IMPROVEMENTS IN TREATING ORES AND SUBSTANCES CONTAINING ANTIMONY TO OBTAIN METALLIC ANTIMONY AND OTHER PRODUCTS, AND IN PROVISIONAL SPECIFICATION
Year: 1881

page_text: LETTERS PATENT to John Hargreaves, of Widnes, in the County of Lancaster,
Chemist, and Thomas Robinson, of the same Place, Ironfounder, for an Inven-
tion of IMPROVEMENTS IN TREATING ORES AND SUBSTANCES CONTAINING
ANTIMONY TO OBTAIN METALLIC ANTIMONY AND OTHER PRODUCTS, AND IN
PROVISIONAL SPECIFICATION left by the said John Hargreaves and
Thomas Robinson at the Office of the Commissioners of Patents on the
19th May 1881.
JOHN HARGREAVES, of Widnes, in the County of Lancaster, Chemist, and
THOMAS ROBINSON, of the same Place, Iron Founder. "IMPROVEMENTS IN TREATING
ORES AND SUBSTANCES CONTAINING ANTIMONY TO OBTAIN METALLIC ANTIMONY
AND OTHER PRODUCTS, AND IN APPARATUS EMPLOYED THEREIN."
Our Invention relates to treating antimonious ores and substances to obtain
metallic antimony and other valuable products, such as gold, silver, mercury,
bismuth, copper, lead, cadmium, and tin, when these metals or one or more of them
are or is contained in the said ores or substances, and also sulphuretted hydrogen.
It further relates to apparatus or appliances used in the said treatment.
First part. When sulphide of antimony, whether pure or mixed with or contained
in other metals or substances, is dissolved in hydrochloric acid for the purpose of
obtaining antimony in solution to be afterwards precipitated in the metallic state,
we use for that purpose the hydrochloric acid between 1·11 and 1.20 specific gravity,
that is, containing 21 to 40 per cent. of dry hydrochloric acid gas, and before.
the termination of the dissolving process being in contact with such hydrochloric
acid an amount of the sulphide of antimony in excess of that finally dissolved by
the said charge of acid, and towards the termination of the dissolving operation we
increase the temperature of the solution until it passes 214° F.; we then by
preference continue to heat the solution until the boiling point is reached.
After the treatment above described we prefer to proceed as follows:-When
the excess of sulphide of antimony has settled and the solution of chloride of
Price Bd1

page_text: antimony has been decanted, fresh or only partially saturated hydrochloric acid is
brought in contact with the said excess of sulphide of antimony, which it wholly
or partially dissolves; an excess of sulphide of antimony is then brought in contact
with the chloride of antimony solution, and this is repeated until sufficient
undissolved residue has accumulated in the dissolving vessel. The number of
dissolving operations repeated before this point is arrived at will necessarily vary
with the amount of material insoluble in hydrochloric acid. When an excess of
hydrochloric acid is added and the sulphide of antimony remaining in the residue
is dissolved, the partially saturated acid is allowed to settle and is run off; the
undissolved residue is then withdrawn, and the said partially saturated hydrochloric
acid brought in contact with an excess of the antimonious ore or substance.
Second part (A). We subject chloride of antimony solutions obtained under the
first part of our Invention, and also the solutions obtained from the residues there-
from after the metals therein contained have been made soluble when they contain
two or more of the metals herein before mentioned to systematic fractional metallic
precipitation. Systematic fractional metallic precipitation is intended to convey
that we first separate when these metals are present, (1) gold, silver, and mercury;
(2) lead; (3) bismuth and copper; (4) antimony; (5) cadmium and tin.
The solutions are placed in suitable vessels or containers, and brought into
contact with precipitated antimony. This may be effected by filtration through
the said precipitate, or by agitating the precipitate in the solution.
In the latter
case we use the precipitate in a very fine state of division, and by so doing metallic
gold, silver, and mercury are precipitated. After the separation of the said
precipitate of gold, silver, and mercury from the solution of chloride of antimony,
which separation may be considerably assited when lead is present by the addition
of sulphuric acid.
(B). The solution after treatment under (A) above is submitted to the action of
finely divided metallic lead after the manner described for gold, silver, and mercury,
for the purpose of precipitating metallic bismuth and copper.
(C). The solution after treatment (B) is preferably cooled, and sulphuric acid
(free from arsenic) added to precipitate any lead remaining in solution as
sulphate.
(D). The antimony contained in the solution after treatment C is precipitated by
metallic iron in the manner described under the following third part.
(E). The cadmium and tin contained in the chloride of iron solution left in D
is precipitated by metallic zinc.
We have herein described under this head the process as though all the metals
hereinbefore mentioned were present in the ores or substances. It will however be
evident that the process of systematic fractional metallic precipitation is equally
applicable when a lesser or larger number of metals is present. The solution con-
taining the several metals is maintained, as will be evident, at suitable temperatures
and degrees of acidity, and the metals used as precipitators are in sufficient fineness
to effect the desired result.
Third part. To obtain antimony precipitate in a desirable condition from a
solution of chloride of antimony containing unneutralized hydrochloric acid to
economize iron, and to diminish the amount of noxious vapors evolved during
precipitation, we keep the said solution of chloride of antimony at a temperature
below 180 degrees Fahr., until the whole or the greater part of the antimony has
been precipitated.
In practice we find the best results obtained by precipitating the solution of
antimony at a temperature of 60 to 80 degrees Fahr., and we prefer to cool the
solution of chloride of antimony coming from the dissolving vessel to or about the
latter named temperature, and if necessary we allow the solution to settle at about
that temperature before it flows into the precipitating vessel.
Fourth part. For the purpose of economizing the amount of hydrochloric acid
used in treating antimonious ores or substances, we subject the said hydrochloric
acid of the strength named under the first head, whilst dissolving the antimony in

page_text: the said ores or substances to pressure and to a higher temperature than that of the
boiling point of the solution under normal atmospheric pressure, and we arrange
suitable vessels made of stone or antimony alloy to withstand the said pressure
and the action of the chloride of antimony.
Fifth part. As it is of the greatest importance that the precipitated antimony
resulting from the treatment mentioned under the third part should be as free from
impurities as possible, we use iron for that purpose presenting a surface of less
than 60 sqr. inches per pound. In practice we prefer to use iron in a condition
which offers only a small amount of surface per unit of weight. To prevent as far
as possible the said precipitate from being contaminated by oxide of iron, we
remove the scale or oxide before bringing the precipitating iron in contact with
the strong chloride of antimony solution. This we effect by immersion in the acid
solution of chloride of iron coming from the precipitating vessel. Any traces of
antimony still remaining in the solution of chloride of iron are precipitated, and
will be found deposited along with the oxide of iron, from which it may be
recovered in any convenient manner.
Sixth part. For the purpose of consolidating into blocks or pieces the precipitated
metallic antimony, leaving it relatively free from moisture and preventing
oxidation, we subject it to pressure in what is commonly known as a
"filter
press." By this means the precipitated antimony is subjected to high pressure
and compressed into solid cakes or blocks. These are afterwards removed and
dried below 300 degrees Fahr. The said drying may be conveniently effected by
placing the wet precipitate on or betwixt plates, heated by means of steam, or by
passing warm or hot gases of such a nature as not to oxidise the metal over or
through the said precipitate.
The said filter press may, as mentioned, be used for extracting the moisture
from, or washing the antimony precipitate. After the precipitated antimony has
been freed from moisture, we prefer to mix with the same the whole or part of the
flux for fusing, and to subject the dried precipitate to a high pressure in any
suitable machine, whereby it is formed into very dense pieces and rendered less
liable to oxidise, and is more easily fused. If the precipitate has to remain a
considerable time after compression before being fused, it is advisable to smear the
outside of the pieces with tar or other hydro-carbon to prevent oxidation.
