IMPROVEMENTS IN THE TREATMENT AND MANUFACTURE OF NATURAL AND OTHER PHOSPHATES
Year: 1876

page_text: LETTERS PATENT to William John Williams, of Vron Deg, Abergele, in the
County of Denbigh, North Wales, Analytical Chemist, for the Invention of
"IMPROVEMENTS IN THE TREATMENT AND MANUFACTURE OF NATURAL AND
OTHER PHOSPHATES."
Sealed the 24th March 1876, and dated the 21st January 1876.
PROVISIONAL SPECIFICATION left by the said William John Williams at
the Office of the Commissioners of Patents on the 21st January 1876.
"
WILLIAM JOHN WILLIAMS, of Vron Deg, Abergele, in the County of Denbigh,
North Wales, Analytical Chemist. IMPROVEMENTS IN THE TREATMENT AND
MANUFACTURE OF NATURAL AND OTHER PHOSPHATES."
This Invention relates to certain processes for the treatment and manufacture of
natural and other phosphates, whereby the same are prepared and produced more
advantageously than by the methods hitherto used:
1. Phosphate of alumina or phosphate of lime, or phosphates of other earths or
alkalies, or phosphate of iron, or phosphates of other metals or mixtures thereof,
whether natural or manufactured artificially, are mixed with sulphate of soda, or
chloride of sodium, or carbonate of soda, or other salts of soda or mixtures thereof,
with coal or charcoal, or some other form of carbon adapted for the purpose (as
will be well understood), and are then heated in a reverberatory or other suitable
furnace, with or without frequent stirring, as may be deemed advisable.
2. The proportions in which the substances above mentioned are mixed are
variable, but it is preferable to mix such substances in such proportions that there
shall be three equivalents of soda present and available for each equivalent of
phosphoric acid contained in the phosphate or phosphates under treatment, with a
sufficient quantity of carbon to reduce or react upon the sulphuric or other acid or
acids which is or are in combination with the soda. The action of heat then sets
up a decomposition, the result of which is that a compound known as trisodic
phosphate is formed.
3. The mass obtained by the process above described is then withdrawn from the
furnace, and may be allowed to cool. It is then, if necessary, conveyed to suitable
tanks and lixiviated in the well known manner, either with hot or cold water, but,

page_text: preferably with hot water. By this lixiviation the trisodic phosphate is dissolved
out of the mass, the alumina or lime, or iron, or other base being left in an insoluble
condition. The aqueous solution may, if desired, be concentrated in the ordinary
way, and the trisodic phosphate crystallized out.
4. Should hydro-disodic-phosphate (common phosphate of soda) be required, it is
obtained by the same process as above described, if the salt or salts of soda is or are
mixed with the phosphate in such proportion that there are two equivalents of soda
present and available for each equivalent of phosphoric acid, and the quantity of
carbon may be decreased.
5. Should sodic-dihydric-phosphate (mono-sodic-phosphate) be required, the salt
or salts is or are mixed in such proportion that there is one equivalent of soda
present and available for each equivalent of phosphoric acid, and the quantity of
carbon may be diminished.
6. Salts of potash or other alkalies may be substituted for salts of soda in the
processes herein-before described, corresponding phosphates of potash or other
alkalies being thereby produced.
7. Salts of line or magnesia may also be substituted for salts of soda in the
processes herein-before described, corresponding phosphates of lime or magnesia
being thereby produced.
8. Products intermediate between those herein-before mentioned are produced by
regulating the proportions of the materials upon the principles above referred to,
and in all cases allowance may be made for the waste which occurs in manufacture.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William John Williams in the Great Seal Patent Office on the 17th
July 1876.
WILLIAM JOHN WILLIAMS, of Vron Deg, Abergele, in the County of Denbigh,
North Wales, Analytical Chemist. "IMPROVEMENTS IN THE TREATMENT AND
MANUFACTURE OF NATURAL AND OTHER PHOSPHATES."
My said Invention relates to certain processes for the treatment and manufacture
of natural and other phosphates, whereby the same are prepared and produced more
advantageously than by the methods hitherto used.
For the purposes of convenience the following paragraphs are numbered con-
secutively.
1. Phosphate of alumina or phosphate of lime, or phosphates of other earths or
alkalies, or phosphate of iron, or phosphates of other metals or mixtures thereof,
whether natural or manufactured, is or are finely powdered and mixed with finely
powdered sulphate of soda or salt cake, and with finely powdered coal or charcoal,
or other form of carbon. The mixture is then placed in a reverberatory or other
suitable furnace, and calcined with frequent stirring, until by the action of heat the
sulphate of soda becomes decomposed, and the soda combines with the phosphoric
acid of the phosphates forming a phosphate of soda.
2. The proportions in which the substances above mentioned are mixed vary
according to the per-centage of phosphoric acid in the phosphate used, but it is
preferable to mix them in such proportion that there are three equivalents of soda
present and available for each equivalent of phosphoric acid in the phosphates; in
practice, a slight excess of sulphate of soda is desirable, with sufficient carbon to
reduce or deoxidize the sulphuric acid, practically about twice the theoretical quantity
will be found desirable. Thus, for a phosphate containing twenty-three per cent. of
phosphoric acid, one ton of phosphate would require fifteen hundredweight of
sulphate of soda, or about ten per cent. in excess of the theoretical quantity, and
about six hundredweight of finely powdered coal or carbon.

