CN107043233A - Process for preparing alkali-based geopolymer ecological material - Google Patents

Abstract

The invention relates to a process for preparing an alkali base polymer ecological material. Take an appropriate amount of kaolin, calcined, grind and sieve to obtain metakaolin; take 50-70 parts of domestic waste incineration fly ash, 30-50 parts of metakaolin, 10-20 parts of activator, mix the dry material with 10-30 parts of water, and stir After uniformity, inject the mixture into the mold and vibrate, then place the mold in a drying oven for dry curing and remove the mold, and finally place the removed brick body in a drying oven at 30-80°C for 12-21 days to obtain alkali Base polymer ecological material. Utilize metakaolin and domestic waste incineration fly ash to produce new environmentally friendly functional materials. Can use industrial waste according to local conditions, effectively protect water and soil resources, and control environmental pollution. It has significant environmental, economic and social benefits.

Description

A kind of technology for preparing alkali-based polymer ecological material

technical field

The invention relates to a resource disposal of solid waste, in particular to a process for preparing alkaline-based polymer ecological materials from domestic waste incineration fly ash.

Background technique

In the process of domestic waste incineration, the tail gas treatment process will produce fly ash which accounts for about 5% of the total waste incineration. It is estimated that the annual output of domestic waste incineration fly ash in my country is about 5 million tons. Fly ash is generally off-white or dark gray, with a particle size of less than 300 μm, a moisture content of 5% to 15%, a heat loss rate of 10% to 15%, and various particle shapes. The pollution caused by fly ash to the environment mainly includes heavy metal pollution, dioxin pollution and dissolved salt pollution. The main heavy metal pollution elements in fly ash are Pb, Cd and Ni. During the waste incineration process, due to incomplete incineration due to waste components, ventilation volume, etc., a certain amount of highly toxic dioxin and furan (PCDD/DFs) organic pollutants are enriched in the fly ash particles. During transportation, storage, handling and disposal, it will pose a threat to the ecological environment and cause harm to human health.

The resource utilization of domestic waste incineration fly ash is the only way to solve the problem of its disposal. The resource utilization of domestic waste incineration fly ash must be considered from two aspects: resource utilization and environmental impact. In the current research, three factors need to be considered for resource utilization of MSW incineration fly ash: (1) Performance and cost. Good performance and low cost are necessary conditions for resource utilization and market promotion. (2) Processing adaptability. This is mainly determined by the physical and chemical properties of fly ash. (3) Comply with environmental standards and have long-term stability.

The main components of domestic waste incineration fly ash belong to the CaO-SiO ₂ -Al ₂ O ₃ -Fe ₂ O ₃ system. After some admixtures are added and stimulated by chemicals, depolymerization reactions of amorphous structures and depolymerization reactions will occur. The polycondensation reaction of monomers, and the formation of geopolymers with zeolite structure, has good adsorption, can play a certain treatment effect on pollutants including heavy metals, and meet environmental protection requirements. Therefore, the economical and environment-friendly alkali-based polymer ecological materials can be prepared from domestic waste incineration fly ash.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and propose a process for preparing alkali-based polymer ecological materials. The present invention utilizes domestic waste incineration fly ash and metakaolin to produce new ecological materials, and realizes "turning waste into treasure". It has significant environmental, economic and social benefits.

The technical solution of the present invention is: a process for preparing an alkali-based polymer ecological material, and the specific steps are as follows:

(1) Take an appropriate amount of kaolin, calcined at a certain temperature to obtain metakaolin, grind and sieve for later use;

(2) Weigh 50-70 parts of waste incineration fly ash, 30-50 parts of metakaolin (dry basis), 10-20 parts of activator, and mix well;

(3) Add 10-30 parts of water, put in a mixer and stir evenly;

⑷, inject the slurry into the mold and vibrate;

⑸. Send the mold after grouting to the drying box, and remove the mold after dry curing at 30-80°C for 12-48 hours;

⑹. After removing the formwork, continue to dry-cure the blocks at 30-80°C for 12-21 days to obtain an alkali-based polymer ecological material.

Preferably, the stable calcination temperature in step (1) is 700-900° C., and the calcination time is 0.5-2 h. Preferably, the grinding and sieving described in step (1) is passing through a 100 mesh sieve.

The preferred step (2) is characterized in that the admixture is metakaolin. Preferably, the activator described in step (2) is one or more of sodium silicate, sodium hydroxide or potassium hydroxide.

Preferably, the stirring speed in step (3) is 50-200 rpm, and the stirring time is 20-30 min. Preferably, the vibration frequency in step (4) is 30-50 times/minute, and the vibration time is 2-6 minutes.