Seventh part. The chloride of iron solution resulting from the precipitation of
antimony by iron as herein before described, is evaporated in a stone vessel. To
recover the hydrochloric acid therein for further use, the products of combustion
employed in evaporating the solution are caused to pass over the surface of the
said solution, but out of contact with the vapor evolved. The whole or part of
the vapor is passed through a muffle furnace in which the concentrated chloride of
iron or other chlorides are undergoing decomposition. The whole or part of the
vapor thus evolved is preferably caused to mix with the comparatively dry
hydrochloric acid gas evolved during the manufacture of sulphate of soda, so that
mixed gases shall contain an amount of moisture so small as to allow the
hydrochloric acid to be condensed sufficiently strong for re-use in dissolving sulphide
of antimony.
Eighth part. In dissolving antimonious ores or substances in hydrocloric acid,
we use a covered stone vessel with parts for carrying away the sulphuretted
hydrogen, as described in our Patent, No. 1584, of the present year. The solution
is heated under our Invention by means of a coil of pipes, or one or more shallow
boxes, covering the whole or a considerable portion of the bottom of the said
covered vessel, through which pipes or boxes, made of antimony or an alloy thereof,
we pass steam maintained under pressure, or we use a double vessel, the inner
structure of which is made, consists of, or is lined with antimony or an alloy of
The steam is maintained under pressure sufficient to supply the necessary
heat to maintain the solution at the temperature mentioned under head I. A
mechanical stirrer is used to agitate the ores or substances whilst being dissolved.
We may here remark that in practice we have found wooden vessel or vessels
the same.

page_text: lined with lead to be altogether unsuitable as dissolving vessels, on account of the
corrosive action of the hot acid solution of chloride of antimony, and the high
temperature of the solution necessary to dissolve the sulphide of antimony.
Ninth part. For fusing the precipitated antimony, we arrange a suitable crucible
or pot in such a manner that as the precipitate is fed in at the top, the fused metal
can be run out at a hole or aperture near the bottom into ingots, or if necessary
directly refined after running the metal into another crucible or pot situated below
the level of the first named, by which means the precipitate is continually fed to
the upper, and the refined metal run directly into ingots from the lower crucible or
pot; suitable arrangements being made in both cases for heating the said crucible
or pot and conveying away the antimonious vapors evolved.
It will be evident that in connection with some or more of the heads hereinbefore
mentioned, the following may be adopted :-
:-
(1.) Economy of time and dissolving space may be secured by heating the
hydrochloric acid to near the boiling point before running it into the dissolving
vessel.
(2.) Cast iron, if sufficiently free from impurities, may be used for precipitating
antimony from solution.
(3.) If the precipitated antimony contain any foreign substance which cannot
conveniently be extracted by washing with chloride of antimony, hydrochloric
acid or water, but soluble in solutions of the chlorides of calcium, magnesium,
sodium, or potassium, we use the most convenient of these solutions with or
without admixture with the solutions mentioned as of our Invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Hargreaves and Thomas Robinson in the Great Seal
Patent Office on the 19th November 1881.
JOHN HARGREAVES, of Widnes, in the County of Lancaster, Chemist, and
THOMAS ROBINSON, of the same Place, Ironfounder. "IMPROVEMENTS IN TREATING
ORES AND SUBSTANCES CONTAINING ANTIMONY TO OBTAIN METALLIC ANTIMONY
AND OTHER PRODUCTS, AND IN APPARATUS EMPLOYED THEREIN."
Our Invention relates to treating antimonious ores and substances to obtain
metallic antimony and other valuable products, such as gold, silver, mercury,
bismuth, copper, lead, cadmium, and tin, when these metals or one or more of
them are or is contained in the said ores or substances, and also sulphuretted
hydrogen. It further relates to apparatus or appliances used in the said treatment.
