Improvements in Roasting Certain Ores in Order to Obtain Metals therefrom, and in Means or Apparatus Employed therein.
Year: 1889

page_text: Date of Application, 26th July, 1889
Complete Specification Left, 28th Apr., 1890-Accepted, 31st May, 1890
PROVISIONAL SPECIFICA
Improvements in Roasting Certain Ores in Order to Obtain Metals
therefrom, and in Means or Apparatus Employed therein.
1, SIDNEY TRIVICK, of 29, Gauden Road, Clapham Road, in the County of Surrey,
Analytical Chemist and Metallurgist, do hereby declare the nature of this invention to
be as follows:-
These improvements relate to the roasting of certain ores in order to obtain metals
therefrom and in means or apparatus employed therein. The description of ores to
which the present method of roasting is suitable are those which do not contain a
greater proportion of lead than 3 per cent. and which contain a sufficient proportion
of sulphur to support combustion." These ores in a finely divided state are roasted
without the employment of special fuel for the purpose of supporting combustion
except that in starting the operation wood or charcoal is employed to first heat the
ovens, but such starting fuel when the ovens are sufficiently heated is withdrawn and
replaced by the ores containing the sulphur, and the combustion is supported
thereby.
In
The finely divided ores are introduced into the roasting chambers either alone or
admixed with other matters according to the purpose for which they are destined.
the event of the ore to be treated containing arsenic, antimony, zine or other readily
volatilizable metals the elimination of which may be desired, the ores may be treated
by first giving them a preliminary roasting, and then adding such salts as after
treatments may require, and finishing the roasting operation to completion.
The roasting furnace is arranged as follows: Upon a suitable bed or foundation
are built suitable shelves, forming chambers constructed thereover, and divided by the
shelves or floors of fire-brick or like resistant material into shallow roasting ovens or
shelves, each communicating one with the next above by means of openings left in
each floor alternately one at back and the next at front, whilst the top floor is covered
in, an opening from above being left conveniently-say about the centre thereof-to
facilitate charging in of the ore from above, where conveniently the top of the
furnace is formed as a floor adapted for preliminary drying of the ores to be burnt."
The bottom floor is preferably of iron and has closable openings and moreover can
Each floor in turn is
be drawn away to deliver its charge to the hearth below.
At
plied from the one above with ores to be roasted, the original charge being received
from the opening in the roof of the first floor from a receiving chamber above.
each of the sides of each chamber is an opening preferably towards the front through
chambers
which heated air enters supplied by passages passing alongside these roasting
front above by passages each joining another vertical rearward passage which again
joins another passage below having access to the atmosphere at front of the oven, the
circuitous passages enabling the incoming air to be brought into prolonged contact
with the heated surfaces of the oven. The products of the combustion of the
sulphides pass through the series of chambers and away from the uppermost by
openings leading by passages to a middle passage below a heating or flue chamber to
be described and away to the stack.
As the ores are successively worked from hearth to hearth combustion being sup-
ported and regulated hy carefully regulated currents of cold and heated air supplied
The heated air being
by suitable inlets and passages controlled by doors or valves.
obtained by passage of the air through passages arranged under, around and over
heated surfaces of the oven, other surfaces thereof also serving to heat a series of
pipes through which liquid passes designed for use in subsequent leaching of the

page_text: The resultant waste gases and products are led off by suitable passage to the flue
chamber and stack.
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001
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1000
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WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Roasting Certain Ores in Order to Obtain Metals
therefrom, and in Means or Apparatus Employed therein.
I, SIDNEY TRIVICK, of 29, Gauden Road, Clapham Road, in the County of Surrey,
Analytical Chemist and Metallurgist, 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:-
These improvements relate to a method of roasting ores sufficiently rich in sulphur
to enable them to support combustion when once sufficiently ignited, without the
employment of special fuel except for the preliminary heating of the furnace in which
they are roasted.
The invention relates to the construction or arrangement of the parts of a furnace
or set of furnaces or ovens in which to effect the roasting of ores rich in sulphur in
order to obtain the metals contained.
In the event of the ore to be treated containing arsenic, antimony, zinc or other
readily volatilizable metals the elimination of which may be of material advantage to
the subsequent operations, the ores may be treated by giving them first a preliminary
roasting and then adding such salts as after treatments may require and then finishing
the roasting operation to completion in suitable ovens.
