| 摘要 |
1,196,092. Production of Cr powder. OFFICE NATIONAL D'ETUDES ET DE RECHERCHES AEROSPATIALES. Feb. 12, 1968 [Feb. 28, 1967], No.6867/68. Heading C7D. Chromium oxide powder masses between 1 and 10 hg. in weight contain Mg ingots embedded therein and are heated to distil the Mg and so reduce the oxide powder, the powder masses being thermally insulated from each other. In Fig. 1 of the drawings the powder 26 and the ingot 25 are contained in a dish 22 (e.g. of iron or mild steel) which rests on an insulating layer 24 [e.g. of powdered Al 2 O 3 or MgO or an agglomerated disc thereof see Fig. 3 (not shown) or a disc of porous carbon] in a graphite crucible 18. The enclosure 15 is heated by resistance heater 12 (which may be divided into vertically distributed sections which may be independently controlled) and an inert gas (e.g. Ar) may be introduced through passage 27.
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