Improvements in the Treatment of a Certain Material (Mineral) Containing Phosphate of Lime for the purpose of Obtaining the latter in a Highly Concentrated Condition, as Dicalcic Phosphate, together with Certain Bye Products.
Year: 1891

page_text: Date of Application, 3rd Mar., 1891
Complete Specification Left, 3rd Dec., 1891-Accepted, 9th Jan., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of a Certain Material (Mineral)
Containing Phosphate of Lime for the purpose of Obtaining the
latter in a Highly Concentrated Condition, as Dicalcic Phosphate,
together with Certain Bye Products.
I JAMES SIMPSON of 84 Rumford Place, Liverpool in the County of Lancaster,
Alkali Manufacturer do hereby declare the nature of this invention to be as
follows:--
This invention refers only to the mineral or slag containing phosphate of lime-
from which the lime originally existing in it as carbonate or oxide has been
separated as sulphydrate of calcium by the process described in British Patent
No. 1267090
The object of my invention is to eliminate the silicate and aluminate of lime as
well as any other insoluble materials which are not brought into solution by the
action of the sulphuretted bydrogen employed in the aforesaid process. For this
purpose I treat the aforesaid mineral containing phosphate of lime with hydro-
chloric acid preferably diluted to about 10° Twaddle-whereby the phosphate of
lime is dissolved-while the insoluble matter subsides to the bottom of the dissolving
vessel.
This insoluble residue may be used for the manufacture of cement or any
other desired purpose-while the phosphatic solution is decanted off and treated
with lime (preferably as milk of lime) in order to precipitate the phosphoric acid
as dicalcic phosphate. The treatment with milk of lime should be conducted in two
operations in order that the dicalcic phosphate may not contain any free lime. In
the first operation-the precipitated dicalcic phosphate is separated from the
solution by decanting the latter before it is completely neutralized.
The solution can then under the second operation be completely neutralized with
lime. By mixing the neutralized solution with a fresh phosphatic solution under-
going the first operation any excess of lime employed in the second operation will
be utilized.
Dated this 2nd day of March 1891.
Per pro J. T. KING,
W. B. Johnson,
Agent.
COMPLETE SPECIFICATION.
Improvements in the Treatment of a Certain Material (Mineral)
Containing Phosphate of Lime for the purpose of Obtaining the
latter in a Highly Concentrated Condition, as Dicalcic Phosphate,
together with Certain Bye Products.
I, JAMES SIMPSON of 8ª Rumford Place, Liverpool, in the County of Lancaster
Alkali Manufacturer, 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 refers to the mineral or slag containing phosphate of lime from
which the carbonate or oxide of lime has been separated as sulphydrate of calcium
by the process described in British Patent No. 12670°.
It is manifest however, that if natural phosphates or slags sufficiently free from
lime can be obtained they may be treated as hereinafter described without being
subjected to the process described in the above mentioned Patent No. 12670⁰⁰.

page_text: The object of my invention is to eliminate the silicate and aluminate of lime as
well as any other insoluble substances existing in the mineral or slag the presence
of which would reduce the percentage of dicalcic phosphate in the finished
product.
For this purpose I treat the aforesaid mineral or slag containing phosphate of
lime with hydrochloric acid, preferably diluted to about 10° Twaddle, whereby the
phosphate of lime is dissolved, while the insoluble matter subsides to the bottom
of the dissolving vessel which latter is preferably fitted with a suitable agitating
apparatus.
This insoluble residue which is the principal bye-product may be used for the
manufacture of cement or any other desired purpose.
The phosphatic solution is decanted off and treated with milk of lime in two
operations, as hereinafter described, in order that the dicalcic phosphate may not
contain any free lime.
In the first operation the precipitated dicalcic phosphate is separated from the
'solution by decanting the latter before it is completely neutralized. The solution
can then under the second operation be completely neutralized with milk of lime.
By mixing the said neutralized solution with a fresh phosphatic solution under-
going the first operation any excess of lime employed in the first operation will be
utilized.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is :-
First. The method of manufacturing dicalcic phosphate from a solution of
phosphate of lime by means of two operations with milk of lime substantially as
described.
Second. In the manufacture of dicalcic phosphate utilizing the insoluble matter
obtained as herein described.
Doted this 2nd day of Donamban 1901
Per pro J. T. KING,
J. Johnson,
Agent.