IMPROVEMENTS IN SEPARAT- ING METALS FROM EACH OTHER, AND FROM CERTAIN COMBINATIONS WITH OTHER' SUBSTANCES
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
TAYLOR, of the Adelphi, in the County of Middlesex, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fifteenth day of April, in the eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Taylor, my exors, admors, and assigns, Her especial licence, full power,
sole privilege and authority, that I, the said John Taylor, my exors, admors,
and assigns, or such others as I, the said John Taylor, my exors, admors, or:
assigns, should at any time agree with, and no others, from time to time>
and at all times during the term of years therein expressed, should and.
lawfully might make, use, exercise, and vend,' within England, Wales, and the
Town of Berwick-upon-Tweed, the Invention of "IMPROVEMENTS IN SEPARAT-
ING METALS FROM EACH OTHER, AND FROM CERTAIN COMBINATIONS WITH OTHER'
SUBSTANCES," communicated to me by a certain Foreigner residing abroad; in
which said Letters Patent is contained a proviso that I, the said John
Taylor, shall cause a particular description of the nature of the said Invention,
and in what manner the same is to be performed, to be inrolled in Her said:
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as-in-

page_text: and by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Taylor, do hereby declare that the nature of the said Invention, and
the manner in which the said Invention is to be performed, are fully
described and ascertained in the following statement thereof, that is to say:-
The Invention has reference to the separation of silver from ores or metallic
combinations containing that metal. I proceed, first, to describe shortly the
principal methods now in operation for the extraction of silver from its ores
and metallic combinations. These are, first, the process known under the
name of the eliquation process, in which the argentiferous substance, whether
ore, regulus, or metal, is mixed and melted with lead or some combination of lead,
when the silver is obtained in combination with the lead, from its great affinity
for that metal; secondly, the amalgamation process, in which a chloride of
silver is formed by mixing common salt with the ore or regulus in calcination,
which chloride of silver is again reduced by means of metallic iron and
mercury, the chlorine passing to the iron and the silver forming an amalgam
with the mercury; thirdly, a process for which a Patent has recently been
obtained, the object of which is the obtaining silver from various known
descriptions of copper regulus, obtained from smelting argentiferous copper
ores, by concentrating the main portion of the silver into a residuam. This is
to be effected by thrice repeated calcination of the regulus, having for its object
the formation of as much sulphate of copper as possible, and lixiviation of the
sulphated materials with sulphuric acid and water. After each calcination
the undissolved residuum from each of the two first calcinations is to be melted.
with some material containing sulphur, so as to form it again into a regulus..
The residuum of. each lixiviation becomes richer from the sulphate of copper
and iron being dissolved out, and from only a small portion of the silver being.
dissolved out as sulphate. When the contents of the first residuum are one
hundred parts or more of copper to one of silver, it is reduced into a regulus:
by melting with partially calcined copper ore or iron pyrites; and this regulus.
is sulphated and lixiviated as before, and the product is a residuum containing
less than one hundred parts of copper to one of silver; this is subjected to the
same process, and the product is a residuum containing less than fifty parts of
copper to one of silver. This residuum is called the rich sulphate residuum,
and is to be calcined and digested in sulphuric acid, nitric acid and water, and'
the silver precipitated from this solution; the residuum of this operation is to:
be added to a residuum containing less than one hundred parts of copper to
one of silver, and melted as above described; or, the silver is to be obtained
.

page_text: from the rich sulphate residuum by melting it with lead or litharge; a portion
of the silver is obtained in each calcination in the state of sulphate, and is
washed out by sulphuric acid and water. With the sulphate of copper this
silver is to be precipitated.
In describing this Invention I shall divide it into two parts:-First, the
formation of a chloride of silver, and the dissolving such chloride of silver
by any of the herein-after mentioned solvents. Secondly, the converting
the whole or practically the whole silver contained in an ore or regulus into
á sulphate of silver, by a process of calcination as herein-after described,'
the other metals contained in the ore or material treated being rendered
insoluble. The sulphate of silver thus formed I dissolve out by hot water.
