Comprising also a Novel Method and Apparatus for Feeding such Furnaces.
Year: 1885

page_text: Comprising also a Novel Method and Apparatus for Feeding
such Furnaces.
We, JOHN DIXON, FREDERICK JAMES BLADES, WILLIAM SELBY DOUGLAS,
DAVID GARLICK, and WILLIAM MALCOLM, Gentlemen all of Adelaide in the Province
of South Australia, do hereby declare the nature of our invention for "IMPROVE-
"
MENTS IN THE PROCESS OF SMELTING PYRITES AND IN THE TUYERES OF BLAST
FURNACES TO BE USED FOR THE PURPOSE COMPRISING ALSO A NOVEL METHOD
and in what manner the same is to
AND APPARATUS FOR FEEDING SUCH FURNACES
be performed, to be particularly described and ascertained in and by the following
statement:-
Our invention relates specially to the smelting of copper pyrites but modifications
of the process and appliances will adapt it to other sulphuretted ores. The furnaces
made use of are those in which a high pressure blast is blown directly through the
melted sulphides to be treated. In combination with such furnaces by means of a
hot blast and the apparatus hereinafter described whereby raw pyrites in a fine
powder is delivered into the body of the melted charge we are enabled to maintain
the necessary heat and to continue the reduction of the ore without further fuel.
We are aware that methods have been devised for treating a regulus in a similar
manner, but we claim as an essential part of our invention the direct introduction
of raw pyrites in the furnace for the purpose of producing a like effect and thus
rendering preliminary calcination unnecessary.
We first proceed to describe the furnace made use of; secondly, the appliances
whereby the ground ore is fed into the melted charge and the supply of the same
regulated as may be required and thirdly, the process of smelting by the use of the
foregoing..
By reference to the accompanying drawings it will be seen that:-
Fig. I Is a side elevation of the furnace and feeding apparatus the former being
shewn in quarter section.
Fig. II A plan of the same.
Fig. III An end elevation of the feed box.

page_text: A. (Figs. I and II) is the main body of a blast cupola furnace supported on four
pillars with suitable foundations. B. an arched cover composed of bricks clamped
together and for convenience removable in sections; the outer ones being securely
attached to the walls of the furnace by cross bars bolted thereto. C the upper tap
hole projecting under a hood and always open for the purpose of allowing the slag
and gases to escape. D the lower tap hole from which the reduced metal is run.
E the lower part of the furnace secured to A by means of bolts passed through
projecting flanges provided for the purpose. Rails may be placed underneath E
whereon it drops when removed for repairs. Between the flanges and reaching
round about two thirds of the circumference of the furnace is a removable semi-
circular channel F which supplies the blast to the tuyeres G. The lower flange
should be fixed to the bottom E. before the channel F is secured in its place.
G. are bricks pierced with two parallel tuyeres of suitable size. Oblong holes are
cut in the furnace casing to correspond with the projections on the outside of the
tuyere bricks G the relative position of three such holes being shown in Fig. IV.
Two rows of G are usually made use of and so arranged that the upper surface of
the top row is in line or nearly so with the upper edge of E. All spaces are filled
with moist fire-clay. H is the main blast pipe leading from a suitable blast engine
into the channel F which it supplies with cold air. I is the feed pipe connected
by airtight joints with the water tuyere built into the side of the furnace A. at a
suitable distance above the blast tuyeres G and with the feed box hereinafter
described. The feed pipe I as also the water tuyere should be of hard metal and
for the size of furnace indicated should have a bore of about one and a quarter inch
diameter though we do not confine ourselves to any particular size. I¹ is the feed
blast pipe forming a branch from the main blast and led through a suitable furnace
or other source of heat. K is a portion of the main framework of the feeding
apparatus provided with suitable bearings in which revolve the spindles of the sets
of chain wheels L. L' L'. These wheels are of various sizes and are driven by
flat linked iron chains in the usual manner. The four wheels composing L may be
of the respective circumferences 70, 67, 64, 61, links of the chain, L¹ may be 70,
58, 50, 44 38 and 35 links, and those composing L² 70, 58, 47, 35, 23, and 11 links,
Ls is a fixed pulley connected with the engine by a similar chain. We wish it to
be distinctly understood that we do not confine ourselves to these proportions but
consider them as applicable to the purpose we have in view which is to increase or
decrease at pleasure the quantity of ore fed into the furnace. The spindles of the
system L and L³ are square and suitable notched levers are provided whereby
those on spindle L' can be removed separately backwards and forwards. The
wheels L' are fixed L* being the only moveable one on that spindle, the rests only
of these levers are shewn as their construction is of any usual character. M. is the
feed box (Figs. I and III) into which project the feed pipe I. and the feed blast
pipe I¹ as shown. To prevent radiation of heat we protect where exposed I and I¹
by means of asbestos or other suitable covering.' The feed box M is provided with
a trumpet shaped mouth (Fig. I) and is constructed as shewn of two parts firmly
bolted together. N. N¹ are two sexagonal wheels having suitable recesses cast in
their rims for the reception of the feed discs O. N. revolves inside the feed box M
in suitable bearings provided with internal stuffing boxes filled with asbestos or
other incombustible packing. N is attached to the spindle of the wheels L (Fig. II)
which also forms the main shaft of any ordinary elevation whereby the crushed
ore can be raised into the feed hopper. The aggregate contents of the elevator
cups should be equal to the capacity of the pipe P so that the supply and discharge
may be practically equal. N revolves in bearings supported by any suitable
framework. This we do not think it necessary to shew or describe. P P¹ are two
pipes of hard steel secured in airtight bosses in M. O are the feed discs con-
Btructed of hard steel and of such size as to pass easily through the pipes P P¹.
The discs are linked together in an endless chain at such distances apart as
shall correspond with the recesses in N N¹. QQ¹ are two hoppers attached to the

