IMPROVEMENTS IN REDUCING METALS FROM THEIR ORES OR CHEMICAL COMPOUNDS, AND IN APPARATUS EMPLOYED THEREFOR
Year: 1883

page_text: LETTERS PATENT to John Clark of Kensington in the County of Middlesex,
Metallurgist. for an Invention of IMPROVEMENTS IN REDUCING METALS
FROM THEIR ORES OR CHEMICAL COMPOUNDS, AND IN APPARATUS EMPLOYED
THEREFOR
PROVISIONAL SPECIFICATION left by the said John Clark at the Office
of the Commissioners of Patents on the 17th February 1883.
JOHN CLARK of Kensington in the County of Middlesex, Metallurgist,
"IMPROVEMENTS IN REDUCING METALS FROM THEIR ORES OR CHEMICAL COMPOUNDS,
AND IN APPARATUS EMPLOYED THEREFOR,"
The object of this invention is to obtain the intense heat necessary for reducing
metals from their natural ores or from chemical compounds, by concentrating the
rays of the sun, by means of a large and powerful lens or reflecting mirror, to a
focus while, at the same time, I blow a suitable gasseous or other reagent upon the
heated ore, and thereby effect its reduction by a direct and economical method.
Most of the ores, whether natural or artificially prepared, are oxides or chlorides
of the metals they contain. This invention reduces the oxides readily, because the
necessary heat is obtained without the combustion of oxygen gas in the atmosphere,
in its combination with carbon, to produce such heat; so that, when treating the
oxides of the metals, I find it facilitates such operation not to use oxygen gas for
generating the heat required, but rather to use a reagent to unite with the oxygen
already combined with the metal, and obtain the necessary heat from another source
to effect the union of such reagent with the oxygen. Further, this invention
reduces the chlorides readily, owing to the well-known fact that chlorine and
hydrogen gases combine with great energy in sunshine; while, from the intense
concentration of sun-light and heat obtained by this invention, the chlorides are
rapidly reduced when exposed in the focus of my apparatus; and, at the same
time, hydrogen or carburetted hydrogen gas is blown upon them as reagents,
thereby dispensing with the use of sodium or potassium as reagents, which are
both expensive.
In carrying my invention into practice, I construct a large and powerful
reflecting mirror, to concentrate the rays of the sun to a short focus; I monat such

page_text: '
mirror in a frame to support it, and I fit such frame with suitable apparatus to
adjust it opposite to the sun, as respects his elevation due to latitude and the season
of the year; and a further movement to cause such mirror to follow his diurnal
course, day by day;' I also use a powerful burning-glass or lens, which may either
be made of solid glass, or be hollow and filled with a transparent fluid, and therewith
concentrate the sun's rays for the same purpose. The ore and chemical compounds,
to be reduced, I prefer to pulverize and afterwards, by powerful compression,
consolidate them into bars or blocks; or, I pulverize them and convey them in a
channel to the focus of such mirror or lens; and, at the same time, I blow or
impinge upon the heated ore or chemical compounds any of the well-known
reducing reagents. The reagent, if gaseous, I convey through a suitable pipe,
having its delivering end near to such focus. When the ore is thus reduced, it falls
as metallic powder or as a spongy mass into a suitable receptacle below.
When I use a solid reagent, such as carbon or carbonaceous matter, I intimately
mix such reagent with the ore before exposing it in such focus; and, at the same
time, I blow a neutral gas through the said pipe to prevent reoxidation of the
metal.
When I use carburetted hydrogen or other hydro-carbon, as a reagent, I prefer
to mix the ore in certain proportions of oxide and chloride, which thereby increases
its affinity for the compound reagent employed, when brought into the focus
described.
When I reduce the oxide or chloride of platinum, it is not necessary to blow a
reagent through the pipe described, as these compounds are both reduced by heat
alone; but the intense heat of my apparatus is afterwards required to consolidate
such metal, to prepare it for welding, and to vaporize any metals which are often
mixed with the natural ores of platinum.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Clark in the Great Seal Patent Office on the 15th August
1883.