I now proceed to describe the means I adopt for the attainment of
these objects and, first, as regards the chloride process of extraction. The
argentiferous materials, which it in all probability will be desirable to
treat, may be divided into two classes: First, those containing sulphur,
and secondly, those containing no sulphur. First, as regards sulphurous
material, if the material to be treated is a regulus of copper or iron, I
prefer first to granulate such regulus by allowing it to flow when hot
into water, I then calcine it in a similar furnace to those used for calcin-
ing copper regulus, for a time varying from twelve to thirty-six hours,
according to the nature of the regulus I am treating and the quantity in the
calcining furnace. I have found twenty-four hours calcination for about three
tons of copper regulus a very suitable time. During this calcination a
moderate fire should be kept up, sufficiently low to prevent the regulus caking..
The material should be stirred or turned over once in about every two hours;:
the object of this process is the evaporation of a portion of the sulphur, by which-
means nearly the whole inconvenience arising from the caking of the material
in the subsequent calcination is avoided. I then grind the regulus so calcined'
and pass it through a fine sieve. I have found a sieve of sixty holes to the
square inch well suited to this purpose. In the same manner sulphurous ore,.
which it might be inadvisable to melt from its being already sufficiently rich
in silver, and needing no concentration, would be most advantageously treated
by calcining it as above described, previous to grinding it, in order to
prevent the formation of lumps in the after process of calcination. Having
been calcined, it is then ground to a fine powder and treated in the following.
manner, which is equally applicable to calcined regulus:-The furnace to be
employed is a simple reverberatory calcining furnace, of such size as to enable
the workman constantly to rake the ore lying on every part of it. The heat
on the introduction of every fresh charge should be moderate, gradually.
i

page_text: increasing until it arrives at a bright red heat approaching yellow. The
operation usually lasts from two to three hours, during which time the material
operated on must be constantly raked for the purpose of thoroughly oxidizing.
the copper, iron, and other metals contained in the ore or regulus. A test
should now be made of the state of the material operated on. This is done
by withdrawing a small portion of the material treated, and at once, while still
hot, pouring water on it, and allowing the water to pass through it. Should
the water appear colorless, or nearly so, the operation of calcination has been
carried sufficiently far; but should it be blue or green, the calcination must be
persisted in until the green or blue color disappear from the liquor derived
from the lixiviation of a small portion withdrawn from the furnace, as
described, that is, until the whole of the sulphate of copper and iron has been
decomposed. When this has been effected, chloride of sodium (common salt)
or, any other suitable.chloride is to be added, in the proportion of from four to
five parts of salt to one hundred parts of the substance treated. A less pro-
portion will do, but to insure the whole silver being converted into a chloride
the above proportions have been found advantageous. The heat of the
substance operated on should be reduced previous to the addition of the salt,
in order to avoid a too great evaporation and loss of chlorine., On the addi-
tion of the salt the material should be well stirred for some time, and a degree
of beat maintained sufficient to cause the chlorine or muriatic acid to rise in
almost invisible fumes, in which the argentiferous substance should be allowed,
as it were, to soak. A test may now be again made for the purpose of
proving whether the calcination has been thoroughly performed. This con-
sists, as before, in withdrawing from the heated furnace a small portion of the
substance treated, and pouring over it a hot saturated solution of chloride of
sodium (common salt), taking care not to add too much. If this solution is
clear and colorless, and becomes, when cold water is added to it, of a whitish
color, the calcination has been complete; but if the solution takes a blueish or
greenish color, the calcination must be continued until the blueish or greenish
color disappears from the solution and it remains colorless, as above described.
(when water is added it assumes a whitish color). The operation may be
hastened by strewing over the substance in the furnace another half pound or
pound of common salt for every one hundred pounds of material in the furnace,
and the whole must be constantly stirred, as above described. So great is the
affinity of silver for chlorine that it has been found in many instances sufficient
to rake the material which has been calcined out of the furnace, and while hot
mix it with salt, when the desired chloride of silver has been produced.
