A kind of preparation method of large-volume industrial waste slag portland cement

Abstract

The invention discloses a preparation method of Portland cement with high-content industrial waste residues and belongs to a preparation method of the Portland cement. On the basis that the strength grade of the cement is not reduced, the industrial waste residues such as fly ash, slag and the like are taken as main raw materials to replace equal amount of cement clinker, meanwhile, other performance indexes of the cement all meet various national standards for common Portland cement, and accordingly, the production cost of the cement is reduced. According to the preparation method, the industrial waste residues after certain treatment can replace equal amount of the cement clinker in a mass ratio being 70%-80%, PC52.5 and PC42.5 Portland cement can be produced, and compared with the common Portland cement, more than 30% of the cost of each ton of the Portland cement can be saved. The strength of all ages of the cement produced with the method is equal to or higher than the strength grade of the conventional Portland cement, and the Portland cement has the advantages that the heat of hydration is low, the early strength is high, the later strength is greatly increased, the energy consumption is low, waste is changed into wealth, prepared concrete has high chemical erosion resistance capacity and the like.

Description

technical field [0001] The invention relates to a method for preparing portland cement with low pollution and low energy consumption, in particular to a method for preparing portland cement with a large amount of industrial waste residue. Background technique [0002] my country's iron and steel, electric power, chemical industry and other industries have released more than 1 billion tons of solid industrial waste on average annually, including: 200 million tons of fly ash, nearly 100 million tons of slag, 20 million tons of steel slag, and more than 200 million tons of coal gangue , more than 1 billion tons of waste concrete and construction waste, 50 million tons of urban sludge, and 260 million tons of industrial tailings. At present, the comprehensive utilization rate of solid waste in my country is less than 40%, and the accumulated solid waste has reached 7 billion tons. About 70,000 Km 2 , causing great environmental pollution and waste of land resources. Among the ab...

AI Technical Summary

Problems solved by technology

However, the current existing research uses the three major effects to increase the amount of industrial waste residue in cement. The common difficult problem is: when a large amount of industrial waste residue is used (the amount of industrial waste residue reaches more than 20%), the strength of the cement is obviously reduced, and the industrial waste residue The larger the dosage, the more the cement strength will decrease, and it is impossible to make high-strength grade cement

This is mainly because the activity of industrial waste slag as an auxiliary cementitious material is much lower than that of cement, and the secondary hydration pozzolanic effect only occurs on the surface of industrial waste slag, and the degree of reaction is low. The space between the particles is limited, and only a small amount of ground industrial waste can be densely filled. However, after the industrial waste such as fly ash is ground, the pores often increase, the water demand increases, and it no longer has the shape effect of reducing water.

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