CERTAIN IMPROVEMENTS IN THE MAKING, PREPARING, OR PRODUCING OF SPELTER OR ZINC
Year: 1824

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, we, FREDERICK
BENECKE, of Deptford, in the County of Kent, Verdigris Manufacturer, and
DANIEL TOWERS SHEARS, and JAMES HENRY SHEARS, of Fleet Market, in the
City of London, Coppersmiths, send greeting.
WHEREAS His present most Excellent Majesty King George the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Seventh day of October, in the fifth year of His reign, did.
give and grant unto us, the said Frederick Benecke, Daniel Towers Shears,
and James Henry Shears, our exors, admors, and assigns, His special
licence, full power, sole privilege and authority, that we, the said Frederick
Benecke, Daniel Towers Shears, and James Henry Shears, our exors, admors,
and assigns, during the term of fourteen years, should and lawfully might
make, use, exercise, and vend, within that part of the United Kingdom of
Great Britain and Ireland called England, the Dominion of Wales, and the
Town of Berwick-upon-Tweed, "CERTAIN IMPROVEMENTS IN THE MAKING,
PREPARING, OR PRODUCING OF SPELTER OR ZINC ;" in which Letters Patent
there is contained a proviso obliging us, the said Frederick Benecke Daniel
Towers Shears, and James Henry Shears, under our hands and seals,
to 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 His Majesty's
High Court of Chancery within six calendar months next immediately
after the date of the said recited Letters Patent, as in and by the same,
relation being thereunto had, may more fully and at large appear..

page_text: NOW KNOW YE, that in compliance with the said proviso, we, the said
Frederick Benecke, Daniel Towers Shears, and James Henry Shears, do
hereby declare that the nature of the said Invention, and the manner in which
the same is to be performed, are particularly described and ascertained in and
by the Drawing hereunto annexed, and the following description thereof
(that is to say):-
:-
The usual method of manufacturing zinc or spelter in this country is by
placing the materials in covered crucibles or pots, with an.iron pipe descending
from the bottom of each, and the metallic vapours are by the assistance of
heat forced downwards, usually into water, by "destillation per decensum."
There was however a Patent granted about thirteen years ago, wherein
"destillation per latus" was employed, and the zinc instead of carrying down
with it the other metals, such as lead, &c., which existed with it in the ores,
was volatilized, leaving those said metals behind, and thereby became consider-
ably more pure and fitter for use than when as usual contaminated with those
metals. Now the Improvements in the Making, Preparing, or Producing of
Spelter or Zinc, for which we have obtained His Majesty's said Letters Patent,
consist in an improved method of preparing the sulphuret of zinc, blendi or
black jack, and in certain additions to and alterations in the apparatus described
in the before-mentioned Patent, and which will be understood by a reference to
the Drawings which as aforesaid are annexed to this Specification, and in
which said Drawing Figures 1, 2, 3, 4, and 5, represent the bodies of the dis-
tilling vessels of various forms, into which the charges of prepared zinc ores
and other materials are to be put, Figure 1 being of the shape of a muffle;
Figure 2, of a square form, or rather that of a parallelopipedon; Figure 3, of
an oval shape; Figure 4, one, the lower part of which is hexagonal, and its
upper part cylindrical; and Figure 5, a cylindrical one; all of these bodies,
as well as the other parts of the distilling apparatus, must be made of the best
fire clay of the strongest and most refractory qualities, and be made perfectly
tight. Figure 6 represents a muffle-shaped body, to which a front end, similar
to that shewn in Figure 7, has been fitted and closed by means of fire lute.
This front end is furnished with a square aperture 6 below, to be closed with a
door or stopper, in order to remove the exhausted materials, and it has a cir-
cular aperture a above, into which is fitted the head of the distilling vessel, and
which may be either made of the forms shewn in Figures 8 and 9, or of any
others fit for the purpose. They have likewise beaks and openings in front of
them closed by proper stoppers, the openings being for the purpose of intro-
during the charges of materials at. These distilling vessels are to be heated
in proper furnaces, one of which is shewn in the plan at Figure 10. Figure 11

