IMPROVEMENTS IN THE UTILIZATION OF ALKALI- WASTE FROM THE LEBLANC PROCESS IN THE MANUFACTURE OF CARBONATE OF SODA WITH PRODUCTION OF SULPHURETTED HYDROGEN
Year: 1885

page_text: We EDWARD WILLIAM PARNELL of N° 151 Bedford Street South Liverpool in
the County of Lancaster, Chemical Manufacturer and JAMES SIMPSON of No SA
Rumford Place in the same city Alkali Manufacturer, do hereby declare the
nature of the said invention for IMPROVEMENTS IN THE UTILIZATION OF ALKALI-
WASTE FROM THE LEBLANC PROCESS IN THE MANUFACTURE OF CARBONATE OF
SODA WITH PRODUCTION OF SULPHURETTED HYDROGEN," to be as follows:-
In the manufacture of carbonate of soda by the well known ammonia process a
considerable expense is incurred by the use of lime for the liberation of ammonia
from its chloride in the free state for repeated use. The object of our invention is
to dispence with the use of lime, for this purpose and by employing alkali waste
from the Le Blanc process (in which we include waste drainage) in the manner
hereinafter described, to liberate the ammonia in a form available for the manu-
facture of carbonate of soda, and also to produce sulphuretted hydrogen in a
condition available for the manufacture of sulphur or its compounds.
In carrying our invention into practice we preferably heat a mixture of alkali
waste with a solution of the chloride of ammonium produced in the ammonia
process in a closed vessel to a temperature of 212° Fah or upwards when
decomposition takes place chloride of calcium being formed in solution while
sulphide of ammonium will be given off with the steam. In order to avoid loss of
aminonia it is advisable to employ a slight excess of waste.
The same result may
also be obtained by treating the waste with chloride of ammonium cold, and
afterwards heating the solution of sulphide of ammonium. This sulphide of
ammonium vapour is absorbed or condensed in water and employed for the
manufacture of carbonate of soda by being conducted into a solution of chloride
of sodium together with carbonic acid in the same manner as free ammonia alone
is employed in the ordinary manufacture of carbonate of soda by the ammonia
process. In this operation the carbonic acid ultimately combines with the soda,
while the chlorine which was united with the latter combines with the ammonia
forming chloride of ammonium which is used for treating a fresh quantity of waste
and the operation is repeated. The sulphur which passes into the absorbing plant

page_text: with the ammonia is liberated in combination with hydrogen and may after
washing with an acid solution to catch any trace of ammonia be burnt or dealt
with by any of the known methods for the manufacture of sulphur or its
compounds, such as vitriol from sulphuretted hydrogen.
It is manifest that if carbonate of soda be made in about equal quantities by the
above process, and by the Le Blanc process respectively, the sulphur required for
the latter process may be recovered for repeated use or sale while the expense of
removing the alkali waste is avoided, and an offensive nuisance will be almost
entirely obviated. By this arrangement the lime which is produced in the kilns
for supplying carbonic acid to the ammonia process will be available for the
manufacture of bleaching powder or caustic soda, and if vitriol be made from the
sulphuretted hydrogen it can either be sold on account of its purity or employed
for the manufacture of sulphate of soda and production of hydrochloric acid.
Dated the 9th day of January 1885.
J. T. KING,
Per J. Johnson, Agent.

