Improvements in the Recovery of Zinc from Zinciferous Slags or Residues.
Year: 1898

page_text: Date of Application, 28th Feb., 1898
Complete Specification Left, 26th Nov., 1898-Accepted, 28th Jan., 1899
PROVISIONAL SPECIFICATION.
Improvements in the Recovery of Zinc from Zinciferous Slags or
Residues.
We, HENRY ERNEST FRY, of Billiter Buildings, Billiter Street, in the City of
London, Mineral Merchant, and ROBERT ADDIE, of Llansamlet, South Wales,
Works Manager, do hereby declare the nature of this invention to be as
follows:-
According to this invention the slags or zinciferous materials are mixed with
carbonaceous materials preferably non-bituminous coal, or coke, the carbonaceous
material being preferably in a fine state of division. The whole is charged into
a regenerative gas fired furnace preferably of the Siemens type, the
furnace hearth or bottom being composed of a material, neutral or basic capable
of withstanding the action of the basic slag, or should the zinciferous material be
acid, an acid or neutral bottom should be put in; for treating basic zinciferous
slags, a basic bottom is preferably used consisting of calcined ground dolomite
mixed with anhydrous tar as a binding material, and the bottom must preferably
have a neutral division between the acid brickwork of the furnace and the basic
bottom, the material usually employed being chrome ore, containing a high per-
centage of sesquioxide of chromium. The gas and air ports of the furnace,
valves, regenerator spaces, flues, etc., are of specially large area in order to
prevent choking and deal with the increased volume of fumes over and above
that from the combustion of the gases from the coal used for heating purposes.
The charge is melted down at a fairly high heat the bulk of the zinc being
eliminated during the melting period. After melting the charge is well stirred
or rabbled at intervals to promote further elimination of the zinc, or it may in
addition and preferably so be stirred with green wood poles for the same purpose.
After the zinc has been eliminated as far as desired as shewn by the fumes
of ZnO becoming less dense the molten slag may be tapped out and a fresh
charge put in. The fumes of zinc oxide may be collected by suitable means
either wet or dry, and the draught of the furnace maintained either by means
of a chimney or by means of a fan or other suitable appliance.
Daith LL
1000
HENRY E. FRY.
ROBERT ADDIE.
Improvements in the Recovery of Zinc from Zinciferous Slags or
Residues.
We, HENRY ERNEST FRY, of Billiter Buildings, Billiter Street, in the City of
London, Mineral Merchant, and ROBERT ADDIE, of Llansamlet, South Wales
[Price 8d.]

page_text: Works Manager, 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: -
According to this invention the slags or zinciferous materials are mixed with
from 10 to 20 per cent. of carbonaceous materials, preferably non-bituminous
coal or coke, the carbonaceous material being preferably in a fine state of divi-
sion. The richer the slag, the more carbonaceous matter required. The whole is
charged into a regenerative gas fired furnace, preferably of the Siemens type, the
furnace hearth or bottom being composed of a material, neutral or basic, capable
of withstanding the action of the basic slag, or should zinciferous material be
acid, an acid or neutral bottom should be put in; for treating basic zinciferous
slags, a basic bottom is preferably used consisting of calcined ground dolomite
mixed with anhydrous tar as a binding material, and the bottom must preferably
have a neutral division between the acid brickwork of the furnace and the basic
bottom, the material usually employed being chrome ore, containing a high per-
centage of sesquioxide of chromium. The gas and air ports of the furnace,
valves, regenerator spaces, flues, etc., are of specially large area in order to
prevent choking, and deal with the increased volume of fumes over and above
that from. the combustion of the gases from the coal used for heating purposes.
The charge is melted down at a fairly high heat say 2000° to 2500° F., the bulk
of the zinc being eliminated during the melting period. After melting the
charge is well stirred or rabbled at intervals, to promote further elimination of
the zinc, or it may in addition, and preferably so, be stirred with green wood
poles for the same purpose. After the zinc has been eliminated as far as desired,
as shown by the fumes of ZnO becoming less dense, the molten slag may be
tapped out and a fresh charge put in. The fumes of zinc oxide may be collected
by suitable means either wet or dry, and the draught of the furnace maintained
either by means of a chimney, or by means of a fan or other suitable appliance.
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 :-
1. The process of recovering zinc from slags or residues, consisting in mixing
them with carbonaceous matter, melting the mixture at a high temperature, and
condensing the fumes.
2. The combination with the subject matter of Claim 1 of:-
(a). The employment of a basic lined furnace.
(b). The employment of a furnace lined with dolomite.
(c). The employment of a regenerative furnace.
(d). Stirring with a green wood pole.