2, gypsum, a water reducing agent, ferrous sulfate and sodium sulfate.

Further, the additive comprises, by mass, 10-15% of cement, 30-45% of quicklime, 1-2% of mirabilite, 22-4% of CaCl, 16-18% of gypsum, 2-3% of a water reducing agent, 3-5% of ferrous sulfate and the balance of sodium sulfate.

Further, the water washing process in the step (3) is secondary water washing, the first water washing condition is that the liquid-solid ratio of water to the household garbage incineration fly ash is 5-6, the frequency oscillation of 220-230 rpm is adopted during water washing, the water washing time is 40-50 min, the second water washing condition is that the liquid-solid ratio of water to the household garbage incineration fly ash is 3-4, the frequency oscillation of 260-280 rpm is adopted during water washing, and the water washing time is 35-45 min.

Further, the pH was controlled to 10 or more during the washing with water.

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

the resource recycling of the incineration fly ash is realized, the baking-free brick which can be used as a building material is prepared, the leaching of the heavy metal of the prepared baking-free brick is completely lower than the national standard, the preparation process is simple and efficient, the life hazardous waste is treated, and the baking-free brick is recycled and has remarkable social and economic values.

Detailed Description