Method for enhancing whiteness of sulphoaluminate clinker

Abstract

The invention discloses a method for enhancing whiteness of sulphoaluminate clinker and belongs to the technical field of cement clinkers. The method for enhancing the whiteness of the sulphoaluminateclinker comprises raw material quality control, raw material preparation and clinker calcining. Raw materials comprise bauxite, gypsum, limestone, high magnesium limestone, dolomite and barite; raw material blending satisfies requirements that the basicity coefficient Cm of the clinker obtained after the raw materials are calcined is 0.92-1.0, and the sulfur aluminum ratio P of the clinker obtained after the raw materials are calcined is less than or equal to 3.82; the content of MgO in the clinker is 1-2.5%, the content of BaSO4 in the clinker is more than 0.1% and less than 2%, the contentof free gypsum in the clinker is 0-1%, and the content of Fe2O3 in the clinker is less than 1.2%; the raw materials are pulverized after being blended; the fineness of the raw materials is controlledin such a way that residues on a 0.08 mm square hole sieve are less than 12%; and then the raw materials enter a kiln to calcine the clinker; under conditions that a decomposing furnace temperature is870+ / -10 degrees centigrade and a burning zone temperature is 1280-1340 degrees centigrade, the clinker is calcined; and therefore, the white sulphoaluminate clinker with whiteness of higher than orequal to 80 can be stably obtained.

Description

technical field [0001] The invention relates to the technical field of cement clinker, in particular to a method for improving the whiteness of sulphoaluminate clinker. Background technique [0002] At present, most of the colored and white decorations in the architectural decoration market are made of white Portland cement, but there are many defects and problems in it: [0003] (1) In the process of production, due to the slow setting and hardening of white Portland cement, low early strength, long demoulding time, and the phenomenon of product returning to alkali, the production efficiency and yield of the product are seriously affected. [0004] (2) The calcination temperature of white Portland cement clinker is high, and the calcination temperature often reaches about 1550°C, which results in high energy consumption and high nitrogen oxide content in kiln tail gas. [0005] (3) The proportion of limestone materials in the ingredients is as high as 80%, and the greenhou...

AI Technical Summary

Problems solved by technology

[0003] (1) In the production process, due to the slow setting and hardening of white Portland cement, low early strength, long demoulding time, and the phenomenon of product returning to alkali, the production efficiency and yield of the product are seriously affected

[0004] (2) The calcination temperature of white Portland cement clinker is high, and the calcination temperature often reaches about 1550°C, which results in high energy consumption and high nitrogen oxide content in kiln exhaust gas.

[0005] (3) The proportion of limestone materials in the ingredients is as high as 80%, and the greenhouse gas CO 2 Emissions are also larger

[0006] (4) In order to improve the whiteness of the clinker, the bleaching process is used when the clinker is discharged from the kiln, resulting in a very high heat loss

[0007] (5) The high-quality raw material resources used are increasingly exhausted

[0011] White sulphoaluminate cement with a whiteness of 60-70 is often restricted in use.

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