Preliminary Investigations in the High-Silica Region of the System BeO-Al₂O₃-SiO₂

Abstract

The nature of the liquidus surface in the high-silica region of the system BeO-Al₂O₃- SiO₂ was investigated by the quenching technique. One ternary eutectic (1515° ± 5°C) and two reaction points were located. The primary phase fields determined were those of bromellite, chrysoberyl, phenacite, mullite and silica. Beryl was obtained by subsolidus reactions at temperatures very close to the eutectic, but the possibility of the presence of a very small primary phase field for beryl could not be ruled out altogether. Results of previous work and present investigation were utilised in an attempt to prepare a composite diagram of the ternary system.