Modified magnesium oxysulfide cement and preparation method thereof

Abstract

The invention relates to modified magnesium oxysulfide cement and a preparation method thereof. A modified magnesium oxysulfide cement raw material comprises the following components: 40-80 parts of light calcined magnesia, 15-50 parts of magnesium sulfate heptahydrate, 20-50 parts of water and 0.1-2 parts of modifier. The preparation method comprises the steps: weighing the raw materials according to a proportion, and dissolving the magnesium sulfate heptahydrate into water to prepare a magnesium sulfate solution with a corresponding baume degree; then, adding the modifier into the magnesiumsulfate solution; and finally, adding light calcined magnesia into the magnesium sulfate solution, and carrying out uniform stirring to form cement paste. The modified magnesium oxysulfide cement is prepared; and due to the addition of the modifier, a main hydration product is changed, 5Mg(OH)2.MgSO4.3H2O (513 phase) is converted into 5Mg(OH)2.MgSO4.7H2O (517 phase), and the 517 phase is a whiskerwith good water tolerance, so that the modified magnesium oxysulfide cement has good performances such as high strength, high folding resistance and high water tolerance, and the problems of poor water tolerance and small application range of magnesium oxysulfide cement are solved.

Description

technical field [0001] The invention belongs to the field of building materials, in particular to a modified magnesium oxysulfide cement and a preparation method thereof. Background technique [0002] Light-burned magnesium oxide and magnesium sulfate heptahydrate solution can be made into magnesium oxysulfate cement, MgO-MgSO 4 -H 2 O is an air-hardening gelling material. my country is rich in magnesite mineral resources, which provides raw material advantages for the production of magnesium cement. [0003] Magnesium oxychloride cement has the advantages of fast setting time, anti-moisture absorption and halogen return, good thermal insulation performance and less corrosion to steel materials, which largely makes up for the shortcomings of magnesium oxychloride cement, but its mechanical properties are far lower than Magnesium Oxychloride Cement. Compared with Portland cement, the manufacturing process of magnesium oxysulfide cement consumes less resources and is easy ...

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Problems solved by technology

[0007] Patent 201510860139.8 discloses a water-resistant magnesium oxysulfide cement concrete material and its preparation method. Phosphoric acid or citrate and fly ash are added at the same time for modification treatment. The modified cement is non-corrosive to steel bars and can be made into steel bars Concrete, but the price of raw material fly ash continues to rise, resulting in a slightly higher cost of modifiers

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