IMPROVEMENTS IN THE TREATMENT OF METALLIC SULPHIDES, AND THE PRODUCTS DERIVABLE THEREFROM
Year: 1879

page_text: LETTERS PATENT to John Berger Spence, of Lombard Street, in the City of
London, Merchant, for the Invention of "IMPROVEMENTS IN THE TREATMENT
OF METALLIC SULPHIDES, AND THE PRODUCTS DERIVABLE THEREFROM."
Sealed the 7th November 1879, and dated the 9th May 1879.
PROVISIONAL SPECIFICATION left by the said John Berger Spence at the
Office of the Commissioners of Patents on the 9th May 1879.
JOHN BERGER SPENCE, of Lombard Street, in the City of London, Merchant.
"IMPROVEMENTS IN THE TREATMENT OF METALLIC SULPHIDES, AND THE PRODUCTS
DERIVABLE THEREFROM."
My Invention refers, firstly, to ores containing sulphides of lead, zinc, iron, copper,
and silver. These are commonly known as mixed ores of lead and zinc, and contain
from 10 to 30 per cent. of lead, and 10 to 30 per cent. of zinc, the copper, silver, and
iron being variable in quantity.
These ores I reduce to a fine powder by any suitable machinery for crushing. I
then levigate and obtain a permanent blue black suitable for a variety of purposes.
When preparing the pigment as a blue black paint, I mix it with oil or varnish,
and I may at pleasure introduce thereto zinc or other white pigment to obtain
lighter tints of grey, or I may combine the blue black with chrome yellow and
obtain a green colour, or I may mix it with any suitable pigment or coloring matter,
or with anti-corrosive or anti-fouling compounds.
Another part of my Invention consists in treating the aforesaid sulphides and
metallic sulphides generally for the manufacture of sulphuric acid by calcining by a
novel method. The ore is ground to a fine powder, and may be calcined in any furnace
specially designed for calcining fine ores, either for the manufacture of sulphuric
acid or otherwise, and I find that in calcining these ores they are difficult to oxidize,
and require many hours to calcine sweet, but this time is considerably reduced by
adding to the ore varying quantities of already calcined ore, which assists to oxidize
the uncalcined ore, and also prevents the ore from agglomerating.
Another part of my Invention consists in the novel mode of separating the metals
contained in metallic sulphides.
I take the calcined ore and add sufficient sulphuric acid to sulphatize all the
metals; I then take the sulphatized mass and calcine it until the iron becomes per-
oxidised and rendered insoluble.

page_text: "
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Berger Spence in the Great Seal Patent Office on the 8th
November 1879.
JOHN BERGER SPENCE, of Lombard Street, in the City of London, Merchant.
* IMPROVEMENTS IN THE TREATMENT OF MEtallic SulphIDES, AND THE PRODUCTS
DERIVABLE THEREFROM."
My Invention refers principally to ores containing sulphides of lead, zinc, iron,
copper, and silver. These are commonly known as mixed ores of lead and zinc, and
are found generally to contain from ten to thirty per cent. of sulphide of lead, and
ten to thirty per cent. of sulphide of zinc, the copper, silver, and iron being variable
in quantity.
In carrying out my Invention I first reduce these ores to an impalpable powder
by crushing or grinding in any suitable machinery. The powder I thus obtain is of
a permanent blue-black colour, and when mixed with oil or varnish forms a blue
black paint of great body and covering property. By adding to this paint zinc or
other white pigments, lighter tints, such as greys, may be obtained. I may also
combine the blue black with chrome yellow, and so obtain a green color, or I may
mix it with any other suitable pigments or coloring matters, or with anticorrosive
or antifouling compounds.
The impalpable powder obtained as above described from the aforesaid sulphides
or from metallic sulphides generally, I use either as a base from which to manufacture
sulphuric acid or for other purposes by calcining in a novel manner.
The powdered ore is calcined in a furnace especially designed for calcining fine
ores. The calcining of these ores sweet in the ordinary way takes many hours to
effect, as they are difficult to oxidize, but by adding to the ore varying quantities of
already calcined ore, which assists in oxidizing the uncalcined ore, the time taken up
in caleining the ore sweet is considerably reduced, and the agglomeration of the ore
is prevented.
My Invention consists, further, in a novel mode of separating the inetals contained
in metallic sulphides, and obtaining various useful products therefrom. To this end I
take the ore, which has been ground and calcined as above described, and add to it
sufficient sulphuric acid to sulphatize all the metals contained therein. I then take
the sulphatized mass and recalcine it until the iron contained in the ore becomes
per-oxidized and rendered insoluble. The mass is then mixed with water, by which
means the sulphates of zinc and of copper with traces of silver are dissolved out,
and the solution thus obtained is drawn off, leaving behind those parts which are
insoluble in water, vist, the sulphate of lead, the silver, and the per-oxide of iron,
with traces of copper. I now add to the solution of the sulphates of zinc and
copper sufficient metallic zinc to precipitate the copper and silver held in suspension,
and the residuum is sulphate of zinc of a high quality. From the remainder of the
mass containing the sulphate of lead, the silver, and the per-oxide of iron, the
sulphate of lead and the silver are dissolved and separated by well known means,
and the undissolved residuum being mainly per-oxide of iron, is dried and constitutes
a fine red pigment, which may be used for making paint.
Having now described the nature of my Invention of "Improvements in the
Treatment of Metallic Sulphides, and the Products Derivable therefrom," and
explained the manner of carrying the same into effect, I wish it to be understood
that under the above in part recited Letters Patent I claim,—
First. Treating the sulphides of lead, zinc, iron, copper, and silver in the manner
herein described, whereby I obtain a pigment which when mixed with oil or varnish
will constitute a paint.

page_text: Second. The mode of treating metallic sulphides generally by calcination, as and
for the purposes herein described.
Third. The mode of separating the metals contained in metallic sulphide, in the
manner and for the purposes herein described.
In witness whereof, I, the said John Berger Spence, have hereunto set my hand
and seal, the Eighth day of November, in the year of our Lord One
thousand eight hundred and seventy nine.
J. B. SPENCE.
(L.S.)