IMPROVEMENTS IN THE TREATMENT OF CELESTINE OR SULPHATE OF STRONTIA AND SULPHIDE OF STRONTIUM FOR THE PRODUCTION OF CAUSTIC STRONTIA AND CARBONATE OF STRONTIA THEREFROM PROAL
Year: 1882

page_text: LETTERS PATENT to Francis John Bolton of No 19 Grosvenor Gardens in the
County of Middlesex for an Invention of IMPROVEMENTS IN THE TREATMENT
OF CELESTINE OR SULPHATE OF STRONTIA AND SULPHIDE OF STRONTIUM
FOR THE PRODUCTION OF CAUSTIC STRONTIA AND CARBONATE OF STRONTIA
THEREFROM
PROVISIONAL SPECIFICATION left by the said Francis John Bolton at the
Office of the Commissioners of Patents on the 9th June 1882.
FRANCIS JOHN BOLTON of N° 19 Grosvenor Gardens in the County of Middlesex
"IMPROVEMENTS IN THE TREATMENT OF CELESTINE OR SULPHATE OF STRONTIA
AND SULPHIDE OF STRONTIUM FOR THE PRODUCTION OF CAUSTIC STRONTIA AND
CARBONATE OF STRONTIA THEREFROM "
According to my present invention I reduce the sulphate of strontia (Celestine)
to a fine powder and mix it with powdered coal, coke or other carbonaceous
substance. The proportion which I find best suited is 16 parts of celestine (by
weight) and 3 parts of coal or coke.
This mixture I roast in a reverberatory furnace of suitable construction and thus
convert the sulphate into sulphide of strontium.
When the roasting is complete I treat the roasted mass with boiling water in a
series of vats provided with steam jackets or other suitable means of maintaining
the temperature at or near boiling point.
By the action of the hot water the sulphide is partly decomposed into caustic
strontia and polysulphide-both of which are soluble in hot water.
This liquid I allow to settle in a vat, still maintaining the temperature near
boiling point, and when clear I run it off into another vessel and allow it to cool.
The caustic strontia being only slightly soluble in cold water crystallises out on
the sides of the vessel and the polysulphide remains in solution.
This solution I then run or pump into a third vessel in which I treat it with
carbonic acid. A further portion of the sulphide is thereby decomposed, carbonate
of strontia being precipitated and sulphuretted bydrogen evolved.

page_text: In order to obtain the strontium still remaining in solution as a carbonate, I run
the clear liquor into a closed vessel and pass carbonate of ammonia or a mixture of
ammonia gas and carbonic acid into it. The remaining strontia is thus precipitated
as carbonate, and sulphurets of ammonium remain in solution.
In order to guard against any loss the vessel in which this operation is carried
out is provided with a condenser to collect any ammonia that may not be taken
up by the solution.
The solution of sulphurets of ammonium resulting from this last operation I
distil in suitable vessels with lime, and thus obtain ammonia gas for the treatment
of the next solution of sulphides of strontium.
When it is not desired to obtain caustic strontia I either omit the removal of
the caustic strontia as above described, subjecting the whole of the sulphide
solution to the consecutive action of carbonic acid and carbonate of ammonia or of
a mixture of carbonic acid and ammonia gas as described or I treat the powdered
sulphate directly with carbonate of Ammonia gas or with a mixture of carbonic
acid and ammonia gas.
In carrying out this part of my invention I place the powdered sulphate, first
thoroughly moistened, on perforated trays in a suitable closed box, and cause the
gases to pass through the mass. The carbonic acid combines with the strontia
forming carbonate of strontia and the sulphuric acid from the sulphate combines
with the ammonia forming sulphate of ammonia.
Or I place sulphide of strontium obtained by roasting as above described on the
trays, and treat in the same manner with carbonate of ammonia gas or with a
mixture of carbonic acid and ammonia gas; or any gases containing the mixture
of carbonic acid and ammonia such as the products of the distillation of coal or
the gases, from blast furnaces, coke ovens or from converters will produce the
reaction.
When the reaction is complete the mass is washed with water and the sulphate
of ammonia dissolved out.
The solution of sulphate of ammonia can be concentrated in the usual manner

