Improvements relating to the Drying and Calcination of Ores and other Substances, and to Apparatus therefor.
Year: 1889

page_text: Date of Application, 5th Apr., 1889
Complete Specification Left, 6th Jan., 1890-Accepted, 22nd Feb., 1890
Improvements relating to the Drying and Calcination of Ores and
other Substances, and to Apparatus therefor.
T, WILLIAM BUTLIN. of Irthlingborough Iron Works, Wellingborough, in the County
of Northampton, Manufacturer, do hereby declare the nature of this invention lo
be as follows:-
My invention relates to the drying and calcination of ores and other substances and
to apparatus therefor.
The main feature of my said invention consists in the utilization of highly heated
air (say for example, air heated to a temperature of from nine hundred to one
thousand degrees Fahrenheit) for drying and calcining ores, limestone and other
substances to prepare the same for the smelting furnace. For this purpose I employ
a furnace or kiln in which I arrange an air chamber preferably of cylindrical form
and built up of boiler-plates or of cast metal cylinders firmly united or in any
other convenient manner: This chamber is closed at the top and is perforated at or
near its lower end to permit the passage of the heated air into the furnace or kiln.
The said air chamber is preferably connected with apparatus for heating the air by
means of the waste gas from the smelting-furnace. The ore or other substance to be
dried or calcined is placed in the kiln around the said air-chamber. Suitable chutes
and doors are provided at the lower end of the furnace or kiln for drawing the
charge.
-
By employing heated air for drying and calcining the ores and other substances,
I obviate the liability to over heating of the said substances, such as frequently
occurs in kilns wherein coat or other fuel is employed, as I can heat. the air to
desired temperature and keep it uniformly at this temperature. The ore or other
substance dried in the manner above described, when taken out of the calcining
apparatus, is immediately put into the smelting furnace in its hot state.
To provide for further heating the air in the said air-chamber, I sometimes utilize
the hot waste gases from the smelting furnace by conducting these gases through a
pipe extending through the said air chamber, the gas being ignited and burned at
the upper end of the said pipe and used if desired for lighting purposes. If desirable
I dry or calcine the ores or other substances when lying in heaps in the open air.
by introducing highly heated air by means of a suitable pipe or otherwise into the
said heaps. prefer, however, to use apparatus constructed substantially as above
mentioned.
Dated this 5th day of tamil 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London.. Agents for the Applicant..
COMPLETE SPECIFICATION.
Improvements relating to the Drying and Calcination of Ores and
other Substances, and to Apparatus therefor.
I, WILLIAM BUTLAN, of Irthlingborough Iron Works, Wellingborough, in the County,
of Northampton, Manufacturer, 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:-
My invention relates to the roasting or drying and calcination of ores and other
substances, and to apparatus therefor.
The main feature of my said invention consists in the utilization of highly heated
[Price Sd.]

page_text: air (say for example, air heated to a temperature of from three hundred and fifty
degrees to nine hundred or one thousand degrees Fahrenheit) for roasting or drying
and calcining ores, limestone and other substances to prepare the same for the
smelting-furnace. My said invention is, however, applicable for the heating of such
substances for other purposes.
I provide apparatus comprising a furnace or kiln in which is arranged a chamber
of cylindrical or other suitable form: built up of boiler:plates or of cast metal
cylinders firmly united, or in any other convenient manner. This chamber is con-
nected with apparatus for the supply of heated air; the said chamber is closed at
the top, and is perforated at or near its lower end to permit the passage of the heated
air into the furnace or kiln.
For heating the air for the purpose above mentioned. I employ a stove or stoves
of any suitable description, or other convenient form of heating apparatus. and I
can use coal or other fuel for this purpose. I prefer. however, to provide for
heating the air by means of the waste heat from the smelting-furnace, and I provide
suitable apparatus hereinafter described for accomplishing this result. In some
instances, I use coal or other fuel in addition to the waste heat from the smelting-
furnaces, for heating the air for the purpose above specified.
In the accompanying drawings, I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure is a vertical central section of my improved apparatus for roasting or
drying and calcining ores and other substances.
Figure 2 is a horizontal section partly on the line a, a, and parily on the line a', ',
Figure 1.
Figure 3 is a vertical section showing apparatus hereinafter described for heating
air by means of the hot slag brought from the smelting-furnaces in bogies or trucks.
Figure 4 is a horizontal section on the line y. y. Figure 3. the bogies or trucks
being removed from one of the chambers, and
Figure 5 is a vertical longitudinal section on the line z, z. Figure 3. -
Like letters indicate corresponding parts throughout the drawings.
A is the furnace or kiln, in which is arranged a cylindrical air-chamber B. This
chamber is preferably built up of boiler-plates; it is supported upon a brickwork or
other foundation B', and is stayed at or near its upper end by means three or other
suitable number of plates or stay-bars B2. The said chamber B is closed at its upper
end, and is perforated at or near its lower end with holes (or slots) B³ to permit the
passage of the air from the said chamber into the furnace or kiln A. The said
air-chamber. is connected, by means of a pipe C, with any suitable apparatus for
heating air to be supplied to the said chamber. The ore or other substance to be
roasted or dried and calcined is to be placed in the space provided in the said furnace
or kiln A around the said air-chamber B. D. D are chutes provided with sliding
doors D' situated at the lower end of the furnace or kiln for convenience of drawing
the charge. Each of the sliding doors D' has attached thereto one end of a wire-rope
or chain E passing over a pulley E' and having secured to its other end a weight E²
for counterbalancing the weight of the said doors D' and thus facilitating the raising
or lowering thereof.
By employing heated air for roasting or drying and calcining the ores and other
substances, I obviate the liability to overheating of the said substances, which
frequently occurs in kilns wherein coal or other fuel is employed, as I can heat the
air to any desired temperature and keep it uniformly at this temperature.
The ore or other substance roasted or dried in the manner above described; when
taken out of the said roasting or calcining apparatus, is immediately put into the
smelting-furnace in its hot state.
I prefer to connect the pipe C with apparatus for heating air by means of the waste
heat from the smelting furnace or furnaces, with or without coal or other fuel, a
suitable fan or blower or Blast-Engine being provided for forcing the heated air into
the air-chamber B through the said pipe.
Jn Figures 3, 4 and 5, I have shown an arrangement whereby I provide for heating