First part. When sulphide of antimony, whether pure or mixed with or contained
in other metals or substances is dissolved in hydrochloric acid for the purpose of
obtaining antimony in solution, to be afterwards precipitated in the metallic state,
we use for that purpose the hydrochloric acid between 111 and 120 specific
gravity when at 60° Fahr., that is, containing from about 21 to 40 per cent. of dry
hydrochloric acid gas, and before the termination of the dissolving process bring in
contact with such hydrochloric acid an amount of the sulphide of antimony in
excess of that finally dissolved by the said charge of acid, and towards the
termination of the dissolving operation we increase the temperature of the solution
until it passes 214° Fahr. We then by preference continue to heat the solution
until the boiling point is reached.
After the treatinent above described we prefer to proceed as follows:-When the
excess of sulphide of antimony has settled, and the solution of chloride of antimony
has been decanted, fresh or only partially saturated hydrochloric acid is brought in
contact with the said excess of sulphide of antimony which it wholly or partially
dissolves. An excess of sulphide of antimony is again brought in contact with the
chloride of antimony solution, and these operations are repeated until sufficient
undissolved residue has accumulated in the dissolving vessel. The number of
dissolving operations repeated before this point is arrived at will necessarily vary
with the amount of material insoluble in hydrochloric acid. At this stage we add
an excess of hydrochloric acid, and the sulphide of antimony remaining in the
residue is dissolved; the partially saturated acid is allowed to settle and is run off.
The undissolved residue is then withdrawn and drained, and the said partially
saturated hydrochloric acid brought in contact with an excess of the antimonious
ore or substance.
In practice we find it advantageous to use a series of vessels for effecting the
solution of antimony as aforesaid, in which case the partially saturated solution of
antimony in the vessel in which the ore is spent is saturated as completely, and is
obtained of as high a specific gravity as practicable, by bringing the said solution
into contact with an excess of fresh ore. We find that pumps inade of antimony,
with antimony or india rubber valves, are suitable for transferring from vessel to
vessel, or from place to place, the said antimonious solutions whether partially or
completely saturated, or for moving the hydrochloric acid or the liquid residues
which remain after the precipitation of metallic antimony.
We find it is important after the operation of dissolving has proceeded for some
time that the temperature of the solution should be maintained as high as
practicable. The hydrochloric acid should in the first instance be strong, so that
the resulting solution of chloride of antimony may contain as much antimony and
as little free acid as possible. Any sulphide of arsenic contained in the antimonious
ores or substances remains undissolved in the solid residue.

page_text: Second part (A.) We subject chloride of antimony solutions obtained under the
first part of our Invention, and also the solutions obtained from the residues
therefrom, after the metals therein contained have been made soluble, and they
contain two or more of the metals herein before mentioned (such metals being
necessarily of sufficient value) to systematic fractional metallic precipitation.
Systematic fractional metallic precipitation is intended to convey that we first
separate when these metals are present in the ores of sulphide of antimony,
(1), gold, silver, and mercury; (2), bismuth and copper; (3), lead; (4), antimony;
and (5), cadmium and tin.
The said solutions are placed in suitable vessels or containers, and brought into
contact with precipitated antimony. This may be effected by filtration through
the said precipitate, or by agitating the precipitate in the solution. In the latter
case we use the precipitate in a very fine state of division, and by so doing metallic
gold, silver, and mercury are precipitated. After the separation of the said
precipitate of gold, silver, and mercury from the solution of chloride of antimony,
which separation may be considerably assisted when lead is present in solution by
the addition of sulphuric acid, such solution is treated under (B), now to be
described.
(B). The solution after treatment under (A) above is submitted to the action of
finely divided metallic lead (after the manner described for gold, silver, and
mercury), for the purpose of precipitating metallic bismuth and copper.
