Liquidus curves have been determined by means of cooling curves and visual examination of the cooling melt. The binary systems of cryolite with aluminum fluoride and calcium fluoride gave, respectively: peritectic point at 30% aluminum fluoride and 739 °C, eutectic point at 40% aluminum fluoride and 694°C; eutectic point at 26% calcium fluoride and 945°C. In the system cryolite‐alumina‐calcium fluoride the ternary eutectic point was at 2.9% alumina, 21% calcium fluoride and 933°C. (Compositions are in weight per cent). Diagrams are given for the cryolite‐rich part of the systems cryolite‐calcium fluoride, cryolite‐alumina‐aluminum fluoride, cryolite‐alumina‐calcium fluoride, and cryolite‐alumina‐aluminum fluoride‐calcium fluoride.

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