Improvements in the Utilization of Tin Plate Scrap.
Year: 1891

page_text: Date of Application, 1st July, 1891
Complete Specification Left. 31st Mar., 1892-Accepted, 7th May, 1892
PROVISIONAL SPECIFICATION.
Improvements in the Utilization of Tin Plate Scrap.
FRANK WILLIAM HARBORD Pennfields Wolverhampton Metallurgist and
WILLIAM HUTCHINSON Jr. Clerk Pennfields Wolverhampton do hereby declare
the nature of this invention to be as follows:-
The object of this our invention is to separate the tin from old or new tin scrap by.
volatilization & at same time to obtain the iron in the form of pig iron suitable
For this
for copper precipitation basic steel manufacture or other purposes.
purpose we inelt or smelt old or new tin scrap, with pig iron, cast iron scrap,
stripped tin scrap, or oxides or silicates. of iron in a blast furnace, cupola, or other
suitable furnace by which we obtain greater part of tin in form of fuine which we
condense in suitable condensers. To obtain pig suitable for basic steel manu-
facture we find it advantageous to add manganese ores as fluxes & also iron->
manganese alloys.
:
Dated this 30th day of June 1891
FRANK WILLIAM HARBORD.
WILLIAM HUTCHINSON, JR.
COMPLETE SPECIFICATION.
Improvements in the Utilization of Tin Plate Scrap.
We, FRANK WILLIAM HARBORD, of Elm Villa, Penn Fields, Wolverhampton,
in the County of Stafford, Metallurgist, and WILLIAM HUCHINSON, Junior, of
The Ferns, Penn Fields, Wolverhampton aforesaid, Clerk, 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 object of our invention is to separate the tin from old or new tinned scrap by.
volatilization, at the same time, removing also the lead where any is present, such as
from the solder of old tin cans, and to obtain the iron in the form of pig iron suit-
able for basic steel manufacture, copper precipitation, and other purposes.
In carrying out our invention we melt or smelt in a blast furnace, cupola or other
suitable furnace, but preferably in a large cupola furnace, the tin-scrap together
with a varying quantity, say from 30% to 50% by weight of cast or pig iron,
and when melted we tap the metal either into pig beds or suitable chills.
The composition of the resulting pig iron can be varied within considerable limits
and a pig iron high or low in silicon and phosphorus obtained by varying the
quantity and composition of the cast or pig iron with which it is melted. We
find it advantageous at times to add considerable quantities of oxides of iron or
silicates such as roll scale or puddlers tap cinder, and also to work with as much
limestone as possible for the purpose of maintaining a basic slag. The furnace we
find most advantageous is a large cupola provided with an offtake and downcomer
connected with long flues through which the products of combustion are drawn
by an exhauster to a suitable condenser or scrubber, and from thence to the
stack-or the scrubber may be dispensed with and the products drawn by the
chimney draught through a long series of flues and chambers where the dust is
deposited. By this means we remove the greater part of the tin and lead oxides
which have been carried over in the form of dust, and these we further treat for
concentration before smelting as hereafter described.
In producing pig iron for basic steel manufacture we find it advantageous to add
manganiferous ores, or preferably small quantities of low grade speigel in sufficient

page_text: quantity to give about 1.5% manganese in the resulting metal. As a considerable
amount of fine lime, oxide of iron, silica &c. is carried over by the blast into the
condenser we find it advantageous to concentrate the flue dust produced as before
described, by passing it through fine meshes, and afterwards by treating it with
very dilute hydrochloric acid which removes the greater part of the impurities,
leaving behind the oxides of tin and lead which can then be smelted with suitable
reducing agents to produce tin lead alloys.
It will be evident that old galvanized scrap may advantageously be treated in
the same way as tin scrap, the zinc being then recovered in the flues in the form of
oxide of zinc in exactly the same way that the tin is recovered when tin scrap is
treated. The product can be sold to smelters direct either with or without
concentration.
In some cases where the coating metal is thin, damaged, or of little value the
collection and condensation of the fumes may be of little moment, and in such a
case the process would be directed to the recovery of the iron alone.
Having now particularly described and ascertained the nature of our said inven-
tion and in what mauner the same is to be performed, we declare that what we
claim is :-
1. The improvements in the utilization of tin plate scrap which consists in
melting same with a suitable proportion of cast or pig iron in a furnace (and
volatilizing the coating metal) for the purpose of producing a pig iron suitable for
basic steel manufacture, or a cast iron, substantially as described.
2. The improvements in the utilization of tin plate scrap which consists in
melting same with a suitable proportion of cast or pig iron to produce a pig or
cast iron, and collecting and condensing the tin and lead fumes in the form of
oxides, substantially as described.
3. In the utilization of tin plate scrap by volatilizing the tin and lead thereon,
condensing and concentrating the fumes for the purpose of removing the impurities
and leaving behind the oxides of the metals in the manner, substantially as
described.
4. The improved process of utilizing coated scrap metal substantially as
described.
Dated the 21st dor of Naval 1902
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Agent for the Applicants.