(C). The solution after treatment (B) is preferably cooled, and sulphuric acid
(free, or after being freed from arsenic), added to precipitate any lead remaining in
solution, as sulphate.
(D). The antimony contained in the solution after treatment (C) is precipitated
by metallic iron in the manner described under the following third part.
(E). The cadmium and tin contained in the chloride of iron solution left in (D)
is precipitated by metallic zinc.
We have herein described under this bead the process as though all the metals
hereinbefore named were present in the above mentioned ores or substances. It
will however be evident that the process of systematic fractional metallic pre-
cipitation is equally applicable when a lesser or larger number of inetals are
present.
The solution containing the several metals is maintained, as will be evident, at
suitable temperatures and degrees of acidity, and the metals used as precipitators
are in sufficient fineness to effect the desired result.
When gold, mercury, and copper exist in the ores in the form of sulphides, the
greater part of such metals remain undissolved in the residues; bismuth in the
metallic state, and silver when in large quantities, will also be found undissolved in
the residues. To render the said metals soluble the residues are oxidized in any
convenient manner, such as by binoxide of manganese, nitrate of soda, or per-
chloride of iron, and dissolved in hydrochloric acid, and the solution treated as
above set forth under the second part.
When cadmium and tin (subdivision E) are present in the solution, the said
metals are precipitated as sulphides from the chloride of iron solutions, re-dissolved
in strong hydrochloric acid, and then precipitated by means of zinc.
Third part. To obtain antimony precipitate in a desirable condition from a
solution of chloride of antimony containing unneutralized hydrochloric acid, to
economize iron, and to diminish the amount of noxious vapours evolved during
precipitation, we keep the said solution of chloride of antimony at a temperature
below 180 degrees Fahr., until the whole or the greater part of the antimony has
been precipitated.
In practice we find the best results obtained by precipitating the solution of
antimony at a temperature of 60 to 80 degrees Fahr., and we prefer to cool the
solution of chloride of antimony coming from the dissolving vessel to or about the
latter named temperature, and we prefer to allow the solution to settle at about
that temperature before it flows into the precipitating vessel.

page_text: We have above indicated 180° Fahr. as the maximum temperature at which
precipitation should be effected. In practice we find the best working temperature
to be about 60° to 80° Fahr. The solution of chloride of antimony may be rapidly
cooled by blowing air therethrough by means of a pump or otherwise, by causing
the said solution to flow in shallow or thin streams through troughs or over
surfaces, so as to obtain a large cooling surface, or the said liquid may surround
pipes, tubes, leaves, or cells, through which brine or cold fluid is caused to pass,
such pipes, tubes, leaves, or cells being made or covered with antimony or an alloy
of antimony. After cooling, the said solution is allowed to settle so as to deposit
all insoluble impurities. It is sometimes advantageous to pass a small current of
air through the solution whilst precipitation of antimony is taking place. We find
wood tanks, such as are used in the precipitation of copper by the wet process,
suitable for use under the above third part.
Fourth part. For the purpose of economizing the amount of hydrochloric acid
used in treating antimonious ores or substances, we subject the said hydrochloric
acid of the strength named under the first head whilst dissolving the antimony in
the said ores or substances to pressure and to a higher temperature than that of
the boiling point of the solution under normal atmospheric pressure, and we arrange
suitable vessels made of stone, or antimony, or its alloy to withstand the said
pressure and the action of the chloride of antimony.
Fifth part. As it is of the greatest importance that the precipitated antimony
resulting from the treatment mentioned under the third part should be as free from
impurities as possible, we use iron for that purpose presenting a surface of less
than 60 square inches per pound. In practice we prefer to use iron in a condition
which offers only a small amount of surface per unit of weight. To prevent when
necessary as far as possible the said precipitate from being contaminated by oxide
of iron, we remove the scale or oxide before bringing the precipitating iron in
contact with the strong chloride of antimony solution. This we effect by immersion
in the acid solution of chloride of iron coming from the precipitating vessel. Any
traces of antimony still remaining in the solution of chloride of iron are precipitated
and will be found deposited along with the oxide of iron, from which it may be
recovered in any convenient manner.