Beneficial effect:

1. The drying and curing time is short, which can reduce the production cycle and has certain economical efficiency;

2. The utilization rate of fly ash is high, and the waste rate of the process is large, which can realize the reuse of waste to a great extent;

3. The product can effectively seal heavy metals in fly ash, and at the same time has good water storage and water permeability performance, and has certain environmental benefits;

detailed description

Example 1:

Take 100 parts of kaolin in a crucible, place it in a muffle furnace at 700°C for calcination for 2 hours, and after cooling to room temperature, grind it through a 100-mesh sieve for use. Take 70 parts of domestic waste incineration fly ash, 30 parts of metakaolin, and 10 parts of sodium hydroxide, put them in a container and mix them evenly, add 30 parts of water, stir at a frequency of 200 rpm for 20 minutes, pour the mixture into the mold to Vibrate at a frequency of 50 times/min for 2 minutes. The mold is placed in a drying oven at 80°C for 12 hours, and then the mold is removed, and the removed block is placed in a drying oven at 30°C for 21 days, and then the alkali-based polymer ecological material is obtained. The detection index of the test piece in embodiment 1 is shown in the subscript.

The test piece detection index in the table 1-1 embodiment 1

The test piece heavy metal leaching value in the embodiment 1 of table 1-2

Example 2:

Take 100 parts of kaolin and place it in a crucible, place it in a muffle furnace at 900°C for calcination for 0.5h, and after cooling to room temperature, grind it through a 100-mesh sieve for use. Take 61 parts of household waste incineration fly ash, 29 parts of metakaolin, and 20 parts of sodium silicate in a container and mix them evenly, add 22 parts of water, stir at 120 rpm for 25 minutes, pour the mixture into the mold for 40 times Vibrate at a frequency of 3 minutes per minute. After the mold is placed in a drying oven at 50°C for 24 hours, the mold is removed, and the molded pieces are placed in a drying oven at 50°C for 16 days to obtain an alkaline-based polymer ecological material. The detection indexes of the test piece in embodiment 2 are shown in the subscript.

The test piece detection index in the table 2-1 embodiment 2

The test piece heavy metal leaching value in the embodiment 2 of table 2-2

Example 3:

Take 100 parts of kaolin and place it in a crucible, place it in a muffle furnace at 800°C for calcination for 1 hour, and after cooling to room temperature, grind it through a 100-mesh sieve for use. Take 50 parts of domestic waste incineration fly ash, 50 parts of metakaolin, 6 parts of potassium hydroxide and sodium silicate and mix them in a container, add 10 parts of water, stir at 50 rpm for 30 minutes, and inject the mixture after stirring Vibrate in the mold for 6 minutes at a frequency of 20 times/min. The mold was placed in a drying oven at 30°C for 48 hours and then removed, and the removed block was placed in a drying oven at 80°C for 12 days to obtain an alkaline-based polymer ecological material. The detection indexes of the test piece in embodiment 3 are shown in the subscript.

The test piece detection index in the table 3-1 embodiment 3

The test piece heavy metal leaching value in the embodiment 3 in table 3-2

Claims (7)

1. A process for preparing an alkali-based polymer ecological material, the concrete steps are as follows: (1) Take an appropriate amount of kaolin, calcined at a certain temperature to obtain metakaolin, grind and sieve for later use; (2) Weigh 50-70 parts of waste incineration fly ash, 30-50 parts of metakaolin, 10-20 parts of activator, and mix well; (3) Add 10-30 parts of water, put in a mixer and stir evenly; ⑷, inject the slurry into the mold and vibrate; ⑸. Send the mold after grouting to the drying box, and remove the mold after dry curing at 30-80°C for 12-48 hours; ⑹. After removing the formwork, continue to dry-cure the blocks at 30-80°C for 12-21 days to obtain an alkali-based polymer ecological material. 2. The process according to claim 1, characterized in that the stable calcination temperature in step (1) is 700-900°C; the calcination time is 0.5-2h. 3. The process according to claim 1, characterized in that the grinding and sieving described in step (1) is to cross 100 mesh sieves. 4. technology according to claim 1 is characterized in that the admixture described in step (2) is metakaolin. 5. The process according to claim 1, characterized in that the activator described in step (2) is one or more of sodium silicate, sodium hydroxide or potassium hydroxide. 6. The process according to claim 1, characterized in that the stirring speed described in step (3) is 50-200 rpm, and the stirring time is 20-30 min. 7. The process according to claim 1, characterized in that the vibration frequency described in step (4) is 30 to 50 times/minute, and the vibration time is 2 to 6 minutes.