The sun., 1878-07-17
REDUCING GOID ORE.
Bintons OF Doi,ar-, ~ L. said. Can be Saved
by q New Process.
Experiments wcro tried at IS Gocrck street

Experiments were tried at IS Goorck street
yesterday In reducing gold ore The saving
applies to gold and silver ores not hitherto
capable ot being worked by rcverbcratory fur
naccs. the method in use In the great mining
reRiOna Of the West The ore. after II IL crushed
to powder. Ia roasted In rcvcrtorntory furnacca
10 drive OF the sulphur with which the gold IL
connected. and from which II is with tho Ereat-
rst dni'ulty separated. To librratc sulphur
from gold ore Ia the problem which the m ner
the chemist. and the assaycr have endcavorcd to
solve since 40. and tho nearest approach to the
solution has been the rcvcrbcrntory furnace.
The proprictors OF theee furnaces in Colorado.
Nevada, and Arizona havc charged tho miner
ESQ a ton to smelt his ores because the cost of
the reduction amounted to Mt lenst from t23 o k25
atom. The nntural result IL that all sulphurottrd
ores that do not assay $50 to the ton are lett un
touched. When II il rcncmb"rcd that ther, IL
Just about ten times ns n uch su uiphureitrd or
lean ore ia of Fat ore In the gold regions, 1t Is
sncn That when process cnn b. ohtained by
which It will pay to handle the hitherto unre-
muncrattve ores then billions Of dollars can be-
saved. Such proc, ss II ~ asserted, has been
invented, and u ton ol orc which formerly would
not be looked M VIII pW the miner SO, and
also the smelling works $40 leaving SO for the
cost Of reducing. the cost OF reducing 10y the old
For exprrim"ntinR n furnace hns heen built
Ut 55 Goerck street hy the Brewster Reduction
Company. and nm experienced assayer from
Colorado, Adolph Brhrs, sup"rnt"nds tho
works. The ronstinR oven IL nearly circular.
twelve iprt in diameter. and has the advantage
OF working nearly automatically. In the ordi-
nary revrrhc rifory roHsting furnaces there arc
two or three and even five trrraccd hearths.
making the machine fifty feet long. The labor
in the old furnaces is done 10y hand. consisting
mostly of rahbling the powdered ore incrssant-
ly, an expenditure of great labor ana time The
production IL small. and the completeness of
the roasting depends on the efforts Of the work
men. The Brewster furnace has fiat. circular
hearth consisting of an iron shell. fllled with
five inches Of fire clay. lis circumference un-
derncnth In fitted with teeth and driven by
genr wheel, giving rotary motion to the
hearth The hearth moves on number OF balls
underneath. Through the centre of this hearth
for the combustion OF the sulphur passes. This
air tube .eNends from the blower outside
through pipe. and, passing NJ through the
centre into four hollow stationary arms. six
inches in diameter, and crossing at right an
giles, II passes into hollow teeth underneath
the red-hot ore, revolving against them
on the circular iron plate. The air
strikes the glowing ore and. heated by ita
passage through the pipes. the combustion OF
the sulphur in the ore II rapid and complete.
The ore. which has been introduced like wheat
into hopper runs out in the same manner.
Twenty-Five tons OF gold ores heavily sulphu-
rrtted. from four mines IN North Carolina,
were experimental with. They carried from
Is to ~ per cent OF sulphurcts in the crude ore.
and after going through the furnace for twenty
minutes not a sign or smell Of sulphur could
bc detected.
The experiments are satisfactory to those
having charge OF them. and a furnace is to be
constructed in Blackhawk. Col. An old Calf
fornia miner who was present said that the
the experiment tried on a larger scale before ho
can believe In its success,