Should the material it is desired to desilverize contain no sulphur or other

page_text: substance which it is necessary to volatilize or oxidize by such a calcination or
calcinations as above described, common salt in the proportions before given,
namely, from four to five of salt to one hundred parts of ore or argentiferous
substance may be at once added, and the argentiferous material placed imme-
diately in the furnace and treated in precisely the manner above described, as
that adopted for the formation of a chloride of silver in argentiferous regulus
or ore, beginning from the point at which the addition of common salt is
directed. The addition of a small portion of sulphurous material, such as
sulphurous copper ore, iron pyrites, or sulphate of copper, has been found to
facilitate this operation. A chloride of silver having been thus formed, the
argentiferous ore or substance prepared as above is to be washed or lixiviated
with a hot saturated solution of chloride of sodium (common salt), or any.
other suitable chloride, alkali, or earth, or with a solution of hyposulphite of
soda, of hyposulphite of potash, or any other suitable hyposulphite of an alkali
or earth, which will dissolve the chloride of silver, separating it from the
insoluble portions of the material treated. From this solution the silver may
be precipitated by any of the known methods. Precipitated copper has been
found an exceedingly good means of effecting this operation. The heat at
which it has been found most advantageous to employ chloride solutions is
their boiling point, or at least sixty degrees of Reaumur, or one hundred and
seventy degrees of Fahrenheit; but I do not confine myself to this degree of
heat. The temperature of the solution is necessarily effected by the tem-
perature of the substance. when subjected to lixiviation. Hyposulphite
solutions need not be so hot as their solvent power is greater. To ascertain
that all the silver has been precipitated, a piece of bright copper or new copper
coin may be put into the solution in the precipitating vessels. If these
maintain their color the liquor may be drawn off, as the precipitation may
then be considered complete;. but if they come out silvered it may be consi-
dered that sufficient time has not been given for the complete precipitation of
the silver. If the material treated has been copper, regulus, some chloride of
copper will of necessity be in the solution; as also, if copper has been used for
precipitation, the liquor in this case from which the silver has been preci-
pitated may then. be passed into vessels containing iron free from oxide scale,
where the copper will be thrown down, together with any silver which may
have remained unprecipitated, and the copper thus obtained may be used for pre-
cipitation of silver as above described. It may be desirable to economize as
much as possible the salt used in this process, in which case the lixiviated
residue may be further washed and the liquor obtained preserved, together
with that obtained from the precipitation, and having been brought up to

page_text: the point of saturation may be again used for the extraction of further
quantities of silver.
The second part of the Invention consists in the conversion of the whole,
or practically the whole, silver contained in any ore or regulus into the state
of sulphate of silver, rendering the other metals contained in the argentiferous
substance insoluble. If the material to be treated is a sulphurous ore or
regulus, it is to be operated on precisely in the manner already described
above, as regards the preparatory calcination of argentiferous ore or regulus
with the ultimate view of forming chloride of silver. This part of the
Invention may be considered to begin from the point at which the ore or
regulus has been finely pulverized, after the calcination of the granulated
regulus or ore. The ore or regulus is then placed in a calcining furnace,
which must be well provided with a current of atmospheric air passing
over the substance treated, and the charge should, throughout the whole of
the operation, be constantly raked. This operation lasts generally about
three hours, and depends entirely on the good management of the furnace
and constant attention to the state of the material acted on. At first the
heat must not be great. This moderate heat should be continued until the
sulphur ceases to rise in thick fumes, and until, by withdrawing a small portion
of the material from the furnace, it is ascertained, by smell or otherwise,
that the greater portion of the sulphur has been dissipated. After this, more
heat may be gradually given, until it at length arrives at a full red heat,
approaching yellow. This must be done very cautiously, and, during the
whole operation, the following test must be constantly put in practice :-A
small portion of the material treated is withdrawn from the furnace, and
water, free from chlorine, poured on it, whilst hot, or hot water must be used.
The liquor thus obtained is then tested by adding a few grains of common
salt. When the operation is not complete the liquor, when first obtained,
will be blueish, and when salt is added greenish. The silver, when only a
small portion has been formed into a soluble salt by the calcination, will
simply cloud the liquor when salt is added. As the operation of calcination
advances, the blue and green color will nearly disappear from the liquor.
obtained from the test, and, when salt is added, chloride of silver will be at
once thrown down, falling to the bottom of the liquor in thick white flakes.
