High-S silicate cement and its preparing process

Abstract

A high sulfur silicate cement contains SO3 (1.5-3.0%), CaO (63-68%) and CaSO4 (2.6-5.1%), and is prepared through calcining at 1350-1400 deg.C while controlling such parameters: KH=0.92-1.0, n=1.90-2.50, p=1.0-1.8 and SR=0.18-0.32, where SR=SO3/Al2O3+Fe2O3. Its advantages are less exhaustion of toxic waste gas, high strength and performance, and low cost.

Description

technical field [0001] The invention belongs to the technical field of cement. Background technique [0002] Portland cement has been widely used in construction projects, and our country has its own national standards. There is no specific regulation on the sulfur trioxide content of clinker in the standard, generally about 1%, and the maximum is 1.2-1.3%. The standard also stipulates that gypsum must be added when grinding clinker to ensure its retarding effect. It has also been found that increasing the content of sulfur trioxide in cement clinker is beneficial to retarding, and some factories have adopted the method of burning clinker with high-sulfur coal in order to achieve the purpose of increasing the content of sulfur trioxide in clinker. However, when using this method, a considerable part of the sulfur in the coal becomes a component of the fluorine-sulfur composite mineralizer, and finally forms sulfoaluminate and fluorosulfate in...

AI Technical Summary

Problems solved by technology

It has also been found that increasing the content of sulfur trioxide in cement clinker is beneficial to retarding, and some factories have adopted the method of burning clinker with high-sulfur coal in order to achieve the purpose of increasing the content of sulfur trioxide in clinker. However, when using this method, a considerable part of the sulfur in the coal becomes a component of the fluorine-sulfur composite mineralizer, and finally forms sulfoaluminate and fluorosulfate in the clinker, while the amount of calcium sulfate is less, resulting in cement Abnormal clinker setting time

At the same time, the coal in the raw meal must first meet the heat consumption required for firing the clinker, and the formation of calcium sulfate is secondary, resulting in an unstable amount of calcium sulfate in the clinker, which cannot meet the expected requirements, and discharges during calcination. More sulfur dioxide, polluting the environment

The inventor once published the article "Experimental Research on Burning High-sulfur Cement Clinker by Adding Citric Acid Slag to Raw Meals" in the second issue of "Cement" magazine in 1999, introducing the use of citric acid slag to burn high-sulfur cement clinker , but the key process parameters are not disclosed

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