| 摘要 |
<p>(Soc. G</>aen</>aerale Metallurgique de Hoboken) Tantalum and/or niobium carbides are obtained by subjecting an ore or a metallurgical bye-product containing one or both of these elements to a reducing operation in the presence of a sufficient amount of iron and of an excess of carbon (coke, charcoal or the like) to obtain an impure alloy containing iron and the whole or the major part of the Ta and/or Nb concentrated in the form of carbides, and subjecting this impure alloy to a chemical treatment in order to separate these carbides therefrom. The chemical treatment may take the form of treatment with sulphuric or other acid and the residue of such treatment may be subjected to a mechanical treatment to separate the heaviest carbide particles therefrom. According to modifications, the primary material is reduced in the presence of iron without the addition of carbon in an electric furnace, the whole or parts of which are made of carbon bricks or are tamped with carbon; or the primary material consisting of a ferro-alloy is melted without the addition of carbon and is afterwards cast into a ladle or the like which is lined with carbon. Metal reducing agents such as p aluminium, magnesium and calcium may be added to the charge for the reducing operation. Specification 457,760 is referred to.</p> |
