Abstract: A process for separating and refining substantially pure aluminum from aluminum-bearing materials including bauxites, clays and metallic scrap, wherein a mixture of such aluminum-bearing materials, calcium chloride and a reducing agent is heated above 1600.degree. C., and gases are vented to a cooling zone where condensed chlorides and aluminum are collected. Condensed aluminum trichloride is recycled and mixed with lime to produce calcium chloride in another starting batch. The reducing agent preferably is a carbon or silicon compound.

Abstract: Apparatus for separation of mixtures wherein a mixture is cooled very slowly in a quiescent, nondisturbed condition to produce large dendritic crystals of solidified solvent, then heated very slowly while liquid of high solute concentration is drained from the large interstices between the crystals, the cooling and reheating being effected by slowly conveying containers of mixture in a continuous circular path through a long heat transfer conduit or tunnel having a central refrigeration zone. Adjacent trains of containers travel through the tunnel in opposite directions. Arrangements are provided for collecting liquid having high concentrations of solute and recycling this liquid back through the foregoing process in said containers after they have been emptied of liquid treated in a preceding cycle.

Abstract: Method and apparatus for separation of mixtures wherein a mixture is cooled very slowly in a quiescent, nondisturbed condition to produce large dendritic crystals of solidified solvent, then heated very slowly while liquid of high solute concentration is drained from the large interstices between the crystals, the cooling and reheating being effected by slowly conveying containers of mixture through a long heat transfer conduit or tunnel having a central refrigeration zone; parallel trains of containers preferably travel through the conduit in opposite directions. The residence time of the mixture in traveling through the conduit or tunnel will be of the order of many hours or a few days, depending upon many factors, and in a large industrial installation the length of a pass through it will be several hundred feet; such factors are interrelated to the quantity and compositions of mixtures being processed.