A New or Improved Process for Manufacturing Neutral Phospho- Guano.
Year: 1886

page_text: Date of Application, 26th July, 1886.
Complete Left, 21st Mar., 1887.
Complete Accepted, 22nd Apr., 1887.
A New or Improved Process for Manufacturing Neutral Phospho-
Guano.
I, LOUIS AUGUSTE CHEVALET, of 8, rue de la Chaussée d'Antin, Paris, France,
Engineer, do hereby declare the nature of this invention to be as follows:-
In the manufacture of the manure known as phospho-guano, it has hitherto been
customary to mix superphosphates more or less rich in phosphoric acid, with sulphate
of ammonia; the manure obtained contains soluble phosphoric acid, free sulphuric
acid, and sulphate of ammonia. This manure is therefore always very acid and is also
objectionable inasmuch as it burns the sacks in which it is packed; moreover in a few
days after mixing it forms itself into hard lumps so that it often requires pounding
afresh when it has to be spread. Now the phospho-guano that I intend to produce by
my new process, will be obtained by mixing superphosphates more or less rich in
phosphoric acid and free sulphuric acid, with carbonate of ammonia containing 24 or
25 per cent of ammonia, a product of which I have described the manufacture in my
provisional specification No. 8819, dated July 6, 1886.
The best way to proceed is to ascertain the acidity of the superphosphate by means
of an alkalimetric liquor, after which, to this superphosphate is added one part of
ammonia (Az.H) to three parts, or three and half parts of free phosphoric acid (Pho')
or considered as such. This quantity of ammonia will be completely absorbed by the
free acids of the superphosphate and the acid phosphates without any loss of ammonia,
and the mixture obtained will be perceptibly neuter when tested by the litmus paper.
The mixing should be performed on a boarded or flagged floor as is usual in mixing
mortar, i.e. the superphosphate should be spread out, hollowed in the middle like a
basin, into which hollow the necessary quantity of concentrated ammoniacal water is
poured as aforesaid, and covered up quickly with superphosphate; when this is fully
absorbed, the whole is stirred up until a homogeneous mixture not having the smell
of ammonia is obtained. When the manure is thus prepared, nothing remains but to
sample it and put it into sacks.
It is obvious that the above process may be executed quite as well in an open or
closed mortar mixing machine; if the machine is closed, a blast of air may be directed

page_text: upon it in any suitable manner, to drive off the noxious gases set free during the
process, by a small spout or column full of small material and watered like the
scrubbers of gas works, and from there under a coke fire to be burnt. The manure
thus obtained will contain mono-basic phosphate of ammonia, sulphate of ammonia,
neutral or precipitated phosphate of lime soluble in citrate of ammonia, and phosphate
of lime basic or insoluble in citrate; it will therefore contain all the elements of a good
phospho-guano in a soluble state and assimilable to plants; it should consequently
produce the same effects as the latter.
The advantages of this process are the following:
1st. The suppression of the sulphuric acid necessary for the formation of sulphate
of ammonia inasmuch as free acids of superphosphates are used to fix the ammonia of
the concentrated ammoniacal waters.
2nd. The production of a non-acid manure, which is neuter, easily pulverized, and
not liable to form into lumps as has been the case with the mixtures hitherto prepared.
3rd. The advantage of being able to use in this manufacture very acid super-
phosphates, when still moist, unpulverizable, and consequently unsaleable directly, in
order to obtain by my process, dry and pulverizable manures.
The process of manufacture above described would be difficult if not impossible with
the ammoniacal waters obtained with known concentrating apparatuses, such waters
only containing at most 14% or 15% of ammonia as they contain too much free
water; it is on the contrary very easy with ammoniacal waters containing from
24 to 26 per cent of ammonia, as these contain, so to speak, no free water, for which
reason the necessity for drying the manure is obviated, so that no loss of ammonia in
the course of drying is possible.