JOHN CLARK of Kensington in the County of Middlesex, Metallurgist,
" IMPROVEMENTS IN REDUCING METALS FROM THEIR ORES OR CHEMICAL
COMPOUNDS, AND IN APPARATUS EMPLOYED THEREFOR
"
The object of this invention is to obtain the intense heat necessary for reducing
metals from their natural ores, or from chemical compounds derived or prepared
therefrom, by concentrating the rays of the sun to a focus, by means of a large and
powerful lens or reflecting mirror, and exposing the ore or chemical compound, to be
reduced, in such focus; while, at the same time, I blow a suitable gaseous or other
reagent upon the heated ore or chemical compound, and thereby effect the reduction
thereof by a direct and economical method.
Most of the ores, whether natural or artificially prepared therefrom are oxides
or chlorides of the metals they contain. This invention reduces the oxides readily,
because the necessary heat is obtained, by the apparatus hereinafter described,
without the combustion of oxygen gas in the atmosphere, in its combination with
carbon, to produce such heat; so that, when reducing oxides of the metals, I find
it facilitates such operations, not to use oxygen gas for generating the heat required,
but rather to use a gaseous or other reagent, which will unite with the oxygen
already combined with the metal; and to obtain the necessary heat from a source
independent of the combustion of oxygen gas, as provided by this invention, to
effect the reduction of such oxides. Further this invention readily reduces the
chlorides of metals, owing to the well-known fact, that chlorine and hydrogen gases
combine with great energy in ordinary sunshine; while, from the intense concen-
tration of sun-light and heat, obtained by this invention, the chlorides of metals
are readily reduced when exposed in the focus of my apparatus; while, at the same
time, bydrogen, or gaseous compounds of hydrogen, or other suitable reagent, is
blown upon the chloride under operation, whereby its reduction is effected, without
the use of sodium or potassium as reagents, both of which are expensive.
In carrying my invention into practice, I construct a large and powerful reflecting
mirror, to concentrate the rays of the sun to a short focus; I mount such mirror in
a frame to support it, and I fit such frame with suitable apparatus to adjust such
mirror opposite the sun, as respects his elevation, due to latitude and the season of
the year; and a further movement to cause such mirror to follow his diurnal course
day by day.
.
I also use a powerful burning-glass or lens, which may either be made of solid
glass or other suitable material, or be made hollow and be filled with a transparent
Huid, and therewith concentrate. the sun's rays for the same purpose. Or the
reflecting mirror and the lens may both be combined in the apparatus, and their
converging rays made to ineet in a common focus, when so desired.
The ores and chemical compounds, to be reduced, I prefer to pulverize and, when
practicable, I afterwards, by powerful compression, consolidate them into bars or
blocks; or, I pulverize them and convey them in a channel to the focus of such
mirror or lens; while, at the same time, I blow or impinge upon the heated ores or
chemical compounds, any of the well-known reducing reagents. The reagent, if
gaseous, I convey through a suitable pipe, having its delivering end near to such
focus. When ore or chemical compound is thus reduced it falls, as metallic powder
or as a spongy mass, into a suitable receptacle below.
When I use a solid or liquid reagent, such as carbon or carbonaceous matter,

page_text: =
I intimately mix such reagent with the ore or chemical compound before exposing
it in such focus; and, at the same time, I blow a neutral gas through the said pipe,
to prevent reoxidation of the metal after reduction.
When I use carburetted hydrogen gas, or other hydro-carbon, as a reagent,
I prefer to mix an oxide and chloride of the metal together, in proportions to suit
such compound reagent.
When I reduce the oxide or chloride of platinum, it is not necessary to blow a
reagent through the pipe, as previously described, as these compounds are both
reduced by heat alone; but the intense heat obtained by my apparatus is
afterwards required to consolidate such metal, to prepare it for welding, and to
volatilize any metals which may be mixed with the natural ores of platinum.
When I reduce the sulphate of a metal, I prepare such sulphate in the following
manner I first gently heat the sulphate to drive off the combined water or water
of crystallization; I then intimately mix it with charcoal or other carbonaceous
_matter, by grinding, and afterwards expose the mixture on the hearth of a
reverberatory furnace; or on plates with the heat applied underneath, or charged
in a suitable retort. I bring the mixed sulphate to a red heat, when the charcoal
takes up one atom of the oxygen, and the resulting sulphurous acid gas and
carbonic oxide escape, leaving the metallic oxide for further treatment.
