IMPROVEMENTS IN THE MANUFACTURE OF ALUM, AND IN OBTAINING BY- PRODUCTS IN SUCH MANUFACTURE APPLICABLE TO CERTAIN USEFUL PURPOSES
Year: 1870

page_text: LETTERS PATENT to Peter Spence, of Newton Heath, Manchester, in
the County of Lancaster, Manufacturing Chemist, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF ALUM, AND IN OBTAINING BY-
PRODUCTS IN SUCH MANUFACTURE APPLICABLE TO CERTAIN USEFUL PURPOSES."
Sealed the 4th October 1870, and dated the 9th June 1870.
PROVISIONAL SPECIFICATION left by the said Peter Spence at the
Office of the Commissioners of Patents, with his Petition, on the
9th June 1870.
I, PETER SPENCE, of Newton Heath, Manchester, in the County of
Lancaster, Manufacturing Chemist, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF ALUM, AND IN
OBTAINING BY-PRODUCTS IN SUCH MANUFACTURE APPLICABLE TO CERTAIN USEFUL
PURPOSES," to be as follows:-
My Invention consists in a method of treating substances consisting of
phosphate of iron and alumina, whereby I obtain alum and by-products
consisting of compounds of ammonia, sulphuric and phosphoric acids,

page_text: and which may be used as manures or fertilizers, or for other known
purposes. The substance I propose to use is at present obtained from
the island of Rodonda, in the West Indies, and is known as Rodonda
phosphate. I take this mineral, and having dissolved it in sulphuric
acid, I add ammonia, potash, or other ordinary substance for forming
alum, which I then crystallize out. To the mother liquor I add gas
ammoniacal water until the iron and remaining alumina are precipitated,
and the clear solution is then boiled down, the aforesaid substances
being the result.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Peter Spence in the Great Seal Patent Office on
the 9th December 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
SPENCE, of Newton Heath, Manchester, in the County of Lancaster,
Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of June, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Peter Spence, Her special license that I,
the said Peter Spence, my executors, administrators, and assigns, or
such others as I, the said Peter Spence, 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 MANUFACTURE
OF ALUM, AND IN OBTAINING BY-PRODUCTS IN SUCH MANUFACTURE APPLICABLE TO
CERTAIN USEFUL PURPOSES," upon the condition, amongst others, that I,
the said Peter Spence, 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.

page_text: NOW KNOW YE, that I, the said Peter Spence, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement (that is to say):-
My Invention consists in the use of compounds of alumina and
phosphoric acid, such as are at present obtained in the island of Rodondo,
near Antigua, in the West Indies, and known under the name of
Rodondo phosphate, and which contain a variable portion of iron, and
of minerals of similar composition obtained in other West India islands
and other places. These minerals I propose to utilize by the manu-
facture of alum, and by obtaining phosphoric acid or compounds
thereof as by-products for use as manures or fertilizers, and for other
purposes, such products when free or comparatively so from alumina
being rendered valuable agents for those purposes, especially so as
manures or fertilizers. The treatment for the aforesaid purposes of the
said minerals may be varied in details, but the following is a description
of that which I have found to answer. I take the mineral in pieces as
it comes to hand and calcine it in kilns similar to those used for lime,
exposing it to a red heat by mixing it with coal or coke, or I take the
mineral as obtained and grind it so that it will pass through a sieve of,
say, twenty meshes to the inch, but I prefer the former plan as it
facilitates the solution of the mineral substance, and renders a portion of
the iron insoluble by oxidation. The mineral having been prepared by
these or by similar means I place it in leaden vessels and add thereto
an equal weight of sulphuric acid of specific gravity 1.6 if the mineral
contain twenty per cent. of alumina, but only three-fifths of its weight
if it contain twelve per cent., and in similar proportions for other
degrees of richness. I then apply heat which I prefer to do by blowing
steam into the vessel containing the mixture. The mineral dissolves
and the specific gravity rises. I now cautiously reduce by water or
weak liquors from subsequent parts of the process (especially the
washings of the sediment hereafter to be mentioned) constantly boiling
until all is dissolved except the insoluble sediment, and the strength of
the liquor becomes 90 Twaddle or 1.45 specific gravity. I now pass this
liquor into a close leaden vessel and distil into it vapour containing
ammonia obtained from gas ammonical liquor subjected to boiling either
by fire or steam injected into the said gas liquor, and the quantity of the

page_text: said gas liquor I use is equal to 600 to 900 gallons to each ton of the
mineral according to its richness. When all the ammonia has been
distilled into the mineral liquor I allow it to settle for a few hours and
then run off all the clear solution (now at a strength or specific gravity
of 14 or 80 Twaddle) into lead coolers, to crystalize alum as is well
understood, and I allow it to remain in these coolers for some days, with
frequent stirring, in order to obtain all the alum possible, and which may
be purified by re-crystalization as well known. I find that when the
mineral contains twenty per cent. of alumina that I obtain one and
a half tons of alum from one ton of the said mineral. The mother
liquors having deposited all the alum that can be obtained is now
chiefly a solution of phosphoric acid with a small quantity of sulphate
of alumina, iron, and sulphate or phosphate of ammonia. This liquid
may be used directly as a fertilizing agent, but I prefer to take the said
mother liquors direct from the coolers and add to them dry sawdust or
other absorbing agent just sufficient in quantity to absorb all the said
liquors so that none will run from the sawdust. I now take the
substance and dry it at a low heat, so as not to char the sawdust, and
when dry it forms an artificial manure containing phosphoric acid and
ammonia in such quantities and condition as to make it a valuable fertilizer.
Instead of ammonia gas liquor used with the mineral solution to pro-
duce alum, salts of potash may be used either alone or in combination
with ammonia, of the former the chloride of potassium of commerce or
preferably sulphate of potash, as although chloride of potassium will
yield a sufficient product of alum the fertilizer would from its use have
a tendency to deliquesce but sulphate of potash will not have that effect.
From the above description it will be seen that by my Invention I
obtain as a by-product a large quantity of phosphoric acid, and it has
been stated how this may be used as a fertilizing agent, but independently
of that it may be applied to the purposes of producing phosphorous in
the usual manner, or phosphoric salts of commerce, as phosphate of soda,
by adding the required base thereto, extraneous matters in the mother
liquors being separated if desired by ordinary processes of precipitation
and crystalization. The operations for making alum above described
leave a sediment of insoluble matters which may be washed, and the
washings used for the reduction of the dissolved mineral as above
alluded to. Having thus described and ascertained the nature of my
said Invention, and the manner in which it is to be performed, I desire

page_text: it to be understood that I claim as secured to me under the above in
part recited Letters Patent, the use of such mineral phosphates as
aforesaid for the combined purposes of the production of alum and
manures or fertilizers, and other substances above mentioned.
In witness whereof, I, the said Peter Spence, have hereunto set
my hand and seal, this Eighth day of December, in the year of
our Lord One thousand eight hundred and seventy.
PETER SPENCE. (L.s.)