IMPROVEMENTS IN THE MANUFACTURE OF COMPOUNDS
Year: 1856

page_text: LETTERS PATENT to Henry Pease, of Pierremont, near Darlington,
Esquire, and Thomas Richardson, of Newcastle-on-Tyne, Chemist, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF COMPOUNDS OF
Sealed tho 6th February 1857, and dated the 12th December 1856.
PROVISIONAL SPECIFICATION left by the said Henry Pease and Thomas
Richardson at the Office of the Commissioners of Patents, with their
Petition, on the 12th December 1856.
We, HENRY PEASE, of Pierremont, near Darlington, Esquire, and THOMAS
RICHARDSON, of Newcastle-on-Tyne, Chemist, do hereby declare the nature of
the Invention for "IMPROVEMENTS IN THE MANUFACTURE OF COMPOUNDS OF
ALUMINA," to be as follows:-
This Invention consists in preparing compounds of alumina in the following
manner: Common salt or muriate of potash is mixed with china clay or
other suitable aluminous material, and sulphuric acid is added, to convert both
the alumina and the muriate into sulphates. The muriatic acid set free is
ovaporated off, and the residue may be used for many of the purposes for which
alum is now used, or alum may be prepared from it by lixiviating with water
and crystallizing in the ordinary manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Pease and Thomas Richardson in the Great Seal
Patent Office on the 11th June 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
PEASE, of Pierremont, near Darlington, Esquire, and THOMAS RICHARDSON, of
Newcastle-on-Tyne, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of December, in the year of our Lord
One thousand cight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us, the
said Henry Pease and Thomas Richardson, Her special licence that we, the
said Henry Pease and Thomas Richardson, our executors, administrators, and
assigns, or such others as we, the said Henry Pease and Thomas Richardson,
our executors, administrators, and assigns, should at any timo agree with,
and no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might mako, 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 COMPOUNDS OF ALUMINA," upon the condition (amongst others) that
we, the said Henry Pease and Thomas Richardson, our executors or adminis-
trators, by an instrument in writing under our or their hands and seals, or
under the hand and seal of one of us or them, 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 Thomas Richardson, on behalf of
myself and the said Henry Pease, do hereby declare the nature of the said
Invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement thereof, that
is to say:-
This Invention consists in preparing compounds of alumina in the following
manner: Common salt or muriate of potash is mixed with china clay or
other suitable aluminous material, and sulphuric acid is added, to convert both
the alumina and the muriate into sulphates. The muriatic acid set free is
evaporated off, and the residue may be used for many of the purposes for which
alum is now used, or alum may be prepared from it by lixiviating with water
and crystallizing in the ordinary manner.

page_text: In carrying out our Invention, we prefer to use the purest forms of aluminous
minerals, such as china or porcelain clay or cryolite. We take, for example,
4 cwt. of an ordinary china clay containing 45 per cent. of alumina, mix it with
1 cwt. of common salt, and calcine the mixture for about an hour after the
mass has become red hot. When cold, we sift out the coarse and grind it to
fine powder. The fine calcined mass is then thrown into an ordinary rever-
beratory furnace, when we run in 7 cwt. of sulphuric acid of about 1.640
specific gravity. The wholo mass is carefully agitated from time to time until
the escape
of gas
has ceased, by which time the mass becomes a dry powder.
This product is removed from the furnace and exposed to the action of the
atmosphere for a few days, by which it is much improved in appearance; the
heat employed should not much exceed 300° to 400° Fahrenheit.
The equivalent of muriate of potash may be substituted for that of common
salt and sulphates of the alkalies may be employed, in which case a correspond-
ing reduction in the sulphuric acid is to be made; we, however, prefer to employ
the muriate, as we find the muriatic acid has a beneficial action in the
preparation of our material.
In each case the resulting product can be employed in the place of ordinary
crystallized alum in the manufacture of paper, the aluminous mordants of the
print works, and otherwise.
When the object is to produce a crystallized alum, we calcine a mixture con-
sisting of 25 parts of china clay, similar to that already named, and 10 parts of
a muriate potash containing 90 per cent. of this salt, and then run upon the
calcined mixture with or without previous grinding, and we complete the batch
with the same precaution as before. We prefer to employ surface heat, as there
is not so much danger from an excess of heat in this process, as the mixturo
does not require to be exposed so long to the drying action of the heated
air. The materials are thrown into hot water or weak liquors as they are
drawn from the furnace, and the liquor clarified and evaporated in the usual
vessels will yield ordinary potash alum. The subsequent exhaustion of the
residuum is accomplished in the usual way.
Alum or coal shales, native, calcined, or exhausted, may be substituted in
this process for china clay, and the preparation of aluminous material is
increased according to the alumina contained in it, which is soluble in acids.
Where the alum manufacture is carried on as in Yorkshire and Scotland, by
roasting the alum shale in heaps, we mix with the natural shale from per
cent. and upwards of muriate potash previous to the formation of the heap, and
with or without the addition of natural or factitious sulphurets of iron. The
subsequent treatment does not deviate from that in common practice.

page_text: Where the presence of oxide of iron is not objectionable, as for instance, in
the manufacture of brown paper, we employ sulphuric acid or acid sulphate
of iron, obtained by weathering iron pyrites and any common aluminous
minerals, such as the shales, already named, or ordinary brick clay, mixed with
common salt to the extent of 5 per cent. or more, which are boiled together
until the acid is neutralized, when the crude muddy liquor is syphoned off
and boiled down (by steam heat or otherwise) to such a consistence, that on
cooling it becomes a solid cake. This latter operation may be hastened by
adding a small quantity of ochre or china clay finely ground.
In witness whereof, I, the said Thomas Richardson, have hereunto set
my hand and seal, this Tenth day of June, in the year of our Lord
One thousand eight hundred and fifty-seven.
Witness,
S. CARPMAEL.
THOMAS RICHARDSON. (L.S.).