Improvements in Smelting Plants.
Year: 1898

page_text: Date of Application, 22nd Mar., 1898-Accepted, 28th May, 1898
COMPLETE SPECIFICATION.
Improvements in Smelting Plants.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, Chancery
Lane, in the County of London, Chartered Patent Agent, do hereby declare the
nature of this invention (as communicated to me from abroad by The Pennsylvania
Salt Manufacturing Company, of Philadelphia, Philadelphia County, Pennsylvania,
United States of America,) and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:
-
This invention relates to the smelting of ores and mattes, more especially mattes
containing copper, whether argentiferous or not, and its object is to provide a
continuous smelting plant, in which handling and remelting of the metal is almost
entirely done away with, while the output is greatly increased, and the mattes are
quickly and continuously reduced.
The mattes from the blast-smelting furnace have hitherto been usually cast into
pigs, which were charged into a reducing furnace, to be blown down, smelted and
tapped forming other pigs, which were charged and remelted in another reducing
furnace, and so on, until the requisite purity of metal was attained. These opera-
tions were expensive and slow, and have led to extensive use of the Bessemer pro-
cess applied to copper.
This invention, however, so reduces the cost of treating the mattes from a blast
smelting furnace in reducing furnaces, that it is cheaper and more efficient than
the Bessemer operation.
The invention is further designed to dispense with the great amount of metal
which has heretofore been necessary in the smelting furnaces by using a double
bottom, the melted metal oozing down through the first or false bottom into a
receptacle from which it is tapped and thus the necessity for locking up a large
amount of material is avoided.
In the accompanying drawings, Fig. 1 is a plan of a smelting plant according to
this invention, and Fig. 2 is a front elevation.
2-2 are a pair of blast smelting furnaces, placed at some distance above the
ground level, 3-3 are down takes leading to a dust catcher 4, from which a flue
leads to a chimney 5. Between these furnaces are two elevators 6-6 whose plat-
forms are provided with tracks registering with tracks 7,7 leading from turn-
tables 8-8 in a charging track 9, which runs past the charging-door 10 of the
furnaces, so that the cars containing the material to be charged pass from the
elevators to this track and are taken to the charging doors. Each smelting furnace
is provided with a settler 11, which has wheels resting upon the rails of a common
track 12 running past the bases of the furnaces. From the slag-spouts 13 of these
settlers lead adjustable inclined troughs 14, through which the slag is directed
into a slag-pit 15 which is supplied with water, so that as the slag enters the water
it is granulated and drops into a receptacle 16 within the pit. The receptacle
containing the granulated slag is lifted out of the pit by a crane 17, and dumped on
to a car or elsewhere as desired. Adjacent to each smelting furnaces at a lower

