Copperpyrites, Zincblende, and other Metallic Sulphides.
Year: 1887

page_text: Copperpyrites, Zincblende, and other Metallic Sulphides.
I, CARL FRIEDRICH CLAUS, of Merton Road, South Wimbledon, in the County
of Surrey, Chemist, do hereby declare the nature of my said invention to be as
follows:
Ironpyrites, copperpyrites, zincblende and other metallic sulphides are broken into
pieces of a suitable size and charged into a deep kiln, chamber or the like receptacle.
Such kilns are built of brick-work and are covered with iron plates.
Highly superheated steam is passed through this deep layer of pyrites. The super-
heating of the steam is effected in apparatus like or similar to those used for
producing hot blast for blast furnaces, a construction similar to that known as
Whitwells being preferred.
The effect of the superheated steam on the pyrites which are bisulphides or may be
sesquisulphides, is that the greatest part of one equivalent of sulphur is expelled in
the form of sulphur vapour. When they have become reduced to monosulphide or
when they are monosulphides such as zincblende to begin with, the further effect
of the superheated steam upon the sulphides is to form sulphide of hydrogen gas.
At various altitudes or in various parts of the length of the kiln, apertures are
provided, through which regulated quantities of atmospheric air, are injected or
admitted into the kiln, to mix with the sulphide of hydrogen. Free sulphur is thereby
produced which is carried away by the residual gases and conveyed into depositing
chambers from which it is collected.
The quantity of air so admitted should not be greater than is necessary for the
oxygen in the same to form water with the hydrogen of the sulphide of hydrogen passing
through the kiln at the time or as nearly so as it is possible to practice.
The admission of superheated steam into the kiln should also be so regulated, that
as little as possible of undecomposed water passes out of the kiln.
The passage of the superheated steam and the air through the kiln may be from
the bottom upwards or from the top downwards as may be found most useful.
If the metallic sulphides contain arsenic or other metals volatile under the existing
conditions, their separate collection in the depositing chamber for the sulphur, should
be provided for in a suitable manner.

page_text: At the bottom of the kiln is a door for discharging the spent pyrites or other
residual oxides. An aperture for the outlet from the kiln of the volatile products of
the operation described into the depositing chamber is also provided. The air
admitted into the kiln may also be heated in a blast heating stove previous to its
entering the kiln.
In smelting works where there is an abundance of waste heat the heating of the
steam or air heating stove may be carried out by means of it.
The kiln or chamber used in the process described may be a vertical erection or it
may be horizontal. In the latter case it may be subdivided into compartments
similarly in principle to the so called annular brickkilns. It is however not necessary
that it should be actually annular, but may be, as some modifications of these kilns
are, of a rectangular form, the term annular in that case signifying more the working
of the various compartments in rotation.

page_text: Copper Pyrites, Zinc Blende, and other Metallic Sulphides.
I CARL FRIEDRICH CLAUS of Merton Road South Wimbledon in the County of
Surrey Chemist, do hereby declare the nature of my said invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
Iron pyrites, copper pyrites zinc blende and other metallic sulphides are broken
into pieces of a suitable size and charged into a deep kiln chamber or the like
receptacle. Such kilns are built of brick work and are covered with iron plates.
Highly superheated steam either alone or mixed with heated air is passed through
this deep layer of pyrites from the top downwards that is to say it passes first through
the ore last charged downwards through the ore partly or fully burned. The super-
heating of the steam and air is effected in apparatus like or similar to those used for
producing hot blast for blast furnaces a construction, similar to that known as
Whitwells" being preferred.
The effect of the superheated steam on the pyrites which are bi-sulphides or may
be sesqui sulphides, is that part of the sulphur is expelled in the form of Sulphur
vapour. When they have become reduced to monosulphide or when they are
monosulphides such as zinc blende to begin with the further effect of the superheated
steam upon the sulphides is to form sulphide of hydrogen gas.
At various heights or in various parts of the length of the kiln, apertures are
provided through which regulated quantities of atmospheric air are injected or
admitted into the kiln, to mix with the sulphide of hydrogen. Or a portion of the
steam may be admitted along with the air through the apertures referred to and used
for injecting the air into the various parts of the kiln. Free sulphur is thereby
produced which is carried away by the residual gases and conveyed into depositing
chambers from which it is collected.
The quantity of air so admitted should not be greater than is necessary for the
oxygen in the same to form water with the hydrogen of the sulphide of hydrogen
passing through the Kiln at the time or as nearly so as it is possible in practice.
The admission of superheated Steam into the kiln should also be so regulated that
as little as possible of undecomposed water passes out of the kiln.
The fresh ores are fed in at the top of the kiln through a charging door or by
means of a bell cover such as are used in blast furnaces there is also at the bottom of
the kiln a door for discharging the spent pyrites or other residual oxides-An aperture
for the outlet from the kiln of the volatile products of the operation described into the
depositing chamber is also provided near the bottom of the kiln. The air admitted
into the Kiln may also be heated in a blast heating stove previous to its entering
the kiln.
In smelting works where there is an abundance of waste heat the heating of the
steam or air heating stove may be carried out by means of it.

page_text: The kiln or chamber used in the process described may be a vertical erection or it
may be horizontal. In the latter case it may be subdivided into compartiments
similarly in principle to the so called annular brick kilns. It is however not necessary
that it should be actually annular, but may be, as some modifications of these kilns are,
of a rectangular form, the term annular in that case signifying more the working of
the various compartments in rotation. Each of such compartments is connected with
the adjoining ones by means of flues which can be closed by dampers and can be
disconnected from the rest for charging or discharging. Each compartment is
further provided with an opening into the sulphur depositing chamber which opening
can also be closed by means of dampers. The heated air and superheated steam
enters the one last charged with fresh ore and passes on from one compartment to
another until it passes out of the one first charged which is connected with the
remainder. From it the sulphur vapour and residual gases pass into the sulphur
depositing chamber.
:
Portions of the heated air and heated steam may be admitted into all or any of the
intermediary compartments.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. Obtaining free sulphur from the sulphide of hydrogen produced from iron and
copper pyrites and other metallic sulphides by passing heated steam or heated steam
and air through the same and by admitting a further quantity of air whereby free
sulphur is produced substantially as described.
2. Heating the steam and air for the purpose aforesaid in a similar manner to that
used in heating the blast for blast furnaces on the regenerative principle.
3. Passing heated steam and heated air through one or more kilns in the direction
from the last charge of ore to the first charge of ore in the kiln or kilns in actual
operation substantially as described.
Dated 19th Mauch 1000