摘要
测定了7个不同厂家的SiO2微粉的化学组成、堆积密度和pH值。研究了不同SiO2微粉对矾土基浇注料的流动性、硬化时间、不同温度热处理后浇注料的强度和显气孔率、加热永久线变化和抗热震性的影响。结果表明:当SiO2微粉的pH值为6.0~6.5时,浇注料的性能最好,碱性或偏酸性的SiO2微粉都不适合在矾土基浇注料中添加;加入pH=6.2的4号和7号SiO2微粉的浇注料的流动性分别为170mm和180mm,硬化时间分别为6h和7h,试样显气孔率较低,强度和抗热震性较好,并且使用寿命较长。
The chemical composition,bulk density and pH of silica micro-powder from seven different manufacturers were measured.The effects of silica micro-powder on the properties of bauxite based castable such as flowability,setting time,strength and apparent porosity after the heat treatment of different temperatures,permanent change in dimension on heating,thermal shock resistance were studied.The results show that the castable adding silica micro-powder with pH 6.0~6.5 has the best properties,either basic or weak acidic silica micro-powder was unsuitable for bauxite based castable.Flowability of the castable 4# and 7# adding silica micro-powder with pH 6.2 reaches 170 mm and 180 mm,setting time is 6 h and 7 h respectively.The castables have lower apparent porosity,better strength and thermal shock resistance,that cause the longger service life.
引文
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