AN IMPROVED PROCESS FOR THE MANUFACTURE OF HYDRATE OF STRONTIA
Year: 1884

page_text: I CARL MARIA PIELSTICKER, of 69 Lombard Street, in the City of London,
Engineer, do hereby declare the nature of my Invention for AN IMPROVED PROCESS
FOR THE MANUFACTURE OF HYDRATE OF STRONTIA to be as follows:-
.
To a solution of sulphide of strontium I add a solution of sulphide of barium in
such proportion that the quantity of sulphide of barium in solution is chemically
equivalent, or nearly so, to the quantity of sulphide of strontium in the sulphide of
strontium solution.
Hydrate of strontia is formed thereby, which crystallises out on the cooling of
the liquid, whilst hydrosulphide (or sulphhydrate) of barium remains in solution.
Both solutions should in preference be used as concentrated and as hot as
possible. Less concentrated and colder solutions do not prevent the reaction from
taking place but the yield of hydrate of strontia is smaller in proportion as they
are diluted.
The crystals of hydrate of strontia are separated from the mother liquor that is
to say from the hydrosulphide of barium solution. They are then washed and
recrystallised once or twice, and are then ready for use or sale.
The mother liquor consisting of the solution of hydrosulphide of barium I use
either as it is for some of the purposes for which monosulphide of barium has
commonly been used in the arts as for instance for the manufacture of chloride of
barium and the like purposes. Or I decompose the same by means of sulphate of
soda for the purpose of producing hydrosulphide of sodium which when boiled
down and crystallised is an article of commerce.
Or I boil down the solution of hydrosulphide of barium to dryness and heat the
dry residue mixed with a small quantity of carbonaceous matter (to prevent
oxidation), to incipient red heat, whereby one equivalent of sulphur is expelled and
monosulphide of barium is formed. The monosulphide of barium I dissolve in hot
water and I use the solution as above described for mixing with a solution of
Bulphide of strontium,
Instead of mixing ready formed solutions of sulphide of strontium with ready
made solutions of sulphide of barium as described I also (but less advantageously)
mix sulphate of strontia with an equivalent quantity of sulphate of baryta, add to
the same the necessary quantity of carbonaceous matter.

page_text: I furnace this mixture and convert the same in the well known manner into the
corresponding mixture of their respective sulphides-From the furnaced material
I obtain a solution of the mixed sulphides by lixiviation with hot water, which
mixed solution I treat further in the above described manner.
As there are native mixtures of sulphate of strontia and sulphate of baryta 5
I prefer to use these. I grind this native mixture to a convenient size, add car-
bonaceous matter to the ground material and reduce the same in a furnace at a
high temperature to the state of sulphides in the same manner usually practised
with the single sulphate of baryta or the single sulphate of strontia.
On lixiviating this furnaced mass in the usual way I obtain a mixed solution of 1
sulphide of barium and sulphide of strontium, which I treat further as described
above.

page_text: I CARL MARIA PIELSTICKER of 69 Lombard Street in the City of London
Engineer do hereby declare the nature of my Invention for AN IMPROVED PROCESS
FOR THE MANUFACTURE OF HYDRATE OF STRONTIA and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:—
To a solution of sulphide of strontium I add a solution of sulphide of barium in
such proportions that the quantity of sulphide of barium in solution is chemically
equivalent, or nearly so, to the quantity of sulphide of strontium in the sulphide of
strontium solution.
Hydrate of strontia is formed thereby, which crystallises out on the cooling of
the liquid, whilst hydro sulphide (or sulphhydrate) of barium remains in solution. ;
The said process may be modified but without any practical advantage resulting
therefrom by first allowing some of the hydrate of strontia to crystallise out of the
solution of sulphide of strontium and then adding to the mother liquid sulphide of
barium solution equivalent in quantity to the strontium sulphide contained in the
original solution.
This method would necessitate two separations instead of one.
Both solutions should in preference be used as concentrated and as hot as
possible-Less concentrated and colder solutions do not prevent the reaction from
taking place but the yield of hydrate of strontia is smaller in proportion as they
are diluted.
The crystals of hydrate of strontia are separated from the mother liquor that is
to say from the hydrosulphide of barium solution. They are then washed and
recrystalised once or twice and are then ready for sale.
Instead of mixing ready formed solutions of sulphide of strontium with ready
made solutions of sulphide of barium as described I also (but less advantageously)
mix sulphate of strontia with an equivalent quantity of sulphate of baryta, add to
the same the necessary quantity of carbonaceous matter, I furnace this mixture and
convert the same in the well known manner into the corresponding mixture of
their respective sulphides-From the furnaced material I obtain a solution of the
mixed sulphides by lixiviation with hot water, which mixed solution I treat
further in the above described manner.
As there are native mixtures of sulphate of strontia and sulphate of baryta
I prefer to use these. I grind this native mixture to a convenient size, add car-
bonaceous matter to the ground material and reduce the same in a furnace at a
high temperature to the state of sulphides in the manner usually practised with the
single sulphate of baryta or the single sulphate of strontia.
On lixiviating this furnaced mass in the usual way I obtain a mixed solution
from which all the strontia crystallises out on cooling, as hydrate of strontia, whilst
the mother liquor contains hydrosulphide of barium,

page_text: 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
The manufacture of hydrate of strontia by the decomposition of sulphide of
strontium by means of sulphide of barium as described.