IMPROVEMENTS IN THE MANUFACTURE OF ALUM AND CERTAIN ALKALINE SALTS, AND IN THE MANUFACTURE OF CEMENT; PART OF WHICH IMPROVEMENTS ARE APPLICABLE IN OBTAINING VOLATILE LIQUIDS
Year: 1850

page_text: ALI
RESEN
COME, 1,
EIER
SPENCE, of Pendleton, Manchester, Manufacturing Chemist, 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 Twelfth day of November
(One thousand eight hundred and fifty); in the fourteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Peter Spence, my exors, admors, and assigns, Her especial licence, full power,
sole privilege and authority, that I, the said Peter Spence, my exors, admiors,
and assigns, or such others as I, the said Peter Spence, my exors, adñiors, 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, my Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
ALUM AND CERTAIN ALKALINE SALTS, AND IN THE MANUFACTURE OF CEMENT; PART
OF WHICH IMPROVEMENTS ARE APPLICABLE IN OBTAINING VOLATILE LIQUIDS;" in
which said Letters Patent is contained a proviso, that I, the said Peter
Spence, shall cause a particular description of the nature of my said Inven-
tion, and in what manner the same is to be performed, by an instrument in
writing under my hand and seal, 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 and by the same,
reference being thereunto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Peter Spence, 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 improvement I shall first describe is in the manufacture of alum from.
shale, schist, fireclay, indurated clay, and other-aluminous matters of a porous
texture, after being calcined, and which, when acted upon by sulphuric acid, as
I shall describe, preserve an open or permeable texture, and do not fall down
into clay or mud. I prefer for my purpose the shale of the coal measures,
and also such as is usually brought up in procuring ironstone for the manu-
facture of iron. These shales I, calcine in heaps in the open air, exactly as is
described in the Specification of the Patent granted me in November, One
thousand eight hundred and forty-five, for Improvements in the Manufacture
of Copperas and Alum, and to which I now refer. My modes of acting on
the shales after they are calcined I shall now describe, and of the three follow-
ing modes I prefer either, according to the texture and quality of the shales
under operation.
First, I have a sunk leaden vat or vessel of about four fect in depth, and any
size and shape according to convenience, and the quantity to be operated upon;
it is surrounded by a sunk wall, the top of the wall being level with the surface
of the ground or floor. I put into this vat about one fourth its fill of sulphuric
acid, of specific gravity 16 to 1.75. I then cause to be wheeled into the vat
shale direct from the calcining heaps, and quite hot, but under a red heat, and
I cause the vat to be stirred up while filling several times, that the shale may
imbibe the sulphuric acid. When the vat is filled to within six inches of the
top, I then cause it to be covered up with spent shale or coal ashes, or any
other non-conducting body, to prevent the loss of heat, and I now leave it for
four to five days, when I find the mass quite dry, and the sulphuric acid nearly
saturated with alamina. It is now thrown out, and another quantity pro-
ceeded with as before. The material thrown out is now taken to another
leaded vat or vessel of any convenient size, by four feet or so in depth, and
with a false bottom of tiles so laid on the lead bottom as to leave a hollow
space of several inches between these tiles and the bottom; this vessel is now
filled with the aforesaid material or shale that has been acted upon as before
described, which is then covered with liquor at a boiling heat. This liquor I
obtain at a boiling heat from the distillation of ammonia gas liquor, as I shall
afterwards describe. After covering, the liquor is allowed to stand for an
hour or so on the materials, and dissolves out all it can take up of sulphate of
alumina, and is then run off from. the bottom into leaden coolers to crystallize

page_text: alum,, and a similar quantity of liquor at a boiling heat is again run on; after
this a third and a fourth, and more if found necessary, then two successive
