Preparation method of lithium-aluminum hydrotalcite derivatives applied to sulphate aluminium cement based material with big water cement ratio

Abstract

The invention provides a preparation method of lithium-aluminum hydrotalcite derivatives applied to a sulphate aluminium cement based material with a big water cement ratio. The preparation method comprises steps as follows: firstly, a prepared mixed salt solution and a prepared mixed alkali solution are subjected to a reaction rapidly in a reactor, mixed slurry is obtained, the mixed slurry is subjected to heating reflux crystallization and then is treated to obtain lithium-aluminum hydrotalcite, the lithium-aluminum hydrotalcite is subjected to high-temperature roasting or hydration, and thelithium-aluminum hydrotalcite derivatives in a roasting state and a hydration state are prepared. The lithium-aluminum hydrotalcite derivatives are added to the sulphate aluminium cement based material with the big water cement ratio according to the mixing amount of 0.2%-5% of the sulphate aluminium cement based material, and the water cement ratio of the prepared cement material is 0.4-3.0. Thepreparation method of the lithium-aluminum hydrotalcite derivatives is easily industrialized and simple to operate, and the lithium-aluminum hydrotalcite derivatives serving as a crystal nucleus material promote generation of cement hydration products, and under the condition of the big water cement ratio, early compressive strength of the sulphate aluminium cement based material is remarkably improved and 28-day compressive strength is not decreased.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a preparation method of lithium-aluminum hydrotalcite derivatives used in sulphoaluminate cement-based materials with a large water-cement ratio. Background technique [0002] Sulphoaluminate cement-based material (CBGM) is an inorganic material with sulphoaluminate (CSA) cement clinker, gypsum and lime as the main components. It has the characteristics of corrosion resistance, early high strength, and impermeability. It has good application in filling engineering of high water-based materials in mines. In the process of grouting application, in order to ensure the slurry has high fluidity and permeability, it is usually selected to construct under the condition of large water-cement ratio or mixed with admixture, but the early compressive strength of the slurry under the above conditions cannot meet the requirements. engineering needs. [0003] The use of nanotech...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a method for preparing lithium aluminum hydrotalcite derivatives used in sulphoaluminate cement-based materials with a large water-cement ratio. The lithium aluminum hydrotalcite derivatives prepared by the present invention are used in large water ash Compared with sulphoaluminate cement-based materials, not only the early compressive strength of cement-based materials is significantly improved, but also the strength does not shrink after 28 days, which solves the problem that the compressive strength of sulphoaluminate cement cannot meet the conditions of high water-cement ratio. asked questions

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