of Baryta.
Year: 1886

page_text: of Baryta.
I, JAMES MACTEAR, of No 2 Victoria Mansions, in the City of Westminster,
Chemist, do hereby declare the nature of this 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 :-
This Invention has for its object the production of the hydrates of strontia and
baryta in an improved and satisfactory manner; also the utilisation of certain bye
products obtained in the manufacture of hydrates of strontia and baryta.
In carrying out my Invention I take sulphate of strontia (or of baryta) and
mix it with rather more than the chemically equivalent quantity of sulphate of
soda, and also with carbonaceous or other reducing matter. T'bis mixture is
heated in a furnace to decompose the sulphates of strontia (or baryta) and soda and
reduce them as completely as possible to sulphides. I then dissolve the resulting
mixed sulphide of strontium (or barium) and sodium in hot water, and crystallise
out the hydrate of strontia (or of baryta).
If the reduction has been carefully made the result is that the whole of the
soluble sulphide of strontium (or of barium) is decomposed by the sulphide of
sodium with the consequent production of hydrate of strontia (or of baryta) and
of hydrosulphide of sodium which latter remains in the mother liquor after the
hydrate has been crystallised out. Some polysulphide compounds are also formed
in small amount but these may be neglected.
In some cases it may be found preferable to reduce the sulphate of strontia (or
of baryta) and the sulphate of soda separately to the state of sulphide and after
dissolving them in water, to mix the solutions of the sulphides in such proportion
as will give a slight excess of the sulphide of sodium over the chemical equivalent,
the solution should be by preference, kept hot and if needed may be evaporated
to such a state of concentration as will give the largest yield of crystals of the
hydrate of strontia (or of baryta).
The remaining mother liquor consisting chiefly of hydrosulphide of sodium, may
be boiled down and the residue used again in reducing another batch of sulphate
of strontia (or of baryta) with carbonaceous matter or other reducing material.
In the process of manufacturing the hydrates of strontia (or of baryta) hitherto
employed in which the sulphide of strontium (or of barium) is split up by solution

page_text: into bydrate and hydrosulphide of strontium (or of barium) the mother liquor
which contains the bydrosulphide of strontium (or of barium) is a bye product, and
I utilise this bye product by mixing it with a solution of sulphide of sodium in
quantity rather more than the chemical equivalent; obtaining as a result hydrate
of strontia (or of baryta) and hydrosulphide of sodium, the hydrate being separated
by crystallisation. The remaining mother liquor containing the hydrosulphide of
sodium may be evaporated and used as herein before described with a fresh batch
of sulphate of strontia (or of baryta).
Sulphate of potash may be used instead of sulphate of soda bub the latter is to
be preferred on account of its lower cost.
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 -
1. The obtaining of the hydrate of strontia or of baryta by reducing a mixture
of the sulphate of strontia or of baryta and the sulphate of soda or of potash to
sulphides and by the solution and the decomposition of such sulphides into the
required hydrate, and hydrosulphide of sodium or potassium substantially as
herein before described.
.
2. The obtaining of the hydrate of strontia or of baryta by mixing a solution of
the sulphide thereof with a solution of sulphide of sodium or of potassium the
resulting decomposition yielding the required hydrate, and hydrosulphide of sodium
or potassium, substantially as herein before described.
3. The decomposing of the hydrosulphide of strontium or of barium by mixing a
solution thereof with a solution of sulphide of sodium or of potassium substantially
as hereinbefore described.
i
4. The using of the hydrosulphide of sodium or of potassium together with
carbonaceous matter in reducing the sulphate of strontin or of baryta for the
purpose of obtaining the hydrate substantially as herein before described.
Dated this thirteenth day of Anril 1886
EDMUND HUNT,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Hydrates of Strontia and
of Baryta.
I, JAMES MACTEAR, of N° 2 Victoria Mansions, in the City of Westminster,
Chemist, do hereby declare the nature of this 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 :-
This Invention has for its object the production of the hydrates of strontia and
baryta in an improved and satisfactory manner; also the utilisation of certain bye
products obtained in the manufacture of hydrates of strontia and baryta.
In carrying out my Invention I take sulphate of strontia (or of baryta) and
mix it with rather more than the chemically equivalent quantity of sulphate of
soda, and also with carbonaceous or other reducing matter. This mixture is
heated in a furnace to decompose the sulphates of strontia (or baryta) and soda and
reduce them as completely as possible to sulphides. I then dissolve the resulting
mixed sulphide of strontium (or barium) and sodium in hot water, and crystallise
out the hydrate of strontia (or of baryta).
If the reduction has been carefully made the result is that the whole of the
soluble sulphide of strontium (or of barium) is decomposed by the sulphide of
sodium with the consequent production of hydrate of strontia (or of baryta) and
of hydrosulphide of sodium which latter remains in the mother liquor after the
hydrate has been crystallised out. Some polysulphide compounds are also formed
in small amount but these may be neglected.
In some cases it may be found preferable to reduce the sulphate of strontia (or
of baryta) and the sulphate of soda separately to the state of sulphide and after
dissolving them in water, to mix the solutions of the sulphides in such proportion
as will give a slight excess of the sulphide of sodium over the chemical equivalent,
the solution should be by preference, kept hot and if needed may be evaporated
to such a state of concentration as will give the largest yield of crystals of the
hydrate of strontia (or of baryta).
The remaining mother liquor consisting chiefly of hydrosulphide of sodium, may
be boiled down and the residue used again in reducing another batch of sulphato
of strontia (or of baryta) with carbonaceous matter or other reducing material.
In the process of manufacturing the hydrates of strontia (or of baryta) hitherto
employed in which the sulphide of strontium (or of barium) is split up by solution

page_text: into hydrate and hydrosulphide of strontium (or of barium) the mother liquor
which contains the hydrosulphide of strontium (or of barium) is a bye product, and
I utilise this bye product by mixing it with a solution of sulphide of sodium in
quantity rather more than the chemical equivalent; obtaining as a result hydrate
of strontia (or of baryta) and hydrosulphide of sodium, the hydrate being separated
by crystallisation. The remaining mother liquor containing the hydrosulphide of
sodium may be evaporated and used as herein before described with a fresh batch
of sulphate of strontia (or of baryta).
Sulphate of potash may be used instead of sulphate of soda but the latter is to
be preferred on account of its lower cost.
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 I do not
claim the operations forming the subject matter of claims 1 and 2 hereof when the
sulphide of sodium used is obtained under the conditions specified in claim 2 of
Trachsel's application 3406/86 but what I claim is
:-
1. The obtaining of the hydrate of strontia or of baryta by mixing a solution of
the sulphide thereof with a solution of sulphide of sodium or of potassium the
resulting decomposition yielding the required hydrate, and bydrosulphide of sodium
or potassium, substantially as hereinbefore described.
2. The decomposing of the hydrosulphide of strontium or of barium by mixing a
solution thereof with a solution of sulphide of sodium or of potassium substantially
as hereinbefore described.
3. The using of the hydrosulphide of sodium or of potassium together with
carbonaceous matter in reducing the sulphate of strontia or of baryta for the
purpose of obtaining the hydrate substantially as hereinbefore described.
Dated this Thirteenth day of Anril 1886
EDMUND HUNT,
Applicant's Agent.