Finely ground beryl was decomposed by mixing with ground limestone and soda ash andheating at 900C for,4-6, hours._x000D_
The sintered material was then crushed and leached by boiling under reflux with 5N sulphuric acid for up to 4 hours. The liquor containing Be, ; Al, . Fe and, other elements as sulphates, was separated from the residue which consisted mainly of silica and gypsum, either' by filtration or by decantation washing._x000D_
The clarified leach liquor.was first treated to remove Fed}: , by contacting with a primary amine-kerosene solution in 2 counter-current stages. The iron free liquor wa,s then passed to a 4-stage counter-current extraction unit where it was con- tacted with 0.5M di-(2 ethyl hexyl), phosphoric acid (EHPA) in kerosene. The'operating conditions were such that at least 99 p'br cent of the Be and only 7' per' cent of the Al- was, extracted The ,B6`= and. Al were ;stripped from the organic phase by sod- ium hydroxide solution of suitable concentration to form soluble "beryllate" and "aluminate" respectively. Most of the Be was subsequently precipTitated a's Bo(OH)2 by-hoating the alkaline solution to 90C, the Al remaining in solution. After filtra- tion and washing, the Bo(OH)2 could be ignited directly to BeO at about 1000 C or used as a feed to further purification stages aimed at producing "nuclear grade" BeO._x000D_
A small coaAter-current extraction unit was operated con- tinuously using liquor derived from the sintering and leaching stages. Data obtained in batch laboratory tests were confirmed._x000D_
A product obtained by ignition of the washed "beryllate" precip- itate contained more than'99 per cent BeO.