Improvements in the Extraction of Tin and other Products from the Refuse Slags and Debris of Tin Smelting Furnaces.
Year: 1892

page_text: Date of Application, 1st Feb., 1892
Complete Specification Left, 28th Oct., 1892-Accepted, 17th Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Extraction of Tin and other Products from
the Refuse Slags and Debris of Tin Smelting Furnaces.
I, WILLIAM MUIB of 5 Angel Place Edmonton and of 8 St. Benet Place
Gracechurch Street E.C. London Merchant do hereby declare the nature of this
invention to be as follows:-
I take the tin slags or debris above mentioned and break them into small pieces
and mix them with ferrous chloride or ferric chloride or calcium chloride or
chloride of lime or magnesium chloride or any mixture of two or more of these
chlorides in excess and fuse them in a retort of any suitable material over a fire.
The metal of the chloride or chlorides combines with the silica in the slag or debris
and the chlorine of the chloride or chlorides combines with the tin tungsten iron
antimony and arsenic in the slag or debris to form volatile chlorides which I collect
in a receiver or condenser fitted to the retort. I then dissolve these mixed chlorides
in acidulated water or separate them by fractional distillation and extract the
metal from the chloride of tin by any method 1 please, and from the other chlorides
also if I choose.
1000
COMPLETE SPECIFICATION.
Improvements in the Extraction of Tin and other Products from
the Refuse Slags and Debris of Tin Smelting Furnaces.
I, WILLIAM MUIR, of 5 Angel Place, Edmonton, in the County of Middlesex,
and of 8 St. Benet Place, Gracechurch Street, London, Merchant, 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:-
I take the tin slags or debris of tin smelting furnaces, break them into small
pieces, or grind them to powder and mix them when so broken, or ground, with
ferrous chloride, ferric chloride, calcium chloride, chloride of lime (usually called
bleaching powder) or magnesium chloride, or with a mixture of two or more of
these chlorides. Í then put this mixture of broken or ground slag and chloride or
chlorides into a retort or into a reverberatory or other suitable furnace heated
in any suitable way and to any suitable degree.
The metals which it is desired to extract are tin, tungsten, antimony and arsenic
or any one or more of them and they (or any one or more of them) exist in the said
slags or debris as oxides combined with silica and when the mixture of slags
or debris and chloride or chlorides is subjected to heat as above described, the
metal of the chloride or chlorides combines with the oxygen of the said oxides and
also with the said silica in the slag or debris, and the chlorine of the chloride or
chlorides combines with the tin, tungsten, antimony and arsenic or with any one or
more of these metals that may be present and with some of the iron of the slags
or debris, forming volatile chlorides of those metals, which volatile chlorides
I collect in a receiver or condenser connected with the retort or furnace.
I then dissolve these mixed chlorides of tin, tungsten, antimony, arsenic and iron,
or any one or more of them that may be present, in water which may or may not
be acidulated (with hydrochloric acid for example) and I then treat this solution
with suitable reagents to precipitate separately the metals or their sulphides,
[Price 8d1

page_text: oxides or other insoluble compounds, and these may be sold in that form, or
the sulphides, oxides or other compounds may be subjected to other known processes
for the extraction of the metal therefrom. Or, if preferred, the mixed chlorides,
instead of being dissolved as above described, may be separated from each other, as
far as practicable, by fractional sublimation and sold as chlorides or they may be
further subjected to known processes for the extraction of the metals therefrom.
The quantity of chloride or chlorides to be mixed with the slags or debris varies
according to the composition of the slag or debris and must be determined for each
particular case by experiment, the object being to extract as much as possible of
the tin, tungsten, antimony and arsenic, and as little as possible of the iron that is
generally present in the slags or debris. But I have found, for example, that
in treating slag or debris containing 5.7 per cent. of tin, 30 per cent. of iron and a
trace of tungsten, I have obtained good results by mixing 100 lbs. of the broken or
ground slag or debris with 10 lbs. of chloride of calcium.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. In the extraction of tin, tungsten, antimony, arsenic and other products in
the form of chlorides from the refuse slags or debris of tin-smelting furnaces, the
improvement which consists in mixing broken or ground slags and debris with
a chloride or chlorides, heating the mixture in a retort or furnace and collecting
the resulting volatile chlorides of tin, tungsten, antimony and arsenic, or any one
or more of them that may be present, in a receiver or condenser substantially as
herein before described.
Second. The production of a chloride of tin, tungsten, antimony or arsenic from
the refuse slags and debris of tin-smelting furnaces by treating such slags and
debris with the chloride of another metal, or with the chlorides of two or more
other metals, substantially as hereinbefore described.
Third. The method or process for extracting tin, tungsten, antimony and arsenic
from the refuse slags aud debris of tin-smelting furnaces which consists in first
obtaining chlorides of those metals by mixing the slags or debris with the chlorides
of other metals, heating in a retort or furnace and collecting the resulting volatile
chlorides in a receiver or condenser, then in separating the said chlorides from each
other by any suitable known means, and subsequently extracting the metals from
such separated chlorides by any suitable known process substantially as herein before
described.
Dated this 28th day of October 1892.