Sixth part. For the purpose of consolidating into blocks or pieces the precipitated
metallic antimony, leaving it relatively free from moisture, and preventing
oxidation, we subject it to what is commonly known as a
"filter press." By this
means the precipitated antimony is subjected to high pressure and compressed into
solid cakes or blocks. These are afterwards removed and dried, the temperature
of the metal during the drying never being allowed to exceed 300° degrees Fahr.
The said drying may be conveniently effected by placing the wet precipitate on or
betwixt plates heated by means of steam, or by passing warm or hot gases of such
a nature as not to oxidize the metal over or through the said precipitate.
The said filter press may, as mentioned, be used for extracting the moisture from
or washing the antimony precipitate. We find in actual working that a pressure
of from 100 to 150 pounds per square inch gives good solid cakes. When a part of
the flux is to be added, the cakes are broken up and the two mixed, or the flux is
spread over or forced into the cakes. A small quantity of carbonaceous matter may
be mixed with the precipitate. The precipitate after coming from the filter press
and after thorough or partial drying may be subjected to a high pressure in any
suitable machine, whereby it is formed into very dense pieces, and rendered less
liable to oxidize and is more easily fused. If the precipitate has to remain a
considerable time after compression before being fused, it is advisable to smear the
outside of the pieces with tar or other hydrocarbon to prevent oxidation.
The precipitate of antimony when dried in contact with air, the temperature
should not be high enough to induce oxidation of the metal to any material extent,
and as the metal is in a fine state of division and is easily oxidized, the temperature
of the precipitate should never exceed 300° Fahr. A low temperature and not too
long time occupied in drying is the best. Drying may be effected upon plates

page_text: beated by steam, or on shelves in a chamber through which products of combustion,
heated gases, or air are caused to pass.
We find in actual working that it is very desirable that the precipitate be
thoroughly washed before passing it through the filter press, so as to eliminate iron
and other impurities. For this purpose we prefer to partially wash it in the
precipitating tank and afterwards run the said precipitate on to an open filter
lined with woollen or hair felt, or other suitable material where the washing is
completed with water preferably hot. Wicker work or the like may be used with
the said felt. If free acid is present in the precipitate when pumped into the
filter press, the interior surfaces of the said filter press and other apparatus with
which the said precipitate comes into contact should be covered with lead, antimony,
or an alloy of antimony.
Seventh part. The chloride of iron solution resulting from the precipitation of
antimony by iron, as hereinbefore described, is evaporated in a stone (or it may be
brick) vessel to recover the hydrochloric acid therein for further use. The products
of combustion employed in evaporating the solution are caused to pass over the
surface of the said solution, but preferably out of contact with the vapour evolved;
a solid chloride of iron is thus obtained. When it is desired to obtain the chlorine
in combination with the iron as hydrochloric acid, the whole or part of the vapour
evolved is passed through a furnace, preferably a muffle or close furnace, in which
the concentrated solid chloride of iron is undergoing decomposition. The whole or
part of the vapour thus evolved is caused to mix with the comparatively dry
hydrochloric acid gas evolved during the manufacture of sulphate of soda, so that
the mixed gases shall contain an amount of moisture so small as to allow the
hydrochloric acid to be condensed sufficiently strong for re-use in dissolving
sulphide of antimony.
The chloride of iron solution after coming from the precipitating tanks usually
contains a small quantity of metallic antimony in suspension and also a trace of
antimony in solution; when such is the case the said chloride of iron solution is
run into a settling tank or is passed through a filter so as to separate the antimony.
A little alkali waste or other ready source of sulphuretted iron may advantageously
be added to the said chloride of iron solution to throw down the antimony in
solution as sulphide.
When economy of fuel is important, a convenient way of evaporating the chloride
or iron solution consists in allowing the solution to flow into a reverberatory
furnace so as always to have a thin layer of liquid on the furnace bottom. Before
passing the solution into the furnace it may advantageously be allowed to descend
a tower packed with bricks, coke, or other suitable inaterial, past which products
of combustion or heated gases ascend. The bydrochloric acid in the vapours may
be collected as above described, or in any convenient manner.
Eighth part. In dissolving antimonious ores or substances in hydrochloric acid,
we use a covered stone vessel with parts for carrying away the sulphuretted
hydrogen, as described in our Patent, No. 1584, of the present year. The solution
is heated under our Invention by means of a coil of pipes or one or more shallow
boxes, covering the whole or a considerable portion of the bottom of the said
covered vessel, through which pipes or boxes, made of antimony or an alloy thereof,
we pass steam maintained under pressure, or we use a double vessel, the inner
structure of which is made, consists of, or is lined with antimony or an alloy of the
The steam is maintained under pressure sufficient to supply the necessary
heat to maintain the solution at the temperature mentioned under the first part.
A mechanical stirrer is used to agitate the ores or substances whilst being
dissolved; such stirrer may be made of or covered externally with ebonite, vulcanite,
or metallic antimony, or an alloy of the latter, or a jet of steam, say superheated,
may be admitted directly into and amongst the solution to stir or agitate.
same.
We may here remark that in practice we have found wooden vessels or vessels
lined with lead to be altogether unsuitable for dissolving vessels, on account of the

page_text: corrosive action of the hot acid solution of chloride of antimony and the high
temperature of the solution necessary to dissolve the sulphide of antimony.
The above mentioned heating pipes or boxes of antimony may advantageously
be placed from six to twelve inches above the bottom of the dissolving vessel; or a
combination may be made in which the antimony box or boxes are laid on the
bottom of the dissolving vessel and the pipes of antimony fixed at the sides of the
lower portion of the dissolving vessel, and hot oil or solutions having high boiling
points may be caused to pass therethrough instead of steam. The joints of the
pipes or boxes are turned or faced, and lead or antimony packing is used so as to
make them tight and close.
The said steam pipe should be of metallic antimony, and may advantageously
have boles at the sides through which the steam may rush out horizontally, and so
effect thorough agitation in the dissolving vessel, which latter should be made in
the form of an inverted cone. The steam should be superheated to from 300°
to 600° Fahr., so as to cause as little dilution of the antimonious solution as possible;
and in order that it may always be delivered at high pressure the aggregate area
of the outlet holes should be less than the transverse section of the pipe.
We have found in practice that the most suitable metal of which to make the
containing vessels, pipes, and connections, is pure or nearly pure antimony, or
antimony only slightly alloyed, inasmuch as the before mentioned acid solutions
rapidly destroy nearly all other practically available metals.
Ninth part. For fusing the precipitated antimony we arrange a suitable crucible
or pot in such a manner that as the precipitate is fed in at the top the fused metal
can be run out at suitable periods and as far as possible out of contact with air at
a hole or aperture near the bottom into ingots, or if necessary directly refined
after running the metals into another crucible or pot situated below the level of
the first named, by which means the precipitate is continually fed to the upper and
the refined metal run directly into ingots from the lower crucible or pot, suitable
arrangements being made in both cases for heating the said crucible or pot and
conveying away the antimonious vapours evolved. The antimonious vapours may
be collected.
For fusing precipitated antimony we use a flux composed of about one part of
common salt to three parts of chloride of calcium, and when the precipitate contains
oxide of antimony, a little carbon. We first fuso a quantity of the flux and add
thereto pieces or blocks of the precipitate in such manner or in such quantities
that the flux covers the said pieces of precipitate. Oxidation is thereby prevented.
