IMPROVEMENTS IN TREATING ORES AND MINERALS, AND IN OBTAINING VARIOUS PRODUCTS THEREFROM, CERTAIN PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE MANUFACTURE OF ALKALI
Year: 1851

page_text: עכע
LONGMAID, of Beaumont Square, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Tenth day of May, One
thousand eight hundred and fifty-one, in the fourteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Longmaid, my exors, adiñors, and assigns, Her especial license, full
power, sole privilege and authority, that I, the said William Longmaid, my
exors, admiors, and assigns, or such others as J, the said William Longmaid,
my exors, adiiors, 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, make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, my Invention of
"IMPROVEMENTS IN TREATING ORES AND MINERALS, AND IN OBTAINING VARIOUS
PRODUCTS THEREFROM, CERTAIN PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE
TO THE MANUFACTURE OF ALKALI;" in which said Letters Patent is contained a
proviso, that I, the said William Longmaid, shall cause a particular descrip-
tion of the nature of my said Invention, and in what manner the same is to be
performed, by an Instrument in writing, under my hand and seal, to be enrolled
in Her said Majesty's High Court of Chancery, within six calendar months

page_text: 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.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Longmaid, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof, that is to say :-
My Inventions consist of improvements in a series of operations based
upon the mutual decomposition of common salt and certain ores and
minerals containing sulphur, which processes are applicable to such ores as
are generally smelted for copper, as well as iron pyrites, regulus, or other
compounds containing silver and copper, whereby I am enabled to separate
various metals when the same are contained in the ores and minerals treated;
and also in the use of anthracite coal, or coke, to facilitate the separation of
some or all of the volatile products of such decomposition; and also in the
application of anthracite coal to a preparation of oxide of iron in smelting the
same.
:
First, in my patented processes for treating ores and minerals, I have found
considerable difficulty in condensing the gas and vapours arising therefrom in
consequence of the volatile carbonaceous matters contained in bituminous coal;
which, when volatilized together with free carbon, have a tendency to choke the
condenser, and thus retard the operations in the furnace, as well as hinder the
condensation of the other volatile products of the process of calcination.
In using coke in the decomposition of common salt and ores and minerals
containing sulphur, I prefer having the fire-place of the furnace closed with a
door, and the ash-pit supplied with water, which, being gradually converted
into vapour, ascends through the fire, and promotes the combustion of
the fuel.
In using anthracite coal in the decomposition of ores and minerals and salt,
I mix a small portion of (coking) bituminous coal, about one-sixth part by
weight of the anthracite coal, which has the effect of causing the mass to
cohere on the application of heat. The opening to the fire-place I-fit with
an iron plate; about two feet by eighteen inches, over which I turn an arch
fifteen inches high, i. e., leaving the opening for charging the furnace with
fuel eighteen inches wide by fifteen inches high in the clear. When the
fire is well raised, I fill the opening with the mixed coal, and whilst in this
position it becomes partially coked; when it is necessary to replenish the
fire with more fuel, I move the partially coked coal-on to the burning mass
in the fire-place, and place a further quantity of coal on the plate, as before;