page_text: level are reducing furnaces 18, 19, of which there may be any desired number, those
of each set being at successively lower levels so that the material tapped from one
may run by gravity into the next. The metal passing from the blast-furnace into
the settler is led from the settler through an inclined trough 21 into the nearest
and uppermost reducing furnace 18, where air is blown in and the metal is reduced
so as to give a larger percentage of metal, after which the metal or matte is tapped
therefrom through a trough 22 into the next lower reducing furnace, where it is
again similarly treated, and so on, until the desired percentage of metal is obtained;
in the case of copper, about 96 per cent., or what is known as "blister-copper."
A refining furnace 20 may be placed below the last reducing furnace so that the
metal can be tapped from the reducing furnace into the refining furnace where
the operation is completed, the copper, or other metal, being cast into cakes, bars
or ingots.
At the ends of the track 12 are provided turntables 23, by which a settler or other
wheeled truck may be transferred from the track 12 to either of two transverse
tracks 24 by which the settler may be taken away or may be moved along the track,
and its contents tapped into any one of the reducing furnaces. If the matte is to
be calcined, it may be run from the settler into the pit 15 and granulated therein
so as to prepare it for calcining.
In Fig. 1, 25 is an engine, 26 are blowers, one for each blast furnace, and one
for each series of reducing furnaces; 27 and 28 are crushers, and 29 is a sample
mill. These parts of the plant may be arranged in any way desired, this invention
consisting in the arrangement of the smelting and reducing furnaces and the parts
operating in conjunction with them.
Fig. 3 is a plan and Fig. 4 is an elevation of a modified arrangement of the
plant, in which settlers are employed between the reducing furnaces. 2,2, are the
blast smelting furnaces, with down-takes 3, 3, which lead to the dust-catcher 4
from which a flue leads to the chimney 5. Between these furnaces are the two
elevators 6, 6, from which the material is dumped into a hopper 7 having spouts 8, 8,
leading to the furnaces. In front of the two furnaces extends an elevated track 9
Each furnace is
which is preferably at about the level of the charging doors 10.
provided with a wheeled settler 11, on a track 12 extending in front of the furnaces.
From the slag spouts 13 of the settlers lead adjustable inclined troughs 14, through
which the slag is directed into a slag-pit 15, which is supplied with water, so that
as the slag flows into the pit it is granulated and drops into the receptacle 16,
which may be lifted out of the pit from time to time by a crane 17 and dumped
upon a car or elsewhere as desired. Adjacent to each smelting furnace are reducing
furnaces 18, of which there may be any desired number, the furnaces of each set
being at successively lower levels, a refining furnace 19 being provided at the end
of each set. Between each of the reducing furnaces are settlers 20, which are pre-
ferably wheeled, so that the material may be tapped from one furnace into the
settler and the settler then run along a track or support to the next furnace, into
which the molten metal is charged from the settler.
Instead of moving the settlers from one furnace to the next, troughs 21 may lead
to and from the furnaces to the settlers between them, so that the metal tapped
from one furnace may be run by gravity into the settler and thence run by gravity
into the next furnace of the set.
If movable settlers are employed between the furnaces, they may be upon the
same general level.
For each set of furnaces there are provided a crane 17' and a slag-pit 15' in which
the slag from the settlers between the furnace may be granulated and handled as
described in relation to the pit 15. These cranes may also be employed, in case of
stoppage of one of the furnaces, to carry the settler from one of the set to any
succeeding one, or to the refining furnace, so as not to interfere with the continuous
operation of the plant.
The arrangement of the settlers between the several furnaces is found to be of

page_text: great advantage in getting rid of the slag and separating the copper and the matte,
thus reducing the amount of work in operating the furnaces.
Fig. 5 is a rear elevation of the lower part, Fig. 6 is a vertical section of
a smelting furnace applicable in the plant described or generally for the smelting
of leady ores. 2 is the lower part of a furnace which may be of the usual form
for smelting ores and mattes, and which is provided with a double bottom. A
large cavity 3 is formed in the bottom 4 and the bottom 5 of the cavity is inclined
so that the metal may flow out into a suitable receptacle 6. The bottom 4 is pre-
ferably composed of porous bricks, preferably the ordinary silica fire-brick laid on
edge. 9 is the spout through which the smelted materials pass out of the furnace.
When leady materials are smelted in this type of furnace the lead oozes down
through the bottom 4 and collects in the cavity 3 in a practically pure form, thus
saving a large amount of metal which is usually locked up in the smelting furnace.
The outlet 9 is on substantially the same level as the upper surface of the
bottom 4.
The advantages of the plant described will be apparent to those skilled in the
art, since in reducing from say, a 40 per cent. matte to fine copper, about eleven
handlings of the metal are dispensed with, and a large amount of labour is saved-
while the output is practically double. A large amount of fuel is saved, as the
metal is not chilled but flows in liquid form from one furnace to another, the fur-
naces being kept hot. There is no mechanical loss from frequent handlings of
the metal or matte and the system is rapid, economical and efficient. The arrange-
ment of the settlers enables the plant to be worked continuously, even when one
or more of the furnaces is stopped for rebuilding or repairs.
In the form shewn in Figs. 3 and 4, the metal from any settler between the
reducing furnaces may be charged into any one of the other reducing furnaces or
into the refining furnace.
The advantages of the double bottom consist in separating the lead from the
smelted material and avoiding the locking up of a large amount of metal in the
furnace.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. A smelting plant comprising blast smelting furnaces, wheeled settlers, sets
of successively operating reducing and refining furnaces, tracks for the settlers
and slag pranged and operating substantially as described with reference to
Figs. 1 and 2.
2. The modified smelting plant substantially as described with reference to
Figs. 3 and 4.
3. A smelting furnace having a porous bottom, an outlet for the molten material
and below the porous bottom a receptacle for the lead that oozes through the porous
bottom substantially as described with reference to Figs. 5 and 6.
4. In combination with a smelting furnace, a slag pit with water supply, a slag
receptacle therein and a crane substantially as described.
Dated this 22nd day of March 1898.
ABEL & IMRAY,
Agents for the Applicant.