Patent GB-378017-A (GB)
Title: Process for obtaining or concentrating germanium
IPC: C22B41/00
Filed: 1931-04-22
Abstract: In a process for obtaining or concentrating germanium, materials containing small quantities of germanium are distilled in a non-oxidizing or reducing atmosphere between 400-1200 DEG  C. and preferably between 600-1050 DEG  C., the temperature being chosen so that melting of the charge is avoided or minimized, and the fraction subliming between these temperatures is collected. Specified raw materials are: bituminous slate, the less volatile fractions from the distillation of coal, flue dust, ashes, slags, and ores, concentrates or dressing waste containing small quantities of germanium.  Free or combined sulphur, say as iron pyrites, may be added to the charge, or gaseous sulphur or hydrogen sulphide may serve as the reducing gas. Other reducing gases specified are carboniferous gases such as producer or illuminating gas, hydrogen, or mixtures thereof.  The germanium, which distils as the monosulphide and oxide, and to some extent as the metal, may be condensed on material to which metals such as zinc or copper, or oxides have been added.  Reference is made to the production of alloys by this means.  The distillate may be further concentrated by repeated distillation.  Volatile metals such as zinc or cadmium or metal compounds may be added to the charge.  A countercurrent method of operation may be employed, and the process may be effected at increased or reduced pressure.  The condensing vessel may be maintained at 350-600 DEG  C.  In an example, the deposit condensed on the walls of the condenser, or on a p refractory material such as corundum, may be extracted with alkaline solvents, or with acids such as hydrochloric or nitric acid or both. The Specification as open to inspection under Sect. 91 (3) (a) refers to working up the distillate by distillation of germanium tetrachloride in a current of chlorine.  This subject-matter does not appear in the Specification as accepted.ALSO:In a process for obtaining or concentrating germanium, materials containing small quantities of germanium are distilled in a non-oxidizing or reducing atmosphere between 400-1200 DEG  C. and preferably between 600-1050 DEG  C., the temperature being chosen so that melting of the charge is avoided or minimized, and the fraction subliming between these temperatures is collected. Specified raw materials are: bituminous slate, the less volatile fractions from the distillation of coal, flue dust, ashes, slags, and ores, concentrates or dressing wastes containing small quantities of germanium.  Free or combined sulphur, say as iron pyrites, may be added to the charge, or gaseous sulphur or hydrogen sulphide may serve as the reducing gas.  Other reducing gases specified are carboniferous gases such as producer or illuminating gas, hydrogen, or mixtures thereof.  The germanium, which distils to some extent as the metal, may be condensed on material to which metals such as zinc or copper, or oxides have been added.  Reference is made to the production of alloys by this means. The distillate may be further concentrated by repeated distillation. Volatile metals such as zinc or cadmium or metal compounds may be added to the charge.  A counter-current method of operation may be employed, and the process may be effected at increased or reduced pressure.  The condensing vessel may be maintained at 350-600 DEG  C. An example relates to the treatment of the deposit condensed on the walls of the condenser, or on a refractory material such as corundum.