IMPROVEMENTS IN THE MANUFACTURE OF PHOSPHORIC ACID, PHOSPHATIC MANURES, ALKALINE AND OTHER PHOSPHATES
Year: 1872

page_text: LETTERS PATENT to Balthasar Wilhelin Gerland, of Buxton Road,
Macclesfield, in the County of Chester, Chemist, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF PHOSPHORIC ACID, PHOSPHATIC
MANURES, ALKALINE AND OTHER PHOSPHATES."-A communication from
abroad by Heinrich and Eugen Albert, of Biebrich, in the Empire
of Germany.
PROVISIONAL SPECIFICATION left by the said Balthasar Wilhelm
Gerland at the Office of the Commissioners of Patents, with his
Petition, on the 3rd September 1872.
IN THE MANUFACTURE
I, BALTHASAR Wilhelm Gerland, of Buxton Road, Macclesfield, in
the County of Chester, Chemist, do hereby declare the nature of the said
OF PHOSPHORIC ACID,
Invention for "IMPROVEMENTS
PHOSPHATIC MANURES, ALKALINE AND OTHER PHOSPHATES," to be as follows:-
The Invention consists in the treatment of phosphatic compounds with
cold dilute sulphuric acid, and is applicable with advantage for coprolites,

page_text: ostrolites, and phosphorites, and in general to substances which contain
besides phosphate of lime, silicates, fluorides, iron and alumina com-
pounds. The dilute acid acts in the cold only upon the phosphate and
the carbonate of lime, and leaves the other constituents intact, so that
the resulting solution contains all, or nearly all, the phosphoric acid of
the raw material, besides the small quantity of sulphate of lime which is
soluble in water, but is free from iron and alumina, whilst the insoluble
part consists of a mixture of the impurities of the raw material and the
sulphate of lime formed by the decomposition. By this method phos-
phoric acid in a comparatively pure state can be prepared at little cost
from the low impure mineral phosphate of lime..
To carry out this part of the Invention the quantity of sulphuric acid
required for the decomposition of the phosphatic raw material is ascer-
tained by estimating in an average sample the amount of lime which is
rendered soluble by digestion with dilute hydrochloric acid of about two
and a half per cent., and by calculating from this the amount of sul-
phuric acid equivalent to the amount of lime in the quantity of material
to be taken into operation.
With the solution of phosphoric acid I prepare marketable manures
by treating with the same suitable materials, such as turf, peat, shoddy,
sawdust, spent tan, wollen rags, straw, stable dung, or other waste
products.
The solution of phosphoric acid 1 also use for the manufacture of
alkaline or other phosphates. For this purpose the solution of phos-
phoric acid is saturated with the corresponding oxide or carbonate of the
metal whose phosphate is to be prepared.
For the manufacture of some phosphates, particularly those of potasse
or soda, it is advantageous to mix the corresponding chloride with the
phosphoric acid solution, and effect the decomposition by evaporation and
heating. The muriatic acid escapes, and can be condensed. The residue
consists of the phosphate, which can be purified by known methods.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Balthasar Wilhelm Gerland in the Great Seal
Patent Office on the 1st March 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BALTHASAR
WILHELM GERLAND, of Buxton Road, Macclesfield, in the County of
Chester, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of September, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Balthasar Wilhelm Gerland,
Her special licence that I, the said Balthasar Wilhelm Gerland, my
executors, administrators, and assigns, or such others as I, the said
Balthasar Wilhelm Gerland, 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 PHOS-
PHORIC ACID, PHOSPHATIC MANURES, ALKALINE AND OTHER PRODUCTS,"
upon the
condition (amongst others), that I, the said Balthasar Wilhelm Gerland,
my executors or administrators, by an instrument in writing under my,
or their, or one of their 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 Office within six calendar months next and immediately
after the date of the said Letters Patent.
$5
NOW KNOW YF, that I, the said Balthasar Wilhelm Gerland, 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 :——
My Invention consists in the treatment of substances containing
phosphoric acid and lime with cold dilute sulphuric acid, whereby the
whole or nearly the whole of the phosphoric acid enters into solution,
whilst the sulphate of lime formed by the action of sulphuric acid together
with the silicates, oxide of iron, alumina, and fluoride of calcium, and
other impurities of the raw material remain undissolved.

