IMPROVEMENTS IN THE TREATMENT OF MINERAL PHOSPHATES OF LIME
Year: 1859

page_text: LETTERS PATENT to Marc Antoine François Mennons, of the British and
Foreign Patent Offices, 39, Rue de l'Echiquier, Paris, in the Empire of
France, for the Invention of "IMPROVEMENTS IN THE TREATMENT OF MINERAL
PHOSPHATES OF LIME."-A communication from B. de Siebenthal, a person
residing in Paris.
Sealed the 7th October 1859, and dated the 8th April 1859.
PROVISIONAL SPECIFICATION left by the said Marc Antoine François
Mennons at the Office of the Commissioners of Patents, with his.
Petition, on the 8th April 1859.
I, MARC ANTOINE FRANÇOIS MENNONS, of the British and Foreign Patent
Offices, 39, Rue de l'Echiquier, Paris, in the Empire of France, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE TREATMENT
OF MINERAL PHOSPHATES OF LIME," a communication, to be as follows:-
The object of the Invention communicated to me is the separation of the
natural phosphate of lime from the silica and carbonate of lime combined with
it, which separation is effected by the following processes:-The mineral or.
fossil phosphate of lime in a pulverised state is first treated by hydrochloric
acid, which dissolves the phosphate and carbonate, leaving the silica unattacked.
The solution thus formed. is decanted from the undissolved matter, and after-.
wards submitted to the action of a centrifugal separating apparatus, by which!
the remainder of the silica is completely cleared off. A quantity of liquid

page_text: ammonia, sufficient for the neutralisation of the hydrochloric acid, is then
added to the solution, the result of which is the precipitation, in a gelatinous
state, of all the phosphate of lime in suspension. This precipitate being
submitted to the action of the centrifugal separating apparatus, a pure dry
phosphate of lime is obtained. The mother liquor may on the other hand be
concentrated and evaporated for the recovery of the ammoniacal salts formed
in the reaction, or may be treated by lime for the production of caustic
ammonia. In certain cases the gelatinous precipitate of phosphate of limo
may be dried directly either with or without the addition of a carbonisable
matter, the ammoniacal residue being afterwards separated by calcination in
suitable recipients. It is obvious that the modes of treatment above noted
may be varied and extended according to circumstances, and that the residues
may be economised by many well known processes.
SPECIFICATION in pursuance of the conditions of the Letters l'atent, filed
by the said Marc Antoine François Mennons in the Great Seal Patent
Office on the 7th October 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARC
ANTOINE FRANÇOIS MENNONS, of the British and Foreign Patent Offices, 39,
Rue de l'Echiquier, Paris, in the Empiro of France, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of April, in the year of our Lord One
thousand eight hundred and fifty-nine, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Marc Antoine François Mennons, Her special licence that I, the said
Marc Antoine François Mennons, my executors, administrators, and assigns,
or such others as I, the said Marc Antoine François Mennons, my executors,
administrators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of Man,
an Invention for "IMPROVEMENTS IN THE TREATMENT OF MINERAL PHOSPHATES OF
LIHE," (a communication,) upon the condition (amongst others) that I, the
said Mare Antoine François Mennons, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed

page_text: in the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Marc Antoine François Mennons, do
hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say :-
The object of the Invention communicated to me is to eliminate from fossil
phosphates of lime the carbonates of lime and silica with which they are
combined in their natural state, so as to render them to a high degree soluble
and assimilable for agricultural purposes, which end is attained by the following
mode of treatment:-A given quantity (say two tons weight) of natural or
crude phosphate of lime, containing from forty to forty-five per cent. of pure
phosphate, is pulverised by any suitable crushing machine, and placed in a
recipient of convenient dimensions. A quantity varying from one and a half
to two tons of concentrated or diluted bydrochloric acid of commerce is then
poured on the mass, its action being accelerated if necessary by agitation.
When the solution of the phosphate and carbonate of lime is completed, the
supernatant liquid is drawn off from the undissolved siliceous residue, which is
then submitted to the action of a centrifugal separating apparatus. The
silica being by this process completely eliminated from the remaining acid
solution by which it was held in suspension, the latter is added to the portion
already drawn off. A quantity of liquid ammonia of commerce is then poured
into the solution, the result of which is the production of a gelatinous pre-
cipitate of pure phosphate of lime (supposing the raw material to have been
free from iron). The quantity of ammonia thus added varies according
to circumstances (say about one tun in ordinary cases), but should iron
be present in the solution, the alkaline saturation should be arrested as
soon as the precipitate changes color. The mother liquor being decanted,
the precipitate is treated by the centrifugal separating apparatus, which
drives off the remaining liquid, and leaves the pure phosphate of lime in
an almost dry state. About one ton of this pure product is obtained from
the quantity of crude phosphate above noted (two tons). Instead of expelling
the remainder of the mother liquor by the centrifugal machine after decantation,
the gelatinous residue may be directly dried by heat (with the addition of a
carbonisable matter, such as coal-dust, if a black product is required), and the
ammoniacal salts may be afterwards eliminated by calcination in suitable
recipients. A certain quantity of pure sublimed chloride of ammonia is thus
obtained, but as in this case the chloride of calcium is still left in combination
with the phosphate, the centrifugal separating process previously described is

page_text: preferable when a pure product is required. As a general rule, the crude
phosphate should, as above mentioned, be pulverised previous to its treatment
by, the hydrochloric acid, but this operation may be dispensed with if attended
with difficulty, and the mineral bo employed in lumps or nodules. The
solution is, of course, in this case much less rapid. The mother liquor from
which the phosphate has been withdrawn may be economised by many.
known processes, among, which may be noted,-
1stly, evaporation and cristallisation for the production of crude chloride of
ammonia. (In this case the product contains a certain amount of chloride of
calcium.)
2dly, saturation with lime and distillation, for the production of caustic
ammonia.
3dly, decomposition by caustic magnesia into ammonia and chloride of
magnesium; the ammonia being removed by distillation, the residue, composed
principally of chloride of magnesium, is decomposed by a higher temperature:
The hydrochloric acid passes off and is collected apart, while a caustic magnesia
containing a small proportion of chloride of calcium remains in the retort.
Having thus described the nature of the said Invention, and the manner of
carrying it into effect; I would have it understood that I do not confine myself
to the precise details laid down, many of which may be modified in practise
or replaced by other known processes; but what I claim as the essential base
of the Invention, is, the treatment, substantially, as above described, of natural
or fossil phosphates of lime by ammoniacal precipitation from their solution
in hydrochloric acid, for the production of a chemically pure and thoroughly,
soluble and assimilable phosphate of lime for agricultural purposes."
In witness whereof; I, the said Marc Antoine François Mennons, have
hereunto set my hand seal, this Third day of October, in the year of
our Lord One thousand eight hundred and fifty-nine.
M. F. MENNONS. (L.S.)