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
"
by the said Francis John Bolton in the Great Seal, Patent Office on the
6th December 1882,
FRANCIS JOHN BOLTON of N° 19 Grosvenor Gardens in the County of Middlesex
IMPROVEMENTS IN THE TREATMENT OF CELESTINE OR SULPHATE OF STRONTIA
AND SULPHIDE OF STRONTIUM FOR THE PRODUCTION OF CAUSTIC STRONTIA AND
CARBONATE OF STRONTIA THEREFROM
"
According to my present invention, I reduce the Sulphate of Strontia (Celestine)
to a fine powder and mix it with powdered coal coke or other carbonaceous
substance. The proportion which I find best suited is 16 parts of Celestine (by
weight) and three parts of coal or coke. This mixture I roast in preference in an
ordinary reverberatory furnace, till all the carbon is burnt out. In order to
prevent any reoxidation, I sometimes add a small quantity of Coal or Sawdust and
stir it well through the heated mass before drawing the charge. During the
roasting the mass must be continually turned over to prevent caking. When the
roasting is complete, I treat the roasted mass with boiling water in a series of vats
provided with steam jackets or other suitable means of maintaining the temperature
at or near boiling point
By the action of the hot water the Sulphide is partly decomposed into Caustic
Strontia and Polysulphide and Sulphydrate, and I obtain a solution of these. This
liquid I allow to settle in a vat, still maintaining the temperature near boiling
point, and when clear I run it off into another vessel and allow it to cool. The
caustic Strontia being only slightly soluble in cold water, crystallises out on the
sides of the vessel and the Polysulphide and Sulphydrate remain in solution.
This solution, I then run or pump into a third vessel in which I treat it with
carbonic acid. A further portion of the Sulphide is thereby decomposed, Carbonate
of Strontia being precipitated and Sulphuretted hydrogen evolved. In order to
maintain an intimate contact between the Carbonic acid and the liquor, I prefer
to construct this vat with a false bottom, perforated with small holes, and I then
cause the Carbonic acid to pass in below this false bottom. The vat should be
sufficiently high to absorb all the Carbonic acid; or two vats, one closed at the top,
and so connected that the gas may pass from it to the bottom of the other, may
be used:
In this case the liquor is run from one to the other in the contrary direction to
the gas The partially carbonated liquor is thus brought into contact with the
fresh gas, which then passes on mixed with sulphuretted hydrogen to the other vat
where it meets fresh liquor.
The clear solution remaining after the Carbonate has settled, I prefer to boil
down till it is nearly saturated and I then treat it a second time with Carbonic
acid as above described. In order to obtain the Strontium still remaining in the
solution as a carbonate, I run the clear liquor into a closed vessel and pass
Carbonate of Ammonia or a mixture of Ammonia Gas and carbonic acid into it.
The remaining Strontia is thus precipated as Carbonate and Sulphurets of Ammonium
remain in solution
In order to guard against any loss, the vessel in which this operation is carried
out is provided with a condenser to collect any Ammonia that may not be taken
up by the solution. The solution of Sulphurets of Ammonium resulting from this
last opération I distil in suitable vessels with lime, and thus obtain Ammonia gas
for the treatment of the next solution of Sulphides of Strontium I sometimes find
it better to evaporate off a portion of the Ammonium Sulphide liquor in order to
obtain a more concentrated solution for the still; this is, however seldom necessary

page_text: when the liquor has been previously concentrated and treated a second time with
Carbonic Acid :
When it is not desired to obtain Caustic Strontia, I either omit the removal of
the Caustic Strontia as above described, subjecting the whole of the Sulphide
solution to the consecutive action of carbonic acid and carbonate of ammonia or of
a mixture of Carbonic Acid and ammonia gas as described or I treat the powdered
Sulphate directly with Carbonate of Ammonia, gas or with a mixture of Carbonio
Acid and ammonia gas
In carrying out this part of my invention, I place the powdered Sulphate, first
thoroughly moistened, on perforated trays in a suitable closed box, and cause the
gases to pass through the mass. The Carbonic Acid combines with the Strontia
forming Carbonate of Strontia and the Sulphuric Acid from the Sulphate combines
with the Ammonia forming Sulphate of Aminonia
Or, I place Sulphide of Strontium obtained by roasting as above described upon
the trays and treat in the same manner with carbonate of Ammonia gas or with a
mixture of Carbonic acid and ammonia gas, or any gases containing the mixture of
Carbonic Acid and Ammonia, such as the products of the distillation of Coal or
the gases from Blast Furnaces, coke ovens or from converters will produce the
reaction
When the re-action is complete the mass is washed with water and the Sulphate
of Ammonia dissolved out
The Solution of Sulphate of Ammonia can be concentrated in the usual manner.
Having thus described the nature of my invention, and in what manner the
same is to be performed, I wish it to be understood that I do not claim by itself
the production of caustic strontia by treating roasted Sulphate of Strontia or
celestine with hot water, nor the treatment of sulphate of strontia by boiling with
carbonate of ammonia, but I claim :-
First: The herein described treatment of sulphate of strontia or celestine for the
production of Caustic strontia and carbonate of strontia, wherein the celestine
previously roasted with carbonaceous matter is first subjected to the action of
hot water for the extraction of the caustic strontia, after which the residuum
is treated first with carbonic acid and then with carbonate of ammonia or
with a mixture of carbonic acid and ammonia gas, in order to convert the
remaining sulphides into carbonate of Strontia
Second-The method of converting sulphide of Strontium into Carbonate of
Strontia by first subjecting the sulphide to the action of carbonic acid for its
partial conversion into carbonate and then treating the remaining liquor with
carbonate of ammonia or with a mixture of carbonic acid, and ammonia gas
substantially as herein described
Third The use, for the conversion of sulphide of strontium or of sulphate of
strontia into carbonate of strontia, of a mixture of carbonic acid and ammonia
gas or of furnace and other gases containing carbonic acid and ammonia
Fourth-The herein described method of converting sulphate of strontia, direct
into carbonate by treating it in a pulverised and moistened condition with
carbonic acid and ammonia or gases containing these in admixture
In witness whereof, I, the said Francis John Bolton, have hereunto set my
hand and seal this fifteenth day of November In the year of our Lord,
One thousand, eight hundred and eighty two.
FRANCIS JOHN BOLTON
(ST)