page_text: pipes P P¹ for the purposes hereinafter indicated. The pipe P should be continued
some distance into Q as shewn for the purpose hereinafter mentioned.
The action of the feeder is as follows:-
On its being thrown into gear the elevator delivers from time to time into the
hopper Q the crushed ore in such quantity as will fill the space between two of the
discs O. As the sexagonal disc N revolves the ore is drawn by the discs O down
the pipe P into the feed box M, driven into the furnace through the feed pipe
and by the hot blast at a temperature below its fusing point. The discs O ascend
the pipe P empty and may carry with them a small quantity of dust which is
collected in the hopper Q1 from which it is removed as necessary. By shifting the
chain on the sets of wheels L L³ the number of revolutions of N and consequently
the quantity of ore delivered into the feed box M. can be regulated at pleasure. The
proportions are so arranged as described that when the fixed engine pulley L³ is
running 30 revolutions per minute and the smallest wheel or pulley of L' is
connected with the largest of L' and L with L the sexagonal disc N will make
5 revolutions per minute and discharge about 47 pounds of ore into the feed
chamber M By the graduated system of wheels indicated this quantity may be
increased to about 110 pounds by suitably varying the gear.
Our method of smelting copper pyrites is as follows:-The ore is first reduced to
a dry fine powder. If this is found to contain too much basic matter to yield a
sufficiently fluid slag clean mundic is added. The quantity of this added is such
that the iron contained in it then forms a slag of the required fluidity. The
furnace before described is heated in the usual manner care being taken to close
the top B and temporarily block up the tap hole C until sufficient blast comes
through the lower tap D to thoroughly heat the lower part of the furnace E.
The lower tap D is then closed and a charge of ore or ore and mundic in small
lumps introduced through the moveable top B. When by the application of the
blasts a bath of melted metal has been obtained the feeder is cautiously started
and the quantity of ore fed into the furnace gradually increased until the slag runs
from the tap C. That which comes after the regulus has been got up to about
60° for copper generally contains that metal and is put aside for further treat-
ment. When it is estimated that 75° is reached the feeder is stopped and the
reduction completed with the air blasts alone. After the lapse of a sufficient time
rough copper is run from the tap D care being taken that in so doing the furnace
charge is not allowed to fall below the aperture of the feeding tuyere I as soon as
it approaches this D is closed and the feeder cautiously started a second time.
The wheels of the feeding apparatus are arranged in such gradations that the
shifting the chain from the one wheel to another on the shaft L will speaking
roughly be equal to the alteration in delivery of half a pound of ore per minute.
This it is estimated is what is required by an alteration of 4° of Fahrenheits
Thermometer or 1 of an inch of the Barometer. These instruments are
placed in a convenient position so that atmospheric disturbances can be roughly
adjusted as they arise it being found that the bigher the Barometer or the lower
the Thermometer the greater the quantity of ore required. No greater pressure is
to be used in the blasts than is just sufficient to overcome the resistance of the
furnace charge. As excess of blast means excess of splash it will be found in
practice that this resistance is less at the beginning than at the end of the process.
Duplicate furnaces of an internal diameter of about 30" to be used alternately are
bere contemplated as also a blowing engine capable of discharging per minute two
thousand (2000) feet of common air at a pressure of about seven (7) pounds per
square inch. We wish it to be clearly understood bowever that we do not confine
ourselves to any special size or to the exact details of the process as we are aware
that it can be considerably varied without interfering with its special features.
When it is required to renew the tuyere bricks the lower part of the furnace E is
removed by unloosing the bolts as before described. The bricks themselves from
their position form and method of attachment can then be easily replaced.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
First. The process of smelting pyrites in air blast furnaces by feeding crushed
raw ore into the body of the melted charge substantially as herein described.
Second. The introducing raw crushed ore into the furnace by means of a hot
blast substantially as herein described.
Third. The construction of furnaces as herein described as a combination of
parts.
Fourth. The use of curved tuyere bricks with projecting ends substantially as
herein described.
1
Fifth. The combination with blast smelting furnaces of a feeding apparatus
supplying crushed ore by means of a hot blast in quantities which can be
regulated.
Sixth. The feeding apparatus as a combination of parts.
Seventh. The feed case M or its equivalent substantially as herein described.
Eighth. The method of regulating the feed by means of a system of wheels of
graduated sizes actuated by flat chains substantially as herein described.
Dated this twenty seventh day of July 1883.
JNO. DIXON.
D. GARLICK.
W. S. DOUGLAS.
WM MALCOLM.
F. J. BLADES.