When this appearance is given by the test, the operation of calcination
may
be
considered to be complete, the whole, or practically the whole of the silver
being in the state of a sulphate, the copper and iron having been oxidized, and
thereby rendered insoluble. The material may then be withdrawn from the:
furnace, and lixiviated with common boiling water, care being taken that it

page_text: shall be free from chlorine, or only contain a trace of chlorine. If the
material lixiviated be sufficiently hot the water need not be boiling. From
this solution the silver may be precipitated by any of the known methods, and
the completeness of the operation may be tested by adding a few grains of
salt to the liquor taken from the precipitating vessels. If the liquor remains
clear the precipitation is complete. The residue obtained from large quantities
I have found to vary from three thousand to two thousand parts of copper to
one of silver, and were therefore practically wholly desilverized. Regulus or
sulphurous ore may also be at once treated in a calcining furnace, having
been first pulverized without any previous calcination, as above described. In
this case very slow heat must be given for the first part of the process, during
which time the sulphur contained in the regulus or ore undergoes combustion.
After a time this combustion ceases, and the process I have described as the
Invention for the conversion of the sulphuret of silver into sulphate begins,
and may be performed precisely in the manner pointed out to be practised on
the regulus already previously calcined and afterwards ground. I do not
consider this an advantageous manner of working, from its being impossible
to prevent the formation of lumps, which must be separated from the fine
parts before lixiviation, and again ground and calcined, and also from the
necessity of passing the calcined material through a sieve, by which the whole
benefit of the heat is wasted. Also, from regulus being much more readily
pulverized when granulated and calcined, and from the saving of labor
effected by calcining three tons, or a large quantity instead of a small quantity,
which must be the case if the process of calcination is performed at once.
Should it be desired to treat an ore by the sulphate process, which, in itself,
contains no sulphur, and at the same time inadvisable to convert it into a
regulus, a small portion of sulphur in any shape, such as sulphurous copper
ore or iron pyrites may be mixed with it, so as to afford sufficient sulphur
to combine with the silver. It may then be calcined as before directed,
particular attention being paid to the test. For the purpose of lixiviation I
have found a round tub, fitted with a strainer, formed of a disc of wood pierced
with holes, a disc of basketwork and linen drawn over the whole, answer
the purpose well, tow being packed round the sides between the strainer
and the tub, the liquor running off perfectly clear.
In witness whereof, I, the said John Taylor, have hereunto set my
hand and seal, this Fourteenth day of October, in the year of our
Lord One thousand eight hundred and forty-five.
JOHN (L.S.) TAYLOR.

page_text: AND BE IT REMEMBERED, that on the Fourteenth day of October, in
year of our Lord 1845, the aforesaid John Taylor came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written: And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Enrolled the Fifteenth day of October in the year of our Lord One

page_text: DISCLAIMER AND MEMORANDUM OF ALTERATION proposed to
be entered by the Assignee of the said Letters Patent, with the Clerk of
the Patents of England, pursuant to the Statutes in that case made and
provided.
WHEREAS I, the said Henry Hussey Vivian, have been advised that the
use of the words "or any other suitable chloride" in the following paragraph,
"when this has been effected, chloride of sodium (common salt) or any other
suitable chloride is to be added in the proportion of from four to five parts of
salt to one hundred parts of the substance treated," may be objected to; and
such words may be considered by a Court of Law to render the Specification
uncertain; for which reason I wish to disclaim, and I do hereby disclaim,
that part of the said Specification which consists of the words "or any other
suitable chloride."

