IMPROVEMENTS IN THE MANUFACTURE OF PAPER
Year: 1855

page_text: LETTERS PATENT to Joseph Hughes, of White Hall Mills, Chapel-en-le-
Frith, in the County of Derby, Paper Manufacturer, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF PAPER."
PROVISIONAL SPECIFICATION left by the said Joseph Hughes at the
Office of the Commissioners of Patents, with his Petition, on the 8th
May 1855.
I, JOSEPH HUGHES, of White Hall Mills, Chapel-en-le-Frith, in the
County of Derby, Paper Manufacturer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF PAPER" to be
as follows:-
Firstly, I propose to use sulphate of alumina to the paper pulp or fibrous
materials in the rag engines instead of the alum of commerce, by which I
produce a harder and better description of paper, capable of sustaining a better
finish on the surface, and causing a saving in the manufacture of full fifty per
cent. I prepare the sulphate of alumina by taking about one thousand pounds
of brown sulphuric acid, 150 degrees Twaddell's hydrometer. To the aforesaid
weight of acid I mix about seven hundred and fifty pounds of pipe clay of
commerce in any convenient vessel, taking care that the materials are well
mixed together. When so mixed I allow the materials to rest about twenty-
four hours. Coal pit clay or shale is preferable on account of the cost, but

page_text: when used the quantity must be increased, say, about one thousand two hun-
dred pounds to the aforesaid quantity of sulphuric acid, and I treat the mixture
the same as if pipe clay was used. The clays must be reduced to a coarse
powder, and when the mixture has remained at rest together about twenty-four
hours it must be removed to a reverberatory furnace and a gentle heat applied
until the desired result is obtained, taking particular care during the process
that the furnace does not get overheated, which might evaporate some of the
acid before it had united with the alumina of the clay. By careful management
during this process, the materials will be in a fit state to be withdrawn from
the furnace in about four hours. The product of the rough supersulphate of
alumina must then be removed from the furnace, and dissolved in any suitable
vessel, by steam or other suitable means, until each gallon of the liquid contains
about two pounds and a half of supersulphate of alumina. When this result
is obtained, the liquid must remain at rest until all the sediment subsides, and
the clear solution is then withdrawn into another vessel, and cream of lime or
fine chalk added to the liquid until the solution slightly shews on litmus paper
a pale red, being well stirred during the time. After the sediment of sulphate
of lime and other matters have subsided, the liquid sulphate of alumina may
be applied at once to the paper pulp without a any further process.
Secondly, by treating paper pulp or fibrous materials in the rag machine, or
other part of the manufacture of paper, with sulphate of baryta ground into a
rough powder and coal, about fifty pounds of the latter to one thousand pounds
of the former, according to quality. I then mix the materials well together,
and place them in a close furnace, heated until the inside is of a bright red
heat, and kept at the proper heat until the desired result is obtained; that is,
the conversion of the sulphate of baryta into a sulphuret of baryta, which can
be ascertained by withdrawing a small portion from the furnace from time to
time, and ascertain if it will dissolve in hot water. The furnace door must bo
kept closed during the process, and about six hours will be found a sufficient
length of time for the above quantity to remain in the furnace, provided it is
kept at the proper heat. The materials are then to be withdrawn from the
furnace, and the sulphuret of baryta dissolved out of the materials by water;
the liquid mixture must then be drawn off clear. I then add good oil of vitriol
of commerce, reduced with two waters to one of acid, to the solution of sul-
phuret of baryta, until all the baryta is precipitated from the liquid. I then
wash the precipitated baryta with pure water until all the sulphuretted
bydrogen gas or other matters disappear from the precipitated sulphate of
baryta; the precipitate is then in a proper condition to be applied to the pulp
or fibrous materials.

page_text: Thirdly, I apply sulphate of baryta in a precipitated form with sulphate of
alumina or supersulphate of alumina, instead of oil of vitriol of commerce,
taking caro that there is not any foreign matter in the solution of alumina,
which might injure the color of the precipitate. I make this double preci-
pitate by taking any given quantity of the clear solution of the sulphuret
of baryta, and add the solution of alumina to the sulphuret of baryta until all
the baryta is precipitated from the solution; I then wash the said double
precipitate with pure water, as already described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Joseph Hughes in the Great Seal Patent Office on the
5th November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPH
HUGHES, of White Hall Mills, Chapel-en-le-Frith, in the County of Derby,
Paper Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of May, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Joseph Hughes, Her special licence that I, the said Joseph Hughes, my
executors, administrators, and assigns, or such others as I, the said Joseph
Hughes, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF PAPER," upon the condition (amongst others) that I, the said
Joseph Hughes, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Joseph Hughes, do hereby declare tho
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-

