Year: 1891

page_text: Date of Application, 16th Dec., 1891-Accepted, 16th Jan., 1892
Imis method of treating is expensive, and not thoroughly effective, as only a
portion of the lead is extracted from the matte, for the matte still retains from 8 to
2% of lead, and is scarcely enriched in copper; moreover, the value of the lead
obtained does not cover the cost of treatment!
12
The resulting matte from such treatment, and plumbiferous copper mattes which
contain less than 15% of lead to begin with; cannot now be treated by any method
whereby the lead is extracted. The lead is therefore a valueless ingredient in such
mattes, and not only so but interferes with the treatment usually adopted for the
extraction of the copper. In other words, the lead present is a detriment, and
reduces the market value of the matte.
By my invention, all the lead contained can lie separated, and moreover utilized
to advantage in the smelting operation, and at the same time, copper in a concen-
trated form and free from lead is obtained.
And my process is conducted substantially as follows:-of which the first
alternative is that described and patented to me under No. 13739 of 1891.
The whole or a portion of the matte or ore, which it is desired to treat, is
crushed and calcined in the ordinary way, but by preference in a revolving calciner,
for the purpose of converting the metals, in whole or in part, to an oxidised state.
So at the conclusion of the calcination the iron, lead and copper are more or less
as oxides according to my aforesaid former Patent or there may be present a
mixture of oxides and sulphates, depending upon the degree to which the calcination
has been carried.
This calcined matte is now melted in a reverberatory furnace, and for this melting
two alternative mixtures may be used.
1. The mixture may be partially calcined matte and silica.
2. The mixture which corresponds to the reactions defined in my said Patent
No. 13739 of 1891, according to the present improvement and as hereinafter
described may be thoroughly calcined matte, raw matte and silica.
In the first case, the copper product will be a rich regulus or a coarse copper,
depending upon the degree to which the calcination has been carried.
In the second case, the copper product will be again a rich regulus or a coarse
copper, depending upon the proportion of raw matte added.
And in both cases the lead is separated, being combined with silica, as a silicate,
[Price Gd1

page_text: which together with the silicate of iron formed, forms a slag, which floats on the
top of the molten charge.
Not only is the rich regulus or coarse copper formed absolutely free from lead,
but the lead slag formed will be nearly free from copper, if the proportion of
silica be so adjusted as to be quite neutralized by the lead and iron present.
Any silver or gold, which may be present in the original matte, is nearly entirely
concentrated in the rich matte, or coarse copper.
The resulting rich regulus (white metal) of about 75% copper or coarse copper
of from 80% to 90% copper, is to be further dealt with by the ordinary copper
works processes, being converted into blister copper" in the "roaster furnace,
and afterwards refined.
"
The resulting lead slag is to be treated by the ordinary processes now in use,
for the recovery of the lead, also any copper or silver which it may contain.
In all cases where I use the term silica" I am to be understood to include,
silica, quartz, sand, sandstone, silicious ore or slag, natural silicates, or any other
silicious material, as a consequence of experiments and as the special subject matter
of the present improvement.
I obtain the most easily worked and economical results, by calcining thoroughly
and beyond the first stage of calcination as formerly described in my first Patent
No. 13739 of 1891, a plumbiferous copper matte, which will easily lend itself to
such complete calcination, that is, one containing not more than 15% of lead, and
I then mix the calcined product with a matte containing over 15% of lead, which
would not so readily lend itself to calcination; and silica.
The exact proportion in which these are to be mixed will vary with the per-
centages of iron, lead and copper, in the respective plumbiferous copper mattes,
but I give the following composition of two plumbiferous copper mattes and the
proportions in which I mix them by way of example:-
These were mixed in the proportion of 8 parts of No. 1 to 3 parts of No. 2, and
1 part of silica, and on melting this mixture, coarse copper of 90% copper free
from lead and a slag containing 19% of lead, were obtained.
Although I give preference to the calcination of the matte, for the purpose of
giving the oxygen, yet I can as an equivalent alternative bring about the same
result by oxidation during fusion, as in the ordinary "roaster process, together
with the gradual addition of silica; or again, the oxygen may be introduced by
oxidized natural substances added in admixture.
And I claim, that all such methods of adding oxygen, for the purpose and with
the object of separating lead from copper in plumbiferous copper mattes, as herein-
before set forth, are included in this my invention.
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
1st. A process for the treatment of plumbiferous copper mattes or ores consisting
of the complete oxidation of such mattes or ores in a calciner or by other means
and a subsequent melting in a reverberatory furnace with an admixture of raw
matte and of silica so that a slag shall form containing all the lead as a silicate and
leaving the copper as a rich regulus or coarse copper free from lead, substantially
as described.
2nd. As an equivalent process for the treatment of plumbiferous copper mattes

page_text: ני
or ores the oxidation by air or by the addition of oxidised natural substances
during fusion of such mattes or ores in a melting furnace, such as a
<< roaster
furnace together with the simultaneous and gradual addition of silica to form a
slag containing all the lead as a silicate and leaving the copper as a rich regulus
or coarse copper free from lead, substantially as described.
Dated this 1st day of December 1891.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.