| 摘要 |
<p>1441736 Refining cadmium PREUSSAG A G METALL 25 Oct 1974 [13 April 1974] 46308/74 Heading C7D Crude cadmium is continuously refined by evaporation in a vacuum and passing the vapour through a reflex condenser to remove the higher boiling point impurities prior to condensing and collecting the purified Cd. The apparatus used comprises an inverted U-shaped steel vacuum chamber 20, with a first and second legs formed by an inclined transition portion 34. In the first e.g., an evaporator portion 22 with a heating jacket 28 leads to a reflex condenser 30 containing a helical baffle 56 and surrounded by a temperature adjustable jacket 32. The outlet of the reflex condenser 30 connects with transition portion 34 which is connected to a condenser 36 in the second leg. A temperature adjustable jacket 38 surrounds condenser 36. A vacuum tube 42, connected to a pump, extends to just above the outlet end of the second leg and has the largest possible diameter to permit a minimum annular space 50 between the tube 42 and the wall of chamber 20 to give the maximum condensing surface. The free end of the second leg feeds via pipe 44 into a heated receiver 46. The crude liquid Cd input to the first leg is from a heated vessel 10 through tube 12, a further tube 16 leading from the first leg to a heated distillation residue container 14, the heights of tubes 12 and 16 being arranged such that the residue cannot feed back into the input tube. The materials in vessels 10, 14 and 46 act as barometric locks. In operation, the pressure and temperatures are adjusted and crude Cd is sucked into evaporator 22 via tube 12. The evaporated vapour passes into the baffled reflex condenser where impurities and some Cd condense and flow back counter current to the ascending vapour, this further purifying the gas. The distillation residue is discharged into receiver 14. The remaining gas passes through the transition portion 34 into condenser 36 in the second leg where it is condensed and collected in vessel 46.</p> |