In treating those descriptions of ores containing the precious metals and not con-
taining a greater proportion of lead than three per cent. and for instance not
containing arsenic, antimony, zinc or other metal requiring preliminary roasting
these ores in a finely divided state are introduced into a furnace constructed as will
be described intimately admixed with from three to ten per centum of chloride of
sodium; and the chloride of sodium, where the presence of copper is necessary for
successful treatment thereof in eliminating the precious metals by subsequent
leaching, is made to contain one quarter to one per centum of sulphide of copper
prepared by precipitation of the leaching fluid produced in such subsequent treat-
ments; but when the ores treated contain naturally a sufficient percentage of copper
it is not requisite to provide for this.
The ores rich in sulphur and not containing an inconvenient proportion of lead are
by the aid of my improved furnace, or oven, enabled to be roasted either alone
sufficiently finely ground or intimately admixed with other added matters without
the employment of fuel extra of that provided by the contained sulphur, except that
fuel which is necessary to give a sufficient preliminary heating to the furnace to
induce combustion of the sulphur at starting the operation, subsequent combustion
being maintained by the partially roasted ore igniting the successive fresh charges.
In order to heat the furnace at starting the operation wood or charcoal is filled
thereinto, ignited, and provides the heating material to the oven, but such starting fuel
when the ovens are sufficiently heated is withdrawn and replaced by the ores con-
taining sufficient quantity of sulphur, and thereafter the combustion of the ores is self
supported.
The furnace or oven, according to my invention, contains a series of hearths or
floors superposed one above another upon a bed or foundation. These floors are
formed of firebrick or like fire resistant material and constituting a series of shallow
ovens cach communicating with the next above and the next below it by means
of openings one, or more, in each floor arranged. not to come one above, or below,
the next and, preferably, one towards the front and the next floor, having the next
towards the back thereof and so on; except that the top floor is roofed over with

page_text: the exception of an opening conveniently but not necessarily centrally located by
which ore dried above the said roof, on the floor formed by its upper surface, may
be raked in, when a fresh charge to the first chamber is needed and the cover to
said opening is off, and the bottom floor is preferably made of iron partly fixed
and partly removabler so that adjustable spaces for air to enter may, be left, and
the movable part, drawn apart to permit dropping of the roasted ore onto the
hearth below ready for removal. At front of each chamber is a door or closing
piece adjustable in its position so as to admit more or less cold air and for the
introduction of the rakes for moving the ore from floor to floor and the bottom
floor admits a stream of like air which perineates the chambers successively in
turns. At each of the sides of each chamber is an opening preferably towards the
front through which heated air enters and aids combustion of the sulphur contained
in the ores from which the 'metals are to be obtained and, this air is conducted and
heatel in its conduction by means of passages carried along the side and up over the
fire chambers joining other passages leading down rearward of and then frontwards
under the bed or through it to the front of the furnace. The products of the com-
bustion of the sulphides pass through the series of chambers and away from the
uppermost by openings leading by passages to a middle or flue passage below a
heating chamber to be described and away to the stack. The heating chamber
provided rearward of each furnace and over the flue chamber serves when packed
with sand to contain tubes suitable for heating leaching or other fluid adapted for
subsequent treatment of the ores.
The adjustments by the opening or closing more or less, of the dampers provided
at the opening of each hot air flue; in the oven, connected with the separate hearths
and the adjustment of the front cold air doors and of the movable bottom floor
enable the combustion of the ores to be controlled with great delicacy and efficiency.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 shews a longitudinal vertical section of a furnace or oven, so constructed,
grouped a side with four like furnaces back to back the line X-X shewing the
line of junction, the flue passages m² and chamber o over being in common to the two
The right hand furnace is shewn as taken on the line M-N of Fig. 3 whilst
the left hand furnace is shewn as taken on the line -F of that same figure through
the centre lengthwise of each chamber of the pair in line.
rows.
Fig. 2 shews on plan an arrangement of eight furnaces constructed as described,
the upper half of the said figure shewing the exterior of two pairs of furnaces. The
left hand bottom quarter of said Figure shewing two furnaces in longitudinal
transverse section taken on the line P-Q of Fig. 1 and the opposite bottoin quarter
of the Figure shewing the air passages for heated air and the position of the regulator
sliding doors provided to each opening therefrom into the chambers b.
