Preparation method of high-volume fly ash-based water permeable brick

Abstract

The invention belongs to the field of solid waste treatment, and discloses a preparation method of a high-volume fly ash-based water permeable brick, which comprises the following steps: (1) a step ofcarrying out alkali excitation on raw material fly ash and active industrial solid waste to prepare a geopolymer material, crushing the geopolymer material, and screening the crushed material to obtain granular fly ash as a coarse aggregate; (2) a step of compounding the coarse aggregate and a natural aggregate to obtain a water permeable brick aggregate; (3) a step of preparing the water permeable brick, namely a step of uniformly mixing raw materials including fly ash and the water permeable brick aggregate with a calcium-based activator, water and an alkaline activator to obtain a mixture,and then putting the mixture into a mold for compression molding to obtain a green brick; and then accelerating hydration reaction in the green brick by utilizing an autoclaved curing process, so asto prepare the high-volume fly ash-based water permeable brick. By improving the whole flow process of the preparation method, including the types of the adopted raw materials, the water permeable brick product with excellent mechanical properties can be prepared, and the dosage ratio of the fly ash is high.

Description

technical field [0001] The invention belongs to the field of solid waste treatment, and more specifically relates to a method for preparing a high-volume fly ash-based permeable brick. Background technique [0002] Fly ash is the fine ash captured from the flue gas of coal combustion. The coal power industry is a major producer of fly ash. Since 2002, with the explosive growth of thermal power installed capacity in my country, the production of fly ash has also increased sharply, from 154 million tons in 2001 to 5.65 in 2016. billion tons, an increase of 3.7 times. At present, fly ash is widely used in industries such as construction and building materials, but the utilization rate is low. According to relevant statistics, affected by the decline of my country's building materials industry market, most of my country's fly ash market has experienced a sharp decline in usage and price, including Nanjing, Shanghai and other regions where fly ash is unsalable . Therefore, it i...

AI Technical Summary

Problems solved by technology

The preparation of permeable bricks by this method requires steam curing for 24 hours, which takes a long time; there are many kinds of raw materials and complex processes; fine sand fly ash particles are mixed with fly ash and cement and then granulated by a ceramsite granulator, which is costly and expensive. The strength mainly comes from the hydration of cement; the amount of fly ash in the whole formula is only about 30wt%, the particle size of the aggregate is relatively single, it is easy to be blocked by cement powder, etc., and the water permeability is not strong

[0005] Generally speaking, there are currently two main preparation processes for fly ash permeable bricks: the advantage of the sintering process is good water permeability, but the disadvantages are high energy consumption, high cost, and environmental pollution problems such as exhaust emissions; the other is concrete Permeable bricks, high cement content, low fly ash content, unable to absorb a large amount of fly ash

Images