Method for directly preparing cement from waste incineration fly ash and prepared cement

Abstract

The invention discloses a method for directly preparing cement from waste incineration fly ash and the prepared cement, and the method comprises the following steps: S1, mixing fly ash and an additive, adding the mixture into a plasma melting furnace, and carrying out plasma melting treatment to obtain high-temperature molten glass; S2, mixing limestone and clay, and conducting treatment to obtain a cement raw material; S3, stirring and mixing the high-temperature molten glass and the cement raw material, conducting heating and preserving heat to obtain cement clinker; S4, quickly cooling the cement clinker; and S5, adding gypsum into the cooled cement clinker obtained in the step S4, and conducting grinding to obtain the cement. After the fly ash is subjected to plasma melting, mixing and stirring, heating and heat preservation, cooling and grinding, the quality of the prepared cement product is superior to the index specified in the national standard. According to the method, the fly ash problem can be thoroughly solved, hazardous waste is converted into products, and reduction, harmlessness and recycling of the fly ash are achieved. The invention also discloses the cement prepared by the method.

Description

technical field [0001] The invention belongs to the technical field of fly ash utilization, and in particular relates to a method for directly preparing cement by using waste incineration fly ash and the prepared cement. Background technique [0002] The fly ash produced by domestic waste incineration contains a large amount of toxic and harmful substances such as heavy metals and dioxins, which are hazardous wastes. Plasma melting is one of the most advanced fly ash disposal technologies at present. The average temperature in the melting pool of the plasma melting furnace can reach above 1500°C, which can decompose dioxin in the fly ash into small molecular gases, and heavy metals are wrapped in the tetrahedron of the glass body. In the network structure, it cannot be leached, which can effectively solve the problem of dioxins and heavy metals in fly ash. However, how to make resource utilization of fly ash and the vitreous body after fly ash plasma melting is an urgent pr...

AI Technical Summary

Problems solved by technology

CN101817650 discloses a method for co-processing domestic waste incineration fly ash in cement kilns. Fly ash can be used as cement raw meal instead of part of raw materials to produce cement, but cement products have higher requirements on chlorine content. In this method, fly ash needs to be washed and pre-washed. processing, the process is complicated, it needs to increase equipment investment, and it significantly increases the cost of fly ash treatment

On the other hand, there are no cement kilns in many areas, and the co-processing of fly ash in cement kilns requires long-distance transportation of fly ash to other places, which poses environmental and safety risks, and the cost of fly ash transportation is relatively high

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