page_text: And I have also been advised that the words "or any other suitable
chloride, alkali, or earth, or with a solution of byposulphite of soda or
hyposulphite of potash or any other suitable hyposulphite of an alkali or
earth, which will dissolve the chloride of silver, separating it from the
"insoluble portions of the material treated," may be objected to, and such
words may by a Court of Law be considered to render the Specification
uncertain; for which reason I wish to disclaim, and I do hereby disclaim, all
parts of the Specification which claim the use of any of the substances above
mentioned, except chloride of sodium (common salt), or of sal ammoniac, or
of the chloride of the metallic base of an alkali or alkaline earth, preferring
chloride of sodium on account of its cheapness; and I alter the Specification
accordingly. And in order to make the Specification more certain in respect
to the ores and metallic combinations to which the Invention is applicable, I
alter the Specification by introducing the following paragraph:-The present
Invention is applicable to those ores and combinations of silver to which any
one of the three processes above named is applicable, the which will be well
known to practical metallurgists.
And in order that, the effect of the above Disclaimer and Memorandum of
Alteration may be better understood, I have hereunto annexed a copy of the
Specification altered in red ink.
In witness whereof, I, the said Henry Hussey Vivian, have hereunto set
my hand and seal, this Fifteenth day of November, in the year of our
Lord One thousand eight hundred and fifty-five.
46
"
66
SPECIFICATION.
[The words printed in italics are in red ink in the original.]
"TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
TAYLOR, of the Adelphi, in the County of Middlesex, Gentleman, send
greeting.
"WHEREAS Her present most Excellent Majesty Queen Victoria, by
"Her Royal Letters Patent under the Great Seal of Great Britain, bearing
date at Westminster, the Fifteenth day of April, in the eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
"the said John Taylor, my exors, admors, and assigns, Her especial license,
"full power, sole privilege and authority, that I, the said John Taylor, my
"exors, adiñors, and assigns, or such others as I, the said John Taylor, my
exors, admors, or assigns, should at any time agree with, and no others,
"from time to time and at all times, during the term of years therein
44

page_text: 66
€6
€6
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, the Invention of
"IMPROVEMENTS IN SEPARATING METALS PROM EACH OTHER, AND FROM CERTAIN
"COMBINATIONS WITH OTHER SUBSTANCES," communicated to me from a certain
Foreigner residing abroad; in which said Letters Patent is contained a
proviso that I, the said John Taylor, shall cause a particular description of
"the nature of the said Invention, and in what manner the same is to be
performed, to be enrolled in Her said Majesty's High Court of Chancery
"within six. calendar months next and immediately after the date of the
"said in part recited Letters Patent, as in and by the same, reference being
"thereunto had, will more fully and at large appear.
66
"NOW KNOW YE, that in compliance with the said proviso, I, the said
"John Taylor, do hereby declare that the nature of the said Invention, and
"the manner in which the said Invention is to be performed, are fully
"described and ascertained in and by the following statement thereof,
"that is to say:-.
:
"The Invention has reference to the separation of silver from ores or
"metallic combinations containing that metal. I proceed, first, to describe
shortly the principal methods now in operation for the extraction of silver
"from its ores and metallic combinations. These are,-
"First, the process known under the name of the eliquation process; in
"which the argentiferous substance, whether ore, regulus, or metal, is mixed
and melted with lead or some combination of lead, when the silver is obtained
"in combination with the lead from its great affinity for that metal.
"
". Secondly, the amalgamation process in which a chloride of silver is
formed by mixing common salt with the ore or regulus in calcination,
"which chloride of silver is again reduced by means of metallic iron and
mercury, the chlorine passing to the iron, and the silver forming an amalgam
with the mercury.
16
.
Thirdly, a process for which a Patent has recently been obtained, the
object of which is the obtaining silver from various known descriptions of
copper regulus obtained from smelting argentiferous copper ores, by con-
centrating the main portion of the silver into a residuum. This is to be
effected by thrice-repeated calcination of the regulus, having for its object
the formation of as much sulphate of copper as possible, and lixiviation of
the sulphated materials. with sulphuric acid and water. After each calcina-
6. tion the undissolved residuum: from each of the two first calcinations is to
-be melted with some material containing sulphur, so as to form it again
into a regulus. The residuum of each lixiviation becomes richer from the

page_text: +66
764
"sulphate of copper and iron being dissolved out, and from only a small
portion of the silver being dissolved out as sulphate. When the con-
tents of the first residuum are one hundred parts or more of copper
to one of silver, it is reduced into a regulus by melting with partially
calcined copper ore or iron pyrites; and this regulus is sulphated and
lixiviated as before, and the product is a residuum containing less than
"one hundred parts of copper to one of silver; this is subjected to the same
process, and the product is a residuum containing less than fifty parts of
copper to one of silver; this residuum is called the rich sulphate residuum,
and is to be calcined and digested in sulphuric acid, nitric acid, and water,
"and the silver precipitated from this solution; the residuum of this operation
"is to be added to a residuum containing less than one hundred parts of
copper to one of silver, and melted as above described; or the silver is to be
obtained from the rich sulphate residuum by melting it with lead or litharge.
