A Process and Apparatus for Conversion of Phosphates into Thermo- phosphates or Phosphates Treated with Heat.
Year: 1887

page_text: A Process and Apparatus for Conversion of Phosphates into Thermo-
phosphates or Phosphates Treated with Heat.
I, LOUIS RAOUL BAZIN of 23 Boulevard de Strasbourg Paris, France, Gentleman
do hereby declare the nature of this invention to be as follows:-
In order to render mineral phosphates capable of being assimilated by plants, they
are usually rendered more or less soluble by treating them with sulphuric acid. My
invention relates to a treatment which, dispensing with the use of acid, renders the
phosphates capable of being readily assimilated. For this purpose, I subject the
phosphates for several hours to a high temperature, 1300° to 1500° Centigrade,
converting them into thermophosphates. This treatment, besides effecting chemical
changes in their composition, so alters their physical condition that, after being.
cooled and reduced to powder, they can at once be applied to plants, by which they
are readily assimilated. The heating may be effected in any suitable retorts and by
any suitable furnace. I prefer however to employ a regenerative gas furnace provided
with special retorts so constructed that the flame and hot gases, besides acting on the
exterior of the retorts, pass also through them and act directly on their contents.
Each of the retorts, for this purpose, is of semi-cylindrical shape having a long slot
Within the
opening through its flat bottom and extending nearly from end to end.
retort, at each side of this slot, is a low partition extending nearly half way up the
interior and walling off a space on each side of the slot between the partition and
the outer wall of the retort. One end of the retort is open, and through its roof there
are holes for passage of flame, gases and vapours. In charging the retort, the slot is
covered temporarily by a lid and the phosphate in nodules or fragments is introduced
through the open end and charged into the spaces on each side of the slot. The
A number of
temporary cover of the slot is then removed and the end is closed.

page_text: these retorts being set in the furnace chamber. flame and hot gases pass through the
slot and the holes of the roof, the heat thus acting on the retorts internally as well as
externally. After several hours of heating, the contents of the retorts, converted into
thermophosphates, are discharged, cooled and pulverised ready for use.
ABEL & IMRAY,
Agents for the Applicant.
A Process and Apparatus for Conversion of Phosphates into Thermo-
phosphates or Phosphates Treated with Heat.
1, LOUIS RAOUL BAZIN, of 23 Boulevard de Strasbourg, Paris, France, Gentleman,
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 :—
In order to render mineral phosphates capable of being assimilated by plants they
are usually rendered more or loss soluble by treating them with sulphuric acid.
My invention relates to a treatment which, dispensing with the use of acid, renders
the phosphates capable of being readily assimilated.
For this purpose, I subject the phosphates for several hours to a high temperature,
1300° to 1500° Centigrade, converting them into thermophosphates.
This treatment, besides effecting chemical changes in their composition, so alters
their physical condition that, after being cooled and reduced to powder, they can at
once be applied to plants by which they are readily assimilated. The heating may be
effected in any suitable retorts and by any suitable furnace. I prefer however to
employ a regenerative gas furnace arranged as I will describe with reference to the
accompanying drawings.
Fig. 1 is a transverse section, Fig. 2 is a longitudinal section and Fig. 3 is a
sectional plan of one of the retorts or muffles of which a number are arranged in a
regenerative gas furnace as shewn in the transverse section Fig. 4 and longitudinal
section Fig. 5.
Each muffle is made of refractory material with an open slot A along its bottom
with walls extending above the bottom of the muffle, so as to part off a space B on each
side. Through the top of the muffle are apertures D.

page_text: For charging each muffle, a temporary cover indicated by the dotted line C is
placed over the slot A, and fragments of the phosphate are then introduced into the
two side spaces B, whereupon the mouth of the muffle is closed by a cover E
(Fig 5). The hot furnace gases act, not only on the outsides of the muffles, but
also pass through them, entering by the slots A and issuing by the apertures D
along with such gases or vapours as are liberated from the phosphate under
treatment.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. The herein described process for rendering phosphates capable of being
assimilated by plants, by calcining them at high temperature and pulverising the
calcined material.
2. For calcining phosphates, the construction and arrangement of muffles heated
both externally and internally, substantially as described with reference to the
accompanying drawings.
ABEL & IMRAY,
Agents for the Applicant.