A Method for Homogenously Modified Fly Ash by Vapor Deposition

Abstract

The invention relates to a method for homogeneously modifying pulverized coal ash by a vapor deposition process. The method comprises the following steps of (1) atomizing a composite grinding aid, then, naturally depositing the atomized composite grinding aid on the surface of the pulverized coal ash, carrying out uniformly mixing, and then, carrying out grinding; (2) naturally depositing an atomized surface modifier on the surface of the ground pulverized coal ash; and (3) mixing a slow-setting slump-resisting component with the pulverized coal ash, thereby obtaining the modified pulverized coal ash. The method has the advantages that (1) the grinding efficiency for the pulverized coal ash is increased; (2) with an efficient dispersion component of the surface modifier, the problem that the volume of water required by the pulverized coal ash is increased due to mechanical activation is avoided, and the workability of concrete is improved; (3) with a reinforcing component of the surface modifier, the early strength of the pulverized coal ash is enhanced; (4) the stability for the properties of the pulverized coal ash is guaranteed; and (5) industrial solid waste, i.e., ardealite, serves as the slow-setting slump-resisting component and is added into the pulverized coal ash, so that the gradual loss of the concrete can be greatly reduced.

Description

technical field [0001] The invention relates to a homogeneously modified fly ash by a vapor deposition method. The modified fly ash can be applied to commercial concrete and belongs to the field of building materials. Background technique [0002] Fly ash is a kind of industrial waste discharged from thermal power plants, and its discharge is large and widely distributed. At present, the use of fly ash as a concrete admixture has become one of the main ways of fly ash treatment. Domestically, the use of fly ash focuses on the direct application of large amounts of fly ash to concrete, but the direct use of large amounts of fly ash cannot give full play to the potential hydration activity of fly ash, resulting in a low utilization rate of fly ash. The added value is small, and if the fly ash is mixed too much or used improperly, it will also cause other disadvantages in the concrete. The existing fly ash activation modification technologies are mainly divided into mechanica...

AI Technical Summary

Problems solved by technology

However, due to the increase of the specific surface area of ​​fly ash, the amount of water adsorbed by fly ash increases, which increases the water demand of fly ash. The simultaneous action of these factors will lead to the fact that when the fly ash is mixed into the concrete, the working performance of the concrete cannot be improved very well.

The modification of alkaline substances can stimulate the activity of fly ash, so that the early strength of concrete can be improved. However, the introduction of alkaline substances will lead to the occurrence of alkali-aggregate reaction in concrete, causing concrete cracking, and the high alkali content of concrete will also cause pan Frost phenomenon, and prone to soft water erosion and chemical erosion, resulting in a decline in the durability of concrete