coverings of hot water are given, and after this the spent shale is thrown out
as useless for further production of alum, unless on trial it be found still to
contain a considerable quantity of alumina, in which, case the whole process
may be repeated on it by calcining it mixed with fresh shale; but I only do
this where shale is expensive to procure. If I find that the shale I am
operating upon does not yield its alumina sufficiently by this first process, then
I put the second in operation, as now to be, described. After filling the shale
into the sunk vat, and letting it stand for about twelve hours to absorb the
sulphuric acid and become. nearly dry, it is then thrown out of the sunk vat
and taken to a reverberatory furnace of large dimensions, seven feet in width
by fifteen feet to twenty feet in length, the bottom a flat bed, and an arch
thrown over the top at the height of three, and a half feet from the bottom;
no fire is used, but I connect the flue of a steam boiler or other fire to pass
through this furnace and over the materials, and I regulate the heat by
dampers as is well understood; and I prefer that the heat should range from
200 to 212 of Fahrenheit's thermometer. The bottom of the furnace being
now covered to the depth of 6 to 8 inches with the shale that has absorbed
sulphuric acid, I now pass the heated air through the furnace, keeping the
heat as near from 200 to 212 Fahrenheit as can be, managed, and I find that
in 8 to 10 hours the material is ready to throw out, and is then ready for
solution of sulphate of alumina, as before described. But when I find that
the shale I use does not absorb at least half its weight of sulphuric acid, and
I prefer that it should absorb rather above half its weight, then I adopt the
third mode of operation, which I shall now describe. In operating by this
mode I construct a reverberatory furnace of the following dimensions, the
length 50 feet and the internal. width 5 feet, and arched over, as is well under-
stood, the top of the arch being 3 feet 6 inches above the bed of the furnace;
the bottom or bed of the furnace is a lead pan, of the length and width of the
furnace, and 1 foot in depth, and there are doors or openings in the front wall,
the bottom of said doors being level with the top of the lead pan; there are
six of these doors, each being about 8 feet apart from the other. The calcined
shale is thrown in by these doors till the lead pan is, nearly full, and sul-
phuric acid of the aforesaid specific gravity is run in over the shale till half
the weight of the shale has been run in, the quantity being proportionably
greater if of less specific gravity. Heat is now applied over the surface of the
materials from two fires, one at each end of the furnace, and a chimney or
flue at the middle of the furnace takes off the draught or smoke. The heat
"

page_text: must be kept moderate, and in 8 to 10 hours the mass begins to dry, and
is then stirred or turned over with an iron paddle or rake; the fires are then
slackened, and in about 12 hours after lighting are withdrawn, and all the
doors are thrown open. The material is now thrown out, and on cooling
becomes a hard dry mass. It is at once removed and another charge proceeded
with. A charge of about 5 tons of shale is thus charged, furnaced, and
removed in 24 hours. After being thus furnaced the sulphate of alumina
is dissolved out of the shale thus acted on for the crystalization of alum in the
same way as before described, for the material from the first mode of operation
after washing the shale may be used a second time if found convenient..
Having thus described the means I ordinarily adopt, I may state, that I do
not confine myself to any of these modes of operation; but what I claim is,
the acting on shales or matters by making them absorb sulphuric acid by a
regulated drying heat causing the formation of sulphate of alumina; the
matters after they are so acted on, being in a condition to yield by maceration
in hot water or heated mother liquors, clear solutions of sulphate of alumina
of sufficient strength for the crystalization of alum without evaporation.
My next improvement in the manufacture of alum. I shall now describe.
