An Improved Process relating to the Reduction of Ores, and Improve. ments in Furnaces therefor
Year: 1897

page_text: An Improved Process relating to the Reduction of Ores, and Improve.
ments in Furnaces therefor,
I, JOSEPH EMERSON DOWSON, M.I.C.E., of 39, Old Queen Street, Westminster,
in the County of London, do hereby declare the nature of this invention to be s
follows:
This invention relates to the class of furnaces used for heating ores or minerals
while in contact with reducing gases.
I am aware that carbonic oxide or hydrogen or both are passed over sulphides,
arsenides, tellurides, and other ores for the purpose of facilitating their reduc-
tion to the metallic state or as a preliminary step for their further treatment.
For instance refractory ores containing telluride of gold may be heated while
in contact with carbonic oxide and hydrogen, so that the gold may be afterwards
recovered by amalgamation. To effect the necessary chemical changes the ores
are usually heated in a chamber or furnace by a fire outside the ore chamber.
According to my invention the ore chamber or furnace is heated by the com-
bustion of producer or other suitable gas instead of by a fire, and the
gas which is to be used for this purpose is passed through the ore chamber on
its way to the combustion chamber under the bed of same, some of it acting
as a reducing agent in contact, with the ore. The whole of the gas is then con-
veyed under the bed or floor of the furnace, its combustible constituents being
burnt there in order to heat the furnace. The incombustible constituents are
at a high temperature and give up some of their heat to the ore chamber or
furnace.
When it is necessary to stop gas from passing over the ore it can be sent into
the combustion chamber direct, or some of the gas can be passed through the
ore chamber, and some of it can be taken direct to the combustion chamber,
the admission of gas and air being regulated by valves or other suitable con-
trivances.
This arrangement is at once simple and effective and the working is well under
control.
Preferably the furnace should be built with a heat regenerator, so that the
ingoing air for combustion may be heated by the outgoing products of com-
bustion. One or more ducts or passages may also be provided over the top, at
the sides or under the ore chamber, and through these the gas may be led on
its way to the ore chamber so as to be heated before it enters therein.
The furnace by means of which this method may be worked comprises suit-
able ducts, passages or flues for the gas and air required in giving effect to the
system of working above described.
Dated this 18th day of November 1897.

page_text: An Improved Process relating to the Reduction of Ores, and Improve-
ments in Furnaces therefor.
I, JOSEPHI EMERSON DOWSON, M.I.C.E., of 39, Old Queen Street, Westminster,
in the County of London, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to the class of furnaces used for heating ores or minerals
while in contact with reducing gases.
I am aware that carbonic oxide or hydrogen or both are passed over sulphides
arsenides, tellurides, and other ores for the purpose of facilitating their reduc-
tion to the metallic state or as a preliminary step for their further treatment.
For instance refractory ores containing telluride of gold may be heated while
in contact with carbonic oxide and hydrogen, so that the gold may be afterwards
recovered by amalgamation. To effect the necessary chemical changes the ores
are usually heated in a chamber or furnace by a fire outside the ore chamber.
According to my invention the ore chamber or furnace is heated by the com-
bustion of producer gas, water gas or other suitable gas instead of by a fire, and the
gas which is to be used for this purpose is passed through the ore chamber on
its way to the combustion chamber under the bed of same, some of it acting
as a reducing agent in contact with the ore. The whole of the gas is then con-
veyed under the bed or floor of the furnace, its combustible constituents being
burnt there in order to heat the furnace. The incombustible constituents are
at a high temperature and give up some of their heat to the ore chamber or
furnace.
When it is necessary to stop gas from passing over the ore it can be sent into
the combustion chamber direct, or some of the gas can be passed through the
ore chamber, and some of it can be taken direct to the combustion chamber,
the admission of gas and air being regulated by valves or other suitable con-
trivances.
This arrangement is at once simple and effective and the working is well under
control.
Preferably the furnace should be built with a heat regenerator, so that the
ingoing air for combustion may be heated by the outgoing products of cor-
bustion. One or more ducts or passages may also be provided over the top, at
the sides, or under the ore chamber, and through these the gas may be led on
its way to the ore chamber so as to be heated before it enters therein.
The furnace by means of which this method may be worked comprises suit-
able ducts, passages or flues for the gas and air required in giving effect to the
system of working above described.
The ore chamber or furnace can be of any convenient shape or size, and where
it is desirable to keep the ore moving while it is in the furnace the latter can be
made to rotate, or it can be a fixture with suitable stirrers or conveyors working
inside the ore chamber or furnace.
Reference being made to the annexed drawings showing the application of
this invention to a furnace with a stationary ore chamber and without mechanical
means of moving the ore.
Fig. 1 is a longitudinal vertical section on line A B Fig. 2 is a transverse
section on line C D & Fig. 3 is a plan of the ore chamber or furnace with flues
for air & products of combustion underneath.

page_text: a is the ore chamber or furnace. b b illustrate combustion chambers of which
there may be one, two or more, under a where gas is burnt for the purpose of
heating the ore chamber a. cc are air flues or passages. d d are flues or
passages under
cc for the products of combustion from the combustion
chambers bb. eis a gas generator with outlet f and valves f¹ f2. 9 is a pipe
which conveys gas to the passages h h over the roof of ore chamber a.
passage leading gas to end of ore chamber a. j is a passage leading gas from
chamber a to combustion chambers bb. is a damper to regulate the quantity
of gas passing through passage j. are passages for introduction of ore to
chamber a.
m m m are doors for access to chamber a.
2 18 a
The usual method of working is for the gas from the generator e to pass
through valve f¹ into the passage thence to passage i and thus into the end of
chamber a where it passes over the ore. After so passing over the ore it issues
at the other end of the chamber a as regulated by the damper k and passes to
the combustion chamber b where it mixes with air from the passage c and so
much of the gas as remains combustible after its passage over the ore is then
burnt, the products passing through passages d to the chimney.
If the gas from chamber a is not sufficient for the amount of combustion
required, an additional supply of gas can be passed direct from the generator to
the combustion chamber b by suitable regulation of the valve f.
By passing through a passage such as hi the gas is heated by the heat of the
furnace, but when the gas is sufficiently hot for the particular ore under treat-
ment, without the use of such passages, they may be dispensed with.
The system of gas utilization may be applied in an analogous manner to any
furnace with rotary ore chamber or with mechanical agitators in the ore chamber,
such needing no special illustration or further description.
This invention is therefore not confined to the particular construction of
furnace here illustrated but:-
this
Having now particularly described and ascertained the nature of
invention, and in what manner the same is to be performed I declare that what
I claim is
1. The improved process for the reduction of ores and furnaces therefor,
wherein combustible gas such as generator gas or similar gas is passed over the
ore in the ore chamber and is subsequently mixed with air and burnt in a com-
bustion chamber for heating the ore chamber, with or without admixture of a
further supply of gas to the same after its passage through the ore chamber,
substantially as herein described.
2. The improved process for the reduction of ores and furnaces therefor, wherein
combustible gas such as generator gas or similar gas is passed through a passage
heated by the furnace and thence into and along an ore chamber and thence into
a combustion chamber beneath the ore chamber where it is mixed with air heated
by passing through a passage or passages heated by said combustion chamber
and by the products of combustion flues the said gas being burnt in said com-
bustion chamber means being also provided for regulating the entrance of gas
to the furnace, its passage from the ore chamber to the combustion chamber and
for controlling the admission direct to the combustion chamber of a further supply
of gas, substantially as set forth.
HERBERT HADDAN & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, London.