A Study On The Preparation And Properties Of Castable For The Tertiary Air Brake Pipe Ram Of Cement Kiln

The tertiary air brake pipe ram is one of the most critical facilities of new dry process cement kiln system, controlled the tertiary air flux. Service life of tertiary air pipe ram is long or short, can affect economic benefits of cement industries, and excellent performance of the tertiary air pipe ram castable can play a decisive role. Owing to the use of harsh environment, service life of the tertiary air brake pipe ram is always so short. So how to enhance performance of the tertiary air pipe ram castable has been one hotpot of refractory.In this paper, collected Al2O3-SiC low cement castable to be subject investigated of the tertiary air pipe ram castable, and used high aluminum homogenizing materials, silicon carbon, flint clay, alumina hollow ball as raw materials. Discussed the effect of grain composition, critical particle size, thermal treatment temperature, holding time, heating rates and application of light aggregate technology on physical property, mechanical property, thermal shock resistance and the alkali resistance of castable. Used XRD and SEM to analysis phase composition and microstructure, and ensured the best recipe on the basis of better comprehensive performance. Combined above-mentioned castable with the tertiary air pipe ram framework to make simulation test performance, and investigated difference among heavy aggregate castable, lightweight aggregate castable and contrast test castable. The results showed:(1) The variety of grain composition and critical particle size would not only affect bulk density of different sizes of particles, but also bore diameter and pore size distribution. So that, samples, based different grain composition and critical particle size, would be divergence in physical property, mechanical property, thermal shock resistance and the alkali resistance, when grain composition q=0.28 and critical particle size is 8mm, the samples would show the best performance.(2) The samples at different temperatures and tested related performance, whose phase composition presented differently, and different phase composition would affect the performances directly. Samples, treated at 400 ℃ and 600 ℃, would possessed worse performances. Compared the performances of samples at different temperatures, samples at 1200℃ would possess the best comprehensive performances.(3) Holding time and heating rates were one of the most important of thermal treatment. If other conditions were invariant, different holding time and heating rates would emerge differences about phase composition and microstructure. The anorthite phase and mullite phase were propitious to enhance physical property, mechanical property, thermal shock resistance performances. Samples, treated by heating rates of 5℃/min and holding time of 3h, would show better comprehensive performances than others.(4) Performances of samples made by alumina hollow ball showed that samples could possess better mechanical property and the alkali resistance when hollow ball instead of quantity is 10%, especially, the thermal shock resistance would enhance outstanding.(5) Combined above-mentioned castable with the tertiary air pipe ram framework to make simulation test performance showed that the performances of optimal castable had been enhanced, and could improve the service life of the tertiary air brake pipe ram.