Method for preparing concrete swelling agent by virtue of calcination-free technology of industrial byproduct gypsum

Abstract

The invention relates to a preparation method of a concrete swelling agent and in particular relates to a method for preparing a concrete swelling agent by virtue of a calcination-free technology of industrial byproduct gypsum, wherein the preparation method provided by the invention is mainly applied to the field of buildings. The method comprises the following steps: simply dewatering the industrial byproduct gypsum until the moisture content is below 10%; modifying by utilizing a Raymond mill so as to prepare a powder material with the fineness of above 200 meshes; and mixing the industrial byproduct gypsum powder material, semi-hydrated gypsum, alumen and kaolin at a ratio of (2-4):(0.5-2):(2-5):(1-3), and ball-milling until the fineness is above 200 meshes. The concrete swelling agent prepared by the method has the advantages of good durability and stable swelling property, thereby greatly improving the crack-resistance and waterproofing capability of a concrete structure, improving the early strength, massively consuming the industrial byproduct gypsum, reducing the secondary energy consumption and CO2 pollution and meeting the low-carbon economic requirement.

Description

technical field [0001] The invention relates to a preparation method of a concrete expansion agent, which is mainly used in the field of construction industry, and in particular relates to a method for preparing a concrete expansion agent by using an industrial by-product gypsum calcination-free technology. Background technique [0002] In 2009, my country's industrial by-product gypsum produced about 118 million tons, and the comprehensive utilization rate was only 38%. Among them, desulfurization gypsum is about 43 million tons, with a comprehensive utilization rate of about 56%; phosphogypsum is about 50 million tons, with a comprehensive utilization rate of about 20%; other by-product gypsum is about 25 million tons, with a comprehensive utilization rate of about 40%. At present, the cumulative stockpiles of industrial by-product gypsum have exceeded 300 million tons, including more than 50 million tons of desulfurized gypsum and more than 200 million tons of phosphogyps...

AI Technical Summary

Problems solved by technology

A large amount of industrial by-product gypsum is piled up, which not only occupies land, but also wastes resources. The acid and other harmful substances contained in it are likely to pollute the surrounding environment. It has become an important factor restricting the sustainable development of my country's coal-fired unit flue gas desulfurization and phosphate fertilizer enterprises.