page_text: 3. The calcined mass (obtained by this process) is then withdrawn from the
furnace, and may be allowed to cool. It is afterwards conveyed into suitable tanks,
and lixiviated by a well known process, either with hot or cold water, but, preferably,
with hot water. By this lixiviation the trisodic phosphate is dissolved out of the
mass, the whole, or nearly the whole, of the alumina, or lime, or iron, or other base,
being left in an insoluble condition. The liquor is then drawn off into suitable
evaporating pans, and is concentrated in the ordinary way, and the trisodic phos-
phate may be crystallized out if required.
+. Should hydro-disodic phosphate (common phosphate of soda) be required, it
may be obtained by a similar process, if the sulphate of soda be mixed with the
phosphates in such proportion that there are two equivalents of soda present and
available for each equivalent of phosphoric acid in the phosphates, and the quantity
of carbon is diminished. Thus, for the phosphate spoken of in paragraph 2 of this
Specification, instead of adding fifteen hundredweight of salt cake or sulphate of
soda, add ten hundredweight, and instead of six hundredweight of fine coal add four
hundredweight.
5. Should sodio-dihydric-phosphate (mono-sodic-phosphate) be required, the
sulphate of soda is mixed in such proportion that there is one equivalent of soda
present and available for each equivalent of phosphoric acid in the phosphates, and
the quantity of carbon is diminished. Thus, for the phosphate spoken of in
paragraph 2 of this Specification, instead of adding fifteen hundredweight of sulphate
of soda add five hundredweight, and instead of adding six hundredweight of fine
coal add two hundredweight.
6. Sulphate of potash or sulphates of other alkalies may be substituted for
sulphates of soda in the processes described, producing corresponding phosphates of
potash or other alkalies. Sulphate of potash is mixed with the phosphate in such
proportion that three equivalents of potash are present and available for cach
equivalent of phosphoric acid, the calcination and lixiviation being conducted in a
manner similar to that described in paragraphs 1 and 3 of this Specification. In
the case of a phosphate containing twenty-three per cent. of phosphoric acid, one ton
of phosphate would require seventeen hundredweight of sulphate of potash, and
seven hundredweight of fine coal or carbon to produce tri-potassic-phosphate. Hydro-
dipotassic-phosphate is produced by decreasing the quantity of sulphate of potash
and of fine coal by one third; instead of using seventeen hundredweight of sulphato
of potash and seven hundredweight of coal, nearly twelve hundredweight of sulphate
of potash and nearly five hundredweight of fine coal are used. Potassio-dihydric-
phosphate is produced by still further reducing the quantity of sulphate of potash
and fine coal to about six hundredweight and two hundredweight respectively. If
other alkalies are used they are taken in their equivalent proportions in a similar
way.
7. Sulphates of lime or magnesia may be substituted for sulphate of soda in tho
processes described, producing corresponding phosphates of lime or magnesia.
8. Products intermediate between those mentioned in the foregoing paragraphs
are produced by regulating the proportions of the materials upon the principles
mentioned, and allowance may be made in all cases for the ordinary waste in
manufacture.
I should here remark that the proportions of coal or carbonaceous matter above
mentioned must be considered as approximative only, as the proportions thereof
may be varied according to circumstances, as will be well understood.
Having thus declared and ascertained the nature of my said Invention, and in
what manner the same is to be performed, I would observe, in conclusion, that what
I consider novel and original, and therefore claim as constituting the Invention
secured to me by the said herein-before in part recited Letters Patent is,-Tho
employment of coal, charcoal, and other carbonaceous matter in conjunction with
sulphates of soda, potash, and other alkaline matters, for the conversion of natural

page_text: and other phosphates into any of the phosphates of soda, potash, and other alkalino
matters, substantially as and for the purposes herein-before described and set forth.
In witness whereof, I, the said William John Williams, have hereunto set my
hand and seal, this Fourteenth day of July, in the year of our Lord One
thousand eight hundred and seventy-six.
WILLIAM JOHN WILLIAMS. (L.S.)