AN IMPROVED MANUFACTURE OF NICKEL AND COBALT FROM THEIR ORES
Year: 1884

page_text: I, CHARLES DENTON ABEL of No 28 Southampton Buildings Chancery Lane in
the County of Middlesex Patent Agent and Consulting Engineer do hereby declare
the nature of this invention for AN IMPROVED MANUFACTURE OF NICKEL AND
COBALT FROM THEIR ORES and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
This invention relates to a novel process for smelting nickel and cobalt in such
manner that the cast metal shall be not only perfectly malleable and ductile but
shall also be compact and free from air bubbles.
This process is based on the peculiar property of molten nickel and cobalt of
absorbing both carbon and oxygen, taking up both simultaneously within certain
limits. On the solidifying of such castings the greater part of the oxygen passes
off and the porous metal produced is mostly unmalleable on account of the greater
or smaller per centage of carbon contained therein.
It is no doubt casy to remove the oxygen completely in the first instance by
long continued smelting in graphite crucibles, particularly under a covering of
carbon; but the casting will at the same time become all the more brittle, gray,
and like cast iron, the longer it is kept in a molten condition, because it takes up
all the more carbon during that time.
Generally speaking, when the smelting is effected in graphite crucibles (and
other crucibles, free from carbon, cannot at present be substituted for these) and
when the metal is not protected by additions containing oxygen, the taking up of
carbon is so rapid that the metal is obtained in a comparatively useless condition,
similar to that of cast iron. But even the castings produced with the addition of
oxygen, have a small percentage of carbon which renders them more
unmalleable, and such castings when not smelted under a carbon covering have a
strong tendency to become porous.
or less
According to the present invention the above defects are obviated and compact
and malleable castings of nickel and cobalt aro obtained by impregnating the
metal with manganate or permanganate of potash or soda or with other inanganates
or permanganates.
For this purpose, pure oxide of nickel or cobalt in the form of cubes or small
pieces is reduced at a moderate heat. The somewhat porous pieces thus obtained

page_text: are then impregnated as much as possible with a solution of manganate or per-
inanganate of potash or soda or of other inanganates or permanganates, containing
not more than four per cent. of the salt. The pieces are then dried and are best
smelted in crucibles in a furnace with air blast, and at a very high temperature
whereupon it will be found that the above named salts render the detrimental
carbonaceous gases in the crucible harmless, while they themselves become in part
reduced, resulting in the production of compact and ductile castings. The action
of the salt consists less in the absorption of the oxygen by means of the carbon,
than in rendering harmless the sinall quantity of carbon which is taken up by the
casting, notwithstanding all precautions.
In order to remove the oxygen introduced into the molten metal by the salt,
there is introduced into it at the moment when the mass becomes liquid, or a little
later, some black flux, obtained by carefully heating tartar to red heat under
exclusion of the air, and some charcoal. The combined action of the charcoal with
the potassium vapours produced from the black flux speedily remove the oxygen
remaining in the metal. In place of the black flux aluminium or calcium or
calcium-zinc produced by Caron's process, or mixtures of two or more of these
substances may be used with effect in combination with charcoal for removing the
last portions of oxygen. For this purpose sufficient charcoal is added to cover the
metal with a layer thereof, and the said metal or metals is or are introduced into
the molten metal through such layer. The said additions of aluminium, or calcium
or calcium zinc are preferably equal to about one tenth per cent. of the mass of
metal.
By this means compact and malleable castings of the best quality are obtained.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
First. In the manufacture of nickel and cobalt from their ores, the method of
impregnating the reduced metal with manganate or permanganate of potash or
soda or with other manganate or permanganate in order to produce compact and
malleable castings therefrom.
Second. In the production of metallic nickel or cobalt as set forth in the
preceding claim covering the metal with black flux at the termination of the
smelting process.
Third. In the production of metallic nickel and cobalt as set forth in the first
claim the addition of small quantities of aluminium or calcium or calcium zinc or
mixtures of these inetals to the molten mass after covering the same with charcoal,
at or after the termination of the smelting process.