IMPROVEMENTS IN THE MANUFACTURE OF SALTS OF ALUMINA
Year: 1860

page_text: LETTERS PATENT to Thomas Richardson, of 20. New Bridge Street, New-
castle-on-Tync. for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF SALTS OF ALUMINA."
Sealed the 8th June 1860, and dated the 21st March 1860.
PROVISIONAL SPECIFICATION left by the said Thomas Richardson at the
Office of the Commissioners of Patents, with his Petition, on the 21st
March 1860.
I, THOMAS RICHARDSON, of 20. New Bridge Street. Newcastle-on-Tyne, do
hereby declare the nature of the Invention for IMPROVEMENTS
MANUFACTURE OF SALTS OF ALUMINA," to be as follows:--
IN THE
This Invention consists in exposing aluminous minerals in a raw or roasted
state to the action of sulphurous acid, and thus to produce sulphite of alumina,
sulphate of alumina, or alum as desired, or muriate of alumina by double decom-
position with muriate of soda or potash.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of March, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Richardson, Iler special licence that I, the said Thomas Richardson,
my executors, administrators, and assigns, or such others as 1, the said Thomas
Richardson 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
THE MANUFACTURE OF SALTS OF ALUMINA," upon the condition (amongst
others) that I, the said Thomas Richardson, my executors or administrators
by an instrument in writing under my, or their, or one of the hands and seals,
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 Ollice within six calendar months next
and immediately after the date of the said Letters Patent.
IN
NOW KNOW YE, that I, the said Thomas Richardson, 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 follow-
ing statement thereof, that is to say:-
This Invention consists in exposing aluminous minerals in a raw or roasted
state to the action of sulphurous acid, and thus to produce sulphite of alumina
sulphate of alumina or alum as desired, or muriate of alumina by double decom-
position with muriate of soda or potash.
The apparatus which employ in carrying out this Invention consists of
one or more condensing towers similar to those in daily use in alkali works for
condensing muriatic acid.
When using two or more such lowers, they are connected alternately at top
and bottom, and the last may either lead direct to some high chimney or
through an ordinary sulphuric acid chamber for the purpose of condensing any
sulphurous acid, which may escape from the tower or towers. These towers
are divided at intervals of a few feet by stone shelves or partitions perforated
with holes to allow a free passage to the fluids, which fall from above and there
are openings through the towers coinciding with the shelves or partitions which
are closed with doors.
I also employ one or more cisterns, divided into several compartments
by partitions, which admit the passage of a fluid from one compartment to

page_text: another through small openings alternately at top and bottom. These towers and
cisterns may be lined with lead, or constructed of a framework in timber and
lined with lead.
I fill the towers and cisterns with alum shale, or coal shale, china or common
clay in a raw or roasted state, and pass a current of sulphurous acid gas from
any well known source through these minerals in the towers, where it meets
a descending shower of water. or of a weak solution after the process has been
long enough in operation to furnish weak liquors. The acid liquor from the
towers is conveyed to the first compartments of the cistern and allowed to pass
slowly from one compartment to another in contact with the aluminous
mineral, by which means a considerable portion of the free acid is taken up by
the alumina. The liquor as it leaves the last compartment is pumped up to
supply the towers, and the operation repeated until the liquor stands ai or
about 16° Twaddell.
This solution may be evaporated down to dryness to make an aluminous
cake or it may be concentrated and mixed with the usual potash or ammoniacal
salts in the well known proportions for the production of a potash or ammonia
alum. If the solution be protected as much as possible from the air, and
rapidly evaporated, the cake which is obtained will consist chiefly of sulphite
of alumina, and by opposite treatment ordinary sulphate of alumina is pro-
duced. also substitute ammoniacal water from gas or other works for
ordinary water in the condensing towers by which obtain an ammonia alum
in one operation. In this case I work the process in the manner already
described.
I also vary the process by making a solution of sulphurous acid in the same
towers filled with flints or other suitable material capable of resisting the action
of the acid and acting on the aluminous mineral with this solution. Or 1
make a thin fluid mixture with any of the aluminous minerals and ordinary or
ammoniacal water and pumping it to the top of the towers. I allow it to fall
over the large surfaces presented by the flints and similar substances above
named, or the shales and clays with which the towers were described as being
filled in the first instance. The stream of gas of course passing through the
Or 1
towers as already detailed, and the subsequent treatment is the same.
fill a close cistern with any of the aluminous minerals, and ordinary or ammo-
niacal water and force in sulphurous acid gas until all or nearly all the
alumina is dissolved.
The subsequent treatment of the liquor is the same as already explained in con-
verting the sulphate of alumina into alum when it is desirable to obtain muriate
of alumina, at the same time I employ muriate of potash, and after crystallizing

page_text: out the potash, alum, the mother liquors will be found to contain the muriate of
alumina. Or instead of the potash, salt muriate of soda may be substituted for
the same purpose; but in this case as a soda alum cannot be crystallized
sulphate of soda will be obtained, and the mothers will contain the muriate
of alumina.
What claim, is the subjecting aluminous minerals to the action of
sulphurous acid,
In witness whereof, I, the said Thomas Richardson have hereunto set
my hand and seal, this Seventeenth day of September, in the year of our
Lord One thousand eight hundred and sixty.
THOMAS RICHARDSON. (L.S.)