1960 Volume 68 Issue 780 Pages 301-306
The previous work (J. Ceram. Assoc., Japan, 68 [778] 237 1960) was extended to the investigation of the reaction during the melting and the change of the structure of the electro-molten dunite when magnesia, dolomite and lime were added to the batch.
Magesia crystallized into periclase, the qantity and grain size of which were growing with increasing amount of MgO making the body more compact and stronger. In this case, however, a considerable amount of magnesia frew off during the melting.
The addition of lime showed the trend of separating periclase.
With less than 30% lime a low melting CaO-MgO-SiO2 compound was formed, which was unstable at high temperatures. It is, therefore, possible to control the condition of melting-by selecting a suitable reducing agent and the time of melting-for the purpose of eliminating the unstable compounds by the decomposition and vaporization, leaving the body composed of lime silicate, being stable at high temperatures.
With more than 30% lime periclase and 2CaO⋅SiO2 were produced, and showed dusting.
Using the radio isotope 45Ca* it was confirmed that Ca was existing in the glass phase between the crystals.
