Preparation method of coal gangue foam concrete

Abstract

The invention discloses a preparation method of coal gangue foam concrete. The preparation method comprises the steps of firstly, weighing 1 part by weight of a foaming agent KD-1 and 10-30 parts by weight of water, uniformly mixing, and then, foaming in a high-speed dispersion machine ( with the rotating speed being 2000-3000rad / min) for 3-5 minutes to prepare foam for later use; then, weighing 20 parts by weight of PO425 cement, 55-65 parts by weight of coal gangue with the particle size of 0.5-6mm, 15-20 parts by weight of water and an additional early strength agent accounting for 3-5% of the cement in weight, and then, uniformly stirring in a stirrer to prepare concrete slurry; next, adding the preparative foam into the concrete slurry, and stirring for 2-6 minutes until the slurry is uniform to obtain foam concrete slurry; and finally, injecting the prepared foam concrete slurry into a mould prepared in advance for molding, standing for 24 hours, then, placing the molded foam concrete slurry into a standard constant-temperature and constant-humidity concrete curing box (at the temperature being 19-21 DEG C, relative humidity being 95-99%) to cure until all stages of concrete are obtained. According to the preparation method, the coal gangue foam concrete is prepared by taking the uncalcined large-particle coal gangue as a raw material, so that the aim of changing waste materials into valuable things is achieved, the production cost is reduced, and the production efficiency is improved.

Description

technical field [0001] The invention relates to a method for preparing uncalcined large-grain coal gangue foam concrete. The coal gangue foam concrete is mainly used for filling goafs in coal mines. Background technique [0002] In order to prevent natural disasters in the coal mine goaf, it is necessary to fill the coal mine goaf. In my country, the modern filling mining method is mainly based on cemented filling. For some coal mines with high underground temperature, as a large amount of filling slurry enters the goaf, mine paste cemented filling can reduce the underground temperature. And for those coal mines where the goaf has a tendency to spontaneously ignite, after the slurry is filled into the goaf, the gangue falling out of the goaf is consolidated into a whole, the air is isolated, and the goaf is prevented from spontaneously igniting. The use of cemented filling has solved the problem of underground environmental pollution, reduced the cost of filling and mining,...

AI Technical Summary

Problems solved by technology

[0009] (1) The technological process is complicated. Before preparing the gangue foam concrete, the gangue should be calcined

[0010] (2) The process conditions are harsh, and the activation and calcination of coal gangue needs to be carried out under high temperature conditions, generally around 750°C, which consumes a lot of energy

[0011] (3) During the calcination process, a large amount of harmful gas is produced, which pollutes the environment

[0012] (4) The amount of cement used in the preparation process is large, the weight ratio of cement to coal gangue is 50:50, and the production cost is high