Method for preparing cement clinker from high-proportion carbide slag through decomposition outside kiln of five-stage preheater

Abstract

The invention relates to a method for preparing cement clinker from high-proportion carbide slag through decomposition outside a kiln of a five-stage preheater. The method is finished by the steps of drying carbide slag, grinding raw materials, and sintering clinker. The step of the drying carbide slag simultaneously comprises the substeps of drying and removing impurities; the step of grinding the raw materials comprises the substeps of grinding, and discharging waste gas; and the step of sintering the clinker comprises the substeps of preheating outside the kiln, decomposing outside the kiln, calcining, and storing the clinker. By implementing the method, the problems of waste residue treatment in the conventional domestic industry for preparing industrial chemicals by an acetylene method are solved, the waste residues such as carbide slag, crushed limestone, limemud and the like can be utilized to the maximum extent, and the problems of environmental pollution caused by waste residue treatment are solved. The carbide slag with water content of less than or equal to 10 percent is directly dried by waste gas of a kiln tail; an additional heat source is saved; waste heat is utilized reasonably; through air separation of the carbide slag in a dryer, ferrosilicon is removed from the carbide slag, the problem that ferrosilicon blocks a grid plate in a mill is solved, the operation of a raw material mill is separated from the operation of a rotary kiln, the operation rate of the raw material mill is reduced, the raw material mill can adapt to various raw materials of carbide slag, and the capacity of the raw material mill is utilized to the maximum extent.

Description

technical field [0001] The invention relates to a cement clinker production method, in particular to a process method for producing cement clinker by decomposition outside a kiln of a five-stage preheater with a high proportion of calcium carbide slag. Background technique [0002] The invention patent No. 200810072854.5 "Technical method for producing cement clinker by dry discharge of calcium carbide slag 100% instead of natural calcareous raw materials" discloses a method of producing cement clinker by using calcium carbide slag as the main raw material and decomposing it outside the kiln. The ratio of raw materials is: calcium carbide slag 71.8~77.8%, sandstone 8~12%, sulfuric acid slag 1.5~2.5%, fly ash 11.2~15.2%. There are following deficiencies in this method: [0003] (1) Dry discharge of calcium carbide slag can replace 100% of natural calcareous raw materials. Only the waste calcium carbide slag discharged from the acetylene production device can be used, and the...

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Problems solved by technology

[0003] (1) Dry discharge of calcium carbide slag can replace 100% of natural calcareous raw materials. Only the waste calcium carbide slag discharged from the acetylene production device can be used, and the limestone slag that cannot be used by the lime kiln specially equipped for the acetylene production device cannot be used. Unusable lime slag also cannot be used

[0004] (2) Since the rotary kiln adopts a three-stage preheater at the kiln tail, the outlet temperature of the preheater reaches 500°C. Such a high temperature is used to dry calcium carbide slag with a moisture content of ≤12%, and the heat energy utilization efficiency is poor, which increases the heat consumption of the system 20%

[0005] (3) The auxiliary raw materials and calcium carbide slag after intermediate unloading and grinding enter the kiln tail drying pipe at the same time to dry and mix into raw meal. The hoist at the kiln end is also prone to aging and shortens its service life

At the same time, raw material grinding and rotary kiln calcination must be carried out simultaneously. Failure of the raw material grinding system will affect the operation of the rotary kiln, reducing the operating rate of the rotary kiln, and at the same time, the capacity of the mill cannot be fully utilized.

[0006] (4) There is no separation treatment measures for ferrosilicon in carbide slag

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