Improvements in the Treatment of Sulphide of Calcium for the Purpose of Obtaining Sulphide of Ammonium and Sulphuretted Hydrogen.
Year: 1888

page_text: Date of Application, 25th Feb., 1888
Complete Specification Left, 18th Dec., 1888
Complete Specification Accepted, 22nd Jan., 1889
Improvements in the Treatment of Sulphide of Calcium for the
Purpose of Obtaining Sulphide of Ammonium and Sulphuretted
Hydrogen.
We EDWARD WILLIAM PARNELL and JAMES SIMPSON of SA Rumford Place
Liverpool in the County of Lancaster Manufacturing Chemists, do hereby declare
the nature of this invention to be as follows:-
In our Patent No. 381 we describe a method of treating Sulphide of Calcium with
an excess of a dilute Solution of Chloride of Ammonium for the purpose of obtaining a
large proportion of the Sulphur contained in the sulphide of Calcium in the form of
Sulphuretted hydrogen in preference to obtaining it as Sulphide of Ammonium.
Under certain circumstances however as for example when the Sulphide of Calcium is
cheap and the Chloride of Ammonium is dear it may be desirable to economise the
latter as much as possible and to get the largest possible yield of Sulphur from the
former either as Sulphide of Ammonium or as Sulphuretted hydrogen or as both.
The object of our Invention is to conduct the distillation of Sulphide of Calcium
with the aid of Chloride of Ammonium in a special manner whereby the Sulphur in
the Sulphide of Calcium may be obtained without the necessity of using as much
Chloride of Ammonium as corresponds to the Chemical equivalent of the Sulphide of
Calcium under treatment.
In carrying out our Invention we use an excess of Sulphide of Calcium over the
Chloride of Ammonium employed but we conduct the distilling operation at a
temperature and pressure sufficient to decompose a portion of the Sulphide of Calcium
thereby forming hydrate of Calcium with evolution of Sulpheretted hydrogen. This
may conveniently be done in a distilling column of sufficient height say 45 to 50 feet
the steam being admitted at the bottom and the Ammonium Chloride and Calcium
Sulphide being fed in at the top. The heat and pressure at the bottom of the Still
cause the dissociation of the Sulphide of Calcium which has escaped the action of the
Chloride of Ammonium hydrate of Calcium being precipitated and Sulphuretted

page_text: hydrogen evolved the latter passing upwards through the Sulphide of Calcium which
is being decomposed by the Chloride of Ammonium from which a mixture of Sulphide
of Ammonium and Sulphuretted hydrogen is given off as described in British Patent
38185 aforesaid.
We find that by thus combining the decomposition of Sulphide of Calcium by
means of heat and pressure in one part of the distilling apparatus, with the decompo-
sition of Sulphide of Calcium by Chloride of Ammonium in another part of the same
apparatus it is possible to extract the Sulphur contained in a quantity of Sulphide of
Calcium with about its chemical equivalent of Chloride of Ammonium and with a
minimum cost for fuel and labour.
Dated the out 1
2000

page_text: COMPLETE SPECIFICATION.
Improvements in the Treatment of Sulphide of Calcium for the
Purpose of Obtaining Sulphide of Ammonium and Sulphuretted
Hydrogen.
We, EDWARD WILLIAM PARNELL and JAMES SIMPSON of 8A Rumford Place
Liverpool in the County of Lancaster, Manufacturing Chemists, do hereby declare the
nature of this invention and in what manner the same is to he performed, to be
particularly described and ascertained in and by the following statement :-
In our complete specification No. 381 of the year 1885 we describe a method of
treating Sulphide of Calcium, with an excess of a dilute solution of Chloride of
Ammonium, for the purpose of obtaining a large proportion of the Sulphur contained
in the Sulphide of Calcium, in the form of Sulphuretted hydrogen. Under certain
circumstances, however, as for example when Sulphide of Calcium is cheap and
Chloride of Ammonium is dear it may be desirable to economise the latter and to get
the largest possible yield of Sulphur from the former either as Sulphide of. Ammonium
or as Sulphuretted hydrogen or as both.
The object of our Invention is in conducting the distillation of Chloride of
Ammonium solution by heating it with Sulphide of Calcium, to do so in a special
manner whereby the Sulphur in the Sulphide of Calcium is obtained without the
necessity of using as much Chloride of Ammonium as corresponds to the chemical
equivalent of the Sulphide of Calcium under treatment. By this means an economy
is effected in the quantity of Chloride of Ammonium required for a given yield of
Sulphur.
In carrying our invention into practice we avail ourselves of the fact that Sulphide
of Calcium and water, when subjected to steam pressure at a sufficient temperature
say 300° Fah. or thereabouts, is decomposed with formation of hydrate of Calcium and
the liberation of Sulphuretted hydrogen. The above reaction was described by
Kranshaar in 1878.
Now our invention consists in distilling Chloride of. Ammonium in the presence of
an excess of Sulphide of Calcium and in conducting the said operation in a still of
sufficient height or in a series of stills communicating with each other of sufficient
aggregate height-to give the temperature and pressure necessary for decomposing the
Sulphide of Calcium when steam is passed through the contents of the apparatus.
By this means the Sulphide of Calcium is decomposed not only by the action of the
Chloride of Ammonium but also by the heat and pressure of the steam with
liberation of Sulphuretted hydrogen and Sulphide of Ammonium and a considerable
economy is effected in the cost of the reagents in proportion to the amount of Sulphur
liberated from the Sulphide of Calcium.
We find that by thus combining the decomposition of Sulphide of Calcium by
means of heat and pressure in one part of the distilling apparatus, with the decompo-
sition of Sulphide of Calcium by Chloride of Ammonium in another part of the

page_text: '
same apparatus it is possible to extract the sulphur contained in a quantity of Sulphide
of Calcium with about half its chemical equivalent of Chloride of Ammonium and with
a minimum cost for fuel and labour.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is.
Decomposing Sulphide of Calcium by the combined and simultaneous actions of
Chloride of Ammonium water and steam under pressure in one operation substantially
as set forth for the purpose of obtaining Sulphide of Ammonium and Sulphuretted
hydrogen.