Oxidation may still further be prevented by maintaining a deoxidizing atmosphere
above the metal in the smelting crucible or pot during fusion. A combined blast
furnace and crucible or pot mounted on trunnions so that the crucible or pot
inay be emptied without taking it out of the furnace. Should any antimony
remain in the flux after fusing, it may be recovered by dissolving the flux in an acid
solution.
It will be evident that in connection with some or more of the heads hereinbefore
mentioned the following would be beneficial:—
(1.) Economy of time and dissolving space may be secured by heating the
hydrochloric acid to near the boiling point before running it into the dissolving
vessel.
A practical means of heating the hydrochloric acid before running it into the
dissolving vessel is by passing the hot gas from the decomposition of salt over the
surface of the hydrochloric acid in the store tank, from which the said hydrochloric
acid is run directly into the dissolving vessel, or a coil of pipes made of antimony
may be placed in the said store tank, and steam or other suitable heating agent
passed therethrough.
(2.) Cast iron, if sufficiently free from impurities, may be used for precipitating
antimony from the acid solution.
(3.) If the precipitated antimony contains any foreign substance which cannot
conveniently be extracted by washing with chloride of antimony, bydrochloric

page_text: acid, or water, but soluble in hot solutions of the chlorides of calcium, magnesium,
sodium, or potassium, we use the most convenient of these solutions with or
without admixture with the solutions mentioned as of our Invention. The
said solutions are afterwards allowed to cool and deposit their dissolved metallic
salts.
A ready practical arrangement of apparatus for the operations herein before
described is obtained in manner following:-Hydrochloric acid tanks or containers
of any usual construction are so placed that their contents may flow into the dis-
solving vessel, such latter being like a manganese still. At a lower level than the
dissolving vessel a well is made to receive the acid antimonious solutions from the
dissolving vessel. A pump is so arranged that the solutions in the well can be
raised and delivered into a settling and cooling vessel, whence the cooled solutions
are allowed to flow into the precipitating vessels placed at a lower level than the
cooling vessels. The precipitating vessels are by preference placed at a higher level
than the open filter, and the whole placed over an asphalted or stone floor so formed
as to drain away and allow of the collection of any of the liquid which may have
leaked or otherwise fallen onto it.
Having now described and particularized the nature of our said Invention in
such manner that others will be enabled to carry our said improvements into effect,
we claim,―
I. Under the first part. Treating sulphide of antimony substantially in the
manner and for the purposes set forth.
II. Under the second part. Treating chloride of antimony solutions obtained
under the first part by the several improvements described under sub divisions A, B,
C, D, and E, and a combination of any two or more of thein, substantially in the
manner and for the purposes set forth.
III. Under the third part. The treatment, substantially as described, to obtain
precipitated metallic antimony.
IV. Under the fourth part. Subjecting antimonious ores or substances to
pressure and temperature, substantially in the manner and for the purposes
set forth.
V. Under the fifth part. Precipitating antimony by the means and agents
substantially as set forth.
VI. Under the sixth part. Freeing precipitated antimony from moisture, also
consolidating such precipitate, substantially in the manner and for the purposes
set forth.
VII. Under the seventh part. Treating chloride of iron solutions, substantially as
described for the purpose set forth.
VIII. Under the eighth part (X). The means and apparatus, hercin described,
for heating solutions of antimonious ores and substances whilst being dissolved,
substantially as set forth (Y). The apparatus as part of the dissolving process or
treatment, made of antimony, or an alloy of antimony, for the purposes
set forth.
IX. Under the ninth part. Fusing precipitated antimony by the means substan-
tially as set forth.
X. Obtaining metallic antimony and the other products herein mentioned by the
operations in combination as a whole.
In witness whereof, I, the said John Hargreaves, have hereunto set my hand
and seal, this Seventeenth day of November, in the year of our Lord Oue
thousand eight hundred and eighty one.
JOHN HARGREAVES.
(L.S.