Fig. 3 shews a vertical section taken transversely of Fig. 1, the left hand half of
this figure being taken on the line C-D of Fig. I and the right hand half on the
line A-B thereof.
Fig. 4 shews a front view of the roasting ovens. a is the roof or drying floor open
to the air. ' is the closable supply hole to the chamber the floor of which is
omitted at to the front of the oven.
The next floor has a like opening at c¹ but located rearwardly and so alternately
with the floors d, e, f, g, h, i and their respective openings d¹, e², f', g², W, i
A indicates a series of openings leading one to each of the front sides of the chambers
from passages leading from the front of the bed block 1, each opering being
closed or partially closed by means of a sliding tile one of which is shewn separately
adjoining Fig. 4 so as to adjust the quantity of hot air supplied through flues to
each hearth. These tiles slide in grooves formed in the furnace and they are moved
to and fro by handles or knobs thereto provided. mare exits. for products of com-
bustion at the rear of the top chamber leading by passages m² to the common
flue m² to four furnaces and thence away to a stack or chimney. nare a series of

page_text: adjustable doors one to the front of each oven chamber by which adjustment of
quantity of cold air admitted to that chamber is obtained, and through the openings
covered by such doors the rakes for moving the ore from floor to floor are admitted.
The iron or other metal floor i is capable of being moved, by means of the handle
relatively to the fixed plates, so as to vary the extent of opening and draught of
air whilst on pulling said plate completely forward the ore supported is thrown
off onto the hearth below from whence it may be carried away to be ground
finely, leached for precious metals or otherwise treated according to its nature and
intended treatment.
The furnace having been heated thoroughly in the first instance throughout by
means of wood charcoal or suitable fuel this primary heating medium is withdrawn
from the uppermost chamber as band its place supplied by ore which becomes
ignited and then in succession each primary charge of fuel is withdrawn from
chambers c, d, e, f, g, h, and i the first charge of ore being progressively raked down
on to the floor next below and its place supplied by a fresh charge from the hole a¹.
Although I have shewn four furnaces a side arranged in one block other number
may be assembled but four is a convenient and most suitable number as one flue
chamber heating chamber over it and contained piping if employed can be used most
readily in common with great economy, and waste of heat by a rear wall avoided for
the eight ovens.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. A furnace or oven for roasting ores rich enough in sulphur to support com-
bustion for their own treatment after the roasting chambers have been primarily
heated by extraneous fuel a series of chambers as b, c, d, e, f, g, h, and i superposed
and communicating by openings as b³, c', d', c¹, f', g', h', and i¹ for successive transfer
of charges of ores being roasted, supply opening a, and closing doors and removable
floor, in combination with hot air passages heated by the furnace itself and exit flues
and flue passages and adjustable dampers to flues leading into each separate hearth
or floor substantially as set forth and illustrated by the accompanying drawings.
2. In a furnace for roasting ores rich in sulphur sufficiently to support com-
bustion after efficient ignition without further use of extraneous fuel the superposed
communicating chambers to contain in succession a charge of ore supplied by an
upper shute as a, in combination with passages controlled by doors for cold air, open
passages for side ventilation of hot air, end exit passages for products of combustion
leading to a chimney substantially as set forth.
3. In a furnace for roasting ores rich enough in sulphur to sustain their own
combustion in the roasting chambers without provision of fresh extraneous fuel after
the primary heating of the furnace by ordinary fuel a series of roasting chambers
communicating, arranged one above another and so that a charge of ore roasted, in
the uppermost may be in succession worked down into the chamber next below its
place being taken by charges of ore successively introduced in combination with
adjustable openings and heated passages for air.
4. The herein described method of roasting ores rich in sulphur without the
employment of special fuel to produce combustion after the first heating of the furnace
and aided by regulated quantities of air substantially as set forth.
5. The herein described method of roasting ores rich in sulphur and not containing
a greater proportion of lead than three per cent., in a finely divided condition, and
intimately admixed with from three to ten per centum of chloride of sodium con-
taining from one quarter to one per centum of sulphide of copper as described all
substantially as and for the purpose set forth.
Dated the 24th day o1 Ap
10
WM. BROOKES & SON,
55 & 56. Chancery Lane, London, Agents for the Applicant.