page_text: is a side elevation of it, shewing the front ends of the vessels; Figure 12 is a
section of it taken at the dotted lines m, m, in Figure 10; Figure 13 is an
elevation of the end of it, and Figure 14 is another section of it taken at the
dotted lines t,, t, e, in Figure 10. In all of these Figures the same letters
and figures of reference indicate similar parts (as well as in Figures 15, 16,
and 17, hereafter to be described). The plan, Figure 10, is taken at the dotted
lines d, e, in Figures 11 and 12, and the furnace may be doubled or extended
in size, as shewn by the fracture at z, s, with its fireplace placed at the opposite
end. p, p, &c., are the walls, brickwork, or masonry of the furnace. 9
the
fireplace from whence the heat passes through the flues h, h, &c., all around
and between the bodies f,f, of the distilling vessels. These bodies are raised
or elevated above the hearth of the furnace a proper height to be heated uni-
formly throughout. Their front ends or mouths are received into the niches
or cells a, a, &c., which are formed or built in the sides of the furnace, and
which are closed around them by pieces of fire brick and lute, so as to be
removed occasionally when it is necessary to change the bodies from time to
time. a, a, &c. are small partition walls with arched tops forming the niches,
and which rest or are supported upon the iron plates w, w; &c., and which
said plates rest upon other partition walls r, r. The front ends or mouths of
the bodies being then closed by means of the end plates Figure 7, or other
properly-shaped plates being luted into them, their heads 8, 8, &c. are then
placed in the round apertures a, a, &c., and are also properly secured by
luting them. The beaks of the heads are received into open recesses #8, 38,
&c. which also have iron plates u, u, &c. at the bottoms of them. The fronts
of the niches &, s, should be capable of being closed by means of the doors
t, t, &c. being luted into them, and which said doors may be formed of frames
of iron crossed with wire lattice work and filled up with clay. These doors
t, t, &c. must also be furnished with apertures having frames around them,
and formed in the wire work, to which said frames, iron doors or stoppers may
be fitted. These doors t, t, &c. may also be further secured in their places by
means of turn buckles, or in any other manner. The body of this furnace is
covered with a fireproof dome o, o, having apertures k, k, through it in various
places to direct and regulate the heat of the furnace, and to suffer the flame
and smoke to escape through them. The air to supply the fire is brought by
the arched calvert v.
Having thus described the construction of the furnace and distilling vessels,
we shall next proceed to shew the manner of operating therewith. The fire
being kindled and the furnace brought to a proper heat, we proceed to charge
the bodies of the distilling vessels with the prepared materials. These said

