Method for preparing cement clinker by using waste concrete

Abstract

A method for preparing cement clinker by using waste concrete is disclosed, which comprises the following steps: collecting, drying and breaking waste concrete, selecting concrete particles with a particle size of 5mm-20mm, adding iron powder or sulfuric acid dregs into the concrete particles, mixing and grinding the mixture, and screening cement raw material powders by use of a square hole screen (80mum) with screen residue being 8%-16%, wherein if the iron powder is added, the mass percent of the concrete is 98.5%-99.5% and the mass percent of the iron powder is 0.5%-1.5%; and if the sulfuric acid dregs are added, the mass percent of the concrete is 95.0%-96.0% and the mass percent of the sulfuric acid dregs is 4.0%-5.0%; and finally balling, calcining and quenching the concrete so as to obtain the cement clinker. According to the method, the mass percent of the waste concrete in the cement clinker is more than 95%, the quality of the cement clinker is equivalent to that of the common cement clinker, and the cement clinker can be taken as raw material to be applied to the concrete preparation, so that a good utilization approach is found for reutilization of the waste concrete.

Description

technical field [0001] The invention relates to a method for preparing cement clinker, in particular to a method for preparing cement clinker by using waste concrete. Background technique [0002] With the development of the country's economy and construction industry, a huge amount of waste concrete is produced every year due to the demolition of old buildings. If these waste concrete are simply landfilled, it will undoubtedly cause serious pollution to the environment and a huge waste of energy. How to deal with these waste concrete has attracted great attention from the construction industry and environmental protection departments. Waste concrete is a kind of hardened concrete, mainly composed of hardened cement slurry (cement stone), sand and gravel aggregates, etc., of which sand and gravel aggregates account for 70% to 80%. The recycling technology of waste concrete is to focus on its overall Or a certain separation component, so far, the research on the reuse of was...

AI Technical Summary

Problems solved by technology

In 2010, the output of cement in my country was 1.868 billion tons, and the output of clinker was 1.152 billion tons. According to the consumption of 0.20-0.21 tons of clay and 1.25-1.27 tons of limestone per ton of clinker, the annual consumption of limestone is about 1.45 billion tons and clay is about 236 million tons. Although most cement plants have replaced clay with shale and sandstone, shale and sandstone are still non-renewable natural resources and are facing the problem of depletion

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