IMPROVEMENTS IN THE MANUFACTURE OF OXALATE OF РоTASH
Year: 1851

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
JORDAN FIRMIN, of Lambeth Street, Goodman's Fields, in the 'County of
Middlesex, 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 Twenty-fourth day of
June, One thousand eight hundred and fifty-one, in the fifteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Jordan Firmin, Her especial licence, full power, sole privi-
lege and authority, that I, the said George Jordan Firmin, my exors, admors,
and assigns, or such others as I, the said George Jordan Firmin, my exors,
admňors, 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 OXALATE OF РоTASH;" in which said Letters Patent is con-
tained a proviso that I, the said George Jordan Firmin, shall cause a parti-
cular description of the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand

page_text: and seal, to be inrolled in Her 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.
NOW KNOW YE, that in compliance with the said proviso, I, the said
George Jordan Firmin, do hereby declare that the nature of my said Inven-
tion, 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 Invention consists of employing oxalic acid, together with water, to act
on a salt of potash, and thus to manufacture oxalate of potash, as hereafter
described.
And in order that my Invention may be most fully understood and readily
carried into effect, I will proceed to describe the means pursued by me;
and as tartrate of potash is the salt of potash I prefer to use in this manu-
facture, I will first explain my Invention when that salt is employed. After
saturating the excess of acid contained in cream of tartar by carbonate
of lime, I run off the supernatant liquor, which contains neutral tartrate of
potash, into a suitable vessel; and having ascertained the quantity of tartrate
of potash, as is well understood, I add for every one hundred pounds of
neutral tartrate of potash about sixty pounds of crystalized oxalic acid (pre-
viously dissolved in about its weight of water), or as much as will combine'
with one
half of the potash, and form neutral oxalate of potash, which is held
in solution while the acid of the tartrate unites with the other half of the
potash, and form cream of tartar, which is precipitated. This I collect in a
filter, and wash to free it from any of the oxalate of potash which may be me-
chanically mixed with it, and again saturate with carbonate of lime, as, above
described. In this manufacture no heat is necessary, the tartrate of potash and
oxalic acids being in a state of solution, the precipitate falls upon mixing them.
To the liquor containing the oxalate of potash I add the 'same quantity of
oxalic acid I used to obtain the neutral oxalate, or as much as is required to
constitute the super-oxalate of potash; this I heat, filter, evaporate, and
crystallize in the usual way. The cream of tartar precipitated in the process.
may be obtained in a fit state for the market by heating and filtering the
neutral tartrate of potash through animal charcoal. If sulphate of potash be the
salt of potash to be employed when manufacturing oxalate of potash according,
to my Invention, I heat a given quantity of sulphate of potash of commerce in
about five times its weight of water to about 180° Fahrenheit, and for ever
100 lbs. of sulphate of potash, as shown by analysis, I add about 160 lbs.

page_text: crystallized oxalic acid (or as much as is required to combine with the potash
of the sulphate and form super-oxalate of potash); these I mix well together,
keeping the heat about 180°, until the salts are dissolved. I then allow them
to get cold, when the super-oxalate is deposited on the bottom and round the
sides of the vessel; this (having previously removed the liquor, which is
sulphuric acid), I wash, dissolve, filter, and evaporate in the usual way. If
muriate. of potash be employed in carrying out my Invention, I dissolve the
muriate of potash of commerce in about four times its weight of water, heated
to about 180°, and add for every 100 lbs. of muriate of potash (ascertained by
analysis) about 140 lbs. of crystallized oxalic acid, or sufficient to decompose the
muriate of potash, and form muriatic acid and super-oxalate of potash; these I
keep well agitated until the salts are dissolved. I then allow them to get cold,
when the super-oxalate is deposited on the bottom and round the sides of the
vessel; this I collect, and after washing to frée it from muriatic acid, I
dissolve, filter, evaporate, and crystallize in the usual way. Should there be
any escape of muriatic acid gas during the process, more water may be
added, or the salt and acid should be decomposed in a.close vessel (having an
agitator attached), from the top of which a pipe should lead into a second
vessel containing water, by which the gas is taken up, and this connected with
as many other vessels, each containing water, as may be necessary to prevent
the gas escaping. The cold liquor run off after the decomposition I evaporate,
collecting the muriatic acid as above described; the residue, consisting of a little
super-oxalate of potass and impurities, I either return with fresh muriate of
potash, or treat according to its value. In the decomposition of the tartrate
and sulphate of potass, and the subsequent treatment of the super-oxalate of
potass, lead vessels may be used; but in any part of the process by muriate of
potass in which its acid is liberated, the vessels should be of stone ware.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the precise details as herein described. But what I claim is, the manu-
facture of oxalate of potash, by employing oxalic acid and water to act on a
salt of potash, as herein described.
In witness whereof, I, the said George Jordan Firmin, have hereunto
set my hand and seal, this Seventeenth day of December, One
thousand eight hundred and fifty-one.
GEORGE JORDAN (L.s.) FIRMIN.
GEORGE JORDAN (L.s.) FIRMIN.

page_text: AND BE IT REMEMBERED, that on the Seventeenth day of December,
in the year of our Lord 1851, the aforesaid George Jordan Firmin came
before our said Lady, the Queen in Her Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained and
specified, in form above written. And also the Specification aforesaid was
stamped according to the tenor of the Statute made for that purpose.