Douglas daily dispatch., 1926-10-03
u. 5. BUREAU OF
MINES SOLVING
.LEACHINC OF ORE

UNIVERSITY or ARIZONA, TUG
solvent for teaching certain ores con-
tanning mixed oxides and sulphides of
copper has been produced in the
Laboratory of the southwest experiment
station Of the United States bureau of
Ir,ines located at the University of
Arizona and is now being tried on a
commercial scale in a smelter at Globe,
Arizona.
This solvent, according TO e. D. Gard :
Incr. superintendent of the local station,
is expected to radically reduce the cost
Of separating copper from certain types
Of ore which heretofore has been inn
possible to leach properly on account
F, of the expense.
no obtain Tho new solution, gases
from the ore roasters, which previously
have been wasted, are run through a
solution containing ferrous sulphate.
The suIpher dioxide gas from the
! roaster converts the ferrous sulphaLe
/ TO ferrc sulphate, which dissolves some
Of the snlphide minerals, and forms
! sulphuric acid, which in turn is sol
vent for The oxide minerals.
This, in brief and on-teehnical Ian.
guage, is the substance of the process
which will revolutionizc the production
:; Of copper from certain mixed ores and
at a cost which is negligible.
This problem was recently completed
bv the bureau and is now receiving
practical application in the state. Four
new problems are being instituted by
| hi inI co r..
! isfactorily solved, will mean great i'm
petus to the mining industry of the
southwest and great savings over the
methods now in use.
| The first among the new problems
now being studied is the investigation
of the requirements for refractories i'll
reverberatory furnaces. 1t is planned
to study conditions preliminary to pro-
ducing a new refractory substance
which will allow a higher temperature
in the furnaces and to increase the ca
pacity and effect other economies. This
problem is being watched with great
deal of interest by the mining COM
panies of the southwest.
The second problem deals with the
study of the form of copper slags to
find methods Of reducing the loss of
this metal in waste slags.
To eliminate the troublesome pro-
cess of smelling flue dust, hte bureau
has begun a study to ascertain the pos
sibility of obtaining metal values from
this dust by rometallurgical methods
and thus obviate the necessity of smelt-
ing an unsatisfactory form of metal
The last problem under consideration
is the fundamental actions involved in
teaching copper sulphide minerals as
contained in middling products in con-
centration mills. At present this prod
uct is not high enough in copper to
ship and with the development .of an
economical 1eaching process the amount
of lost mineral would be lessened.
One of the chief studies of the bureau
and one of which it is recognized an
authority is that of blasting powders
and their effects. This year, according
to Gardner, the station will study the
best and safest kind of explosive for
blasting metal mines and to ascertain
the best methods for blasting under
various conditions. The work in the
laboratories and in the field is at pres
ent devoted to a study of drilling and
blasting drift rocks, large number
of rounds having been blasted in
Arizona mines. More experiments are
contemplated before the study is COM