Studies on the Behaviour of Magnesia in the Cource of Preparation of Calcium Silicate or Calcium Aluminate

Abstract

CaO-MgO-SiO₂ and CaO-MgO-Al₂O₃ Systems containing CaO and MgO at the same molecular ratio were studied. The results obtained are as follows:
1) It was comfirmed by X-ray analysis and chemical analysis that binary and ternary compounds containing MgO are formed in the system CaO-MgO-SiO₂ (CaO/MgO=1) when CaO/SiO₂ ratio is below 2. But above 2, these compounds are not formed and MgO exists as free MgO, and also when CaO/SiO₂ ratio is 1, CaO⋅MgO⋅SiO₂ is formed.
2) In the system CaO-MgO-Al₂O₃ (CaO/MgO=1) the binary compounds MgO⋅Al₂O₃ is formed only when CaO/Al₂O₃ ratio is below 1.66. These results are different from those reported by H. E. Schwiete and H. zur Strassen concluding that the combination of MgO and Al₂O₃ was found only when CaO/Al₂O₃ is below 1.