IMPROVEMENTS IN THE EXTRACTION OF SULPHUR COMPOUNDS FROM ALKALI WASTE
Year: 1883

page_text: LETTERS PATENT to James Simpson of Liverpool in the County of Lancaster
Manufacturing Chemist for an Invention of IMPROVEMENTS IN THE
EXTRACTION OF SULPHUR COMPOUNDS FROM ALKALI WASTE
(via vy reason of the Patentee having neglected to file a Specification in
pursuance of the conditions of the Letters Patent.)
PROVISIONAL SPECIFICATION left by the said James Simpson at the Office
of the Commissioners of Patents on the 24th July 1883.
JAMES SIMPSON of Liverpool in the County of Lancaster Manufacturing Chemist
"IMPROVEMENTS IN THE EXTRACTION
WASTE
The objects of our invention are
OF SULPHUR COMPOUNDS FROM ALKALI
First. To operate with suitable reagents in a cheap and convenient manner on
the sulphur compounds existing in Alkali waste, so as to convert them into a
solution and,
Second. To separate the said solution so produced from the residue.
My invention consists in
A Subjecting waste and a solution containing Hyposulphite of Lime or sulphurous
acid to the direct action of steam pressure in a closed vessel constructed substantially
as hereinafter setforth whereby a high temperature is attained and the sulphur
compounds in the alkali waste are to a large extent converted into a soluble form.
dissolving in the Hyposulphite or Sulphurous acid solution, and
B In drawing off the solution so produced downward through the residue or
insoluble portion of the waste. It is manifest that if partially oxydized waste be
operated upon the required solution containing Hyposulphite of Lime may be
formed in the closed vessel itself by the addition of water alone.
The process above described is most conveniently carried on in apparatus
consisting of a closed vessel fitted with a false bottom of perforated material, and
having the necessary arrangements for charging, stirring and discharging the
ГРmion 921

page_text: waste; as also a steam pipe fitted with a tap, and a valve arrangement for drawing
off the solution from underneath the false bottom. The apparatus described in
the specification to British Patent 73983 is. specially adapted for conducting the
operation.
In practice we prefer to conduct the operation as follows:-
:-
65
The pressure apparatus for treating the waste should be erected as close to the
. Black ash vats, or to the waste heap as convenient in order that the waste may be
operated upon with as little manual labor as possible. The "Yellow liquor"
drainage from the waste heaps which is usually a nuisance and cause of annoyance
in the neighbourhood of alkali works is pumped into a large deep-vessel preferably
of cylindrical, shape fitted with a Kortings blower" or steam jet apparatus for
injecting air into the liquor. A perforated false bottom or grating may be
employed for dispersing the current of air. When the "yellow liquor" has been
sufficiently oxydized by the action of the air, it is run into the pressure-apparatus
with a quantity of waste, the charging door is then closed the steam is turned on
and after the charge has been sufficiently treated or digested the steam is turned
off the tap underneath the false bottom is opened and the sulphur liquor is run off
to a convenient receptacle for treatment by any known process such as
A. For the precipitation of sulphur by partial oxydation and treatment with
muriatic acid. or
B The production of precipitated sulphur and sulphuretted hydrogen by the
addition of acid without previous oxydation of the liquor.
The sulphuretted hydrogen may be used for the manufacture of vitriol by burning
it in suitable kilns and treating the resulting sulphurous acid in the usual well
known manner; or it may be burned with a limited supply of air for the production
of flour sulphur and any residue arising from imperfect working passed into the
kilns above mentioned or into pyrites burners for the manufacture of vitriol.
When the sulphur liquor is to be treated with acid it should previously be freed
from hydrate of lime by subsidence and decantation.
If the supply of "Yellow liquor" drainage is insufficient some of the sulphur
liquor from the pressure apparatus with water added, may be used in its stead in
the oxydizing vessel; or, a solution of sulphurous acid in water made by any
convenient method, such as by burning pyrites can be employed in place of the
Hyposulphite of lime solution.
The oxydation of the "Yellow liquor" in the blowing vessel can be facilitated
by the addition of some per oxide of manganese, such as is known by the name of
"Weldon mud."
I am aware that the solvent action at high temperatures of Hyposulphite of Lime
on the sulphur compounds in alkali waste is known; as also that "Yellow liquor"
may be oxydized by injecting air and steam with or without the addition of
manganese.