Comprehensive utilization of low-grade limestone in Portland cement clinker and production process thereof

Abstract

The invention discloses comprehensive utilization of low-grade limestone in Portland cement clinker, and relates to the technical field of cement, the Portland cement clinker comprises the following raw materials by mass: 84-86% of limestone, 4.0% of pyrite slag, 0-4% of black coal gangue, and 8-12% of wet fly ash; the limestone comprises low-grade limestone and common limestone, and the total CaO mass content in the limestone is generally controlled to be not less than 49%. According to the present invention, the low-grade limestone is adopted as the raw material, the low-grade limestone is matched with the common limestone according to the certain ratio, the raw material ratio is adjusted, and the cement clinker is prepared through comprehensive utilization, such that the clinker quality is ensured, and the wear of the production equipment is not significantly increased, the low-grade limestone with the certain ratio is added to the raw material, so that the problem that original low-grade limestone cannot be used for cement clinker production can be solved, the production cost of enterprises can be saved, and common limestone resources can be saved.

Description

technical field [0001] The invention relates to the technical field of cement, in particular to a comprehensive utilization of low-grade limestone for Portland cement clinker and a production process thereof. Background technique [0002] The applicant currently owns two rotary kilns, 2500t / d and 4500t / d respectively, and the two rotary kilns are currently using new dry process rotary kilns to produce Portland cement clinker. Portland cement clinker refers to a kind of Mainly contain CaO, SiO 2 、Al 2 o 3 , Fe 2 o 3 The raw materials are ground into fine powder according to the appropriate ratio, and burned until they are partially melted to obtain a product with calcium silicate as the main mineral component. According to statistics, in Portland cement clinker, the mass fraction fluctuation range of four main oxides is generally: CaO 62-67%, SiO 2 20-24%, Al 2 o 3 4-7%, Fe 2 o 3 2.5-6%. The basic chemical properties of Portland cement clinker meet the following...

AI Technical Summary

Problems solved by technology

[0007] Portland cement production raw materials are generally composed of calcareous raw materials, clay raw materials and correction raw materials (iron, silicon and aluminum). Limestone raw materials often account for more than 80% of the raw material ratio, and limestone is composed of calcium carbonate. The chemical and biochemical sedimentary rocks, the main mineral is calcite, the appearance of pure calcite is white, but it has other colors due to impurities, and the impurities are more common. The main component of the stone is crystalline silica, usually brown Black, its texture is hard, from the point of view of Mohs hardness, pure calcite is Mohs grade 3, quartz is Mohs grade 7 (the main mineral of flint is α quartz), its crystal hardness is high, hard to grind and burn, reduce kiln, The output of the mill affects the quality of the clinker

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