Year: 1896

page_text: Date of Application, 8th Oct., 1896-Accepted, 28th Aug., 1897
A communication by ALF SINDING-LARSEN of 49 Huitfeldtsgade, Christiania, in the
Kingdom of Norway.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in
the County of Lancaster, 118 New Street, Birmingham in the County of Warwick and
322 High Holborn in the County of Middlesex, Civil Engineer, 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 rational mechanico-electrical process for extracting
metals from their compounds, inore particularly from raw materials containing
sulphur (such for instance as copper pyrites) and which are found at places where
coals are difficult to obtain or are expensive, but on the other hand where electrical
power is cheaply accessible.
The process consists of the following operations:-
I. The ores or raw materials are pulverised in the ordinary manner and if necessary
washed.
II. The disintegrated ores are exposed to the action of a current of chlorine gas,
air being excluded, and are agitated or stirred up. Instead of chlorine any other
suitable gaseous halogen inay be employed.
III. The salts capable of being electrolysed which thereby result are electrolysed by
the wet or dry process, electrodes being employed which are not attacked by the
halogen. The chlorine, or other halogen gas recovered by means of the electrolysis is
again utilised for operation II.
IV. The volatile halogen compounds formed by the chlorination are conveyed into
water or other suitable absorbent and the soluble halogen compounds thus formed
are electrolysed as in operation III and the chlorine thus obtained is used
over again.
V. When the operation described as III is carried out by the wet process, the
separation of iron from copper (if it be a question of copper pyrites) is obtained by
precipitating the salt solution by means of metallic iron. By this means there is
obtained metallic copper and an iron halogen salt which latter is again electrolysed,
halogen gas and iron being recovered for further re-utilisation.
VI. If on the other hand the further treatment of the substances obtained by.
chlorination is to take place by the dry process, the chlorination must take place in
such a way that the various metalloids and other halogen compounds are obtained
separately. This is a main point of the process and is rendered possible by
maintaining in the raw material during the chlorination such a temperature that the
greater part of the halogen compounds formed are volatilised; the fumes thus
obtained are then conducted through a series of receivers or vessels all warmed to a
given temperature, the temperature of condensation of the various substances.
The process assumes the form of a complete cycle as appears from the foregoing,
immaterially whether the operation be carried out under modification V. or VI. This

page_text: process may be expressed by means of general formula given below (M indicates a
metal, A an element of the oxygen group, B a halogen.
It must be noted that an addition of heat is not generally necessary; if the raw
materials are treated in a pulverised condition the necessary heat will be developed
by the chlorination, and therefore the use of combustibles may be dispensed with.
If the electrolysis be effected by the wet process, the electrolyte is obtained by
treating the chlorinated ore with water so that the soluble salts.are extracted. If the
remaining residuum contain valuable substances undissolved, such as sulphur and the
like, it is washed with water in order to recover such substances.
In order to illustrate the practical working of the invention there is shown in the
accompanying drawing a system of apparatus, which may be used when treating
copper pyrites. The drawing shows a longitudinal section of an apparatus. A is the
feed hopper for pulverised ore leading into the side of a drum B at one end of the
same. Below this drum there is another similar one B' and there may 'be still more
such arranged the one below the other. These drums are provided with a stirring
apparatus B2 by aid of which the ore is ultimately moved from one to the other
drum and simultaneously stirred about in the druins in order to be intermixed with
the chlorine gas that passes up through the drums, from a part of the apparatus which
will hereinafter 'be described.
C is a basin having an inclined bottom and connected with the lower one of the
said drums through a funnel (, the wall C² of which reaches down into the water in
the basin. The chlorinated ore drops down into this basin and the soluble parts are
here dissolved while the remainder is from time to time lifted out of the basin.
DD are electrolytic cells of any suitable construction and number, and M M¹ are
pipes leading from the aforesaid basin to the bottom of the first electrolyser and
from the upper part of this one to the next and so on. From the top of the
electrolyser lead pipes F F to the aforesaid funnel C. The solution from the basin C
is in this manner electrolised in the cells D and the chlorine gas so formed carried
through the pipes F F and funnel C¹ to the drums to be utilised for the chlorination
of the ore.
E is an auxiliary basin connected through a pipe N with the electrolyser D¹. By
means of a pump G and the pipe G₁ the electrolised solution is taken from the basin E
back to the dissolver C to be utilised anew.
L is a pipe leading from the upper drum B down to the bottom of a coke-tower I,
which latter is placed into a water reservoir H. From this reservoir leads to the top
of tower I a pipe K provided with a pump K¹ keeping in this manner the coke in the
tower wet. The gases created in the drums B inclusive of remaining chlorine gas are
carried through the pipe L and pass up through the tower wherein the water will
absorb the greater part of the same, so that they may in this manner be saved and
utilised.
In the foregoing, mention is repeatedly made of chlorination and chlorine, but
under certain circumstances, other halogens may be used, for which reason the process
is not limited to chlorine.

page_text: Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, as cominunicated to me by my
foreign correspondent, I declare that what I claim is :-
1. A process for extracting metals from their compounds more particularly from
ores containing sulphur, characterised by a gaseous halogen (for instance chlorine)
being supplied to the heated raw materials with the object of forming electrolysable
salts (one or more) and by a subsequent electrolysing of these salts in order thereby
to again recover the halogen gas, anodes being employed which are not attacked by
the gas, substantially as herein before set forth.
2. In a process such as described, the production of the heat necessary for the
halogenation (chlorination) by the use of pulverised ore, whereby the reaction heat is
increased, substantially as described.
3. In a process such as described, the conducting through a series of receptacles
heated to various determined temperatures of the volatile halogen compounds formed
in order to bring about a separate condensation of the various compounds according to
their respective temperatures of condensation substantially as described.
4. In a process such as described, the recovery of the halogen gas from the
non-metallic halogen compounds by conducting the same into water or other suitable
absorbent and subsequent electrolysis of the soluble halogen compounds thereby
obtained, substantially as described.
5. In a process such as described and where the further treatment is to take place
by the wet process and it is a question of treating copper pyrites, the separation by
precipitating with metallic iron of the iron from the copper in the salt solution
obtained, by which means metallic copper is obtained, and also on iron halogen salt
which is again electrolysed for recovering the halogen gas and iron which are further
utilised, substantially as described.