Preparation method for cement-free castable

Abstract

The invention belongs to the technical field of refractory materials, in particular to a preparation method for cement-free castable which can be applied to a cement kiln coal injection pipe. In the castable, electrically-molten brown fused alumina, SiA and alpha-Al2O3 micro-powder are taken as main raw materials, hydrated alumina (rho-Al2O3) and MgO-SiO2-H2O are taken as a combined system, sodium tripolyphosphate is taken as a deflocculant, citric acid is taken as a retarding agent, and metal silicon powder and metal aluminum powder serving as antioxidants and anti-explosion fibers are contained. A large quantity of dichroite phases and a small quantity of spinel and mullite phases are generated by using a part of a substrate treated at a high temperature of the cement-free Al2O3-SiC refractory castable prepared with the method, so that the medium-temperature sintering performance of the Al2O3-SiC castable is improved, and the high-temperature mechanical property, oxidation resistance, wearing resistance, alkali resistance and thermal shock stability of the castable are enhanced. The adding amount of water is less than 4.5 percent, rupture strength at the using temperature of 1,100-1,400 DEG C is more than 25 MPa, apparent porosity is less than 14 percent, the wearing resistance value is less than 5cc, and the thermal shock stability is tested with a water cooling method for more than 50 times.

Description

technical field [0001] The invention belongs to the field of refractory materials and relates to a preparation method of a cement-free castable which can be applied to a coal injection pipe of a cement kiln. Background technique [0002] The coal injection pipe of cement kiln is a key part of the cement kiln. The front end of the coal injection pipe is located in the high temperature zone of the cement kiln. It is mainly affected by the clinker radiation in the rotary kiln, the flame radiation and the heat conduction of the secondary air. The temperature ranges from 1100°C to 1400°C. internal fluctuations. During the working process of the coal injection pipe, the pouring material of the coal injection pipe is eroded by the alkali steam at the kiln head and the erosion and abrasion of the cement clinker flying sand, and the coal injection pipe itself will vibrate. [0003] Traditional cement kiln coal injection pipes generally use steel fiber reinforced corundum and high al...

AI Technical Summary

Problems solved by technology

[0012] The purpose of this invention is to provide a kind of Al that does not contain hydraulic cement for cement kiln coal injection pipe 2 o 3 -Preparation method of SiC refractory castable, and solve the problem of low initial strength of cementless castable, improve Al 2 o 3 - The medium temperature sintering performance of SiC castables can improve the high temperature mechanical properties, oxidation resistance, wear resistance, alkali resistance and thermal shock stability of castables

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