RECRYSTALLIZATION OF BERYL SINGLE CRYSTAL

摘要

PURPOSE:The recrystallization of natural beryl single crystals including many defects and contaminants is effected in an autoclave using LiCl saturated solu tion as a solvent at prescribed temperature and pressure to produce beryl single crystals of high purity. CONSTITUTION:A powder 6 of beryl single crystals with many defects or contaminants such as naturally occurring beryl single crystals or beryl single crystals synthesized by the flux method and saturated aqueous solution of LiCl 7 of 10mol% or higher concentration are charged in a metallic capsule 5 and the capsule is placed in an autoclave 1. The autoclave is heated in an electric furnace and high pressure is generated in the metallic capsule. At this time, distilled water is forcibly introduced into the autoclave by means of an outer pump to balance the pressure between the inside and the outside of the capsule to avoid its bursting. The temperature and the pressure are kept at 480-500 deg.C and 750kg/cm<2> or higher for 7 or more days whereby beryl single crystals of high purity are recrystallized in the capsule.