Method for preparing novel low-alkaline liquid setting accelerator

Abstract

The invention relates to the field of building materials, in particular to a method for preparing a novel low-alkaline liquid setting accelerator. The novel low-alkaline liquid setting accelerator is prepared by the following steps: adding sodium hydroxide, potassium hydroxide and aluminum hydroxide into water according to proportion, and reacting for 2-3h under the temperature being 95-120 DEG C, thereby obtaining aluminate mother liquor; dissolving sodium fluoride in water, and adding silicate into the water solution under a certain temperature, thereby obtaining a modifier; and finally, dropping the modifier into the aluminate composite mother liquor, and reacting fully, thereby obtaining the novel low-alkaline liquid setting accelerator. The setting accelerator has the properties of short setting time, low alkali content and good cement adaptability.

Description

technical field [0001] The invention relates to the field of building materials, in particular to a preparation method of a novel low-alkali liquid accelerator. The prepared low-alkali liquid quick-setting agent is suitable for wet shotcrete, and is widely used in the construction of shotcrete in underground engineering constructions such as mines and tunnels. Background technique [0002] Accelerator is an admixture that can quickly set and harden concrete or mortar. It is mainly used in shotcrete and mortar machine plugging and emergency projects. The liquid quick-setting agent for shotcrete improves the shortcomings of uneven powder mixing, large dust and poor construction environment, accelerates the setting of the concrete mixture, and improves the early strength, which can increase the thickness of the sprayed layer and shorten the next spraying time. Time has greatly expanded its scope of use. [0003] Liquid accelerators mainly include alkali-free liquid accelerato...

AI Technical Summary

Problems solved by technology

The main component of non-alkali liquid quick-setting agent is sulfoaluminate, because its price height, dosage are big (4~10%), early strength is low, thereby has influenced the extensive use of material, as CN00816806.7 will sulfuric acid Aluminum and amorphous aluminum hydroxide are dissolved in water containing amine, and the non-alkali liquid quick-setting agent synthesized by adding a non-alkaline salt stabilizer has a dosage of 7% to Portland cement; CN200910028321.1 uses aluminum sulfate and Metal sodium fluoride is the main component, and some amine substances and regulators are added to prepare the alkali-free accelerator, which has high cost, large dosage, and precipitation and flocculation after long-term storage; patent CN200580046556.3 is based on fluorine-containing Sodium chloride aluminum complex aqueous solution is a liquid coagulant as the main component. Although it has good low temperature stability, its synthetic raw material HF is highly corrosive and seriously damages human teeth and bones.

[0004] The traditional aluminate liquid quick-setting agent has a single component, high alkali content, and poor adaptability to ordinary Portland cement, so the scope of application is limited

Such as the U.S. Patent US 4046584 liquid quick-setting agent is a composite quick-setting agent of sodium aluminate and potassium aluminate, which greatly improves the phenomenon that the sodium aluminate liquid is easily precipitated in long-term storage, but its cement adaptability is poor, and it increases the amount of copolymers. It is modified to increase the cost of the liquid quick-setting agent. Patent US4504345 reports a liquid quick-setting agent prepared from potassium aluminate and potassium carbonate. The alkali content of this product exceeds 20%, and the cost is relatively high, which is not conducive to Large-scale promotion and use

[0005] Aiming at the poor adaptability of aluminate liquid quick-setting agent to cement, most of the domestic work focuses on the composite modification of silicate and carbonate, such as the patent CN200910183568.0 low-alkali liquid quick-setting agent and CN200910183428.3 modified aluminum Acid acid low-alkali liquid accelerator, and high shear conditions are demanding, conventional methods are difficult to achieve, and water needs to be added immediately when gel appears in the middle of the reaction, the control process is complicated, especially the cost of using mixers and homogenizers is high , it is difficult to meet large-scale industrial production

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