IMPROVEMENTS IN THE PRO- DUCTION OF PROTO-SULPHURET OF IRON AND SULPHURETTED HYDROGEN GAS FOR THE EXTRACTION OF COPPER FROM MOTHER LIQUORS AND FOR OTHER PUR- POSES
Year: 1875

page_text: LETTERS PATENT to Georgo Tomlinson Bousfield, of Sutton, in the
County of Surrey, for the Invention of "IMPROVEMENTS IN THE PRO-
DUCTION OF PROTO-SULPHURET OF IRON AND SULPHURETTED HYDROGEN GAS FOR
THE EXTRACTION OF COPPER FROM MOTHER LIQUORS AND FOR OTHER PUR-
POSES." A communication from abroad by the Société Anonyme
du Cuivre Francais. of Paris. in the Republic of France.
COMPLETE SPECIFICATION filed by the said George Tomlinson
Bousfield at the Office of the Commissioners of Patents, with his
Petition and Declaration, on the 3rd June 1875, pursuant to the
9th Section of the Patent Law Amendment Act, 1852.

page_text: FOR THE EXTRACTION OF COPPER FROM MOTHER LIQUIDS AND FOR OTHER PURPOSES,"
and have petitioned Her Majesty to grant unto me, my executors,
administrators, and assigns, Her Royal Letters Patent for the same,
and have made solemn Declaration that it has been communicated to
me from abroad by the Société Anonyme du Cuivre Français, of Paris,
in the Republic of France.
'NOW KNOW YE, that I, the said George Tomlinson Bousfield, do
hereby declare that the following Complete Specification, under my
hand and seal, fully describes and ascertains the nature of the said In-
vention, and in what manner the same is to be performed in and by
the following statement :-
This Invention has for its object improvements in the production of
proto-sulphuret of iron and sulphuretted hydrogon gas for the extraction
of copper from mother liquors and for other purposes.
Those who have to treat great quantities of mother liquors produced
in the manufacture of sulphate of copper have to encounter a manu-
facturing difficulty of the first order, viz., the separation of the copper-
from the metals and salts which are allied with it in the mother liquors.
To submit these mother liquors to the action of sulphuretted hydrogen
gas, which is caused to bubble up in them, to thus separate the copper
in the form of sulphuret of copper, which is insoluble in the water con-
taining the sulphuric acid which has been liberated and the salts
remaining soluble, is certainly not a new idea, for it is the process
always employed in like circumstances in chemical manipulation, but
the process has up to this time been only a laboratory operation.
Many manufacturers have attempted to carry out this treatment on a
large scale, but all after vain efforts have had to abandon it on account
of the dangers attendant on the use of sulphuretted hydrogen gas, from
its deleterious explosive and inflammatory qualities, from its attacking
the vessels, from the choking of the passages, from the frequent
breakage of the vessel, and the difficulty experienced in producing the
gas in large quantity and causing it to be absorbed without appreciable
escape, and on account of the heavy cost of the processes.
My foreign correspondents like their predecessors have made many
unfruitful attempts, but persevering in their researches have solved the
problem in the most complete manner, and can now treat up to thirty

page_text: thousand kilogrammes of proto-sulphuret of iron a month, producing
in consequence about twelve thousand kilogrammes of sulphuretted
hydrogen gas without accident or sensible odour, the work proceeding
in a continuous manner and without interruption, with a minimum
expense, which besides is compensated for by the value of the sulphato
of iron which is obtained of an exceptional purity as a secondary product
resulting from the reaction.
.
They employ in operating upon proto-sulphuret of iron by dilute
sulphuric acid vessels which are secure from fractures caused by the
pressure of the gas given off inside, and which oppose a great resistance
to changes of temperature. They use oil casks lined with lead. The
leaden top is pierced with several openings, as is shown in the annexed
Drawing. A is a hole for introducing the charge of proto-sulphuret of
iron; it is provided with a close-fitting cover; B is a tubular neck
traversed by a dipping pipe m, n, which is made of lead, and is a con-
tinuation of the tube 7. The tube is fitted with a caoutchouc obturator
or stop valve, and is connected with the pipe tube X, which is supplied
with dilute sulphuric acid heated to 50° or 60° C. in a cistern above.
G is a tubular neck, to which is secured by flanges and bolts the lead
pipe H, H, which plunges into the water of a glass washing bottle.
The sulphuretted hydrogen gas issues from the generator by the
pipe H, H, and the gas escapes from the washer by the lead pipe K, K,
which goes directly to one or other of the vats containing the cúpréous
liquid to be treated; a glass safety tube h, h, shows the pressure in the
apparatus, as in all similar apparatus. A tube O at the bottom connected
to the collecting pipe Y by the india-rubber tube a, b, is for the with-
drawal of the sulphate of iron produced by the reaction of the sulphuric
acid on the proto-sulphuret of iron. The communication between the
vessel and the collector Y is intercepted by pinching the india-rubber
tube with a screw clip P.

page_text: however the interior pressure is not sufficient to make all the sulphate
run out, as the collector Y is of considerable length and dips to some
depth into the receiving tank, air will enter the vessel by the safety tube
of the washing bottle. The sulphate having run out the clip P is
tightened, then the interior of the vessel is purged by means of a suitable
volume of air which is compressed into it by a small force pump.
This volume of air replaces the sulphuretted hydrogen which remained
at the end of the operation, expelling it and passing with it by the
conduit H, H, to the washing bottle, and it goes ultimately to the
absorption vat. The mixture of the gas with air does not cause any
inconvenience. The last remains of the sulphuretted hydrogen being
expelled the cover A is opened and the charge of proto-sulphuret in
large pieces is introduced; the weight of a charge is from five to six
hundred kilogrammes; the cover is then secured in its place, the
acid introduced, and the operation continues without danger to the
workmen.
My correspondents' process for manufacturing proto-sulphuret of iron
in quantity giving at a low price a product of great purity consists in
heating on the charcoal bed of a reverberatory furnace native. iron
pyrites in presence with old scrap iron or turnings, or any iron waste,
either wrought or cast. The iron scizes the excess of sulphur of the
pyrites, and then brings the mass to the state of proto-sulphuret of iron,
which is run into moulds. The slags which are formed carry off all the
impurities and gangues.
That which I wish to claim for my correspondents is,―
The new combination of apparatus and means resulting in a pro-
duction of sulphuretted hydrogen gas on a large scale, and in a new
manufacture which has not been hitherto practically realized, and which
my correspondents attain by their construction, disposition, and grouping
of the apparatus by heating the acid for the attack before its intro-
duction into the vessels, which hastens the reaction on the proto-
sulphuret, and in consequence increases the quantity of gas, which can
be disengaged in a given time by the withdrawal of the sulphate of iron
at the lower part of the vessel which permits its extraction, even during
the production of the gas, and gives the means of drawing off the acid
to stop the disengagement of the sulphuretted hydrogen when desired
by employing a helix as tho means of stirring.

page_text: I also claim the method herein described for the manufacture of proto-
sulphuret of iron.
In witness whereof, I, the said George Tomlinson Bousfield, have
hereunto set my hand and seal, this Second day of June, in
the year of our Lord One thousand eight hundred and seventy-
five.