page_text: materials may consist of any of the zinc ores, such as calaminis blende, or the
sulphuret of zinc, commonly known by the name of black jack, even the
poorer calamines or other ores of zinc, which are generally rejected, will answer
our purpose. In the old ways of working either the pure calaminis were
used separately or with a small admixture of blende. We can also use the
ores mixed, but we prefer to have the calamini and the blende separate. We
take the ores finely powdered in preference, as they mix better with the carbon-
accous substances in this state, and which are added to the ores to effect their
reduction into the metallic state, and to facilitate the distillation of the zinc. The
caliminis do not require any other previous preparation than roasting or calcining
and pulverizing them. The sulphuret of zinc we prefer to prepare in the fol-
lowing manner:-The ore is first roasted or calcined, either in a roasting furnace
or by forming it into a heap, with the fuel stratified alternately, the fire being
properly managed so as not to overheat it. The roasted ore is then laid in an
open place, and properly spread and exposed to the action of the oxygen of
the atmosphere, being occasionally watered, and, when properly decomposed, it
must be lixiviated, in order to extract from it any sulphate of zinc which may
be formed. It is then to be dried and pulverized by any proper mechanical
means, and must be again calcined, until the whole or nearly the whole of the
sulphur is dispelled, when it will be fit for use. We then mix the calcined ore
either with charcoal, pit coal, wood, or other carbonaceous substances, inti-
mately; generally, however, we also prefer to use cinders, and either separately
or mixed with any of the before-mentioned substances. Of these, one part
ought to be finely divided, and the other part in larger pieces; and in working
some sorts of blende, we besides add an alkaline ley, or solution of pearl or
potash in water, or else a solution of muriate of soda or common salt, as also
some slaked or dried lime, in order to procure a better product of zinc, and
with less trouble. On account, however, of the great variety in these ores, no
certain proportion or proportions of these ingredients can be stated, and
accordingly in working new ores the best proportions must be previously
ascertained by experiments made for the purpose, and they also even depend
upon the quality of the coals used as fuel, as a greater or less degree of heat
in the furnace greatly influences the operations. The materials being properly
prepared, charges of them must be introduced into the bodies f, f, &c. of the
distilling vessels in the following manner:-The stoppers c, c, in the heads of
the distilling vessels being taken out, and also those in the doors t, t, &c., each
charge is put in by means of a proper scoop or ladle, and spread uniformly
over the bottoms of the vessels of a proper thickness, according to the nature
of the ores, but so as that the reduction and distillation of the zinc may be

page_text: carried on in the readiest manner. The stoppers c, c, must then be replaced
and secured by luting them, and the openings in the doors t, t, must also be
closed. In order to communicate a proper degree of heat to the heads of the
distilling vessels, openings are occasionally to be made in the wallings around
the mouths of the bodies of the vessels, through which the flame can pass from
the interior of the furnace; and when it is found, by inspection through the
holes in the doors t, t, that the heads are become sufficiently heated, those
openings in the wallings may be stopped up by ramming wet clay or lute into
them. In a little time the zinc will begin to distil, and to fall in drops from
the beaks of the heads upon the iron plates u, u, &c., in the recesses 83, 88, &c.,
and will so continue to fall until the materials in the distilling vessels become
exhausted, when they must be again charged with fresh materials as before;
and these charges may be repeated until the quantity of residuum in each
vessel shall have become so considerable as to require to be removed, and
which is effected in the following manner:-The doors t, t, &c. must now be
unluted and removed, and the stoppers 6, 6, &c., and the heads 8, 8, &c. taken
out of the apertures in the fronts of the bodies of the distilling vessels, when the
residuums may be withdrawn by any proper instruments. The stoppers b, b, and
the heads 8, 8, with their stoppers c, c, must then again be luted into their
apertures, the doors t, t, replaced, and the apparatus may again be charged
with fresh materials, as before mentioned. In Figure 11, f1 represents a
muffle-shaped body, open in front, the door a, b, Figure 7, being removed;
it is shewn as being charged with the materials for distillation. f 2 represents
the body as empty. f 8 represents the door, Figure 7, with its two openings
a and b, as being fixed in its place in the body. f4 shews a body with its
doors fixed in it, and a head 8 adapted to it as in use, some the distilled zinc
being shewn lodged upon the iron plate u; and f 5 represents the niche as
being closed in front by the outer door in order to preserve a due heat in the
niche, as before described. q, q, are iron bars employed to bind the brickwork
of the furnace more firmly together.
Figure 15 is a plan, Figure 16 a front elevation, and Figure 17 a perpen-
dicular section of another furnace for distilling zinc from its ores of a different
construction from that before described; this is preferred when cylindrical,
oval, or other shaped bodies of smaller dimensions than those intended to be
used with the former furnaces are to be employed. These may be set, not only
alongside of each other, as in the furnace already described, but also in several
rows one above the other, as here shewn, so that a greater number of them
may be placed in one furnace, nay, even two, three, four or more of such furnaces
may be built adjoining each other, so as to form nests or clusters of them, the