page_text: I also apply water to the ash-pit, in the same manner as above described
when coke is the fuel used.
The volatile products of the sulphating process possess great affinity for
water, and their condensation is facilitated by the introduction of steam into
the flue leading from the sulphating furnace to the condenser at a convenient
distance from the furnace, the object of the application of steam is, to obtain
an intimate mixture of aqueous vapour with the volatilized matters, and thereby
to promote their more perfect condensation.
I will now describe the second part of my Invention. In the Specifications
of Letters Patent granted to me, bearing date respectively on or about the
Twentieth day of October, One thousand eight hundred and forty-two, the
Fourth day of January, One thousand eight hundred and forty-four, the Fourth
day of August, One thousand eight hundred and forty-five, and the Second day
of November, One thousand eight hundred and forty-seven, I have described
processes for treating ores and minerals, and the manufacture of alkali, copper,
and other products, by mixing such ores and minerals with common salt, and
subjecting the mixture to heat in a furnace. In carrying these processes into
practical operation, when treating ores and minerals containing silver and
copper, these metals have been converted into a condition soluble in a solution
of alkaline and metallic salts, being the product of some of these processes,
and I have hitherto precipitated them by means of metallic iron, and then pro-
ceeded to oxidize the copper of such precipitate, and dissolve the oxide of
copper so obtained with sulphuric acid, producing sulphate of copper in the
well-known manner; the residual product, containing the silver, has hitherto
been separated by the ordinary process of smelting silvery lead ores.
I will now describe my improved processes for treating ores and minerals con-
taining silver and copper, and the manner in which the same are performed.
I treat ores and minerals containing sulphur in the manner described in the
Specification of my Patent of the Twentieth of October, One thousand eight
hundred and forty-two; I grind the ore and minerals containing sulphur, and
mix with common salt, and calcine the mixed material, and obtain solutions
therefrom, which I treat as herein-after described; but if the minerals contain
a considerable quantity of arsenic, antimony, or zinc, or any of them, I prefer
to calcine such mineral, in order to drive off some or all of these volatile.
metals; I then mix the calcined material with ore or mineral rich in sulphur,
so as to make the average quality about twenty to thirty of sulphur, i. e., when
one of my principle objects is to obtain sulphate of soda.
If the ores or minerals be rich in sulphur, and I have none of the calcined
ore, I prefer to reduce the per-centage of sulphur by the addition of oxide of

page_text: iron in a finely divided condition; in all cases the process is best conducted
when the sulphur in the mixed material is about thirty parts by weight to one
hundred parts of salt employed.
If the primary object be to separate silver and copper from ores and
minerals, it is sometimes convenient to calcine the material until the sulphur
is nearly driven off, and then to add common salt to the charge, and subject it
to further calcination; from eight to twelve hours will generally be found suf-
ficient to convert the silver into the state of chloride, as is well known.
I usually grind the ores and minerals sufficiently fine to pass through a
sieve of at least six holes to the inch; the richer the ores and minerals are in
silver and copper, the finer I prefer to grind them, in order to ensure the
whole or nearly the whole of the silver and copper being converted into a con-
dition soluble in the sulphate liquor herein described.
Having made these remarks, I will proceed to explain this part of my
Invention I place the calcined mass, which I call sulphate ash, in a suitable
vessel or vessels, and dissolve the soluble portions in water; the solution thus
obtained, consists of sulphate. of soda, and soluble salts of silver and copper,
and other. matters, this solution I call sulphate liquor; I cause it to flow
through a vessel or series of vessels furnished with metallic copper, the liquor
coming into contact with the copper, the silver is precipitated, and an equiva-
lent of the metallic copper is dissolved; when the silver is precipitated, I run
the liquor into another vessel or set of vessels, in which the copper is precipi-
tated by iron, or other means, herein-after described. If, however, the liquor
be so rich in these metallic salts, that the whole of the silver or copper is not
readily precipitated, I encrease the number or size of the vats or repeat the
operation. Having carefully examined the liquor, to ascertain that the pre-
cipitation of the silver and copper is complete, I run the liquor into the alkali
department of the works, to convert the sulphate of soda into carbonate.
In order to dissolve the whole of the soluble portions of the sulphate ash, I
repeat the washing until no more sulphate of soda or metallic salts are
obtained; I preserve the weak liquor, and apply it to further portions of the
sulphate ash; I convert the precipitate obtained by means of iron, above
mentioned, and, in fact, any copper containing silver into regulus, by the well-
known means. I prefer to granulate the regulus, in order to facilitate the
further operations whereby the copper and silver are separated by common
salt, as herein-after explained.
I will now describe the third part of my Invention:-In the manufacture
of sulphate of copper, I find it convenient to convert the sulphide of copper
into sulphate by calcining the regulus or other sulphide, being the product

