GB553098A - Improvements in methods of manufacturing alkaline earth metal beryllates - Google Patents

Abstract

553,098. Beryllium compounds. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Oct. 31, 1941, No. 14010. Convention date, Oct. 31, 1940. [Class 1 (iii)] [Also in Group XL] Alkaline earth metal beryllates, including magnesium beryllate. and described with special reference to barium are prepared, in states rendering them suitable for gettering purposes in electron discharge devices, by sintering a mixture of beryllium oxide, alkaline earth oxide (which may result from the heating of the carbonate) and a small amount of an inorganic oxide reagent selected from boric anhydride, calcium oxide, sodium oxide, potassium oxide, lithium oxide. The mixture may be produced by mixing in a liquid medium (e.g. water or alcohol) beryllium oxide, barium (or barium strontium) carbonate, with boric acid, or calcium oxide, or a carbonate of the alkali metals, drying and firing in hydrogen. Some excess of beryllium oxide may be used and appears to enter into solid solution in the beryllate. When used as a getter the crushed material may be coated as a paste on a refractory metal core and to facilitate liberation of metallic barium on heating a reducing agent such as powdered titanium may be mixed with the beryllate or the core may be a reducing metal such as tantalum. Specification 521,818 is referred to.