page_text: My Invention consists of, firstly, the use of sulphate of alumina to the paper
pulp or fibrous materials in the rag engine, or other part of the process of
manufacturing paper, instead of the alum of commerce now generally used,
by which I produce a better description of paper, being harder, and capable of
sustaining a better finish on the surface, as well as effecting a saving of full fifty
per cent.
I use about the same amount or weight of the sulphate of alumina
as is now commonly used of alum. In preparing the sulphate of alumina, I
take about 1000 lbs. of brown sulphuric acid, 150 degrees Twaddle's hydrometer,
and mix with it about 750 lbs. of pipe clay of commerce, in any convenient vessel,
taking care to mix the materials properly together, and then allow them to
rest about twenty-four hours. I then remove the mixture into a reverberatory
furnace, and apply heat to it until the desired effect is obtained. Particular
care must be taken that the furnace does not become overheated, so as to
evaporate the acid before it becomes united with the alumina of the clay.
With proper attention the materials will be in a fit state to be withdrawn from
the furnace in about four hours, but practice alone will determine these details.
The product of rough supersulphate of alumina must then be withdrawn from
the furnace and dissolved, by the aid of steam or other convenient manner,
until each gallon of liquid contains two and a half pounds of supersulphate
of alumina. When this result is obtained, the liquid must remain at rest until
all the sediment subsides, when the clear solution may be withdrawn into
another vessel, and cream of lime or chalk added to the liquid until the solu-
tion slightly shews on litmus paper a pale red color, the said mixture being
well stirred during the process. After the sediment of sulphate of lime and
other matters have subsided, the liquid sulphate of alumina may be applied to
the paper pulp without any further process.
Secondly, in the use and application to the aforesaid purpose of sulphate of
barytes as obtained from the mines, ground or pulverised in any convenient
manner to a coarse powder, with which I mix ground or pulverised coal in the
following proportions:-To every thousand pounds weight of barytes I add
about 350 lbs. weight of coal, which proportion, however, must vary according
to the quality of each substance. I then mix well the barytes and coal
together, and place them in a close furnace, the fire of which must play under
the bottom of the furnace and over the arch, the inside to be heated to a
bright red heat, the said furnace to be kept to a proper degree of heat until
the desired result is obtained, (that is to say,) the conversion of the sulphate of
barytes into a sulphuret of barytes, which may be easily ascertained by
withdrawing a small portion from the furnace from time to time to see if the
barytes is nearly dissoluble in water; about six hours will generally be found

page_text: sufficient time for the above quantities to remain in the furnace if it is kept at
its proper heat. I then withdraw the said materials from the furnace, and put
them in a vessel of any suitable construction and material, and dissolve the
sulphuret of barytes out of them by the aid of water; the liquid must then be
drawn off into another vessel free from any other matter, which might injure
the color of the barytes. I also take salt cake or sulphate of soda and place it
in a reverberatory furnace, to which heat is applied to roast off any excess of
acid it may contain, and then dissolve it by the steam or other suitable means,
until I obtain a liquid which will stand about 20 degrees Twaddle's hydrometer,
and add at the same time cream of lime to neutralize any excess of acid which
may remain in the salt cake, testing also the liquid to ascertain if any iron or
other metals are in solution, which may be ascertained by prussiate of potash.
If the liquid shews a blue color, more lime must be added until it becomes
pure. I now take this pure sulphate of soda whilst in solution, and add to
the liquid sulphuret of barytes, until all the barytes is precipitated, and then
allow the precipitated sulphate of barytes to subside. I withdraw the sulphuret
of soda which remains in a liquid state into an iron pan, and evaporate the
liquid by heat to about 70 degrees of the aforesaid hydrometer, and allow the
sulphuret of soda to settle, and withdraw it from the vessel into what is
technically called a white ash furnace, with heat applied to evaporate the
liquid to a salt, and add to every 100 lbs. of wet salt about 20 lbs. of dry deal
sawdust; the said quantity of sawdust may vary a little, according to its state
of dryness. I continue this process, stirring the mass until the sulphur is
removed from the soda; then the soda ash must be withdrawn from the
furnace. I wash the precipitated sulphate of barytes with pure water until all
the sulphuret of soda is freed from it; it is then in a proper state to be applied
to the pulp.
As another method or modification of obtaining the precipitated sulphate of
barytes, I take good oil of vitriol, reduced with three waters to one of acid, and
add the acid to the sulphuret of barytes, until all the barytes is precipitated. I
then wash the precipitate with pure water until all the sulphuretted hydrogen
gas or any other foreign matter disappears; this precipitate is then in a proper
state to be applied to the pulp or fibrous materials in the rag engine, or
other part of the process used in manufacturing paper. I find the application
of the precipitated sulphate of barytes to paper pulp superior to mineral white,
china clay, or any other mineral now in general use, as it makes the manu-
factured paper more solid, a better white, and gives it a better finish on the
surface.
As another mode or method of applying sulphate of barytes in a precipitated

page_text: form to the aforesaid purpose, I take the aforesaid sulphate of alumina
(when properly freed from iron by the use of prussiate of potash, as is well
understood), and add to the said pure sulphate of alumina any given quantity
of sulphuret of barytes, until all the barytes is precipitated. I then wash this
double precipitate with pure water, as already described. I find this double
precipitate, for some descriptions of paper, makes it a finer description, being
fuller in the hand, filling up the interstices of the fibrous materials, and
capable of sustaining a better finish than paper made by the methods and
minerals now in general use.
"Having thus fully described the nature and particulars of my Invention, I
desire it to be distinctly understood that I do not confine myself to the exact
proportions of the materials herein described, as such may be varied or modified
without departing from the principle of my Invention; neither do I claim the
exclusive manufacture of the said materials separately; but I claim as my
Invention, and which, to the best of my knowledge and belief, has not been
hitherto used within this realm,-
Firstly, the application and use of sulphate of alumina instead of the alum
of commerce in the manufacture of paper.
Secondly, the application and use of the precipitated sulphate of barytes for
the same purpose.
And, thirdly, the application and use of the precipitated sulphate of barytes
and alumina, as such improvements are hercin set forth and described.
In witness whereof, I, the said Joseph Hughes, have hereunto set my
hand and seal, this Eight day of October, One thousand eight
hundred and fifty-five.
JOSEPH HUGHES. (L.S.)
Signed, sealed, and delivered by the within-named
Joseph Hughes, in the presence of
JOHN GRIME HUGHES,
Warth Cottage,
Chapel-en-le-Frith.