Blackfoot news. (Blackfoot, Idaho) 1891-1902, 1900-02-24
ORE CONCENTRATION.
various Phases of the Process C.refull,
CoDsidered.

colorado mill man, speaking OF the
10" grade ores OF that state. such as
are round Ia Boulder and Giipin
sounlies, says that In his opinion no
Improvement over existing methods
employed In the district are needed.
concentrating" he says In the Ward
"iher' 10 make clean product, re-
saruiess OF making a close saving. se-
cures all the values that can be easily |
ana eheaply had by concentration. and |
'he use OF cynide for the final treat
iieht VIII In nearly all cases get from
iiiiety-nNe TO ninety-nine per cent. OF
'iie Naiues, Clean concentrates are a /
very desirable product for the smelt- |
ers' ana / have no doubt they will do |
All they can 10 encourage this system |
OF milling. There is no excuse now for |
any good and well located concentrate |
ing NH To stand idle The addition OF |
a cyanide plant fills the missing link. |
we nave made very extensive tests |
on THIS line here In Boulder county,
ana always With tifst-class results. Ii
IN very safe TO say that any method |
I that VIII handle Boulder county ore
| VIII answer for any other ores pro
uuced Ia this state. Our tests show
that with a well-equlpped concentrate
Ing mill and cyanide plant-of fifty tons
/ per day capacity low grade ore can be
converted into money at an expense
not exceeding $l.d per ton. In the
TWO operations of concentrating and
4 eyaniding nearly full assay value is
saved. This Sl.50 per ton will include
The expense OF shipping and smelling
| charges ON the concentrates"
In some ores the heavy sulphide ma
ierial does not carry the highest value
the gnngiie being richer than the con-
I cenirates, but such instances are com
paratlsely rare. There are mines, too,
| wherein are found both high-grade and
Low. grade snlphides, and unless these
can be distinguished and separated In
the mine the low grade material will he
saved on the cOncentrntors, together
with the high-grade. reducing the aver
age value. III the lower grade sulphlle
contains sufficient value TO pay for
treatment at the mine, or for treatment
AT the smelters. IL makes no difference,
but, not containing such value the low
grade material should be separated. If
possible. from that containing the high
grade. Where there are two clearly
recognized classes Of ore occurring in
mine. each OF different character and
value. and where each can be easily
mined separately. their treatment in
separate batteries would give better re
suits than II these ores OF differing ma
ierial or value were mixed and worked
together
There are however. few mines where
the ores, having sufficient value 10 pay
for the cost OF mining and milling, and
containing sulphides as well. do not
Justify concentration, and rs, in the
t.reater number of such eases, the sui
plides contain higher value than m
equal weight OF gangue, clean concen-
tratton Is desirable. 10 he reason that
am admlsture of the relatively worth
less sands reduces the grade OF the con-
csntrates, and transportation and re-
ductIon charges have TO he paid on n
, quantity Of material containing no val
tie. or Mt least value below the cost
of transportation and treatment.
II is true. concentration may be ear
ried mechanically beyond the limit OF
economy, and when the point is reach
{ ed where closer concentration does mol
. result in profit II should cease.
Sorting hy hand Is a rude concentra
ton aud should be regulated by the re
: suit, III the silieiotis portion Is suscep
: tihle TO profitable treatment at TIN
mine IL should not he sent to the sfnei
Ter. where the cost of Transportation
and treatment Is higher. ON the othe
hand. IL the cost Of more closely han'
sorting this ore is greater than the cos
!, of transportation and smelling, thei
close hand sorting should be dlscontin
! ned. IL often occurs that the gangu
; remaining in hand-sorted ore. whicl
3 might be treated at the mine at profi'
y does not contain sufficient value TO pa.
a for shipment and treatment charges
:. which makes the situation still worse
hut the fact that such gangue doe
contain sufficient value TO pay thes
Is charges and possibly leave profit doe
l. NOT Justify its shipment when 1t may u
Is hand sorted and treated Mt the min
= with greater profit,
n A, most mines where hand sorting
= ,rartlced the ore Is broken down wit
hammers hy n number of cheap mel
:" who laboriousiy break and almost MI
q chemically separate the high grade su
u nhid,, from the gangue. Necessa
k, ,,v This process. unless carried to a
r. extreme and expensive point, leaves
4. large amount of ore In the selected oil
Ix I EuFkpU Itf rfiiffhtNh'
:, and will afford much more satisfactoi
- results. to run the ore through brea'
~ or and. II necessary, through set
ie rolls.
Oh Ore I'm which the high values occur
Sc lunches or ribbons of sulphide mat
Sc rial In gangue OF quartz, calcit
Al harytn or other material may usual
" be cheaply hand.sorted. as suggest,
above. when the ore Is first brougl
W from the mine II should be dumpt
Ut onto a fat grizzly made Of railroa
p iron or heavy bars set half inch apal
The ore should be washed by stres
~ water from hose. the fine materi
raising through the grizzly into a Ok
NJ or hin beneath. The large masses no
=, he,ng clean. may be picked over
- hand and often quantity OF cw'
en- sulnhide mineral obtained, while
VS. rough breaking with hammer W
Al often result in the recovery OF 81
ed more. The remaining ore should th'
or ha shoyeled off the grizzly into g
ed below and sent TO the breaker passll
=, which n stream is again turned on
~ mo ore. cleaning II for further ha'
a. sorting. The solid pieces OF sulpn
he nFh'' t,,, .sf1irklN mex