page_text: Improvements in the Utilization of Alkali Waste from the
Le Blanc Process in the Manufacture of Carbonate of Soda
We EDWARD WILLIAM PARNELL of N° 151 Bedford Street South Liverpool in
the County of Lancaster, Chemical Manufacturer, and JAMES SIMPSON of N° 84
Rumford Place in the same City, Alkali Manufacturer, do hereby declare the
nature of our invention for "IMPROVEMENTS IN THE UTILIZATION OF ALKALI
WASTE FROM THE LE BLANC PROCESS IN THE MANUFACTURE OF CARBONATE OF
SODA WITH PRODUCTION OF SULPHURETTED HYDROGEN" and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
In the manufacture of carbonate of soda by the well known ammonia process a
considerable expense is incurred by the use of lime for the liberation in the free
state of ammonia from chloride of ammonium for repeated use. The object of our
invention is to dispense with the use of lime for this purpose and by employing in
its place alkali waste from the Le Blanc process which consists principally of
sulphide of calcium in the manner hereinafter described, to liberate the ammonia
in a form available for the manufacture of carbonate of soda and also to produce
sulphuretted hydrogen in a condition available for the manufacture of sulphur or
its compounds. In referring to alkali waste we include drainage from said waste
usually termed "yellow liquor."
In carrying our Invention into practice we preferably heat a mixture of alkali
waste with a solution of the chloride of ammonium, produced in the ammonia
alkali process, in a closed vessel to a temperature of 212° Fah or thereabouts
when decomposition takes place, chloride of calcium being formed in solution while
sulphide of ammonium will be given off with the steam. The sulphide of
ammonium is not entirely given off in the combined form, the vapors which are
first evolved containing an excess of sulphuretted hydrogen, while the ammonia
predominates at the final stage. We therefore prefer to collect the said sulphuretted
hydrogen in the manner hereinafter described rather than allow it to be absorbed
by coming in contact with the uncombined portion of the ammonia. In order to
avoid loss of ammonia it is advisable to employ a slight excess of waste, before
running off the residue of a batch or of a series of operations.
Sulphide of ammonium vapor may also be obtained by treating the waste with
chloride of ammonium without heat, and boiling the resulting solution of chloride
of calcium and sulphide of ammonium, but this is somewhat inconvenient. This
sulphide of ammonium vapor or mixture of ammonia and sulphide of ammonium
is absorbed or condensed in water or brine and employed for the manufacture of
carbonate of soda by being conducted into a solution of chloride of sodium together
with carbonic acid in the same manner as free ammonia alone is ordinarily employed
in the manufacture of carbonate of soda by the ammonia process.
In this operation the carbonic acid ultimately combines with the soda while the
chlorine which was united with the latter combines with the ammonia forming
chloride of ammonium which is used for treating a fresh quantity of waste and the

page_text: operation is repeated. The sulphur which passes into the absorbing plant with
the ammonia in the form of sulphide of ammonium is liberated in combination with
hydrogen and may after washing with an acid solution to arrest any traces of
ammonia be burnt or dealt with by any of the known methods for the
manufacture of sulphur or its compounds such as vitriol from sulphuretted
hydrogen.
If dilute carbonic acid gas be employed for the manufacture of carbonate of
soda it is manifest that the sulphurette hydrogen given off from the absorbing
plant will be correspondingly weak and under certain circumstances may from this
cause be unsuitable for the manufacture of vitriol with convenience and economy.
We therefore prefer to employ carbonic acid of greater purity or strength than
that ordinarily obtained from lime kilns through which a current of air is allowed
to pass, which strong carbonic acid may be obtained in various ways such for
example as by heating lime stone in retorts without access of air and adding water
spray or steam. But where such supply of strong carbonic acid is not available
we can obtain a large proportion of the sulphur originally contained in the waste
in the form of strong sulphuretted hydrogen by employing the solution of chloride
of ammonium in a dilute form and keeping same in excess of the waste up to the
last charge in the series of operations when it will be necessary to have the waste
slightly in excess to prevent loss of the ammonia remaining in the liquor from
previous charges as previously stated. When a dilute solution of chloride of
ammonium in excess is employed a considerable amount, say 50 per cent of the
sulphur will be given off at an early stage of the decomposition of the waste in
combination with hydrogen uncombined with ammonia and before the latter is
evolved. Later on sulphide of ammonium will be given off, and finally free
ammonia. By passing these vapors or gases as evolved into a condensing
apparatus in which a quantity of water is maintained at a low temperature, the
sulphuretted hydrogen which is given off at the early stage of the decomposition
will pass through; and after washing in an acid solution to arrest any traces of
ammonia may be conducted to a gasometer or other suitable receptacle and
employed for the manufacture of sulphur or sulphur compounds such as vitriol
by any of the well known methods for dealing with sulphuretted hydrogen while
the sulphide of ammonium and ammonia which are given off at a later stage will
be condensed or absorbed by the water in the condenser and will be available for
the manufacture of carbonate of soda by the ammonia alkali process. The passage
between the condenser and the gasometer should be fitted with water locks or
valves to prevent the sulphuretted hydrogen from passing backwards.
In order that our invention may be clearly understood we have appended
hereto a drawing indicating an arrangement of apparatus suitable for carrying our
said invention into practice.
a represents a black ash vat or tank from which the waste is transferred into a
closed vessel b through a hopper d closed with a door e, f perforated bottom on
which the mixture rests, 9 raking out door, h draw off cock. The chloride of
ammonium solution is introduced to the decomposing tank through the hopper d
or in any other convenient manner, i is a steam coil whereby the mixed mass is
heated until decomposition takes place and sulphide of ammonium mixed with
sulphuretted hydrogen and steam is given off. j pipe leading from to the
condenser through which the sulphuretted hydrogen will pass, the sulphide of
ammonium and water vapour being condensed and drawn off through a pipe land
led to ammonia alkali plant to be used in lieu of gaseous ammonia. The
sulphuretted hydrogen then passes through a pipe m to the washing tower n where
the last traces of ammonia will be removed. The sulphuretted hydrogen is then
conducted through the pipe o to the gasometer p whence it is drawn as required to
be utilized in any convenient manner.
It will be obvious that in conducting the operations herein set forth the
construction of the various parts of the apparatus may be varied to a large extent
to suit individual requirement.

