Bisbee daily review., 1920-03-07

Douglas was described In detail, wal
given last Wednesday by w. b. BogGs
chief metallurgist, to the Coppe
Queen classes in practical mining a
the Y. NJ. c. \.
The speaker said in part:
1.-The metallurgy of the ores at Bis
bee is an illustration OF several pro
cesses combined for the extract of cop
per. Shortly when the ore is taken
from Sacramento Hill, first it will be
concentrated (the process of ore dress
ing); secondly, smelted (extraction oil
the metal by nre); thirdly, the bullion
or blister copper will be shipped east
to be refined (the process of electro
lysis.
when the ores from the Bisbee
mines were first smelted in Bisbee
they were rich oxide ores. These ores
were smelted until 1898 in cupolas by
single fusion and cast into a bar
known as black copper, carrying about
95 per cent copper with some silver
and gold. Gradually the grade OF cop
per in these bars declined, owing to
a film of matte which was on top. At
ter 1898 the direct method of making
copper was abandoned, matte was
made and then converted.
with the direct method Stag was
made which ran from to per cent
copper
ITO show you how the metallurgy of
copper has advanced, il is only neces-
sary to tell you that Slags which were
thrown upon the dump UP until 1898
contained about as much copper as
many thousands of tons of ore which
you ship from Bisbee now each month.
Previously to 1898 the copper bars
made by the direct method carried
about 80 per cent copper. Today the
bullion or blister bar contains 99.3 per
cent copper.
In the case of each kind of bar ii
was, and still is, necessary to give the
copper Il refining in the east IN UrQer
to make a refined copper carrying
1924 per cent copper and TO extract
the silver and gold.
AS the rich oxide ores decreased
in quantity and became lower in grade
the sulphide ores were developed. AS
soon as the conVerteTs became an as
sured success, the matte from the mix
ed charge (oxide and suiphioe) was
remylted and the higher grade matte
converted Later the first matte naue
di,aAe.tisr s,a..,-+lAe I.ia arrr1a cons,
verted.
.Frorn that time until the present
there has been gradual Improvement
in blast furnace, reverberatory furnace
and converter practice until at the
present time very low grade matte car
rvinp even as low as IL to IL per cent
conner can be successfully handled IN
a basic lined converter.
las the ores from Bisbee have oeen
ouite fine and made considerable tue
dust in the blast furnaces, the smelt-
ing of fine ore, concentrates and the
dust from the blast furnaces became
ouite a problem. About 1910 reVer
beratory was built to handle TINS KIM
of material.
"Verv recent improvements IN the
roasting and smelling of fine ores ana
concentrates at Douglas, together WIFI
the prospect in the near future OIL re-
ce;ving a largo tonnage OF conceh-
trstes from Sacramento Hill at Bisbee'
has made it advisable probably TO 0is-
continue smelling in the blast furnaces
sIt is very evident that when body
of ore IS too low grade to mine, snip
and smelt it very often may pc pay
ing proposition to concentrate the ore
and then ship the concentrates. sun
is tho case with the Sacramento Hill
orebody, the ore at Burro Mountain
Tyrone, New Mexico. and the ore az
Nacozari, Sonora, Mexico
"Manv methods were tried IN treat
ing the flue dust from the blast tur-
nacas. raw fine ores and concentrates
but today, with few exceptions the
raw fine ores and concentrates are
roasted and then smelted Directly IL
thu reverberatories. The flue dust ls
drawn from tho blast furnace tlueS
and charged directly into the reveroer
atories.
'eThis. then, describes very brletil
the stages in the advance in the ART o
smelling of the Bisbee ores at blsoe'
L
opened
'rhe Grade of ore--that Is TN
amount of copper in the ore-haS
great bearing on the method and cos
of treatment. Not only the grade @
ore. but the form of the mineral a
well as the amount and KIND OF ms
terial in the gangue or waste ROCK.
"In one mining district the vast
material may be very difficult and e.
pensive to smelt while in another oil
trict there may be very little trouoi
in fluxing the waste material
"The copper ores in Bisbeo are col
sidered fairly pure and do not contal
appreciable amounts of metals VINO
affect the purity of the copper nor
uangue which is very difficult 10 III
and smelt in a furnace.
In these ores the mineral IL most
in the form OF an oxide or one or mo-
of the various sulphidrs. The gang'