page_text: the air by means of the hot slag from the smelting furnace or furnaces, the heat of
which would otherwise be lost. For this purpose, I provide two or more chambers F
formed of brick or other suitable material and provided upon the upper part or crown
thereof with a layer F' of concrete, and with a roof or covering F2 of sheet metal or
other suitable material. G. G are spaces provided in the outer walls of the said
chambers F and filled with dry sand for the purpose of retaining the heat in the said
Chambers. H, H are ties secured to straps or plates H' upon the exterior of the
said walls, to increase the strength of the structure. The chambers F are provided
with railways I, and doors J. K. Kare the trucks or bogies for carrying the hot slag
from the smelting.furnace or furnaces. L. L are pipes for conveying the heated air
from the chambers F to the air-chamber B through the pipe c. M. M are pipes for
admitting atmospheric air to the said chambers F. The pipes L. and M are provided
with suitable stop cocks or valves L'. M'.
The operation of this heating apparatus is as follows, viz. A suitable number of
the trucks or bogies K being run into one of the said chambers F upon the railways I
thereof, the doors J of the said chamber are closed. The air in the said chamber is
then raised to the required degree of temperature by the heat given off from the hot
slag contained in the said trucks or bogies. Other trucks or bogies K containing hoi
slag are run into the other chamber F. so that, while the heated air from the one
chamber is being utilized, the air in the other chamber will be heated.
By keeping the chambers F constantly supplied with trucks or bogies filled with
hot slag from the smelting-furnace,the air in the said chambers may be heated to.and
maintained for a considerable time at a high degree of temperature. The heated air
drawn from the said chambers through the pipes L is forced into the air-chamber B
of the calcining apparatus through the aforesaid pipe C.
I thus provide very, advantageously for utilizing the waste heat from the smelting-
furnaces for heating the air to be used for roasting or drying and calcining the ores
or other substances in the kiln or furnace A.
Instead of the above described arrangement.I sometimes employ a stove such as is
ordinarily used for heating the blast for a blast-furnace. Or I use other suitable
means for heating the air by means of the waste heat from the smelting furnace or
furnaces, with or without coal or other fuel.
To provide for further heating the air in the air-chamber B, I sometimes utilize the
waste heat from the smelting furnace or furnaces for conducting the hot waste gases
through a suitable pipe extending completely through the said air-chamber; the gas
may, if desired, be ignited and burned at the upper end of the said pipe and used for
lighting or other purposes.
If desirable I can roast or dry and calcine the ores or other substances when lying
in heaps in the open air, by introducing highly heated air by means of a suitable pipe
or otherwise into the said heaps. I prefer, however, to use apparatus constructed
substantially as above described.
It is obvious that I can somewhat modify the construction of my apparatus without
departing from the nature of my said invention. For instance I sometimes arrange
any suitable number of air-heating chambers F beneath the furnace or kiln A or
beneath a series of such furnaces or kilns, the chambers F serving, if desired, as
supports for the said furnaces or kilns.
It is, moreover, evident that my improved apparatus can be used for roasting or
drying and calcining ores and other substances for various purposes other than that
hereinbefore specified.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I wish it understood that I
claim:
First. The herein described method of roasting or drying and calcining ores and
other substances by means of highly heated air to prepare them for the smelting-

page_text: Second. The employment of the waste heat from a smelting-furnace (with or
without coal or other fuel) for heating air to be used for roasting or drying and
calcining ores or other substances to prepare the same for the smelting-furnace,
substantially as described.
Third. An apparatus comprising a furnace or kiln having a perforated chamber
arranged within the same and connected with a pipe for the supply of highly heated
air, for the purposes above specified.
Fourth. The combination.with the air-chamber arranged within the furnace or kiln,
of a pipe which extends through the said chamber and through which the hot waste
gases from the smelting furnace or furnaces are conducted for the purpose of further
heating the air in the said chamber, as above specified.
Fifth. The combination, with my apparatus for roasting or drying and calcining
ores and other substances, of a chamber or chambers in which the air to be supplied
to the said apparatus is raised to the required temperature by means of the hot slag
from the smelting furnace or furnaces, substantially as set forth.
Sixth. The improved apparatus constructed substantially as described with refer-
ence to Figures 1 and 2 of the drawings and operating in the manner hereinbefore
specified.
Seventh. The combination of the drying and calcining apparatus constructed
substantially as described with reference to Figures and 2 and the air-heating
apparatus constructed substantially as described with reference to Figures 3, 4 and 5
of the drawings, all operating as, and for the purposes, above specified.
Dated this 3rd day of 1900
WILLIAM BUTLIN.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.