page_text: It is manifest that if a works he designed to manufacture carbonate of soda in
about equal quantities by the above process and by the Le Blanc process respectively,
the sulphur required by the latter process may be recovered for repeated use, or
sale, by means of the chloride of ammonium of the former process while the
expense of removing the alkali waste is avoided, and an offensive nuisance will be
almost entirely obviated. By this arrangement the lime which is produced in the
kilns or retorts for supplying carbonic acid to the ammonia alkali process will be
available for the manufacture of bleaching powder or caustic soda, and if vitriol be
made from the sulphuretted hydrogen, it can either be sold on account of its
purity or employed for the manufacture of sulphate of soda and production of
hydrochloric acid,
We wish it to be understood that we do not claim the production of sulphide of
animonium by heating alkali waste and chloride of ammonium, nor do we claim
any improvement in the manner of dealing with sulphuretted hydrogen, for the
manufacture of vitriol or sulphur, for which there are several well known processes,
nor do we limit ourselves to any special modification of the ammonia alkali process.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed we declare that what
we claim is
First. The process herein described for the utilization of alkali waste from the
Le Blanc process (or drainage from said waste) consisting in heating the waste in
a closed vessel with the chloride of ammonium produced in the ammonia alkali
process or heating the sulphide of ammonium produced by treating the waste with
chloride of ammonium without heat, and treating the sulphide of ammonium
vapour which is formed or evolved with carbonic acid and chloride of sodium in
the absorbing plant of the said ammonia alkali process by which reaction the
sulphide of ammonium and chloride of sodium are each decomposed with resulting
products of carbonate of soda and sulphur in combination with hydrogen.
Second. The employment of sulphide of ammonium (produced by treating in
the manner hereinbefore described alkali waste from the Le Blanc process with the
chloride of ammonium produced in the ammonia alkali process) for the decom-
position of chloride of sodium in solution by means of carbonic acid in the manner
described.
Third. Heating alkali waste from the Le Blanc process in a closed vessel with
an excess of a dilute solution of the chloride of ammonium produced in the
ammonia alkali process for the purpose of obtaining a portion of the sulphur in the
form of strong sulphuretted hydrogen in the manner described.
Fourth. Separating sulphuretted hydrogen produced as above described from
ammonia and sulphide of ammonium by passing the gases or vapours of the said
substances into a condensing apparatus and conducting the sulphuretted hydrogen
to a gasometer or other receptacle in the manner described.
Fifth. The above described method of combining the manufacture of carbonate
of soda by the Le Blanc process with the ammonia alkali process so as to recover
the sulphur employed in the form of sulphuretted hydrogen, prevent the accu-
mulation of noxious alkali waste, and obtain increased economy by avoiding the
use of lime.
J. T. KING,
Per J. Johnson, Agent.