IMPROVEMENTS IN TREATING IRON PYRITES AND OTHER ORES CONTAINING COPPER. SILVER. AND TIN OR EITHER OF THEM. AND SULPHUR
Year: 1860

page_text: LETTERS PATENT to John Longmaid, of Inver, in the County of Galway,
Ireland, Manure Manufacturer, for the Invention of "IMPROVEMENTS IN
TREATING IRON PYRITES AND OTHER ORES CONTAINING COPPER. SILVER. AND
TIN OR EITHER OF THEM. AND SULPHUR "
Sealed the 6th November 1860), and dated the 19th May 1860.
PROVISIONAL SPECIFICATION loft by the said John Longmaid at the
Office of the Commissioners of Patents, with his Petition, on the 19th
May, 1860.
I, JOHN LONGMAID, of Inver, in the County of Galway, Ireland, Manure
Manufacturer, do hereby declare the nature of the Invention for "IMPROVE-
MENTS IN TREATING IRON PYRITES AND OTHER ORES CONTAINING COPPER, SILVER
AND TIN, OR EITHER OF THEM AND SULPHUB," to be as follows:-
This Invention has for its object improvements in treating iron pryites and
other ores containing copper, silver, and tin, or either of them, and sulphur.
For these purposes the pyrites or other ores are first ground or reduced so as
to pass through a sieve, by preference, having about one hundred holes in a
square inch; they are then introduced into a furnace, where two precosses
are constantly being carried on by the same heat; first, the calcining of the
pyrites or other ores so as to reduce the sulphur contained to about five per
cent., and, secondly, the decomposing such calcined ores by meaus of common
salt.
The ground nvrites are introduced into one compartment or chamber of the

page_text: furnace, and the heat of such compartiment causes the same to be calcined, and
the sulphurous acid evolved passes off and is converted into sulphuric acid.
The calcined pyrites or other ores are then combined with common salt and
placed in another compartment of the same furnace. The products obtained
are then treated in the well known manner. It is preferred to employ a
reverberatory furnace divided horizontally, so that the products of combustion
pass through the lower compartment and heat both it and the chamber above.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Longmaid in the Great Seal Patent Office on
the 19th November 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LONGMAID, of Inver, in the County of Galway, Ireland, Manure Manufacturer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of May, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said John Longmaid, Her special license that I, the said John
Longmaid, my executors, administrators, and assigns, or such others as I,
the said John Longmaid, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "Im-
PROVEMENTS IN TREATING IRON PYRITES AND OTHER ORES CONTAINING COPPER, SILVER
AND TIN. OR EITHER OF THEM, AND SULPHUR," upon the condition (amongst others)
that I, the said John Longmaid, my executors or administrators, by an instru.
ment in writing under ny, or their, or one of their hands and scals, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the saine to be filed
in the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Longmaid, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-

page_text: This Invention has for its object improvements in treating iron pyrites and
other ores containing copper, silver, and tin, or either of them, and sulphur.
For these purposes the pyrites or other ores are first ground or reduced so as
to pass through a sieve, by preference, having about one hundred holes in a
square inch; they are then introduced into a furnace where two processes are
constantly being carried on by the same heat; First, the calcining of the
pyrites or other ores, so as to reduce the sulphur contained to about five per
cent.,and,secondly, the decomposing such calcined ores by means of common
salt.
The ground pyrites are introduced into one compartment or chamber of the
furnace,and the heat of such compartment causes the same to be calcined, and
the sulphurous acid evolved passes off and is converted into sulphuric acid
The calcined pyrites or other ores are then combined with common salt and
placed in another compartment of the same furnace. The products obtained
are then treated in tho well known mannor. It is preferred to employ a
reverberatory furnace divided horizontally, so that the products of combustion
passthrough the lower compartment, and heat both it and the chamber above.
The furnace,such as is above mentioned, having been heated to dull redness,
a charge of the ground pyrites or other ores is introduced and spread over one-
half of thebed of the higher chamber of the furnace; the charge is occasionally
stirred in order to present fresh surfaces to the action of the air which is
admitted to oxidise the pyrites or other ores; this operation is continued until
the bulk of the sulphur has been converted into sulphurous acid. Another
charge is then placed on the second half of the bed of the higher chamber
of the furnace, and the operation continued the length of time required to
complete the calcination will vary according to the nature of the pyrites or
other ores employed, some yielding their sulphur more readily than others; the
workman will be able to judge when the charge is sufficiently calcined, when
the first charge is withdrawn and a fresh one introduced, and the operation
goos on continuously. It is preferred to work the charge in two divisions, as
above described, in order to produce a continuous evolution of sulphurous
acid, which is passed into a leaden chamber, as is well understood in the
manufacture of sulphuric acid. The partially calcined pyrites or other ores
are mixed with common salt & a charge introduced into the lower chamber
of the furnace, and is kept at a dull red heat; mutual decomposition ensues;
the commou salt is for the most part converted into sulphate of soda, and
the copper and silver into chlorides of those metals, soluble in water; if
oxide of tin exists in the pyrites or other ores it will be separated from the
copper, sulphur, & other substances that usually deteriorate the quality of tin

page_text: ores; the oxide of tin is separated by washing in the manner practised in the
tin mines of Cornwall. The solution obtained from the calcined pyrites or
other ores and common salt contains the alkaline salts and chlorides of
copper and silver, from which these metals are precipitated by means of
iron, as is well known.
Having thus described the nature of my Invention and the manner of per-
forming the same, I would have it understood that I make no claim to any of
the processes herein described when separately considered, but what I claim is
the carrying on the two processes of calcining pyrites or other ores, and the
decomposing such ores by common salt simultaneously in the same furnace.
In witness whereof, I, the said John Longmaid, have hereunto set my
hand and seal, this Fifteenth day of November, in the year of our
Lord One thousand eight hundred and sixty.
JOHN LONGMAID. (LS.)