| 摘要 |
<p>797,854. Distilling calcium. PECHINEY COMPAGNIE DE PRODUITS CHEMIQUES ET ELECTROMETALURGIQUE'S. April 4, 1956 [April 7, 1955], No. 10333/56. Class 82(1) [Also in Group XII] Calcium is produced by decomposing commercial calcium carbide in a vacuum at a temperature of 1400-1700‹C., any calcium oxide and calcium carbide in the vapours being fractionally condensed at a temperature between 1100‹C. and 1200‹C., the metallic calcium being separately condensed. In the apparatus shown in the Figure calcium carbide, preferably in the form of granules 3/15 mm. diameter are fed from hopper 1 to an annular decomposer chamber between graphite sleeve 5 and gas collector 7. This chamber is heated by resistances 6 separately controlled to produce a uniform temperature. Gases pass through apertures into the gas collector and downwards to condensation zone 12 where any oxide and carbide are deposited, calcium being deposited in a water cooled zone 14. Vacuum is applied to the apparatus through pipe 18. When the charge of carbide is decomposed gas collector 7 is lowered by means of lever 8 to discharge the residue which is deflected by screen 13 into an annular receiver 17. The lower part of the apparatus comprising condenser 14 and receiver 17 may be disconnected periodically for removal of the condensed calcium and residues.</p> |