"A portion of the silver is obtained in each calcination in the state of sul-
phate, and is washed out by sulphuric acid and water with the sulphate of
.46 copper.
. This silver is to be precipitated." The present Invention is appli-
cable to those ores and combinations of silver to which any one of the three
processes above named is applicable, the which will be well known to practical
metallurgists.
+66
"
+
"In describing this Invention I shall divide it into two parts:-First, the
"formation of a chloride of silver, and the dissolving such chloride of silver
66
by any of the herein-after mentioned solvents. Secondly, the converting the
"whole, or practically the whole, silver contained in an ore or regulus into a
sulphate of silver by a process of calcination, as herein-after described, the
"other metals contained in the ore or material treated being rendered insoluble:
The sulphate of silver, thus formed, I dissolve out by hot water.
66
"I now proceed to describe the means I adopt for the attainment of these
objects; and, first, as regards the chloride process of extraction. The 'argenti
"ferous materials, which it in all probability will be desirable to treat, may be
*"divided into two classes :-First, those containing sulphur; and, secondly,
"those containing no sulphur. First, as regards sulphurous material. If the
"material to be treated is a regulus of copper or iron, I prefer first to granu
"late such regulus by allowing it to flow, when hot, into water; I then calcine
"it in a similar furnace to those used for calcining copper regulus, for a time
"varying from twelve to thirty-six hours, according to the nature of the
regulus I am treating, and the quantity in the calcining furnace; I have
"found-twenty-four hours' calcination, for about three tons of copper regulus,
a very suitable time. During this calcination a moderate fire. should be kept

page_text: "
66
66
66
"
"
up, sufficiently low to prevent the regulus caking; the material should be
stirred or turned over once in about every two hours. The object of this
process is the evaporation of a portion of the sulphur, by which means
nearly the whole inconvenience arising from the, caking of the material in
"the subsequent calcination is avoided; I then grind the regulus so calcined,
"and pass it through a fine sieve. I have found a sieve of sixty holes to the
square inch well suited to this purpose. In the same manner sulphurous
ore, which it might be inadvisable to melt, from its being already sufficiently
"rich in silver, and needing no concentration, would be most advantageously.
"treated by calcining it as above described previous to grinding it, in order to.
"prevent the formation of lumps in the after process of calcination. Having.
"been calcined it is then ground to a fine powder, and treated in the follow-
"ing manner, which is equally applicable to calcined regulus:-The furnace.
"to be employed is a simple reverberatory calcining furnace, of such size as to.
"enable the workman constantly to rake the ore lying on every part of it...
"The heat on the introduction of every fresh charge should be moderate,.
"gradually increasing until it arrives at a bright red heat approaching yellow,.
"the operation usually lasts from two to three hours, during which time the
"material operated on must be constantly raked for the purpose of thoroughly,
oxidizing the copper, iron, and other metals contained in the ore or regulus..
A test should now be made of the state of the material operated on; this.
"is done by withdrawing a small portion of the material treated, and at once,
"while still hot, pouring water on it, and allowing the water to pass through.
"it; should the water appear colourless, or nearly so, the operation of calcina-.
tion has been carried sufficiently far; but should it be blue or green, the.
"calcination must be persisted in until the green or blue colour disappear.
"from the liquor derived from the lixiviation of a small portion withdrawn.
from the furnace as described,—that is, until the whole of the sulphate of.