In the production of alum by digesting diluted sulphuric acid or shale,
according to the mode specified in the Patent granted me in November, One
thousand eight hundred and forty-five, and before referred to, and also in
manufacturing alum by the mode now specified, I find that the mother liquors,
after the alum is crystalized out, always contain a considerable quantity of
free sulphuric acid. I therefore pump them into a tank or vessel lined with
lead, and furnished with a close wooden cover, having a wooden funnel or pipe
leading to a flue or chimney. Along the bottom of the. tank or vessel lies a
lead pipe, 3 inches diameter, pierced with holes of -inch diameter, distant
6 inches from each other, these holes being confined to that part of the pipe
that lies at the bottom of the vessel. The pipe is continued out of the vessel,
and connected with a boiler or vessel. When ammoniacal gas liquor is being
boiled or distilled by any convenient mode, the ammoniacal compounds and
vapour of water pass through the pipe and emerge among the mother liquors
through the small holes before mentioned; sulphuretted hydrogen flies off, but
the free sulphuric acid among the mother liquors combines with and retains all
the ammonia which is then ready, as sulphate of ammonia, for entering into
the constitution of alum forming ammonia alum as soon as it comes into contact
with sulphate of alumina. After the vapour has for a short time emerged
among it the mother liquor becomes boiling hot, and the vapour of water now
flies off along with the sulphuretted hydrogen gas, and both are conveyed to a

page_text: flue or chimney. When a sufficient quantity of amnionia has been thrown into
the liquor, which is easily known by its becoining yellow in color, it is run off*
at a boiling heat on to the furnaced or prepared shale, as before described, or,
when digesting by my Patent process of One thousand eight hundred and forty-
five, it is run on to the digesting vessel along with sulphuric acid.
=
What I claim here is, in distilling ammonia into acid mother liquors of the
aforesaid alum processes, using' said heated liquors. for digesting on shale, and
also for dissolving, out sulphate of alumina, as before described.
My next improvement is connected with the. manufacture of alum in so far
as it is used for the distillation of gas ammoniacal liquor, as before described,
but is also equally applicable to the manufacture of all the ammoniacal salts,
and also to the distillation of various other volatile liquids, and I apply it to all
such purposes when it is found preferable to the ordinary arrangements for
distilling. I shall now describe it as applied to the distillation of gas ammo-
niacal liquor. In distilling gas liquor, which I prefer doing by the use of high
pressure steam from a steam boiler, I form a range of vessels or boilers, or
they may be cast-iron tanks of sufficient and equal size and strength, but
I prefer the cylindrical shape indicated in No. 3, and I place and connect
them together so that I can run the animoniacal gas liquor through the whole
range of vessels, as indicated in No. 3, from the boiler A to the boiler B,
from B to C, 'from C to D, which, being the last, the liquor is from it
run away as useless. When in regular operation I run off by the cock P
all the charge in the boiler D, then shut this cock. I now run down by
the cock R into D all the charge contained in the boiler C, then shut the
cock R. I now open the cock O, and run down all the charge in B into
the boiler C, then by the cock K run down all the charge of A into B, and
then give the boiler A a charge of fresh gas liquor by the funnel E. I now
turn on the steam from the steam boiler by the cock G on the steam pipe S,
which passes along the bottom of the boiler D, and is pierced with small holes,
or it may be open at the end. The liquor in D is soon boiling, and steam,
partially loaded with the volatile ammonia compounds, passes on by the pipe X
into the boiler C. As soon. as this is boiling, the steam, still more charged with
ammonial compounds, passes on through the pipe T to the boiler B; here, when
aboil, the steam, loading itself still more with volatile matter, goes on through
the pipe Z into the boiler A, where it gets fully charged with ammoniacal
vapour from the fresh charge of liquor, and is now carried off by the pipe x to
be passed through mother liquors in the alum process, as before described, or
passed among any of the acids to form the corresponding ammoniacal salt.
After boiling about one fourth of the time it would require to distill a charge

page_text: in one boiler, the steam is shut off, the lowest boiler is discharged, the charge
being run away as before described, and the others are run down successively
as before described; a new charge is run into A by the funnel E and the
process is resumed. The advantages of this mode are, a saving of considerable
fuel, the more complete exhaustion of the liquor before being run off at D,
and the constant, supply of vapour charged to the highest point with volatile
matter by the pipe x, this being of great importance in the distillation of
many volatile substances. If it be found more convenient it is quite prac-
ticable to have a constant stream of fresh liquor run into the vessel A by the
funnel E, the cocks being all kept partially open so as to run it through
the whole range of vessels in quantity equivalent to the supply by the funnel E.
