Retardant preparation method

Abstract

The invention discloses a retardant preparation method. The method is characterized in that by weight percent in the total weight, 25-85 percent of water, 20-30 percent of aluminium hydroxide, 10-20 percent of tartaric acid and 25-35 percent of phosphate are adopted as raw materials. According to the method, after being added in magnesite slurry, the retardant is reacted with Mg<2+> of the slurry to generate sparingly soluble salts which are coated on the surface and can prohibit the Mg2 from being in contact with water molecules, thereby playing a role of delaying coagulation; the more the retardant is added, the larger the cover degree is and the more obvious the coagulation delaying effect is. Besides, water molecules can permeate the MgO coated by the retardant through diffusion, so as to generate an osmotic pressure; and when the pressure reaches a certain extent, the cover layer is broken, the MgO is further hydrated, and the hydration and rigidification speed is slower.

Description

technical field [0001] The invention relates to a magnesite cementitious material modifier, in particular to a preparation method of a retarder. Background technique [0002] Magnesite cement, also known as magnesite cement, is a kind of air-hardening cement. When using this material to manufacture products, it has the characteristics of no need for moisture curing, fast strength growth, high flexural and compressive strength, weak alkali Non-toxic, low corrosion, high elasticity, good toughness, light weight, good cementation to organic and inorganic materials or fibers, etc., widely used in construction, decoration, urban construction, agriculture and other fields. Even so, due to the short initial setting time of the slurry of this material and the poor water resistance of the product, it is not conducive to the molding operation of the slurry in the process of manufacturing the finished product, and it is difficult to ensure the appearance quality of the product. This is...

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Problems solved by technology

Even so, due to the short initial setting time of the slurry of this material and the poor water resistance of the product, it is not conducive to the molding operation of the slurry in the process of manufacturing the finished product, and it is difficult to ensure the appearance quality of the product. This is the existing magnesite cementitious material. insurmountable flaws