Improvements in the Method of Separating Metals from Ores and from other Mixtures of Insoluble Substances therewith.
Year: 1893

page_text: Date of Application, 8th Dec., 1893-Accepted, 7th July, 1894
GUDDUID
Improvements in the Method of Separating Metals from Ores and
from other Mixtures of Insoluble Substances therewith.
I, EDUARD RUDOLF BESEMFELDER, D.Ph. of 88 Tauentzienstrasse Grosse
Mochbern bei Breslau Silesia in the Kingdom of Prussia and German Empire,
Chemist, do hereby declare the nature of this invention, 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 method of or process for the separation of metals from
ores and other insoluble materials in combination or mixture therewith, and is
especially applicable in the utilisation of certain waste materials such as the
strontian residues from the desaccharisation of molasses, the process being
continuous and permitting the recovery and re-employment of the reagents
employed.
The new process consists in treating the compound material at the critical
pressure and temperature, with a decomposing material and particularly with
ammonium chloride, in a dry state. The superfluous reagents together with the
volatile products are separated by distillation or sublimation from the non-volatile
residue and from this the soluble part is separated by a solvent.
In carrying out the process practically, the dry and preferably pulverised material
is mixed with a suitable quantity of ammonium chloride to be determined in each
case in rather more than molecular proportions, and the mixture is introduced into
a vessel in which it can be subjected to pressure and heat. During the process
the mixture is agitated, which may be effected by rotation or suitable movement of
the vessel. The pressure and the heat may vary within certain limits, the condition
being that the heat employed is sufficient for the dissociation of the ammonium
chloride or other dissociation compound at the pressure used. This being so, the
'component parts of the mixture are subject to the action of the liberated hydro-
chloric acid and of ammonium gas under pressure.
After having been treated thus for a sufficient time, the volatile constituents or
contents of the vessel are distilled or sublimed and condensed in a suitable
receiver.
The residue is treated with a convenient solvent such as water, for the separation
of the soluble portions therefrom.
The total matters from the vessel are thus separated into volatile, soluble
and insoluble parts, each of which may be treated and purified as desired by
known means.
The ammonia contained in tbe sublimate or distillate can be re-converted into
ammonium chloride by combination with the hydrochloric acid arising from the
decomposition of the chlorides produced by the process, so that there need be
no loss of acid or base, the procedure being similar to that adopted in the
soda-ammonia process.
As an example of the method of procedure which I may adopt I will now
describe in what manner my invention may be carried into effect with reference to
the utilisation of the strontian residues from the desaccharisation of molasses. The
quantities given are those which I find to give the best results, but they may be
varied without departing from the spirit of my invention.
The dry pulverised residue is mixed with chloride of ammonia in the proportions
of about one part of residue to two parts of chloride of ammonia. The mixture
is placed in a suitable rotating vessel and is subjected for about an hour to a heat
of 350 degrees Celsius under a pressure of from 3 to 6 atmospheres. The effect of

page_text: the rotation of the vessel is to constantly expose fresh particles of the mixture to
the action of the dissociated vapours. If desired, however, other known means
or devices for agitating the mixture may be employed in lieu of the rotating
vessel.
The volatile products which are separated by 'the heat consist chiefly of unaltered
chloride of ammonia, carbonate of ammonia and sulphide and sulphite, of ammonia.
These products are distilled or sublimed and condensed in a suitable receiver or
series of receivers. The free ammonia can be re-converted into chloride of ammonia
by known treatinent with hydrochloric acid in an apparatus resembling a Glover
tower. The carbonate and other ammonia salts contained in the sublimate or
distillate are changed into chloride of ammonia by the addition of water and coal
dust together with crystallised chloride of magnesium the resulting mixture
being again sublimed. The sublimed chloride, of ammonia is sufficiently pure to
be of practical use.
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The soluble,portion of the non-volatile strontian residues remaining in the boiler
or vessel are removed by water and their constituents as well as those of the insoluble
portions may be recovered by any known means.
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As a further example, I will describe my method of treating ores of cobalt and
manganese containing from 5 to 6 per cent. of cobalt, or of nickel containing about
5 per cent. These ores are treated in the manner herein before described for the
strontian residues, that is to say chloride of ammonia is added thereto and the
mixture is digested in an autoclave under high pressure and the unsublimated
residue is treated with water. The insoluble residues on drying rare found to
contain from 2 to 4 per cent. of cobalt, or from 2 to 5 per cent. of nickel as the case
may be. Therefore 63 per cent. of the cobalt, or 50 per cent of the nickel is
dissolved and if the operation has been properly carried out, 'the solution will
Contain no iron. The small quantity of manganese which may be contained in the
solution will be precipitated by the action of the air.
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Having now particularly described and ascertained the nature of my said inven
tion and in what manner the same is to be performed I declare that what I
claim is
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The hereinbefore described method of or process for the separation of metal
from ores and other similar materials, which consists in exposing them to heat
under pressure in contact with ammonium chloride or a similar salt, substantially
as set forth.
Dated this 7th day of December A D .1893
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