If it is preferred to operate by fire directly then the boiler or vessel D
must be filled up with a furnace for that purpose, the steam passing from D
as before described; but I prefer heating all directly from a high-pressure
steam boiler. In distilling ammoniacal gas liquor, I generally find a small
portion of fixed ammoniacal salts in the liquor, in which case I put into the
lowest distilling vessel a quantity of lime or alkali sufficient to decompose the
fixed salt and allow the ammonia to be distilled off.
I claim the distilling of ammoniacal gas liquor and other volatile or par-
tially volatile liquids by an arrangement of two or more boilers or vessels,
by which the liquid to be distilled can be run from one to the other through
the whole range, and the passing of steam charged with the volatile matter
from the one to the other through the whole range in the opposite direction.
My next improvement is in the manufacture of cement or hydraulic mortar,
and for producing this article I use the spent shale of my aforesaid processes
in manufacturing alum; and also the spent shale from the manufacture of
alum by my Patent process of November, One thousand eight hundred and
forty-five; and I also use for the manufacture of cement the spent lime from
the purifying of gas for illumination, and I prefer for this purpose the spent
line from the dry lime purifiers, although the solid which subsides when cream.
of lime is used for purifying is also fitted for my said process. I also use a
solution of sulphate of zinc, as I shall now describe..
In manufacturing this cement, which I call Patent Zinc Cement, I proceed
as follows:-The spent shale from my alum process of November, One thou-
sand eight hundred and forty-five, and also the spent shale from my processes
of alum manufacture now described, I allow to lie in heaps out of doors 'till
dry and crumbling down, when I pass it through sieves or screens of inch
to the mesh.
I also pass the spent lime of the gasworks through sieves of
same size. Of the two powders thus obtained I take one third part by weight

page_text: of the spent shale and two third parts by weight of the spent lime, and mix
them together. I now take a solution of about one pound of sulphate of zinc
to one gallon of water, and this solution I obtain from the refuse of sulphur
ore or iron pyrites used in the manufacture of sulphuric acid, and which
is brought from Wicklow in Ireland, and other places. By acting on this
burnt ore with diluted sulphuric acid, allowing it to macerate for some time
on the ore, I get a solution of sulphate of zinc and a small portion of sulphate
of copper. After removing the copper I use the solution of sulphate of zinc,
and I pour it into the mixture of spent shale and spent lime, stirring up with
rakes or shovels till it becomes of the consistance of mortar. I now cause it
to be made up into lumps about the size of bricks, and set to dry. When dry,
I calcine or burn these lumps in an ordinary limekiln, care being taken that
they are only exposed to a moderate red heat. I cause them to be drawn out
at bottom in charges, successively adding more at top along with fuel to keep
up the requisite moderate heat, as is well understood. After being coarsely
broken up and cooling, the material is now ground with horizontal millstones,
as is well understood, and the cement is then fit for use, and is packed into
casks to prevent it being deteriorated by the action of the atmosphere. The
cement made as now described is of a rich grey stone colour inclining to
yellow. The oxide of zinc from its powerful affinity for oxygen, prevents the
oxydisation of any iron present in the materials, and which would otherwise
degrade the colour. Its deleterious effects on vegetation will also prevent the.
cement getting covered over with moss in moist situations.
I claim the sole use of the spent shale from my Patent process of alum
manufacture of November, One thousand eight hundred and forty-five, and
also the spent shale from my Patent process of alum manufacture now
described from the manufacture of cement or hydraulic mortar. I claim the
sole use of the spent lime of the gas manufacture for the manufacture of
cement or hydraulic mortar, and I claim the introduction of zinc or oxide of
zine as one of the component parts of cement or hydraulic mortar.
My next improvement in the manufacture of certain alkaline salts I shall
now describe. In this I produce carbonate of soda from sulphate of soda, and
carbonate of potash from sulphate of potash. I proceed as follows, and I shall
only describe the manufacture of carbonate of soda, as the same operations are
applicable to the manufacture of carbonate of potash, and the same materials,
excepting that sulphate of potash is used instead of sulphate of soda. In this
process I use sulphate of baryta, or, when it is abundant, sulphate of strontia
may be used.
