Improvements in Treating the Liquors known as Yellow Liquors Draining from Alkali Waste Heaps to Obtain Sulphuretted Hydrogen and in Apparatus Employed therein.
Year: 1888

page_text: Date of Application, 2nd Mar., 1888
Complete Specification Left, 1st Dec., 1888
Complete Specification Accepted, 8th Jan., 1889
Improvements in Treating the Liquors known as Yellow Liquors
Draining from Alkali Waste Heaps to Obtain Sulphuretted
Hydrogen and in Apparatus Employed therein.
We ALEXANDER MACOMB CHANCE and JAMES FREDERICK CHANCE of Oldbury in the
County of Worcester Alkali Manufacturers do hereby declare the nature of this inven-
tion to be as follows:
--
The yellow liquors which drain from heaps of alkali waste contain a considerable
quantity of sulphydrate of calcium together with poly sulphides of calcium and thio-
sulphate or byposulphite of lime. If these liquors be placed in closed vessels, and
gases containing carbonic acid, such as those evolved from a closed lime kiln, be
pumped or passed through them, the carbonic acid decomposes the sulphydrate and the
polysulphides with evolution of sulphuretted hydrogen and, in the case of the poly-
sulphides, with deposition of sulphur, and since in the decomposition of the sulphydrate
for each equivalent of carbonic acid absorbed two equivalents of sulphuretted hydrogen
are evolved, the issuing gases contain a considerably larger proportion of sulphuretted
hydrogen than the entering gases contained of carbonic acid, and they are suited for
the manufacture of sulphurous and sulphuric acids or of sulphur or for other purposes.
We prefer to pass the gases containing carbonic acid through the liquors contained in
a series of vessels, in order that the carbonic acid may be completely absorbed and
the vessels will be so furnished with pipes and connections that they may be worked in
series in the well known manner, each vessel being capable of being made the first
intermediate or last of the series as may be desired.
:
To obtain an increased proportion of sulphuretted hydrogen in the issuing gases, the
method for the treatment of alkali waste by gases containing carbonic acid described in
our complete specification No. 8666 of the year 1887 may be applied here, and the
apparatus there described employed that is to say. A series of vessels furnished with
pipes and connections as there described may be filled with the liquors, and the gases
containing carbonic acid be pumped or passed through them when the sulphuretted
hydrogen at first reaching the last vessels will be absorbed therein by the polysulphide

page_text: with formation of sulphydrate and deposition of sulphur, so that at first the gases
issuing from the last vessel contain no sulphuretted hydrogen or merely traces thereof,
and may be delivered into the atmosphere directly or through purifiers to free then
from any sulphuretted hydrogen which they may contain. Before the issuing gases
began to contain sulphuretted hydrogen in appreciable quantity, we should close the
outlet from the last vessel, and open that from some one of the intermediate vessels and
conduct away the gases from this outlet so long as they contained sulphuretted hydrogen
in sufficient quantity preferably into a gas holder, and apply them for any convenient
purpose.
When the quantity of sulphuretted hydrogen became too small we should close this
outlet, and having emptied the first vessel or vessels in which the carbonation is completed,
and filled another or others later in the series with fresh liquors we should resume our
operations as at first and so proceed continuously.
By the above treatment we should get rid of, during the first portion of the operation,
a certain quantity of gases other than sulphuretted hydrogen, and should by so much
raise the proportion of this latter in the gases utilized, besides making such proportion
more constant.
The precipitated carbonate of lime will contain some free sulphur, but will otherwise
be very pure.
The process above described may be combined with our process for obtaining
sulphuretted hydrogen from alkali waste described in our complete specification
No. 8666 of the year 1887 by mixing the alkali waste with yellow liquors instead of
with water, and carbonating the two together in the mauner set forth.
Dated thin thi
1000

page_text: Improvements in Treating the Liquors known as Yellow Liquors
Draining from Alkali Waste Heaps to Obtain Sulphuretted
Hydrogen and in Apparatus Employed therein.
We ALEXANDER MACOMB CHANCE, and JAMES FREDERICK CHANCE, of Oldbury, in
the County of Worcester Alkali Manufacturers, 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:-
The yellow liquors which drain from heaps of alkali waste contain a considerable
quantity of sulphydrate of calcium together with polysulphides of calcium and thiosul-
phate or hyposulphite of lime.
If these liquors are placed in closed vessels, and gases containing carbonic acid, such
as those evolved from a closed lime kiln are pumped or passed through them, the
carbonic acid decomposes the sulphydrate and the polysulphides with evolution of
sulphuretted hydrogen and, in the case of the polysulphides with deposition of sulphur,
and since in the decomposition of the sulphydrate for each equivalent of carbonic acid
absorbed two equivalents of sulphuretted hydrogen are evolved, the issuing gases
contain a considerably larger proportion of sulphuretted hydrogen than the entering
gases contained of carbonic acid, and such issuing gases are suited for the manufacture
of sulphurous and sulphuric acids or of sulphur or for other purposes.
We prefer to pass the gases containing carbonic acid through the liquors contained
in a series of vessels, in order that the carbonic acid may be completely absorbed : and
the vessels will be so furnished with pipes and connections that they may be worked in
series in the well known manner, each vessel being capable of being made the first
intermediate or last of the series as may be desired.
To obtain an increased proportion of sulphuretted hydrogen in the issuing gases the
method for the treatment of alkali waste by gases coutaining carbonic acid described
in our complete specification No. 8666 of the year 1887 may be applied here, and the
apparatus there described employed, that is to say: a series of vessels furnished with
pipes and connections as there described may be filled with the liquors, and the gases
containing carbonic acid be pumped or passed through them when the sulphuretted
hydrogen at first reaching the last vessels will be absorbed therein by the polysulphides
with formation of sulphydrate and deposition of sulphur, so that at first the gases issuing
from the last vessel contain no sulphuretted hydrogen or merely traces thereof and
may be delivered into the atmosphere directly or through purifiers to free them from
any sulphuretted hydrogen which they may contain. Before the issuing gases begin
to contain sulphuretted hydrogen in appreciable quantity we close the outlet from the
last vessel and open that from some one of the intermediate vessels and conduct
away the gases from this outlet so long as they contain sulphuretted hydrogen in
sufficient quantity, preferably into a gasholder, and apply them for any convenient
purpose.

page_text: When the quantity of sulphuretted hydrogen becomes too small we close this outlet,
and having emptied the first vessel or vessels in which the carbonation is completed
and filled another or others later in the series with fresh liquors, we resume our opera-
tions as at first and so proceed continuously.
By the above treatment we get rid, during the first portion of the operation of a
certain quantity of gases other than sulphuretted hydrogen, and by so much raise the
proportion of this latter in the gases utilized, besides making such proportion more
constant.
The precipitated carbonate of lime will contain some free sulphur, but will otherwise
be very pure.
The process above described may be combined with our process for obtaining
sulphuretted hydrogen from alkali waste described in our complete specification No. 8666
of the year 1887 by mixing the alkali waste with yellow liquors instead of with water,
and carbonating the two together in the manner set forth.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.
First. Obtaining sulphuretted hydrogen from yellow liquors by the treatment
substantially as herein set forth.
Second. In treating yellow liquors to obtain sulphuretted hydrogen separating the
sulphuretted hydrogon from other gases substantially as set forth.
Third Treating yellow liquors and alkali waste in combination to obtain sulphuretted
hydrogen substantially as set forth.
Fourth. Apparatus for obtaining sulphuretted hydrogen from yellow liquors or
yellow liquors and alkali waste combined substantially as set forth.
Dated this 30th day of November 1888.