A method for preparing low-carbon cement clinker from iron tailings

Abstract

The invention provides a method for preparing low-carbon cement clinker by utilizing iron tailings. The method for preparing the low-carbon cement clinker comprises the step of firing the iron tailings and limestone as main raw materials at the temperature lower than 1400 DEG C. The low-carbon cement clinker comprises the following mineral compositions: 70-85% of dicalcium silicate, 5-15% of tricalcium silicate, 0-5% of tricalcium aluminate and 4-15% of tetra calcium aluminoferrite. The method has the advantages that the proportion of iron tailings in the raw materials can be up to 32%; in addition, compared with the firing temperature 1450 DEG C of traditional portland cement clinker, the firing temperature is reduced by 50-150 DEG C; compared with the emission of the greenhouse gases in traditional cement production, the emission of CO2 and other NOx-based greenhouse gases is reduced by about 20%. The cement prepared by utilizing the low-carbon cement clinker has the advantages that the 28-day strength can be up to 65-75 MPa; the strength grade is up to 62.5; the cement mortar dispersion degree can be up to 135-200mm; the cement is low in the hydration heat, good in safety and excellent in working performance.

Description

technical field [0001] The invention relates to the technical field of preparing cement clinker. Specifically, it relates to a method for preparing low-carbon cement clinker from iron tailings. Background technique [0002] Iron tailings are the wastes discharged from the concentrator after grinding iron ore and selecting useful components. Its main chemical components are oxides of silicon, aluminum, iron, magnesium, and calcium. The stockpiling of iron tailings not only occupies a large amount of land resources, but also causes serious environmental pollution. At present, as a secondary resource, iron tailings have few large-scale and effective utilization methods, and the utilization rate is very low. [0003] The raw materials for the production of Portland cement are mainly limestone, clay and their correction materials. The main mineral components of cement clinker are tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite. Usu...

AI Technical Summary

Problems solved by technology

Although the main chemical composition of iron tailings is suitable as a raw material for the production of cement clinker, in the existing research literature, there is no iron tailings content of more than 15% in cement raw materials, and the sintering temperature is lower than 1400 ° C, and the CO 2 Documents or patents on low-carbon cement clinker with 20% reduction in greenhouse gas emissions and 28-day strength rating of 62.5