Modified fly ash with surface coated with SiO2 and preparation method and use thereof

Abstract

The invention belongs to the technical field of inorganic powder surface modification, and in particular relates to modified fly ash with surface coated with SiO2 and a preparation method and use thereof, the method is as follows: Step 1) fly ash iron removal, step 2) capillary adsorption paraffin, step 3) coating of the surface with SiO2, the water absorption rate of the modified fly ash prepared by the method is 20%-22%, the whiteness is 20-30, the near infrared reflectivity is 60-80%, the coefficient of thermal conductivity is less than 0.25W / M.K; and the modified fly ash prepared by the method has good barrier thermal insulation and reflective thermal insulation performances. A thermal insulation coating prepared from the modified fly ash has excellent thermal insulating property, can be used in epoxy floor coatings, acrylic coatings for exterior wall, casting coatings and the like, and is free of the color and the construction problems, and high in added value.

Description

technical field

[0001] The invention belongs to the technical field of inorganic powder surface modification, in particular to a surface-coated SiO 2 Modified fly ash and its preparation method and use. Background technique

[0002] In the 1970s, the global energy crisis, environmental pollution and the depletion of mineral resources strongly stimulated the research and development of fly ash utilization, and the resource utilization of fly ash has always been a matter of great concern to governments, experts and scholars all over the world. . According to relevant data, the total annual discharge of fly ash in my country has exceeded 1 billion tons, and is still increasing at a rate of 120 million tons per year, while the utilization rate is less than 50% of the annual discharge. Compared with Germany's 65% utilization rate of fly ash, France's 75% utilization rate of fly ash, and Japan's 100% utilization rate of fly ash, the utilization rate of fly ash in my country is s...