| 摘要 |
Carbon cathode waste material contg. Na3AlF6, AlF3, CaF2, NaF is heated (600-1200 deg.C) in the presence of water, oxygen and SO2 to generate HF. The waste is preferably 1-5 mm particles and the heating may take place in a fluidised bed reactor, packed bed reactor or closed furnace reactor and the SO2 may be produced in situ by adding S to the heated waste. The generated HF may be reacted with agents to form AlF3 or cryolite. - Recovering fluoride values from waste cathodes and linings of Al electrolytic cells. EPAB- EP--78304 B A process for the recovery of fluoride values from carbonaceous cell linings and/or cathodes, which process comprises liberating the fluorine as gaseous hydrogen fluoride by heating the carbon-aceous materials in the presence of oxygen, water, and sulphur dioxide. (9pp) |