I now proceed to describe the apparatus whereby I carry my said invention into
practice, referring to the accompanying drawing by the reference letters-marked_
thereon.
When I use a lens for concentrating the sun's rays, I construct it as shown in
fig. 1; where a is a large and powerful lens or burning glass. It is made of solid
glass, crystal, or other suitable transparent material. It is held in its place by a
circular rim-case b, having attached thereto two trunnions c, c, upon which it
oscillates as required. It is supported at one side upon a fixed bracket d, resting
on the floor line 7; and at the other side upon an adjustable screw d', to enable
such lens to be set opposite the sun as respects his-elevation due to the season of
the year; the joint pins a allowing such movement freely. In order to give
such lens the necessary diurnal movement, to follow the sun by day, I fit a lever e
upon the trunnion c, and connect it by a rope or chain o to the spindle 8, which
may have the necessary motion imparted to it by hand; but I prefer to effect such
movement by a train of clockwork, or by the dropping of a liquid from a vessel, so
as to impart a regular and progressive motion to the said lens, as required. Or,
instead of the lever e, I fit a toothed quadrant, worked by a worm-screw, to effect
the same object; and, when I construct several such lenses to work together, I
connect their several levers by suitable rods, so as to work the series simultaneously.
The dotted lines show the direction of the concentrated rays of the sun to the
focus a¹; and the ore to be reduced is conveyed by the channel or shoot f, having
its delivering end f¹ near such focus. When the ore has been reduced, it falls into
the box g, for removal.
The gaseous or liquid reagent is conveyed, through the pipe h, from a suitable
vessel or tank for containing such reagent. The said pipe has its delivering
end h¹ near to the focus a' of the lens a; and is supported by an arm i fixed to the
trunnion c¹, so as to move the pipe with the lens a, in its diurnal motion, and
maintain its delivering end h¹ near to the focus a².
When I construct the lens a bollow, instead of solid as described, I form it as
shown in fig. 2, with a top and bottom plate or sheet of glass or other suitable
material, and join them by a rim-case b; I fill the interior cavity m with any
suitable transparent fluid. The lens, when so prepared, I fit with a precisely
similar arrangement to that described under fig. 1, and operate it in the same
manner. The convexity of the lens a, in figs. 1 and 2, may be altered as required,
and one side may even be flat, without impairing its efficiency for the purpose of
my invention.
When I use a concave reflecting mirror for the purpose of my invention, I
construct it as shown in elevation in fig. 3; fig. 4 being a plan of the same.
The

page_text: apparatus consists of a frame having radiated arms a bolted to the central ring or
hoop b, and to the rim-hoop c; to the arms a is fixed a powerful reflecting mirror,
consisting of a single concave sheet or of segments d of silvered glass or burnished
metal sheets, which may be plated with silver, nickel, or other suitable metal; they
are bent so that the sun's rays falling thereon, shall be reflected to a focus at e, as
shown by the dotted lines f. In the focus e, I expose the ore g to be reduced,
which I prefer to prepare in the form of a consolidated bar or block, as previously
described; I fix such bar to the arm h, supported by the line ' carried over &
pulley h, or other suitable means, whereby it is lowered into the focus e as
required; and is thus moved forward as the end g' gets reduced. Through the
pipe k, I convey the gaseous or other reducing reagent, as described under fig. 1.
When I blow a gaseous reagent through the pipe k, the excess of such roagent,
surrounding the reducing focus, usually prevents the reoxidation of the metal; but
to prevent still further such a result, I inclose the whole apparatus in a chambor
with a glass roof, and fill such chamber with the reducing gaseous reagent.
In order to give my said apparatus the necessary adjustment to suit the
elevation of the sun, as described under fig. 1, I suspend the rim-hoop c in
gimballs in the concentric rings j, j; the outer ring jis supported upon brackets l,
and to this ring is fixed the radial arm m, which slides in a slot in l, and is secured
in its place by the lock-bolt n, whereby the necessary adjustment is effected. To
give the reflecting mirror d a movement suiting the sun's diurnal motion, I fix
a pulley o on the axis of the inner ring j³, and pass a line p around such pulley o;
I connect the line p to a train of clock-work, or other suitable motor, as described
under fig. 1; and also work several such mirrors simultaneously when required,
as already described. The arm 7 and the pipe k are attached, in any suitable
manner, to the inner ring j¹. When the ore has been reduced, it falls into the
funnels and box 8', for removal.
