466,763. Distilling metals. BLACKWELL, H. A., and TURNER, W. L. Sept. 4, 1935, Nos. 24623 and 28052. [Class 82 (i)] [Also in Group XI] Magnesium, beryllium, calcium, strontium and barium are separated from their ores or compounds by mixing the latter with a subdivided solid reducing agent of such a nature that transitory or eddy currents can be generated therein and heating the mix by high frequency induction of not less than 50,000 periods in a continuously evacuated container at a pressure less than the dissociation pressure of the ore or compound. The reducing agent may be graphite, silicon, aluminium, calcium, or alloys thereof and it may be partly in powder form and partly in the form of lumps. Alternatively, a nonconducting reducing agent such as calcium carbide may be employed, in which case a conductive primer is placed within or around the mix, e.g. the mix may be contained in a graphite crucible. A furnace for carrying out the process comprises a steel container 10 with copper shield 11. Coil 13 and refractory lining 15 ; water is circulated through the coil 13 which is connected at terminal 14 to a thermionic valve generator 28. The mix is charged into the lining 15 or into a crucible 38 and the vapours are condensed in a dome 19 provided with a coil 25 serving as a conduit for cooling water and as a high frequency coil for fusing metal condensed in the dome. An internal channel 20 provided with a valve outlet 21 serves to collect the fused metal; alternatively, the dome may be removed for fusion of the condensed metal. An outlet 22 is connected to a vacuum pump 26.
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