When this has been effected, chlo-..
copper and iron has been decomposed.
" is to be added.
"ride of sodium (common salt) or any other suitable chloride
"in the proportion of from four to five parts of salt to one hundred parts of
"the substance treated, or less proportion will do; but, to insure the whole,
"silver being converted into a chloride, the above proportions have been found.
advantageous. The heat of the substance operated on should be reduced.
previous to the addition of the salt, in order to avoid a too great evaporation,
"and loss of chlorine. On the addition of the salt the material should be
"well stirred for some time, and a degree of heat maintained sufficient to.
"cause the chlorine or muriatic acid to rise in almost invisible fumes, in which.
the argentiferous substance should be allowed, as it were, to soak. A test.
26
46
66
66
"

page_text: 46
66
"
"
"
may now be again made, for the purpose of proving whether the calcination
has been thoroughly performed. This consists, as before, in withdrawing from
"the heated furnace a small portion of the substance treated and pouring over
"it a hot saturated solution of chloride of sodium (common salt), taking care
"not to add too much. If this solution is clear and colorless, and becomes,
"when cold water is added to it, of a whitish color, the calcination has been
complete; but if the solution takes a bluish or greenish colour the calcina-
tion must be continued until the blueish or greenish color disappears from
"the solution, and it remains colorless as above described (when water is added
it assumes a whitish color). The operation may be hastened by strewing
"over the substance in the furnace another half pound or pound of common
"salt for every one hundred pounds of material in the furnace, and the whole
"must be constantly stirred, as above described. So great is the affinity of
"silver for chlorine that it has been found in many instances sufficient to rake
"the material which has been calcined out of the furnace, and, while hot, mix
"it with salt, when the desired chloride of silver has been produced. Should the
"material it is desired to desilverize contain no sulphur, or other substance
which it is necessary to volatilize or oxidize by such a calcination or calcina-
tions, as above described, common salt in the proportions before given, namely,
from four to five of salt to one hundred parts of ore or argentiferous
"substance may be at once added, and the argentiferous material placed
"immediately in the furnace and treated in precisely the manner above
"described as that adopted for the formation of a chloride of silver in
argentiferous regulus or ore, beginning from the point at which the
" addition of common salt is directed. The addition of a small portion
of sulphurous material, such as sulphurous copper ore, iron pyrites, or
sulphate of copper, has been found to facilitate this operation. A
"chloride of silver having been thus formed, the argentiferous ore or
substance prepared as above, is to be washed or lixiviated with a hot
saturated solution of chloride of sodium (common salt), or any other
"suitable chloride alkali, or earth, or-with-a-solution of hyposulphite of soda, of
"-hyposulphite-of-potash, or any other suitable hyposulphite of an alkali or-earth
"-which--will-dissolve the chloride of silver, separating it from the insoluble
"portions--of-the--material--treated," of sal ammoniac, or of the chloride of the
metallic base of an alkali or alkaline earth, preferring chloride of sodium on
account of its cheapness. "From this solution the silver may be precipitated
by any of the known methods. Precipitated copper has been found an
exceedingly good means of effecting this operation. The heat at which
it has been found most advantageous to employ chloride solutions is their
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boiling point, or at least sixty degrees of Reaumur, or one hundred and
seventy degrees of Fahrenheit; but I do not confine myself to this degree
"of heat. The temperature of the solution is necessarily affected by the
temperature of the substance when subjected to lixiviation. Hyposulphite
"solutions need not be so hot, as their solvent power is greater. To ascertain
"that all the silver has been precipitated, a piece of bright copper or new
copper coin may be put into the solution in the precipitating vessels. If
"these maintain their colour, the liquor may be drawn off as the precipitation
may then be considered complete; but if they come out silvered it may be
"considered that sufficient time has not been given for the complete precipi-
"tation of the silver. If the material treated has been copper regulus, some
"chloride of copper will of necessity be in the solution, as also if copper
"has been used for precipitation. The liquor, in this case, from which the
"silver has been precipitated may then be passed into vessels containing iron
"free from oxide scale, where the copper will be thrown down together with
any silver which may have remained unprecipitated; and the copper thus
"obtained may be used for precipitation of silver, as above described. It
may be desirable to economize as much as possible the salt used in this
process; in which case the lixiviated residue may be further washed, and
"the liquor obtained preserved, together with that obtained from the precipi-
"tation, and having been brought up to the point of saturation may be again
"used for the extraction of further quantities of silver."
