Improvements in the Manufacture of Hydrates of Barium and Strontium.
Year: 1887

page_text: Date of Application, 1st Mar., 1887
Complete Left, 1st Dec., 1887
Complete Accepted, 6th Jan., 1888
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Hydrates of Barium and
Strontium.
I HUGH LEE PATTINSON Junior of Felling on Tyne in the County of Durham
Chemical Manufacturer do hereby declare the nature of this invention to be as
follows:-
In the Specification of a former invention for which Letters Patent were granted
to me No. 16989 of 1884 I described a process of manufacturing hydrates of barium
and strontium in the course of which I obtained a liquor containing hydrate and
tersulphide of barium or strontium which I crystallized,so as to obtain hydrate, of
barium or strontium which was wetted with a solution of tersulphide. I washed the
crystals with water to remove the tersulphide adhering to them, the crystals being
for this purpose either allowed to drain or being washed in a hydro extractor. I then
redissolved the washed crystals in hot water and either crystallized them again or I
blew in air to remove the last traces of sulphur and I then recrystallized.
Now according to the present invention I remove the sulphur from crystals of
hydrates of barium or strontium by washing the crystals with cold water in either of
the ways hereinafter described. According to the first way I employ a series of tanks
arranged so that the bottom of the first communicates with the top of the second, the
bottom of the second with the top of the third and so on like the black ash tanks used
in the ordinary Leblanc process of soda making. The liquor from one tank which
has been almost exhausted of sulphides goes on to the next tank with a considerable
quantity of sulphides in it; the solvent powers of the water so far as sulphides are
concerned are thus fully utilized while as the water is cold the minimum quantity of
barium or strontium hydrate is dissolved whereas when the crystals are washed in a
hydro-extractor the water used is not fully charged with sulphides and consequently
dissolves too much hydrate. According to the second way I employ cylindrical tanks
agitated mechanically so that the barium or strontium hydrate is kept stirred up in
the water. The cylinders are filled from the bottom and have a filtering arrangement
at the top through which the water passes out, the solid particles being left behind.
The water is put in at a slight pressure and is thus made to circulate through the

page_text: cylinders. When a cylinder is ready to be emptied I put air pressure on the top and
force the magma of water and hydrate up into filters where the hydrate is drained.
The crystals thus obtained may either be hydro extracted to get rid of the water or
dried by heat, the latter way being preferred as less expensive.
The liquor at the end of the operation is tersulphide of barium or strontium
together with a little hydrate. In order to obtain the latter I concentrate the liquor
by heat and then cool down so as to separate the hydrate crystals. The tersulphide
liquor need not therefore be returned to the tanks.
Dated this binst dose of Mana 1997

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Hydrates of Barium and
Strontium.
I HUGH LEE PATTINSON, Junior, of Felling on Tyne, in the County of Durham,
Chemical Manufacturer, 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 :-
In the Specification of a former invention for which Letters Patent were granted
to me, No. 16,989 of 1884, I described a process of manufacturing hydrates of barium
and strontium in the course of which 1 obtained a liquor containing hydrate and
tersulphide of barium or strontium which I crystallized so as to obtain hydrate of
barium or strontium which was wetted with a solution of tersulphide. I washed the
crystals with water to remove the tersulphide adhering to them, the crystals being for
this purpose either allowed to drain or being washed in a hydro-extractor. I then
redissolved the washed crystals in hot water and either crystallized them again or I
blew in air to remove the last traces of sulphur and I then recrystallized.
Now according to the present invention I remove the sulphur from crystals of
hydrates of barium or strontium by washing the crystals with cold water in any of
the ways hereinafter described. According to the first way I employ a series of tanks
arranged so that the bottom of each tank communicates with the top of the next tank
and so on throughout the series like the black ash tanks used in the ordinary Leblanc
process of soda making. As the liquor or water from one tank which has been almost
exhausted of sulphides goes on to the next tank which has a considerable quantity of
sulphides in it, the solvent powers of the water so far as sulphides are concerned are
fully utilized while as the water is cold the minimum quantity of barium or strontium
hydrate is dissolved whereas when the crystals are washed in a hydro-extractor the
water used is not fully charged with sulphides and consequently dissolves too much
hydrate. According to the second way I employ cylindrical tanks agitated
mechanically so that the barium or strontium hydrate is kept stirred up in the water.
The cylinders are filled at the bottom or top and have a filtering arrangement at the
top or bottom through which the water passes out, the solid particles remaining
behind. The water is made to traverse the cylinder; if it enters by the top it leaves
by the bottom and vice versa. The water is put in at a slight pressure and is made
to circulate through the series of cylinders; it becomes more and more charged with
sulphide as it passes through the successive cylinders. When a cylinder is ready to
be emptied I put air pressure on the top (which is tight) and force the magma of
water and hydrate up into filters where the hydrate is drained. The crystals thus
obtained may either be hydro-extracted to get rid of the water or dried by heat, the
latter way being preferred as less expensive.
Experience has however shown me that the filtration either upward or downward
of a magma in agitation is very slow if solid matter is to be excluded from the
filtrate; in order to hasten or facilitate the operation I find it advantageous to place

