A process for calcining phase-separated clinker with externally cast high-calcium granular slag

Abstract

The invention provides a phase-separated clinker calcination process for outside-thrown high-calcium granulated slag. According to the process, in a novel dry firing system, a feeder is arranged between a pre-decomposition furnace and the tail of a rotary kiln and is connected with the rotary kiln, high-calcium granulated slag is continuously and uniformly thrown to the tail of the rotary kiln by the feeder and is mixed with a pre-decomposed cement crude material, and a mixture is calcined in the rotary kiln after mixing, so as to produce a phase-separated clinker mixture of silicate cement clinker and heat-treated high-calcium granulated slag, wherein chemical ingredients of the high-calcium granulated slag comprise calcium oxide and ferric oxide, the content of calcium oxide is 20-60wt%, and the content of ferric oxide is not lower than 12wt%. The process has the advantages that the phase-separated cement clinker is prepared by using a simple process, so that slag of the steel-making industry is utilized effectively, the problem of environmental pollution is solved, and the production cost of cement is reduced; the high-calcium granulated slag is directly thrown into the rotary kiln and is heated, and a previous grinding step is avoided, so that energy sources are saved.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a phase-separation clinker process for externally throwing high-calcium granular slag and calcining phase-separated clinker. Background technique [0002] The output of my country's metal smelting industry ranks first in the world, producing about 80 million tons of steel slag every year, and the current comprehensive utilization rate is less than 15%. There are three main ways to use steel slag in the cement concrete industry in my country: 1) Grinding it into raw cement; 2) Grinding it as admixture or concrete mineral admixture; 3) Crushing it into concrete aggregate. Steel slag has a chemical composition similar to that of cement clinker. Because it contains f-CaO that expands with water, its stability has always been a factor that restricts its use as cement admixtures, mineral admixtures, and aggregates; in addition, steel slag contains a certain amount of The ...

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Problems solved by technology

[0002] The output of my country's metal smelting industry ranks first in the world, producing about 80 million tons of steel slag every year, and the current comprehensive utilization rate is less than 15%

The large discharge of metallurgical slag not only occupies a large amount of land, but may also cause varying degrees of pollution to the soil and water environment

[0003] In order to break through the two major restrictive factors (stability and grindability) in the popularization and application of steel slag, some enterprises at home and abroad have adopted thermal braising, slag pre-method, etc. to solve its stability; Grinding problem, but these methods also effectively solve the problem, but also increase the difficulty of the process

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