High-magnesium moderate-heat portland cement and production method thereof

Abstract

The invention relates to a high-magnesium moderate heat portland cement, which is characterized in that (1) the contents of MgO and SO3 in the cement are 3.0-6.5% and 1.4-2.2% respectively; (2) the weight percentages of the mineral composition for grinding cement clinker are 35-55% of C3S, 15-35% of C2S, 1-6% of C3A and 10-25% of C4AF; and the content of MgO in the cement clinker is 3.0-6.5%; (3) in the raw materials for calcining the clinker, the contents of MgO, CaO and Fe2O3 are respectively controlled at a certain value within the ranges of 2.5-3.8%, 38.0-42.0% and 3.5-4.5%, and the variation ranges thereof are respectively controlled within plus or minus 0.10%, plus or minus 0.20% and plus or minus 0.15%. The production method of the cement mainly comprises three procedures of raw material milling, clinker calcining and cement grinding, namely, 'two grinding and one calcining'. The concrete made from the cement is characterized by good fluidity, low water requirement, moderate cement heat, high later strength, good durability, microdilatancy performance, and the like; compared with the conventional portland cement and moderate heat portland cement, the high-magnesium moderate heat portland cement is more favorable for realizing high performance of the concrete.

Description

technical field [0001] The invention relates to a cement and a preparation method thereof, in particular to a high-magnesium medium-heat cement produced by industrial waste residues such as coal gangue, stone coal, stone cinder, slag, fly ash, desulfurized gypsum, sulfuric acid slag, and high-magnesia limestone. Portland cement and its preparation method. Background technique [0002] With the continuous deepening of people's understanding of the problems of high energy consumption, high resource consumption, and relatively serious environmental load in the cement industry, and the increasing emphasis on improving the durability of cement concrete, energy saving, consumption reduction, environmental protection, and further improvement of cement concrete performance have become international. The direction of sustainable development of the cement industry. For large-volume concrete projects, especially dam concrete, the increase in the internal temperature of the concrete is...

AI Technical Summary

Problems solved by technology

Therefore, in general large-volume concrete projects, especially hydropower dam projects, medium-heat, low-heat, and low-heat slag Portland cement with relatively little hydration heat release is usually used as the cementitious material. However, in the process of application and research, it is found that its The autogenous volume deformation of poured concrete has micro-shrinkage, which is detrimental to the crack resistance of concrete. For this reason, a medium-heat Portland cement with high magnesium oxide content has been researched and developed to compensate for the later shrinkage of concrete.

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