An Improved Method of Treating Plumbiferous Copper Mattes" and Ores.
Year: 1891

page_text: Date of Application, 14th Aug., 1891-Accepted, 17th Oct., 1891
COMPLETE SPECIFICATION.
66
An Improved Method of Treating Plumbiferous Copper Mattes"
and Ores.
I CHRISTOPHER JAMES of Ida Villa, Swansea, Metallurgist, 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:—
My invention relates to the more economical treatment of plumbiferous copper
matte & ores, to enable the lead to be almost wholly extracted from the charge as
a floating silicate, whilst the copper also as a consequence, comes down as a rich
27
& pure "matte or regulus,
Leady or plumbiferous mattes containing 15% of lead and upwards are now
generally treated by melting them in a specially constructed reverberatory furnace.
After the charge is smelted metallic iron is added to it, whereby about one half
of the lead is replaced by it, as expressed by the equation.
PbS Fe FeS + Pb.
=
This method of treatment is expensive and not thorough, only one half of the
lead is extracted, leaving the resulting copper regulus still containing a variable
quantity of lead of from 8 to 12%, which is entirely lost, as is also the lead in
mattes containing less than 15%, which cannot be treated economically by the
above process. These products have now to be mixed gradually in small quantities
with other material and worked through the ordinary process of copper smelting,
to the great detriment of copper making, and the furnaces, wherein they are
conducted.
By my invention I utilize all the lead and concentrate the copper in the matte
to "white metal," leaving it practically free from lead, and my process is conducted
substantially as follows
The matte is crushed, partially calcined in the ordinary way, by preference in a
revolving calciner, the object being to convert the whole of the lead and iron
to oxides, and so leaving a mixture of oxide of lead, iron, & copper, with sulphide
of copper.
This partially calcined matte is then mixed with silica (quartz, sand, sandstone)
a silicious ore, or a highly silicious slag or other silicious material, and melted.
And I find good results when I add 6% of silica to a calcined matte containing
20% of lead.
The copper combines with the sulphur & forms a rich regulus (white metal)
containing nearly all the gold and silver (if those metals were originally present)
the oxides of lead & iron combine with the silica to form a slag, floating on the
top, consisting essentially of double silicate of lead & iron, which is skimmed off';
the lead is afterwards extracted from this slag by well known methods now in use,
the rich copper regulus is afterwards tapped perfectly or nearly free from lead,
and is now ready in a concentrated form to be further dealt with.
The proportion of silica to be used, will entirely depend upon the per-centage of
lead and iron in the "matte" operated on, the object being to form a double
silicate of these metals, upon the example as above indicated.
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 :-
The production in plumbiferous copper mattes or ores of oxide of lead by
calcination-the copper being left in part or whole as a sulphide, the after

page_text: smelting of the said calcined plumbiferous copper matte or ores, mixed with silica
or silicious material, to produce a floating slag of silicate of lead, convenient for
further commercial treatment, the copper regulus reducing down-in a pure & rich
condition, substantially as described.
Dated this 13th day of August 1891
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.