CERTAIN IMPROVEMENTS IN THE BURNING OF SULPHURET ORES FOR MAKING SULPHURIC ACID AND FOR SMELTING
Year: 1854

page_text: LETTERS PATENT to Llewellyn William Evans and James McBryde, of
Saint Helens, in the County of Lancaster, Manufacturing Chemists, for
the Invention of "CERTAIN IMPROVEMENTS IN THE BURNING OF SULPHURET
ORES FOR MAKING SULPHURIC ACID AND FOR SMELTING."
Sealed the 5th June 1855, and dated the 14th December 1854.
PROVISIONAL SPECIFICATION left by the said Llewellyn winam Evans
and James McBryde at the Office of the Commissioners of Patents, with
their Petition, on the 14th December 1854.
We, LLEWELLYN WILLIAM EVANS and JAMES MCBRYDE, of Saint Helens, in
the County of Lancaster, Manufacturing Chemists, do hereby declare that
the nature of the said Invention for "CERTAIN IMPROVEMENTS IN THE BURNING
OF SULPHURET ORES FOR MAKING SULPHURIC ACID AND FOR SMELTING" to be as
follows:-
Sulphuret ores employed in the making of sulphuric acid and in the pro-
duction of metals are at present burned or roasted in a kiln or furnace into
which the atmospheric air necessary for combustion is supplied by the natural
indraft current of air passing from the atmosphere through the furnace bars
and door into the furnace, and thence to the chimney, created by rarefaction.
This is the ordinary method.
Our Invention consists in employing for the like objects close kilns or
furnaces, into which the necesary air is forced by mechanical means, and
the use of kilns or furnaces in connexion with a blast pipe or pipes, or other
mechanical agents, whereby the air necessary for combustion is driven into the
furnace and among the ores under treatment.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Llewellyn William Evans and James McBryde in the Great
Seal Patent Office on the 11th June 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, LLEWELLYN
WILLIAM EVANS and JAMES MCBRYDE, of Saint Helens, in the County of
Lancaster, Manufacturing Chemists, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of December, in the year of our
Lord One thousand eight hundred and fifty-four, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said Llewellyn William Evans and James McBryde, Her special license that
we, the said Llewellyn William Evans and James M Bryde, our executors,
administrators, and assigns, or such others as we, the said Llewellyn William
Evans and James M Bryde, our 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 "CERTAIN
IMPROVEMENTS IN THE BURNING OF SULPHURETS FOR MAKING SULPHURIC ACID AND
FOR SMELTING," upon the condition (amongst others) that we, the said Llewellyn
William Evans and James McBryde, by an instrument in writing under our
hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the said Letters Patent.
NOW KNOW YE, that we, the said Llewellyn William Evans and James
McBryde, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement, that is to say:-
In order that our Invention may be easily comprehended, we first describe
the ordinary methods generally used for burning sulphuret ores of iron or copper
in the manufacture of sulphuric acid. These ores are commonly known as
pyrites, and are characterised as large and small pyrites, in the burning of
which different methods are adopted. The large pyrites are broken to the size
of one inch cube, or thereabouts, and burned in a kiln, as shewn in the
Diagram No. 1 of the accompanying Drawings, which kiln has grate bars at
the bottom, a charging door, and a stirring door, and an exit pipe or flue
communicating with the sulphuric acid chambers.

page_text: The kiln is nied with broken pyrites from the grate to about the level of
the charging door; the upper portion being ignited, the pyrites continue to
burn until it becomes necessary to introduce a new charge. A portion of
the burned stones is then withdrawn from the kiln through the grate below,
and fresh pyrites being thrown on to the top of the burning mass remaining
in the kiln, are ignited, and the process continues. The sulphurous gas
generated during the process is conducted through a pipe or flue in the top
of the kiln into the sulphuric acid chambers in the ordinary manner. The
air necessary to maintain the combustion of the charge is obtained by the
indraft through the grate bars, resulting from the burning, and the action of
the chimney draft connected with the chambers and kilns.
The method herein-before described not permitting the necessary supply of
air for burning small pyrites, owing to the compact close mass which they
naturally assume, other methods have been employed, varying according to
the respective characters of the ores to be burned. Some are formed into
artificial cubes or balls, and treated in the manner already described for large
pyrites; others are spread in thin layers on the beds or shelves of ovens or
furnaces, and there roasted, heat being externally applied. Sufficient air is
admitted into the oven or furnace through the doors, and the sulphurous gas
produced during the process is conducted into the chambers, as before described.
All these processes or methods of burning sulphuret ores are well known.
Our Invention has reference to the burning of sulphuret ores of iron and
copper, commonly called iron pyrites and copper pyrites, only, and consists
in the burning of those ores by means of the combination of a kiln or
kilns of the ordinary or the like construction to that in general use for
burning broken pyrites, with a blast pipe or pipes introduced into it, whereby
a blast of atmospheric air is driven by a fan or other well-known mechanical
agents into the charge of ore under treatment sufficient to permeate the mass,
to arrive at the portion ignited, and to maintain combustion, and a sliding
grate at the bottom, to facilitate the removal of the oxides after the burning or
roasting.
The Diagram No. 2 in the annexed Drawings exhibits a vertical section
of the kiln of the ordinary construction, shewing the application thereto of
the blast pipe and sliding grate; and No. 3 is a horizontal section of the
same kiln.
The blast pipe A must be perforated with holes or slots to effect a proper dis-
tribution of the air. The sliding grate B is to be kept closed during the burning
of a charge, to resist the egress of the air supplied through the blast pipe.
C is a conical plug inserted into the blast pipe, to enable the workman in

page_text: charge of the kiln to regulate the air blast, the intensity of which must be
regulated by the character of the sulphurets to be burned. The mode of
charging the kiln or furnace, and of working off the charge, does not in other
respects differ from the ordinary method.
Our Invention is also applicable to the treatment of sulphuret ores of iron
or copper for smelting in that part of the process of smelting commonly called
roasting, which is necessary with some ores previous to being smelted.
We do not confine ourselves to the details or arrangements of our Invention
as before described, nor to the size or form of the kilns, or blast pipe or pipes,
or sliding grate; but we do claim the burning of the sulphuret ores, before
mentioned, in the manufacture of sulphuric acid, and for smelting in close kilns
or furnaces, in combination with a blast pipe or pipes or other mechanical
agents, whereby the air necessary for combustion is driven into the kiln or
furnace and among the sulphuret ores under treatment.
In witness whereof, we, the said Llewellyn William Evans and James
McBryde, have hereto set our hands and seals, this Ninth day of
June, in the year of our Lord One thousand eight hundred and
fifty five
L. WILLIAM EVANS. (L.S.)
JAMES MCBRYDE.
Signed, sealed, and delivered (being first duly
stamped), by the above-named Llewellyn
William Evans and James McBryde, in
the presence of
EDW JOHNSON, Sol",
St. Helen's.
ROB THOMAS, his Clerk.
(L.S.)