When I require to deflect the sun's rays downwards, as when the ore to be
reduced is in a state of powder, I fit a reflecting disc or mirror r, as shown in
elevation in fig. 5, and attach it to an arch or bracket t, by which the rays from
the mirror d are reflected and concentrated in a focus e below such disc. I introduce
the ore through a tube u, and raise it to the upper or delivery end of such tube by
pushing a plunger or piston inside and fitting the said tube. The ore, when
reduced, falls into a funnel 8, around the tube u, and is conveyed to a box s¹ for
removal. The gaseous or liquid reagent I convey through the pipe / which passes
through a hole in the disc r. The other reference letters in the figure refer to
similar parts as are described under figs. 3 and 4.
When I combine the lens and reflecting mirror in one apparatus, for the purpose
of this invention, so that the concentrated rays of the sun therefrom shall meet
in a common focus, I construct it as shown in elevation in fig. 6, wherein a is the
lens; constructed as described under figs. 1 and 2, and supported by the bracket b
c, d are the reflecting mirror and its frame, as described under figs 3 and 4; the
dotted lines f show the converging rays to the common focus e. The ore to be
reduced is prepared as a block g, as previously described, and held in the arm h,
which is fitted with a screw, or suitable mechanism, to propel the bar g forward
into the focus e as it gets reduced; the ore, when reduced, falls into the box 8, for
removal. The gaseous or liquid reagent is conveyed through the pipe k, as
described under figs. 3 and 4. The other reference letters in the fig. refer to similar
parts as are previously described under figs. 3 and 4.
Having thus fully described and ascertained the nature of my said invention
and the method of performing the same, I would further state that I do not
restrict myself to the precise details herein explained and illustrated because,
from the nature of my said invention, they may be modified in practice, without
departing from the main characteristics of my said invention; but what I consider
novel and, desire to secure by the before-mentioned in part recited Letters
Patent, is :-
Firstly-The application of the concentrated rays or heat of the sun in

page_text: reducing natural metallic ores or chemical compounds derived or prepared
therefrom.
Secondly--The method of reducing natural metallic ores or chemical compounds
derived or prepared therefrom, by concentrating the sun's rays to a focus and
exposing such ores or chemical compounds therein; and, at the same time,
blowing or impinging upon such heated ores or chemical compounds any suitable
reagent to reduce such ores or chemical compounds to the metallic state, sub-
stantially as described.
:
Thirdly―The method of reducing natural metallic ores or chemical compounds
derived or prepared therefrom, when the reagent, in a solid or liquid form, is mixed
with such ores or chemical compounds before being exposed in the said focus,
substantially as described.
Fourthly The method of reducing oxides and chlorides of the metals, by
mixing such oxides and chlorides together when the reagent is carburetted-
hydrogen gas, or other hydro-carbon in the gaseous or liquid form, substantially
as described.
Fifthly The method of reducing the natural ore of platinum, and for con-
solidating and heating metallic platinum to prepare it for welding, substantially
as described.
Sixthly The method of preparing the sulphate of a metal, so as to reduce it
-to-an-oxide-of-such metal, to be afterwards reduced to the metallic state, sub-
stantially as described.
Seventhly The apparatus for concentrating the sun's rays to a focus, for the
purpose of my invention, substantially as described.
Eighthly—The apparatus for moving the lens or reflecting mirror opposite the
sun, for the purpose of my invention, substantially as described.
Ninthly The apparatus for exposing the ore or chemical compound, to be
reduced, in the focus of the said lens or mirror, for the purpose of my said
invention, substantially as described.
In witness whereof I, the said John Clark, have hereunto set my hand and
seal this fourteenth day of August in the year of our Lord one thousand eight
hundred and eighty-three.
JOHN CLARK (19)
JOHN CLARK
(TG)