page_text: of my processes for precipitating silver and copper from thin solutions, by
means of the compounds of sulphur, which I use for precipitating the sulphides
of silver and copper or the sulphides, carbonates, or oxides of these metals
from their solutions at a low temperature with access of atmospheric air,
and thus produce sulphate of copper and a soluble salt of silver; these I
dissolve with water. I precipitate the silver from this solution by means of
metallic copper, and draw off and crystrallise the liquor containing the sul-
phate of copper, the silver being obtained as a residual product. If the
sulphate of copper be not wholly converted into sulphate, or if it be the mixed
precipitate containing carbonate, or oxide, or both, I add sulphuric acid, and
thereby dissolve the copper.
I will now describe the fourth part of my Invention:-I precipitate silver
and copper from thin solutions (these being the products of my patented
processes for treating ores and minerals with common salt) by means of
sulphide of calcium, such as alkali waste, which compound contains sulphide of
calcium. I also precipitate silver and copper from thin solutions, as herein
described, by means of compounds containing alkaline and metallic sulphides
and other alkaline salts, such as the third product (which I call green ash)
described in my Patent dated Second day of November, One thousand eight
hundred and forty-seven, which product contains sulphides of iron and sodium,
carbonate of soda, caustic soda, and other matters, or one or more of these
alkaline compounds; or I use solutions thereof. I also precipitate silver and
copper from thin solutions by means of black ash or crude alkali, which
contains sulphides of calcium and sodium, carbonate of soda, and caustic soda,
or one or more of these alkaline compounds; or I use solutions thereof. When
I use the earthy sulphides, or the alkali waste containing sulphide of calcium,
I find it convenient to sift these substances through a sieve of six or more holes
to the inch, in order to separate the coal and cinder and the larger aggregated
masses of the alkaline earthy matters; having thus prepared a sufficient
quantity, I place a layer in the bottom of the precipitating yessel; having pre-
viously provided means for filtering the liquor, I prefer to put a layer of straw,
coke broken into fragments, or cinders, and on this I place the precipitant,
and proceed to fill the vessel or vessels with the liquor containing the metals to
be precipitated. Into a vessel or series of vessels about fifteen to twenty feet
square and about six feet deep, I put a layer of alkali waste or other earthy
sulphide, about eighteen inches deep, through which I cause the liquors to
permiate slowly; the silver and copper during this operation combine with the
sulphur of the sulphides and the chlorine or acid, as the case may be, and the
oxigen, in the latter case, pass over from the metallic salts to the alkaline earthy

page_text: matters, the metallic sulphides are precipitated, being insoluble in the sulphate
liquor; or I allow the solution containing the metallic salts to remain in contact
with the precipitant until the metals are precipitated. This operation will usually
occupy only an hour or two, but it is desirable that sufficient time be allowed
in order to obtain deposition of the precipitated matters; this will be ascer-
tained on examining the liquors from time to time. When the precipitation and
deposition are complete, the liquor is to be drawn off, and the residual product
fluxed to convert the silver and copper into regulus. The black or green
ash, herein described, may be used in the solid form in a similar manner
to that described when using alkaline earthy sulphide; but I prefer to
make a strong and hot solution, and having asertained the quantity of silver
and copper in the sulphate solution, I run a quantity of the sulphide
solution into a vessel, or set of vessels, and then add the sulphate solution
thereto. If the whole of the silver and copper are not precipitated, I add a
further quantity of the precipitant. When the precipitate is fully subsided, I
carefully draw off or filter the sulphate liquor which is to be used in the manu-
facture of sulphate of soda, and for the purposes to which sulphate of soda is
usually applied. When the precipitate is sufficiently accumulated I wash and
dry it, and proceed to heat the precipitate, as herein described, to manufacture
silver and sulphate of copper, or silver and copper, as the case may be."
I will now describe the fifth part of my Invention:-From such ores and.
minerals as are rich in silver, but containing little sulphur, with or without
copper, I obtain as herein-before mentioned, or otherwise, solutions containing
silver or silver and copper, as the case may be. I dilute the strong solutions
with water; I heat the diluted solution by preference to boiling, and the silver
is precipitated in the state of the chloride. I usually find this accomplished
when Twaddle's hydrometer stands at 30 when applied to the diluted liquors.
When the chloride of silver is fully subsided, I run the liquor, if it contain
copper,
into another vessel or set of vessels, and precipitate the copper by any
of the means herein described, and I collect the chloride of silver and smelt it
in the well-known manner. I can treat such ores and minerals as ore rich in
silver, but with little sulphur, when containing copper, with common salt, as
herein described, and obtain solutions containing silver and copper. I produce
a weak or diluted solution and thereby precipitate. the silver in the state of
chloride on the residual matters of the ores or minerals. I mix the precipitate.
in this case with lead or lead orcs, and smelt in the ordinary manner, of smelt-
ing silvery lead ores; but if the silver has been precipitated separately by
dilution, it may at once be smelted and metallic silver obtained. The copper
solution I treat by any of the well-known methods for separating copper....

page_text: I will now describe the sixth part of my Invention:-In treating regulus
containing silver and copper, I mix it with five or ten per cent. of common
salt by weight of the regulus, and grind it so as to pass through a sieve of
ten or more holes to the inch, and calcine the ground material in a furnace.
As it is better to conduct this operation gradually, I prefer a furnace of three
or more beds, each bed of about twelve feet square, but a furnace with one or
more beds may be used. I place the first charge on the bed farthest from the
fire, and when it has remained about eight hours in the back bed I move it on
to the next bed, and so on in rotation, occasionally stirring it and drawing the
finished charge at the bed nearest the fire; the calcined material is put into
vessels. When the soluble portions are dissolved, if the calcined material does
not contain sufficient alkaline and metallic salts, I add strong and hot sulphate
liquor, this solution having the property of dissolving chloride of silver; if,
however, the whole of the chloride of silver is not dissolved by the first opera-
tion, I repeat it. In treating such ores, if the sulphate of soda be not an
object of importance to the manufacturer, as will sometimes happen, I pre-
cipitate the chloride of silver by means of diluting the solution with water;
having obtained the dilute solution, I heat it as before mentioned; this operation
of licating causes the particles of chloride of silver to aggregate, and facilitates
its deposition. I allow the liquor to rest until the chloride of silver has subsided,
and then draw off the clear liquor; about forty-eight hours will generally be
sufficient for its subsidence. I collect this precipitate and smelt it for silver.
The ordinary regulus of the copper smelter frequently contains a notable
quantity of antimony; in this case, having obtained solutions as before, I
proceed to precipitate the silver and antimony together by the process of
dilution with water; I collect and smelt the precipitate with lead, or a
compound of lead, in the well-known manner of smelting silvery lead ores, and
thereby obtain the antimony and silver. But if the ore or mineral treated bo
a sulphide of copper containing silver mixed with any compound of iron, I mix
such material with common salt, calcine and dissolve the copper with hot
water, taking care that the solution be so weak as not to dissolve the chloride
of silver, which is obtained with the oxide of iron as a residual product, which
I smelt with lead or compound of lead, as above described. If the ore or
mineral I treat be a mixed mineral, such as sulphides of silver, lead, and
copper, I proceed to mix such ore with common salt and calcine the mass, and
dissolve the copper with water, and I prefer the use of a solution so dilute
that the chlorides of silver and lead are not retained in the cold solution, but
are deposited with the mass of the lead contained in the ore; the copper of the
weak solution I precipitate by any of the means herein described. But if it

page_text: be desired to produce chloride salts of lead, I dilute it, and thereby precipitate
the silver; I draw off the hot solution and allow the chloride of lead to subside
on cooling, after which, I precipitate the copper as before. If the mineral I
treat be regulus of copper, or the sulphide precipitate herein described, a
portion of the copper only will be rendered soluble; this portion may be
precipitated by any of the means herein described, but I prefer to use solution
of black or green ash, and smelt the precipitate separately with great care; by
this improvement, I produce copper of a superior quality; the portion remaining
undissolved I smelt in the well-known manner. It is sometimes convenient
to precipitate the silver and copper by means of other compounds of sulphur.
To produce sulphides of silver and copper in all cases, I treat such sulphides
as herein-before explained, when describing my processes for treating such
sulphides.
Lastly, I select such product of the calcined ores and minerals as consist of
oxide of iron; I separate the oxide of iron from the earthy matters by washing,
and mix it with sufficient carbon to deoxidize the oxide of iron, and a small
quantity of clay to cause it to cohere; I then mould the mixture into balls, or
other convenient shape, and subject it to a smelting process in a reverberatory
furnace; the product is iron of fine quality. The carbon I use by preference to
anthracite coal or charcoal, and in all cases the clay and carbon should be as
free as possible from sulphur.
In witness whereof, I, the said William Longmaid, have hereunto set
my hand and seal this Tenth day of November, in the year of our Lord
One thousand eight hundred and fifty-one.
WILLIAM (L.B.) LONGMAID.
AND BE IT REMEMBERED, that on the Tenth day of November, in the
year of our Lord 1851, the aforesaid William Longmaid came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, 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.