作者：Eizo MAEDA and Sadao KAKUMA*

作者单位：

刊名：Journal of the Technical Association of Refractories, Japan

ISSN：

出版年：2013-01-01

卷：33

期：1

起页：

止页：

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语种：英文

关键词：low-cement castable, setting mechanism, coagulation, hydration of alumina cement, pH-value

内容简介

Changes in the hardness, ultrasound velocity, temperature, ion concentration and pH-value in low-cement castables were analyzed to investigate in detail three insufficiently clarified points on the setting mechanism of castables: (1) the process to coagulation, (2) hydration of alumina cement, and (3) influence of pH-value. The obtained results, which correct an error and reinforce the setting mechanism reported earlier, are as follows: We previously thought that coagulation occurs when the Ca2+ ion concentration attains some value and the colloid of the superfine powder becomes unstable. We correct that hypothesis to say that the colloid is already unstable just after the mixing, the instability increases with time and coagulation occurs. The hydration of alumina cement clearly takes place after the setting of the castables and is absolutely different from the setting of the castables. The coagulation in the lowcement castables is not controlled by pH change.