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"The second part of the Invention consists in the conversion of the whole
or practically the whole silver contained in any ore or regulus into the state
"of sulphate of silver, rendering the other metals contained in the argen-
tiferous substance insoluble. If the material to be treated is a sulphurous
"ore or regulus, it is to be operated on precisely in the manner already
"described above, as regards the preparatory calcination of argentiferous ore
or regulus with the ultimate view of forming chloride of silver. This part
"of the Invention may be considered to begin from the point at which the
ore or regulus has been finely pulverized after the calcination of the
granulated regulus or ore. The ore or regulus is then placed in a calcining
"furnace, which must be well provided with a current of atmospheric air
passing over the substance treated; and the charge should, throughout the
"whole of the operation, be constantly raked. This operation lasts generally
"about three hours, and depends entirely on the good management of the
"furnace, and constant attention to the state of the material acted on. At
"first the heat must not be great; this moderate heat should be continued
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"until the sulphur ceases to rise in thick fumes, and until, by withdrawing a
"small portion of the material from the furnace, it. is ascertained by smell-
"or otherwise that the greater portion of the sulphur has been dissipated.
"After this more heat may be gradually given until it at length arrives at a
"full red heat approaching yellow. This must be done very cautiously, and
during the whole operation the following test must be constantly put in-
practice: A small portion of the material treated is withdrawn from the
furnace, and water, free from chlorine, poured on. it whilst hot, or hot water
"must be used. The liquor thus obtained is then tested by adding a few
grains of common salt. When the operation is not complete the liquor when
"first obtained will be blueish, and when salt is added, greenish. The silver,"
"when only a small portion has been formed into a soluble salt by the calci-
"nation, will simply cloud the liquor when salt is added. As the operation of
"calcination advances, the blue and green color will nearly disappear from the
liquor obtained from the test; and when salt is added chloride of silver will be
"at once thrown down, falling to the bottom of the liquor in thick white flakes.
"When this appearance is given by the test the operation of calcination may
"be considered to be complete, the whole or practically the whole of the silver
being in the state of a sulphate, the copper and iron having been oxidized
"and thereby rendered insoluble. The material may then be withdrawn
"from the furnace and lixiviated with common boiling water, care being.
"taken that it shall be free from chlorine or only contain a trace of chlorine.
"If the material lixiviated be sufficiently hot, the water need not be boiling.
From this solution the silver may be precipitated by any of the known
methods, and the completeness of the operation may be tested by adding a
"few grains of salt to the liquor taken from the precipitating vessels; if the
liquor remains clear the precipitation is complete. The residue obtained
"from large quantities I have found to vary from three thousand to two
"thousand parts of copper to one of silver, and were therefore practially
wholly desilverized. Regulus or sulphurous ore may also be at once
"treated in a calcining furnace, having been first pulverized without any
previous calcination, as above described. In this case very slow heat must
"be given for the first part of the process, during which time the sulphur
"contained in the regulus or ore undergoes combustion. After a time this
"combustion ceases, and the process I have described as the Invention for
"the conversion of the sulphuret of silver into sulphate begins, and may
"be performed precisely in the manner pointed out to be practised on the
regulus already previously calcined and afterwards ground. I do not con-
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page_text: AND BE IT REMEMBERED, that on the Fifteenth day of November,
in the year of our Lord 1855, the aforesaid Henry Hussey Vivian came
before our said Lady the Queen in Her Chancery, and acknowledged the
Disclaimer aforesaid, and all and every thing therein contained and specified,
in form above written. And also the Disclaimer aforesaid was stamped
according to the tenor of the Statute made for that purpose.
Enrolled the Tenth day of December, .in the year of our Lord One
thousand eight hundred and fifty-five.