IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF BICALCIUM PHOSPHATES AND SUPER- PHOSPHATES
Year: 1880

page_text: LETTERS PATENT to Gerard Wenzeslaus von Nawrocki, of the Firm of
s
J. Brandt and G. W. v. Nawrocki, of 124, Leipzigerstrasse, Berlin, in the
German Empire, Patent Agent, for an Invention of IMPROVEMENTS IN THE
MANUFACTURE OR PRODUCTION OF BICALCIUM PHOSPHATES AND SUPER-
PHOSPHATES." A communication from Doctor Wilhelm Hasenbach, of Munich,
in Bavaria, in the German Empire.
PROVISIONAL SPECIFICATION left by the said Gerard Wenzeslaus von
Nawrocki at the Office of the Commissioners of Patents on the 26th January
1880.
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W.
v. Nawrocki, of 124, Leipzigerstrasse, Berlin, in the German Empire, Patent Agent,
"IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF BICALCIUM PHOSPHATES
AND SUPERPHOSPHATES. (A communication from Doctor Wilhelm Hasenbach, of
Munich, in Bavaria, in the German Empire.)
"
This Invention refers to the production of bicalcium phosphates and strong
superphosphates from guano, animal charcoal, phosphorite, or mixtures of these
substances, and generally from all materials of mineral or organic origin containing
tricalcium phosphate, by the agency of muriatic acid or generally by all acids
capable of dissolving triphosphate of calcium.
The raw material pulverized in the usual manner is mixed with a quantity of
muriatic acid, required for neutralizing an equivalent of oxide of calcium in the
tricalcium phosphate and of the carbonate of lime contained in the raw material.
Any other acid capable of dissolving the triphosphate of calcium may be used, if
desired.
The mixture produced, consisting of chlorcalcium, mono calcium phosphate, and
tricalcium phosphate, is then either digested in a closed vessel under pressure, the
length of the operation and height of temperature depending upon the nature of
the raw materials, or else it is allowed to lie a long time.
In the former case the monocalcium phosphate combines in a few hours with the
tricalcium phosphate, the result being a bicalcium phosphate; in the latter case it
takes some months.
A small amount of monocalcium phosphate remains in solution, and may be
thrown down by a thin lime solution.
The chlorcalcium remaining in solution is removed by washing, and the substance
thus cleaned is then dried by a temperature below 212° F.
For producing superphosphate the material now containing bicalcium phosphate
is enclosed in a vessel, together with the proper calculated quantity of sulphuric
acid, in the usual manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Gerard Wenzeslaus von Nawrocki in the Great Seal Patent Office on
the 26th July 1880.
"C
GERARD WENZESLAUS VON NAWROCKI, of the Firm of J. Brandt and G. W. v.
Nawrocki, of 124, Leipzigerstrasse, Berlin, in the German Empire, Patent Agent.
IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF BICALCIUM PHOSPHATES
AND SUPERPHOSPHATES." A communication from Doctor Wilhelm Hasenbach, of
Munich, in Bavaria, in the German Empire.
This Invention refers to the production of bicalcium phosphates and strong super
phosphates from guano, animal charcoal phosphorite, or mixture of these substances,
and generally from all materials of mineral or organic origin containing tricalcium
phosphate, by the agency of muriatic acid, or generally by all acids capable of
dissolving triphosphate of calcium.
The raw material pulverized in the usual manner is mixed with so much muriatic
acid as is required for neutralizing an equivalent of calcium oxide in the tricalcium
phosphate and in the accompanying impurities soluble in muriatic acid. Many raw
materials require besides, according to their nature, a surplus of muriatic acid,
which on an average may be taken as about 20 per cent. of the muriatic acid. Any
other acid forming salts of calcium soluble in water may, if desired, be used instead
of muriatic acid.
The mixture produced by the application of muriatic acid, and consisting of chlor-
calcium, monocalcium phosphate, and tricalcium phosphate, is exposed to a high
temperature in a closed or open vessel; a temperature of 120 to 160° Celsius (250
to 320° Fahrenheit) will suffice for most cases. The duration of the process and
the elevation of temperature varies with the nature of the raw material
The monocalcium phosphate and tricalcium phosphate hereby become bicalcium
phosphate.
Solutions of monocalcium phosphate obtained from the raw material by the
influence of muriatic acid on raw phosphates, and separated from their insoluble
admixtures, may also be used for the transformation of tricalcium phosphate. When
using other acids than muriatic acid the process is similar, and instead of the chlor
calcium the salt of the acid used is produced.
The product of monocalcium phosphate reacting on tricalcium phosphate is mixed
in and stirred with water. If monocalcium phosphate not entering in reaction
should be dissolved, it may be precipitated by careful treatment with thin lime
water; the addition of lime must be in such a quantity that the liquid is very
little acid.
The chlorcalcium remaining in solution is removed by washing, and the thus
cleansed substance containing phosphoric acid soluble in a citrate is then dried.
Should the prepared raw material contain manganese, nickel, and cobalt the same
remains in solution after the phosphoric acid precipitation, and may, after separating
the solution from the precipitate, be precipitated and saved by further addition of
lime water or of an alkaline sulphur solution.
When applying sulphuric acid the process of reaction of monocalcium phosphate
and tricalcium phosphate takes its course in the same way; the lime that is over
remains in the form of plaster of Paris in the product.
In general it may be assumed that the reaction takes place the more completely
the finer the raw material is subdivided and the more intimately it is mixed with
the acid.
It is in many cases advisable to work with mixtures of heavy and light raw
materials.
For the production of superphosphate the product containing bicalcium phosphate
is treated with sulphuric or phosphoric acid.”

page_text: And having thus described and ascertained the nature of this Invention
communicated to me, I declare that I claim,-
Firstly. The production of bicalcium phosphate by the reaction of monocalcium
phosphate on tricalcium phosphate at a high temperature.
Secondly. The production of superphosphates from materials which, treated
in the manner described, contain the bulk of the phosphoric acid in the form of
bicalcium phosphate.
In witness whereof, I, the said Gerard Wenzeslaus von Nawrocki, have here-
unto set my hand and seal, this Twenty second day of July, in the year of
our Lord One thousand eight hundred and eighty.
GERARD WENZESLAUS VON NAWROCKI. (L.S.)