Improvements relating to the Production of Phosphorus, its Acids, and Salts from Mineral Phosphates, Bones, and other Materials containing Phosphoric Acid.
Year: 1895

page_text: Date of Application, 7th Oct., 1895
Complete Specification Left, 7th July, 1896-Accepted, 7th Oct. 1896
PROVISIONAL SPECIFICATION.
Improvements relating to the Production of Phosphorus, its Acids,
and Salts from Mineral Phosphates, Bones, and other Materials
containing Phosphoric Acid.
We, HERMANN HILBERT, of Biebrich on the Rhine, Chemist, and ALBERT FRANK,
of No. 80 Leibnitzstrasse, Charlottenburg, Chemist, both in the German Empire, do
hereby declare the nature of this invention to be as follows:-
This invention relates to the production of phosphorus from materials containing
phosphoric acid, (such, for example, as mineral phosphates, bones, or slag containing
phosphoric acid, which materials contain the phosphoric acid in the form of phosphates)
by utilizing the property of carbon at a high temperature to form carbides with the
metals or bases of such materials.
Experiments based on this property of carbon, showed that in fusing or heating a
mixture of carbon and a material containing phosphoric acid in suitable proportions,
in the electric are, the base previously combined with the phosphoric acid, forms with
the carbon the corresponding metallic carbide, and the phosphorus is simultaneously
given off, and can be easily converted into its acids, for example, by burning, and into
the corresponding salts (in a pure form). The reaction may be explained by the
following equation which is for tricalcium phosphate :
From the above the necessary mixing proportions may be easily calculated, in
which calculation allowance must also be made, in ascertaining the amount of carbon
to be added, for other substances present in the phosphates, such as calcium carbonate,
calcium fluoride, etc.
Phosphates containing aluminium phosphate, as well as other phosphates, such as
phosphate of soda, e'c. may also be split up similarly to the calcium phosphate.
The subject of the present invention accordingly is the manufacture of phosphorus,
or its acids and salts, from materials containing phosphoric acid, such as mineral
phosphates, bones, and slag containing phosphoric acid, these materials being subjecte.
to a process of forming carbides, in which process the bases of the said materials are
converted into the corresponding metallic carbides preferably by heating such
materials to a sufficiently high temperature in admixture with carbon, whereby the
phosphorus is driven off.
In carrying our said process into practice, the desired materials containing
phosphoric acid (phosphates) and the carbon may be intimately mixed together in
suitable proportions according to the reaction explained above, and the mixture is
heated in an electric furnace or in any other suitable apparatus capable of giving the
temperature necessary for the formation of carbide whilst preventing the access of air.
The phosphorus thus set free is received in suitable condensers and can be converted,
if desired, into its acids and salts in any well-known manner. The carbides formed.
can be run out or otherwise removed, and a fresh batch of the mixed raw material put
into the furnace, in order to carry on the process as nearly as possible uninterruptedly
in the most advantageous manner.
Dated this Seventh day of October 1895
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicants.

page_text: Improvements relating to the Production of Phosphorus, its Acids,
and Salts from Mineral Phosphates, Bones, and other Materials
containing Phosphoric Acid.
We, Dr. HERMANN HILBERT, Chemist, of Biebrich on the Rhine, and ALBERT
FRANK, Chemist, of No. 80 Leibnitzstrasse, Charlottenburg, both in the German
Empire, do hereby declare the nature of this invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the following
statement —
This invention relates to the production of phosphorus from materials containing
phosphoric acid (such, for example, as mineral phosphates, bones, or slag containing
the phosphoric acid in the form of phosphates) by utilizing the property which carbon
possesses, at high temperatures, of forming carbides with the metals or bases of such
materials.
Experiments based on this property of carbon, showed that, in fusing or heating a
mixture of carbon and a material containing phosphoric acid in suitable proportions,
in the electric arc, the base, previously combined with the phosphoric acid, forms with
the carbon, the corresponding metallic carbide, and the phosphorus is simultaneously
given off, and can be easily converted into its acids, for example, by burning, and into
the corresponding salts (in a pure form). The reaction may be explained, for
example, when tri-calcium phosphate is employed for forming a carbide of the
formula CaC, by the following equation:-
4 Air + 10 = A} \ 3 + 4 ] +100.
The subject of the present invention accordingly is the manufacture of phosphorus,
or its acids and salts, from materials containing phosphoric acid, such as mineral
phosphates, bones, and slag containing phosphoric acid, these materials being subjected
to a process of forming carbides, in which process the bases of the said materials are
converted into the corresponding metallic carbides, by heating such materials to a
sufficiently high temperature in admixture with carbon, whereby the phosphorus is
set free.
In carrying our said process into practice, the desired materials containing
phosphoric acid (phosphates) and the carbon may be intimately mixed together in
suitable proportions according to the reaction explained above, and the mixture is
heated in an electric furnace or in any other suitable apparatus (for instance, in a
nickel-furnace) capable of giving the temperature necessary for the formation of
carbide whilst preventing the access of air. The phosphorus thus set free is received

page_text: in suitable condensers and can be converted, if desired, into its acids and salts in any
well-known manner. The carbides formed can be run out or otherwise removed, and
a fresh batch of the mixed raw material put into the furnace, in order to carry on the
process as nearly as possible uninterruptedly in the most advantageous manner.
The present process differs essentially from the known processes for the manufacture
of phosphorus (for instance as described in the Specifications of Letters Patent
No. 17719 of 1888 and No. 10437 of 1889), in which processes phosphates or
metaphosphates mixed with carbon and silica or with carbon alone are heated so as
to set free phosphorus ; because in these processes other reactions take place than in
the present process, as may be seen by comparing the equations before stated with
the following equations illustrating the reactions taking place in the said known
processes:
Call 3) † 2010₂ + 10 = 2 CasiÙ³ + 4 + 10 CO.
From these equations it can be seen that, in the said known processes, the carbon is
converted entirely into oxide of carbon, but the carbon has not formed carbide,
which formation is, however, intended by the present process.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
The production of phosphorus or its acids and salts from materials containing
phosphoric acid, such for example as mineral phosphates, bones, and slag containing
phosphoric acid, by a process in which the material is subjected to treatment for the
formation of carbides in such a manner that the base contained in the said material
forms the corresponding carbide, and phosphorus is simultaneously set free,
substantially as hereinbefore described.
day of y
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicants.