IMPROVED PROCESSES OF TREATING CALCAREOUS PHOSPHORITES OR ORES FOR CONVERTING THE CARBONATE OF LIME CONTAINED IN THE SAME INTO PHOSPHATE OF LIME communicated
Year: 1883

page_text: 65
LETTERS PATENT to William Robert Lake of the firm of Haseltinė, Lake
& Co, Patent Agents, Southampton Buildings, London for an Invention of
'IMPROVED PROCESSES OF TREATING CALCAREOUS PHOSPHORITES OR ORES
FOR CONVERTING THE CARBONATE OF LIME CONTAINED IN THE SAME INTO
PHOSPHATE OF LIME communicated to him from abroad by John Cox of
Mulheim on the Rhine in the Empire of Germany
"
PROVISIONAL SPECIFICATION left by the said William Robert Lake at
the Office of the Commissioners of Patents on the 13th November 1883.
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents
Southampton Buildings, London, "IMPROVED PROCESSES OF TREATING CALCAREOUS
PHOSPHORITES OR ORES FOR CONVERTING THE CARBONATE OF LIME CONTAINED
IN THE SAME INTO PHOSPHATE OF LIME" [A communication to him from abroad
by John Cox of Mulheim on the Rhine in the Empire of Germany]
This invention relates to the conversion, by means of phosphoric acid, of the
carbonate of lime contained in ores or calcareous phosphorites into phosphate of
lime soluble in water.
For this purpose I mix desiccated and finely pulverized ore with a solution of
phosphoric acid in the proportions necessary to convert the carbonate of lime into
phosphate of lime soluble in water.
According to the product which it is desired to obtain, I employ one of the three
following processes, that is to say :-
Firstly. I filter the said mixture with the addition of water, the resulting
products being on the one hand, a substance containing a relatively large pro-
portion of tribasic phosphate of lime, from which the carbonate of lime is separated
by reason of its conversion into soluble phosphate of lime and carbonic acid; and
on the other hand a solution of soluble phosphate of lime resulting from this
conversion of the said carbonate of lime. This solution may be concentrated.
These two substances are utilizable for industrial purposes.
FD 137

page_text: Secondly. I add to the mixture of calcareous phosphorite and phosphoric acid,
sulphuric acid in sufficient quantity to convert the tribasic phosphate of lime
which the said mixture contains, either into free phosphoric acid and sulphate of
lime or into soluble phosphate of lime; I then desiccate and disaggregate the
mixture. The product thus obtained will be a mixture either of soluble
phosphate, phosphoric acid, sulphate of lime and various insoluble substances, or
of soluble phosphate, sulphate of lime and various insoluble substances. This
product is utilizable for industrial purposes
Thirdly. I proceed as stated under the heading "secondly," but instead of
desiccating and disaggregating the mixture I filter the same with the addition of
water. I thus obtain a solution either of soluble phosphate and phosphoric acid,
or of soluble phosphate only, a substance which may be utilized for industrial
purposes; the solution obtained may be concentrated. The residue contains only
sulphate of lime and various insoluble substances
It is obvious, that instead of using phosphoric acid in sufficient quantity to
convert the carbonate of lime into soluble phosphate of lime, I may simply convert
the carbonate of lime into assimilable dibasic phosphate of lime which is
assimilable, or into tribasic phosphate of lime, both results depending upon the
proportion of phosphoric acid employed.
I may also, in the second treatment above mentioned, by changing the proportion
of sulphuric acid, convert the tribasic phosphate of lime, not only into phosphoric
acid or into monobasic phosphate of lime as above stated, but into dibasic
phosphate of lime.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Patent Office on the 6th February
1884.
WILLIAM ROBERT LAKE, of the firm of Haseltine. Lake, and Co. Patent Agents,
Southampton Buildings, London, "IMPROVED PROCESSES OF TREATING CALCAREOUS,
PHOSPHORITES OR ORES FOR CONVERTING THE CARBONATE OF LIME CONTAINED
IN THE SAME INTO PHOSPHATE OF LIME," A communication to me from abroad:
by John Cox, of Mulheim-on-the-Rhine, in the Empire of Germany.
This invention relates to the conversion, by means of phosphoric acid, of the
carbonate of lime contained in calcareous ores or phosphorites into phosphate of
lime
For this purpose I mix desiccated and finely pulverized ore with a solution of
phosphoric acid in, the proportions necessary to convert the carbonate of lime into
phosphate of lime soluble in water.
Then, according to the product which it is desired to obtain, I employ one or
other of the three following modes of treatment, that is to say:
A. I filter the mixture with the addition of water, the resulting products being
on the one hand a substance containing a relatively large proportion of tribasic
phosphate of lime from which the carbonate of lime is separated by reason of its
conversion into soluble phosphate of lime and carbonic acid; and on the other
hand a solution of soluble phosphate of lime resulting from this conversion of the
carbonate of lime. This solution may be concentrated. These two substances
are utilizable for industrial or manufacturing purposes.
B. I add to the mixture of calcareous phosphorite and phosphoric acid, sulphuric
acid in sufficient quantity to convert the tribasic phosphate of lime which the
said mixture contains, either into free phosphoric acid and sulphate of lime or into
soluble phosphate of lime and sulphate of lime; I then desiccate and disaggregate
the mixture. The product thus obtained will be a mixture either of soluble
phosphate, phosphoric acid, sulphate of lime and various insoluble substances, or a
mixture of soluble phosphate, sulphate of lime and various insoluble substances.
This product is utilizable for industrial purposes.
C. I proceed as described under the heading B, but, instead of desiccating and
disaggregating the mixture, I filter the same with the addition of water. I thus
obtain a solution either of soluble phosphate and phosphoric acid; or of soluble
phosphate only, a substance which may be utilized for industrial purposes; the
solution obtained may be concentrated. The residue contains only sulphate of
lime and various insoluble substances.
It is obvious that, instead of using phosphoric acid in sufficient quantity to
convert the carbonate of lime into soluble phosphate of lime, I may simply convert
the carbonate of lime into assimilable bibasic phosphate of lime or into tribasic
phosphate of lime, the result in either case depending upon the proportion of
phosphoric acid employed.
may also, in the mode of treatment B above. described, by changing the
proportion of sulphuric acid, convert the tribasic phosphate of lime, not only into
phosphoric acid or into monobasic phosphate of lime as above stated, but into
bibasic phosphate of lime..
Having thus fully described the said invention as communicated to me by my
foreign Correspondent, and the manner of performing the same, I wish it understood
that I claim :-
First. The above described process consisting essentially in converting, by means
of phosphoric acid, the carbonate of lime contained in calcareous phosphorites or

page_text: ores either into phosphate of lime soluble in water or into assimilable bibasic
phosphate of lime, or into tribasic phosphate of lime, or into a mixture of these
substances.
Second. In the said process, either of the above described modes of treatment,
that is to say, the treatment A consisting in separating the soluble phosphate of
lime in such a manner that the remaining substance contains a relatively large
proportion of tribasic phosphate of lime, or the treatment B consisting in
converting the tribasic phosphate of lime contained in the mixture either into free
phosphoric acid and sulphate of lime, or into phosphate of lime (soluble in water)
and sulphate of lime, which remain mixed in the product, or into bibasic phosphate
of lime and sulphate of lime, which also remain mixed in the product; or the
treatment C consisting in supplementing the operation B by separating from the
mixture the soluble portions leaving a residue containing only phosphated
matters.
In Witness whereof I the said William Robert Lake have hereunto set my
hand and seal this Fifth day of February in the year of our Lord One thousand
eight hundred and eighty four
W. ROBT. LAKE (L.S.)