The Coalville times. [volume] (Coalville, Utah) 1894-1923, 1900-02-02
ORE CONCENTRATION.
Various Phases OF the Process Careful
Considered.

counties. says that In his opinion 70
Improvement over existing methods
employed Ia the district are needed.
Concentrating hc says In the Ward
Miner TO make a clean product. re-
CARELESS Of making close saving. Sc
cures all the values that can be- easily
and cheaply had 10y concentration. aud
the use Of cynidc for the final treat
ment VIII In nearly all eases get from
ninety-tivc TO ninety-nlne per cont OF
Tie values. Clean concentrates are n
very desirable product for the smclt
crs, ANA have no doubt they win do
an they can 20 encourage this system
OF milling. There n no excuse now for
any good and well located conccntrat.
ing mill 10 stand Idle The addition OF
a cyanide plant fills the missing link
We have made very extensive tests
on this line here In Boulder county,
and always with nrst.clnss results. II
IL very safe 10 say that any method
that VIII handle Boulder county ore
VIII answer for any other ores pro
duccd In this state. our tests show
that with a well.equipped cOncentrnt-
Ing mill and cyanide plant OF fifty tons
per day capacity lowgrade ore can he
converted into money at an expense
not exceeding Sl.5C per ton. In the
two operations Of concentrating and
cyanldlng nearly full assay value Is
saved. This Sl.50 per ton viii include
the expense of shipping and smelling
charges ON the concentrates"
In some ores the heavy sulphlde ma
tcrinl does not carry the highest value,
the gangue being richer than the con-
contratcs, but such instances are com.
parauvely rare. There are mines, too,
wherein are found both high.grnde and
low-gade sulphidcs. and unless these
can be- distinguished nnd separated IN
the mine the lOwgradc material viii be
saved ON the concentrnt0rs. together
with the hlgh-grade. reducing the aver
a.r value II the lower grade sulphide
contains sufficient value TO pay for
treatment Mt the mine. or for treatment
nt the shelters, Il makes NO difference,
but. not containing such value the low
grade material should be- separated. II
possible, from that containing the high
grade. Where there ARE two clearly
recognized classes OF ore occurring In
mine, each OF different character aud
value. and where each can be- easily
mined separately. their treatment In
separate batteries would give better re-
suits than " these ores OF differing ma.
terlnl or value were mixed and worked
together.
There are however, few mines where
the ores, having sufficient value to pay
for the cost Of mining aud milling. and
containing sulphides ms well, do not
Justify concentration, and ms, In the
greater number OF such eases, the sui
plildes contain higher value than an
equal weight Of gnngue, clean concen-
tratlon IL desirable. 70 he reason that
an ndmlNture OF the relatively worth
less sands reduces the grade OF the con-
ccntrates, and transportation ana re-
ductlon charges have to be paid ON n
Quantity OF material containing no val
ne, or nj least n value below the cost
of transportation and treatment.
II II true concentration may be car
ricd mechanically beyond the Limit Of
economy. and when the point Is reach
ed where closer concentration does not
result In profit Il should cease.
Sorting by hand Is u rude concentra'
ton and should be regulated by the re-
suit. II the sillclous portion Is suscop'
tlble TO profitable treatment nj tho
mine, II should not be sent TO the smell
ter where the cost OF transportation
and treatment Is higher. ON the Other
hand. II the cost of more closely hand
sorting this ore IL greater than the cosI
OF transportation aud smelling, thef
close hand sorting should be dlscontin
ued. II often occurs that the gnngu,
remaining In hand-sorted ore, which
might be- treated at the mine at profit
does not contain sufficient value TO pay
for shipment and treatment charges
which makes the situation still worse
but the fact that such gangue doe
contain sufficient value To pay thes
charges and possibly leave n profit doe
aIl ttshan II In
hnnd-sorted and treated ut the min
with greater profit.
Al most mines where hand sorting !
practlced the ore Is broken down Wit
hammers by number OF cheap mel
who laborlously break and almost me
chanlcally separate the hlgh-grnde su
phldes from the gangue. Necessai
ily this process. unless carried to n
extreme and expensive point, leaves
large amount OF ore In the selected or
sacked for shipment II Is cheaper
and will afford much more satisfactor
results. TO run the ore through breal
or aud, II necessary, through a sot
rolls.
Ore I'm which the high values occur
lunches or ribbons OF sulphide matt
rial In n gnngue OF quartz, calclt
bnryta or other material may usual
be cheaply handsorled. as suggeste
above when the ore Is first brougl
from the mine II should be dumpe
onto Hat grizzly made OF rnilroa
iron or heavy bars set half Inch apar
The ore should be washed by streal
J OF water from n hose, the fine malerli
y posslnrl through the grizzly into be
" or hin beneath. The large masses, no
bd,l9 clean, may be picked over l
hal and often quantity OF clen
sukde mineral obtained, while
rod breaking with n hammer vi
oft Aesult In the recovery OF ST
mo XThe remaining ore should the
be neled on the grizzly into q
bell nd sent TO the breaker pasrif
VIII stream Is again turned on
the cleaning 1t for further haI
sort y The solid pieces OF sulphi'
MINI may here be quickly plck'
out. he remainder going TO the mill (
redmion and mechanical concentr
ton. A grizzly similar to the first mi
also q provided at the breaker 4
passlg the fine material washed fro
the b,ken ore. The ore passing q
~ hlsrl. "a