Method for recycling fly ash

Abstract

The invention discloses a method for recycling fly ash. The method comprises the steps: pulverizing the fly ash until the specific surface area of the pulverized fly ash is 300m<2> / kg to 550m<2> / kg, and compounding the fly ash with the specific surface area of 300m<2> / kg to 350m<2> / kg, the fly ash with the specific surface area of 400m<2> / kg to 450m<2> / kg and the fly ash with the specific surface area of 500m<2> / kg to 550m<2> / kg according to the ratio of (10% to 20%): (30% to 40%): (50% to 70%), so as to obtain modified compounded fly ash; and adding the obtained modified compounded fly ash into cement clinker according to a mixing proportion of 15% to 35%, meanwhile, adding desulfurized gypsum, of which the mass accounts for 1% to 3% that of the fly ash, into the cement clinker, and carrying out mixing and pulverizing. According to the method, the activity of the fly ash is improved through improving the fineness of the fly ash and optimizing the grain size distribution of grains, and industrial waste residues can be extensively utilized so as to achieve energy saving and emission reduction.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a method for recovering and reusing fly ash. Background technique [0002] Fly ash is one of the largest industrial wastes in my country, with an annual discharge of more than 200 million tons, and the burden on the economy, society and environment is getting heavier. The research, development and utilization of fly ash in my country began in the 1950s, mainly focusing on the development and experimental research of cement and concrete, and has been widely used in engineering construction. However, cement mixtures and concrete admixtures have high requirements on the quality of fly ash, and at the same time, there are certain restrictions on the amount of fly ash. Only a small part of high-quality fly ash is allowed to be used in concrete structural engineering. Part of the fly ash cannot be effectively utilized in the cement system due to its coarse parti...

AI Technical Summary

Problems solved by technology

[0003] At the same time, in the "Eleventh Five-Year" environmental plan, the country has increased investment in flue gas desulfurization projects in large coal-fired enterprises, and the efficient use of desulfurization gypsum, an industrial by-product, has aroused widespread concern. If it is not handled properly, flue gas desulfurization The project only transformed the form of pollution, but did not fundamentally solve the pollution of sulfur dioxide, and piled up will be more serious