The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1912-01-14
PROGRESS OF THE
YEAR IN COPPER
Improvements Were Made on
Lines Which Were Already
Established.
CONVERTER CHANGES
Losses in Milling Low-Grade
Porphyry Ore Are Be-
ing Remedied.
CONVERTER CHANGES

In reviewing 1911 from q metallurgical
standpoint, the Metallurgical and Chem!-
cal Engineering Journal says. In part;
No very striking developments In the
metallurgy OF copper have taken place
within the past twelve months Progress
has been made along established lines,
and such improvements as have been ac-
compished have, in general. occupied
several years In gaining permanent
place. Among these Is the general adop-
ton Of the basic-lned converter. AL
though not a new practice, II is only
within the past year that there has been
a practically complete abandonment OF
acid d-lned converters In favor Of those
with basic Innings, Saving In cost by con-
verting with basic Innings has amounted
TO approximately 81 per ton. A campaign
on g. single acid lining was rarely Of
greater duration than day. with q duty
Of frcm go to 100 tons of matte; where
as, with the costly magnesite brick lin
ing 5000 to 5000 tons have been treated
In a campaign, and the converting cost
per ton has been greatly reduced.
Question Of Silica.
Contrary to expectations. the difficult
ties anticipated In changing the manner
of supplying the silica required by the
iron Of the matte as 1t became oxidized,
proved to be OF little Importance. While
formerly the question Of silica supply
caused the metallurgist no concern when
acid Innings were used, because the iron
oxide formed would seize the necessary
nnes SGa fsG nG s ihe npS snpes ooss %s o Sasc
no more concern is felt, for the range
of silica to ferrous oxide Is so great that
fusiole .slags will form with any of the
verter at any given time. Add to this
the fact that converter slags are always
resmelted In blast or revcrberatory fur
naces. and 1t Will be seen that basic con-
t'n In lS clp nj ma rtce
should be exhibited on seeing successful
work being done with basic converters
by workmen who, but few months be-
fore, were familiar only with acid prac-
tice,
In smelling operations there seems to
be no good reason for expecting any
marked change in current practice,
decade. IN this period the giant furnaces
were introduced: reverberatories with a
hearth area of 116 feet by 10 feet smelt-
Ing goo tons Of charge sr day a with
coal, and blast furnaces sc inches by 81
feet at the tuyeres. with daily capacity
OF 1000 tons of charge, using but per
conclusion that there is not much chance
for Improvement in this direction. In
favored localities the application OF fuel
oil to reyerberatory furnaces has been
at the use OF powdered fuel. as in cement
practice. have so far met with no sue
cess when applied to smelling.
Porphyry Practices.
The recent great development OF the
much a3tenton to tSe I copper
deposits. With copper present In such
small percentages. approximating In
many cases but Is per cent. and also
Its beneficiation is really a matter more
OF ore dressing than OF smelling. The
great losses during concentration, rang
ing close to 30 per cent, are the source
Of much alarm and the cause Of much
A study OF the subject
shows that the losses occur mainly In the
very finely divided material. and that
the vanners, which are almost exclusive
poor devices when considered from the
standpoint OF percentage OF saving OF
course. these or similar machines saving
which otherwise would be lost.
may he said to be producing a product
that deserves to be ranked as velvet"
yet SO inefficient are they that attention
should be directed to the development OF
machines. which truly merit the name OF
"simers'
One large copper company is endeav
oring to overcome this slime difficulty
tremely careful classification before final
While this improves the
Il cannot be said to soive Tue
are attacking the slime prob
EN- In another and more logical way.
aiming to secure n real slime concentra-
tor. Much promise Is given by centrlfu-
gal separators. one type OF which, op-
Grating on material finer than 200-mesh,
produces concentrates ranging from 10
per cent to 13 per cent copper with ac-
taiings OF less than 05 per
cent copper. representing q saving OF
over SO per cent; this. too on a rated
OF $50 tons per day per sepa-
-ator Active efforts are also being d. |
-ected toward the recovery Of the copper |
N the tailings OF the Lake Superior prop |
critics,