Coal ash-based mullite light heat-insulation brick and preparation method thereof

Abstract

The invention relates to a coal ash-based mullite light heat-insulation brick and a preparation method thereof. According to the adopted technical scheme, the preparation method comprises the steps of: firstly, preparing 50-90wt% of coal ash and 10-50wt% of alumina serving as raw materials, adding 0.5-5.0wt% of swelling agent, 25-60wt% of water and 0.1-1.0wt% of water reducer relative to the raw materials, mixing 3-15min to obtain pug; then adding foam made by 0.5-2.0wt% of foaming agent relative to the raw materials, uniformly stirring, adding 1-5wt% of gel, 0.1-1.0wt% of thermosetting resin and 1-3wt% of curing agent relative to the raw materials, stirring 3-15min, moulding by casting, naturally drying for 3-10h, demoulding, baking for 12-24h at a temperature of 60-120 DEG C; and finally, preserving the heat for 3-12h at a temperature of 1150-1550 DEG C to obtain the coal ash-based mullite light heat-insulation brick. The preparation method has the characteristics of resource saving, environment friendliness, short demoulding time, short drying period and suitability for large-scale industrial production; and the coal ash-based mullite light heat-insulation brick has the advantages of high strength, low volume density and low heat conductivity coefficient.

Description

technical field [0001] The invention belongs to the technical field of lightweight heat insulating bricks, and in particular relates to a fly ash-based mullite lightweight heat insulating brick and a preparation method thereof. Background technique [0002] Fly ash is the main solid waste discharged from coal-fired power plants, and it is also one of the largest industrial wastes in my country. With the development of the electric power industry, the discharge of fly ash from coal-fired power plants is increasing year by year. If a large amount of fly ash is not treated, it will generate dust and pollute the atmosphere. If it is discharged into the water system, it will cause river silting, and the fly ash will Toxic chemicals can also cause harm to human body and living things. At present, the effective utilization rate of fly ash is low, and it is only used in a small amount in the cement industry and refractory industry. Therefore, how to effectively utilize these solid...

AI Technical Summary

Problems solved by technology

However, this method needs to add a large amount of binder, and there are disadvantages such as long drying cycle and large product shrinkage, which seriously restrict the performance of lightweight materials.

[0005] The patented technology "A method for preparing lightweight foam porous bricks using fly ash" (CN 101550021A) discloses a method for preparing lightweight thermal insulation materials using fly ash as the main raw material. This patented technology has the following disadvantages: (1) The aging time of the slurry is long, which is not conducive to industrial production; (2) The fly ash has complex components and contains a large amount of impurities which can be used as a co-solvent. This method not only does not avoid its negative effects, but adds a co-solvent again. After firing at ±50°C, the product shrinks severely and cannot be used normally

[0006] The patented technology of "ultra-light cement-based composite foaming material and its preparation method" (CN 102285778 A) discloses a method for preparing lightweight thermal insulation materials by foaming method using cement and fly ash as main raw materials. The main disadvantages of the method are as follows: (1) a large amount of cement is used to combine, which increases the cost; (2) due to the large amount of CaO in the cement, it is easy to combine with SiO at high temperature 2 The eutectic phase is formed, which limits its application range and cannot be applied to high temperature fields; (3) The sample curing time is long and the process is complicated, which is not conducive to industrial production