I use the sulphate of baryta in powder, and I mix it with
carbonaceous matter, such as small coal or charcoal powder or coal tar, and

page_text: calcine the mixture in a reverberatory furnace, as is well understood, or I
make the mixture into bricks or lumps and burn them in an ordinary lime-
kiln, and I expose it by either mode to a high red heat. When burnt I
dissolve in hot water, and filter out the clear solution of sulphide of bariuni
or hydrosulphuret of baryta. I now add to the solution thus obtained a
solution in hot water of sulphate of soda, till, on adding more, no further
precipitate is thrown down. I have now sulphate of baryta in a solid form at
the bottom of the vessel and sulphite of sodium or hydrosulphuret of soda in
solution. I run off the clear solution of hydrosulphuret of soda, and after
washing the sulphate of baryta mix it again with carbonaceous matter for
calcination, as before described. The bydrosulphuret of soda solution I now
pump up into an iron cistern O, No. 1, heated by a steam pipe coiled within it,
and I raise the heat of the liquor to the boiling point and keep it constantly at
this heat, and add more liquor to the cistern as it is taken away. I also arrange
other apparatus as in No. 1. A is a vessel of plate iron, twenty feet high by
eight feet diameter each way. The lower pipe B is for conveyance into the vessel
of a supply of carbonic acid gas heated to two hundred degrees of Fahrenheit's
thermometer, or thereabout. D is for the supply of a regular flow of the
boiling hot solution of hydrosulphuret of soda into the vessel A, falling on an
iron plate pierced with small holes, which spread the solution over the surface
of the coke with which the vessel A is filled; the liquor trickles down through
the coke, and is exposed to the hot atmosphere of carbonic acid gas, which
combines with the soda, while sulphuretted hydrogen gas is evolved, and is
carried off along the pipe C, and, after being cooled to condense the vapour of
water, is used for the manufacture of sulphuric acid by burning, as is well
understood. The carbonic acid gas I obtain by acting on chalk or limestone
with muriatic or by any other acid, as is well known and practised. The
liquor, when it reaches the bottom, runs out into the cistern E, and is now a
solution of carbonate of soda; but if it is preferred not to use the sulphuretted
hydrogen gas, or if it is not convenient to obtain carbonic acid gas from carbo-
nate of linie and hydrochloric acid, then I proceed as follows:-The hydro-
sulphuret of soda solution is pumped up into the cistern A, No.. 2; from this
it is run boiling hot into the vessel B, which is an exact counterpart of A,
No. 1, and also filled with coke at the bottom of B; a pipe enters from the
small furnace C, where charcoal is constantly, burning, the carbonic acid gas
from which passes up the vessel B, and effects the carbonisation of the soda
solution, as before described. The mixed gases pass off through the pipe E,
and are conveyed to a chimney; the liquor runs out into the cistern Dat the
bottom, and is from thence, as also from the cistern E, No. 1, conveyed into

page_text: evaporating vessels to be converted into soda ash, as is well understood; but
if soda crystals are to be made, it is sufficient to evaporate the liquor to the
proper specific gravity, and run it, after settling, into the crystallizing vessels,
thus avoiding the necessity of converting it into ash, carbonating, and again
dissolving, as is practised in the ordinary mode of manufacturing crystal soda.
I am aware that it has been proposed to produce carbonates of soda and
potash by a process nearly the same as that now described, the chief point of
difference being that the hydro-sulphuret of soda is passed through carbonic
acid gas at the ordinary temperature of the atmosphere; but the process by
this means is inefficient. By passing the solution through an atmosphere of
carbonic acid gas at an elevated temperature a highly beneficial result is
obtained.
I do not confine myself to the mode now specified of obtaining solutions
of hydrosulphurets of soda and potash, nor to the details of my mode of
carbonating the same; but I claim the production of carbonate of soda and
carbonate of potash by passing solutions of hydro-sulphuret of soda and
hydrosulphuret of potash through an atmosphere of carbonic acid gas while
at an elevated temperature.
In witness whereof, I, the said Peter Spence, have hereunto set my
hand and seal, this Sixteenth day of April, in the year of our Lord