page_text: COMPLETE SPECIFICATION.
A New or Improved Process for Manufacturing Neutral Phospho-
Guano.
I, LOUIS AUGUSTE CHEVALET of 22 Chaussée d'Antin, Paris, France Engineer, 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 the manufacture of the manure known as phospho-guano, it has hitherto been
customary to mix superphosphates more or less rich in phosphoric acid with sulphate
of ammonia; the manure obtained contains soluble phosphoric acid, free sulphuric acid
and sulphate of ammonia. This manure is therefore always very acid and is also
objectionable inasmuch as it burns the sacks in which it is packed; moreover in a few
days after mixing it forms itself into hard lumps so that it often requires pounding
afresh when it has to be spread. Now the phospho-guano that I intend to produce
by iny new process, will be obtained by mixing superphosphates more or less rich in
phosphoric acid and free sulphuric acid, with carbonate of ammonia containing 24 or
25 per cent of ammonia (a product of which I have described the manufacture in my
Complete Specification, No. 8819, dated July 6/1886). The best way to proceed is to
ascertain the acidity of the superphosphate by means of an alkalimetric liquor, after
which, to this superphosphate is added one part of ammonia (AzH³) to three parts or
three and half parts of free phosphoric acid (Pho°) or considered as such. This
quantity of ammonia will be completely absorbed by the free acids of the super-
phosphate and the acid phosphates without any loss of ammonia, and the mixture
obtained will be perceptibly neuter when tested by the litmus paper.
The mixing should be performed on a boarded or flagged floor; as is usual in
mixing mortar, i.e. the superphosphate should be spread out, hollowed in the middle
like a basin, into which hollow, the necessary quantity of concentrated ammoniacal
water is poured as aforesaid, and covered up quickly with superphosphate; when this
is fully absorbed, the whole is stirred up until a homogeneous mixture not having the
smell of ammonia is obtained. When the manure is thus prepared nothing remains
but to sample it and put it into sacks. It is obvious that the above process may be
executed quite as well in an open or closed mortar mixing machine; if the machine is
closed, a blast of air may be directed upon it in any suitable manner, to drive off the
noxious gases set free during the mixture, by a small spout or column full of small
material and watered like the scrubbers of gas works, and from there under a coke fire
to be burnt.
This mixing apparatus may be such as is in ordinary use in the manufacture of
superphosphates, in which to save labour, a superphosphate should first be made in the
mixing apparatus, after which the required quantity of concentrated ammoniacal water
is added to the superphosphate to saturate the free acids. It is obvious that the
concentrated ammoniacal liquid may be replaced by an ammoniacal liquid containing

page_text: from 20 to 25 per cent of ammonia but the manure will then cost more; for liquid
ammonia is dearer to make than concentrated ammoniacal liquid of the same degree of
richness.
The manure thus obtained, will contain mono-basic phosphate of ammonia, sulphate
of ammonia, neutral or precipitated phosphate of lime soluble in citrate of ammonia
and phosphate of lime basic or insoluble in citrate; it will therefore contain all the
elements of a good phospho-guano in a soluble state and assimilable to plants, it should
consequently produce the same effects as the latter. The advantages of this process
are the following: 1st. The suppression of the sulphuric acid necessary for the
formation of sulphate of ammonia inasmuch as free acids of superphosphates are used
to fix the ammonia of the concentrated ammoniacal waters. 2nd. The production of a
non-acid manure, which is neuter, easily pulverized and not liable to form into lumps.
as has been the case with the mixtures hitherto prepared. 3rd. The advantage of
being able to use in this manufacture very acid superphosphates when still moist,
unpulverizable, and consequently unsaleable directly, in order to obtain by my process
dry and pulverizable manures. The process of manufacture above described would be
difficult if not impossible with the concentrated ammoniacal waters obtained with
known concentrating apparatuses such waters only containing at most 14% or 15%
of ammonia as they contain too much free water, it is on the contrary very easy with
ammoniacal waters containing from 24 to 25 per cent of ammonia, as these contain so
to speak, no free water for which reason, the necessity for drying the manure is
obviated, so that no loss of ammonia in the course of drying is possible.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is
1. The use of concentrated ammoniacal liquid and of liquid ammonia containing
from 23 to 25 per cent of ammonia in the production of a neutral phospho-guano.
2. The use of crystallized carbonate of ammonia even in a solid state prepared from
said concentrated liquids in the production of a neutral phospho-guano.
3. The use of the above described mixing processes.