page_text: This part of the Invention is carried out in the following manner :—
For every 28 parts of lime soluble in cold dilute acid which the quantity
of the raw material to be taken into operation contains a quantity of
sulphuric acid containing forty parts of anhydrous sulphuric acid is
taken. The latter is diluted with water or with a weak solution of
.phosphoric acid, the washings of residues of previous operations, so that
it contains about eight per cent. anhydrous sulphuric acid, and after
cooling mixed with the previously ground phosphate. This operation
can be performed in wooden tanks. If the raw material does not.contain
much carbonate of lime, the sulphuric acid can be used more concen-
trated, up to sixteen per cent., but in that case it is advisable, first, to
mix part of the acid with the ground phosphate, and to add the remain-
ing part of the acid after complete cooling. Or instead of diluting the
sulphuric acid the ground phosphate may be mixed with water, or the
weak phosphoric acid solution in the tank and the sulphuric acid slowly
added to it, so that the mixture does not become too hot. The tem-
perature should be kept as low as possible to get the smallest amount of
iron and alumina to enter into solution. Whichever way the operation
is performed, the mixture must be repeatedly stirred for two or three
days. After sufficient rest the clear solution is separated from the
insoluble part by decantation and washing.
In order to avoid too great dilution of the liquor this washing is best
performed methodically, as is now regularly done with black ash in soda
works.
The solutions of phosphoric acid and the wash waters, if they are
weak, I use for mixing with the sulphuric acid or for mixing with the
In this manner the
mineral phosphate in a subsequent operation.
process can be conveniently worked so that all, or nearly all, the phos-
phoric acid is extracted from the raw material, and obtained in solution
of 10 per cent. anhydrous acid containing very little sulphate of lime,
iron, and alumina. Some mineral phosphates yield a purer phosphoric
acid when calcined previous to the treatment with dilute sulphuric acid.
The concentration of the phosphoric acid solution I prefer to perform
in a reverberatory furnace, with the fire gases passing over the surface
of the liquor. The bottom of this furnace may be shaped like a pan
and lined with lead, or only made of fire-bricks set in fire-clay, to which
is added a small portion of cement or plaster of Paris. It is advisable to
the
build beneath the furnace bed channels opening into a tank outside

page_text: furnace, to save any liquor which might leak through the bed. The
furnace is best built long and narrow; and to economise fuel the fire-
gases are made to pass over a second pan. The latter is fed from the
reservoir with the phosphoric acid in solution, and empties itself into the
first pan at the hottest part of the furnace at the same rate that the
concentrated acid is removed from it. The phosphoric acid can be
concentrated in this furnace to any desired strength.
For the conversion of the phosphoric acid solution into marketable
manure I mix the concentrated solution of phosphoric acid as it is drawn
from the evaporating apparatus, with turf, spent tan, straw litter, stable
dung, or sewage products,; and, if desired, dry the material in stoves or
other convenient apparatus.
I also use this phosphoric acid to prepare nitrogenized manures, by
mixing the concentrated solution with horn, hair, wool, skin, leather,
other animal refuse and bones, the refuse from glue works, either by
themselves, or with mixtures of either of them, and support the action
by heat until these substances are so acted upon by the phosphoric acid
that the organic matter becomes disintegrated or dissolved, and now
contains the nitrogen in a condition readily assimilable by vegetation.
The solution or paste thus obtained I convert into a dry powder by
mixing it with porous substances, such as turf, spent tan, litter, stable
dung, or sewage products; or I mix the same with a phosphate, such as
ground bones, bone ash, or guano, or precipitated phosphate of lime, and
convert thereby the insoluble phosphate into superphosphate by means
of the free phosphoric acid, and the manure is rendered dry at the same
time. But if the manure is not to contain any nitrogen I also mix at
once the concentrated solution of phosphoric acid with any of the last
enumerated phosphate materials, and thus produce a superphosphate
which is, if properly manipulated a dry powder, but can be rendered.
perfectly dry by the addition of a small per-centage of vitriol.
It is obvious that for these mixtures the proper proportion of lime and
sulphuric acid and phosphoric acid must be observed, so that all the
phosphate of lime is converted into soluble phosphate without leaving a
great excess of free acid. By these methods I can prepare manures
containing any desired quantity of soluble phosphoric acid, nitrogen,
and organic matter.
The last part of my Invention relates to the manufacture of phosphates
of soda and potasse. I mix the concentrated solution of phosphoria enid

page_text: with the chloride of the metal whose phosphate is to be prepared,
evaporate and heat gently, when hydrochloric acid is expelled. The
decomposition not being complete it is desirable to add to every
equivalent of phosphoric acid, only one and a half equivalents of the
chloride. The residue is dissolved in water, and neutralized with the
carbonate or oxide of the metal after clarification, and of necessary
concentration; the alkaline phosphate is obtained by crystallization.
Having described the nature of my Invention, and the mode of carry-
ing it out, I desire it to be understood that what I claim under the
above in part recited Letters Patent is,-
First. The manufacture of phosphoric acid in solution from phosphates
of lime by decomposing the same with cold sulphuric acid diluted with
water, or with weak phosphoric acid solution in the manner described,
and the concentration of such phosphoric acid solution in reverberatory.
furnaces, that is, by the fire-gases playing over the same.
Second. The manufacture of phosphate of soda and phosphate of
potasse by evaporating and heating the mixture of concentrated phos-
phoric acid solution and the respective chloride, and neutralizing the
solution of the residue with soda or potasse, or their carbonates, in the
manner described.
Third. The manufacture of manure and superphosphate of lime, rich
in nitrogen, by treating hair, horn, skin, leather, wool, bone substances,
or other animal refuse, or turf, spent tan, litter, straw, stable dung,
and sewage products with the phosphoric acid solution; and also by
treating the acid mixture thus obtained with insoluble phosphate, as
hereinbefore described.
In witness whereof, I, the said Balthasar Wilhelm Gerland, have
hereunto set my hand and seal, this Twenty-seventh day of
February, in the year of our Lord One thousand eight hundred
and seventy-three.
(L.S.) BALTHASAR WILHELM GERLAND.
Witness,
JAMES WILLIAM HUDSON.