page_text: In
over the agitating cylinders (which in this case are not fitted with a filtering arrange-
ment) an equal number of tanks with filtering apparatus at the bottom and cocks at
the sides. The contents of the first cylinder containing the most impure crystals are
forced into the first filter and the liquor from this is either decanted or filtered away
or both.
This liquor being considerably charged with sulphides is not returned to
the process.
The wet crystals however thus improved are transferred to the second
cylinder, washed and then forced into the second filter whence the liquor flows into
the first cylinder to assist in the washing of crude crystals while the crystals of the
second cylinder are after subsidence transferred to the third cylinder and so on.
the last cylinder the washing agent is fresh water. If the sulphur is found not to
be sufficiently reduced by feeding one cylinder of the series with fresh water two or
more of the cylinders may be so fed; and for each cylinder supplied with fresh water
the impure liquor from another cylinder must cease to he employed in the process.
By this method the filtering takes place while the magma is not in agitation while the
sulphur is removed with the minimum of water. It will thus be seen that the crystals
undergo successive improvements at each washing and I generally find that after four
washings they are sufficiently pure for all practical purposes.
The liquor at the end of the operation is tersulphide of barium or strontium together
with a little hydrate. In order to obtain the latter I concentrate the liquor by heat
and then cool down so as to separate the hydrate crystals. The tersulphide liquor need
not therefore be returned to the tanks.
my
Having now particularly described and ascertained the nature of said
Invention, and in what manner the same is to be performed, I declare that what I
claim, in respect of the manufacture of hydrates of barium and strontium, is :-
1. The process or method of removing sulphur from crude crystals of hydrates of
barium or strontium, which consists in washing them with cold water in a succession
of operations, the water travelling in one direction during the process and the crystals
improving inversely, as set forth.
2. The process or method of removing sulphur from crude crystals of hydrates of
barium or strontium, which consists in washing them with cold water in a series of
tanks, like those employed in the Leblanc process of soda making, the water travelling
in one direction from tank to tank during the process and the crystals improving
inversely, as set forth.
3. The process or method of removing sulphur from crude crystals of hydrates of
barium or strontium, which consists in washing them with cold water in a succession of
operations in a series of tanks agitated mechanically and fitted with filters through
which filtration takes place during agitation, the water travelling from tank to tank
during the process, as set forth.
4. The process or method of removing sulphur from crude crystals of hydrates of
barium or strontium which consists in washing them with cold water in a succession of
operations in a series of cylinders or tanks having filter-tanks above them, the water
during the process travelling in one direction from cylinder to cylinder through an
intermediate filter-tank and the crystals proceeding in the reverse direction, as set
forth.
5. The method of moving the masses of crystals and magma by forcing them from
the bottom of the tank or vessel in which they are agitated by means of air pressure
on the top of the tank which in this case is tight at the top, as set forth.
J. C. MEWBURN,
169, Fleet Street, London,
Agent.