Improvements in the Manufacture or Production of Mono-calcic Phosphate and Ammonia.
Year: 1893

page_text: Date of Application, 6th Apr., 1893
Complete Specification Left, 6th Jan., 1894-Accepted, 10th Feb., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture or Production of Mono-calcic
Phosphate and Ammonia.
I FERDINAND HURTER Ph.D. of Widnes in the County of Lancaster
Analytical Chemist do hereby declare the nature of this invention (which has been
communicated to me from abroad by Johannes Omholt of Christiania (Kristian 4
Gade No. 12 III) in the Kingdom of Norway Chemist) to be as follows:-
This invention has for its object to manufacture mono-calcic-phosphate and
ammonia.
According to this invention sulphate of ammonia in the form of the dry salt is
heated to a high temperature with ground or divided tri-calcic phosphate preferably
in the presence of steam. The sulphate of ammonia is decomposed ammonia gas
being given off it being conducted away as it is generated for use for any desired
purpose. The sulphuric acid of the said sulphate combining with some of the lime
of the tri-calcic-phosphate, mono-calcic phosphate (mixed with some sulphate of
lime) is produced and constitutes a useful manure.
remain as tri-calcic phosphate it may be converted into mono-calcic phosphate by
If any of the phosphate should
the addition of a suitable proportion of sulphuric acid.
Dated this 6th day of April 1893.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in the Manufacture or Production of Mono-calcic
Phosphate and Ammonia.
I, FERDINAND HURTER, Ph.D., of Widnes, in the County of Lancaster,
Analytical Chemist, do hereby declare the nature of this invention (which has been
communicated to me from abroad by Johannes Omholt, of Christiania (Kristian 4
Gade No. 12 III) in the Kingdom of Norway, Chemist) and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :-
This invention has for its object to manufacture mono-calcic phosphate and
ammonia.
According to this invention sulphate of ammonia in the form of dry salt is heated
to a high temperature with ground or finely divided tri-calcic phosphate, preferably
in the presence of steam. The sulphate of ammonia is decomposed, ammonia gas
being given off, it being conducted away as it is generated for use for any desired
purpose. The sulphuric acid of the said sulphate combining with some of the lime
of the tri-calcic phosphate, mono-calcic phosphate (mixed with some sulphate of
lime) is produced which constitutes a useful manure. The process may be
represented by the following chemical equation: CPO, +2 (NH),SỐ¸ =
CaH PO, +2 CaSO, +4 NH,. In practice I use native mineral phosphates and
I prefer high grade phosphates. The relative amounts of phosphate and of
sulphate of ammonia to be used depend upon the richness of the phosphate. For
every one per cent. of tri-calcic phosphate which the mineral contains I add to it
and intimately mix with it about 0.85 per cent. of sulphate of ammonia. For
[Price 8d.]
=

page_text: instance I add to 100 parts of a phosphate containing 75 per cent. of tri-calcic
phosphate 75 x 0.85 = 63-75 parts of sulphate of ammonia. I prefer however to
use the phosphate in excess.
When the mixture has been prepared it is placed in a retort or equivalent vessel
and heated to a temperature of from 550° to 650° Fahrenheit or thereabouts, a
slow current of steam (preferably superheated) being passed through the retort or
vessel.
Ammonia gas is evolved and passes from the retort or vessel through an exit
pipe or passage to suitable cooling and condensing apparatus where the steam is
condensed, together with a small amount of sulphate of ammonia which volatilises
with the ammonia gas. The comparatively dry ammonia gas may then be utilised
for any purpose, such as for the manufacture of soda by the ammonia process.
When the evolution of ammonia gas ceases (which may be ascertained by
testing) the solid residue in the retort or vessel is allowed to cool down in an
atmosphere of steam to about 220° Fahrenheit. This cooling may be hastened by
shutting off the superheated steam, and passing ordinary low pressure steam
through the retort or vessel. During this cooling in an atmosphere of steam the
mono-calcic phosphate re-absorbs, to a great extent, any water which it may have
lost at the higher temperature.
The residue is then withdrawn and is ground if necessary, and constitutes a
useful inanure. It consists of a mixture of mono-calcic phosphate, sulphate of
lime, and small quantites of sulphate of ammonia, and unaltered tri-calcic
phosphate.
I prefer to add to the residue a certain quantity of sulphuric acid in order to
render more of the phosphate soluble. The quantity to be added depends upon the
amount of unaltered tri-calcic phosphate left in the residue, but I have obtained
good results by the addition of from 10 to 15 per cent. of sulphuric acid of a
strength of 120° Twaddle. If the mass becomes too damp it may be dried at a
temperature not exceeding 212° Fahrenheit.
The retort or vessel may be a retort of the ordinary type, viz.: a horizontal
cast iron cylinder, set in brick work and capable of being heated externally by
direct fire. It may be provided with a mechanical agitator and be charged through
a door capable of being hermetically closed, and the finished charge can be
withdrawn through the same door. The ammonia gas escapes from the top of the
retort through an exit pipe or passage provided for that purpose, and steam can
be admitted through a small pipe.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The manufacture or production of mono-calcic phosphate and ammonia by
beating together tri-calcic phosphate and sulphate of ammonia substantially as
hereinbefore described.
2. The manufacture or production of mono-calcic phosphate and ammonia by
heating together tri-calcic phosphate and sulphate of ammonia in an atmosphere
of steam substantially as hereinbefore described.
3. In the manufacture of mono-calcic phosphate and ammonia by heating
together tri-calcic phosphate and sulphate of ammonia as hereinbefore claimed
the addition of a small quantity of sulphuric acid to the mono-calcic phosphate,
for the purposes hereinbefore set forth and substantially as described.
Dated this 6th day of January 1894.
JOHNSONS & WILLCOX,
Agents.