page_text: were.
same principle being applicable to all of them. The ground plan, Figure 15,
is taken at the dotted line d, e. In Figure 16, ff, &c. are the bodies of the
distilling vessels, having their front ends or mouths closed by doors, in a similar
manner to those already described, and heads or pipes 8, 8, &c, fitted to them
for the metallic zinc to distil through. h, h, &c. are flues surrounding the
bodies which receive heat from the fire beneath them. m is the throat and
the door of the fireplace (shewn by dotted lines). p, p, &c. the brickwork.
Figure 16 the front elevation of this furnace, and Figure 17 the section of
it taken in the direction of the dotted line t, a, in Figure 15, represent the
bodies f.f, &c. as being placed in the furnace nearly horizontally, and lying side
by side, and in rows one above the other; the bodies are supported at their
back ends upon pieces of fire bricks let into the wall of the furnace, and in
front upon bearers formed of fire clay, and laid in horizontal rows supporting
upright pieces between them, and thus forming a reticulated framework as it
In Figure 17, the three uppermost bodies are represented in section,
and the three undermost as entire; their heads or outlet pipes 8, 8, &c. are
shewn in f1, f4, f 5, and ƒ 6, as being placed near the bottoms of the bodies,
in f 2 as near the upper part, and in f3 as in the centre of the bodies.
In Figure 16, f7 and f8 represent differently shaped bodies, and the fifth
row from the top are shewn as being open at their mouths or without doors
to them. g, in Figures 16 & 17, represents the fireplace, and bars set in the
brickwork p, p, &c., and having above it the arch o, o, with the holes or
passages y, y, through it for the heat to ascend through, and which said arch
serves to defend the bodies from the immediate action of the fire. k, k, &c.
are openings in the upper part of the furnace, which can be opened or closed
more or less, so as to regulate the escape of the heat or flame, and direct it to
any of the bodies as may be required. a, z, a door leading into the upper part
of the furnacer, and furnished with a stopper, through which door the openings
or registers k, k, &c. can be governed as required. vis the ash and air pit.
The upper part of this furnace is also represented as being contracted above
the registers.
Having thus described the construction of two furnaces, and of the distilling
vessels, we hereby declare that we do not hereby claim the exclusive use of any
of the said parts which may be already known or in use; but we do hereby claim
the particular disposition of the several parts in the furnaces, whereby we are
enabled the more readily to charge the bodies with the materials to be
distilled, to remove and replace any of the said parts when necessary, to
watch and observe the progress of the operations from time to time, to keep
the heads in a due temperature in the niches, and to regulate and govern the

page_text: temperature of the furnaces, and the manner of preparing the sulphuret of zinc,
blende, or black jack. We also claim the mode of producing a proper degree of
heat in the furnaces, sufficient to effect the distillation of the zinc, but not to
destroy the distilling vessels, and which is chiefly effected by the employment
of a large and deep culvert, answering the purposes of an ash and air pit,
whereby the air is afforded in an uniform manner in a gentle draught, and
without the aid of a stack or chimney; we also contribute to the preservation
of this desirable equality of temperature by continually supplying the fire at
short intervals with small quantities of fuel thrown into it, and thus advoiding
the mischief which would arise from suffering the furnace to cool, either by
neglecting to supply it with fuel or from throwing into it too large a portion at
a time, as is usually the practice, and we find that we also effect a considirable
saving thereby in the quantity of fuel employed. We also claim the appli-
cation of an addition in front of the furnace, shewn in Figures 16 and 17,
answering the purpose of that exhibited at f 5 in Figure 11, and likewise the
liberty of using any of the distilling vessels in either of the furnaces.
In witness whereof, we have hereunto set our hands and seals, the
Seventh day of April, in the sixth year of the reign of His present
Majesty George the Fourth, by the grace of God of the United
Kingdom of Great Britain and Ireland King, Defender of the
Faith, and in the year of our Lord One thousand eight hundred
and twenty-five.