The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1910-01-27
BUNKER HILLS new MILL
Description of Modern Concentrator
Recently Put Into Operation
at Kellogg

at Kellogg
complete description of the mill Of the Bunker Hill
Sullivan company by Gaso Caetian for years manager the
milling department of that pany appeared in issue of
the Mining and Scientific Press From this article copy
part follows:
The concentration of the Bunker Hill Sullivan Mining
Concentrating Co. completed and put in operation Decem
last The design of this plant has been the result of
thorough mentaurgca investigation carried during the past
three years. and though does differ essentially from the
ohe eadsver mills of the Occur dAene contains many fea
which novel, The plant divided into three main de-
parten which mechanically independent of each other
They "a the crushing plant 0 the concentrating de
partment and (3) the slime plant.
The gaena sidere and quartzte
The sidee is the predomnang mineral and represents from
40 R per of the The gaena measomac replace
ment the sidee and this replacement has seldom been
complete the gaena and derte intimately ntemnged the
gaena being often minue disseminated through the iron
bonae The from II to IL cent ea and contains
about 0.42 OF. silver per unit of lead.
Electric haul the from the mine in trains of Is
each of 81 capacity and dump into the bins
which hold 14O0 From these bins it fed by chutes
sowravang 42n betconveyor that dumps on an in
clned grizzly with him carance intervals The oversize
No. Kennedy gyratory crusher set to about 1sn ma
aperture while the underze fed to 24in jeffrey belt
conveyor and bed which discharged the from
the cushe This coneyo eevae the angle of 20 de-
grees three 30mm ommes it. diam and p tt long The
screening discharged another 24n conveyor while the
oversize goes of IA by 3Gn rolls bucket elevator
raises recrushed product Omm romme the oversize
Of which is returned the rolls with the from the gyraoy
crushe All the which has been screened through 30
passes through the sampler before being elevated to the mill
storagebns where it is distributed by jeffrey setmovng
tripper.
Coarse Concentrating PanThe mill soagebins rest directly
on the ground and fed by five Challenge feeders
24in belt-conveyor which eevates it to the MILL 1hls
arrangement copied from the old Dominion mill
at Globe Arizona the only difference being that the
feeders are operated 8peed induction motor controlled
from the jig floor The feeders revove about twice minute
r,1o+oJ hv fho;r mod
With the epa half open two feeders sufficient to de-
liver which the rated capacity OF the MILL This feed
ing the perfect have seen for comparatively
dry Ores The conveyor eevae the at angle Of 20 de-
rees and speed of 25 it. minute to the top OF the MILL
about so it. the ground AS the ore dumped passes in
thin stream under 12in Browning magnet which catches
the spikes nails other pieces Of iron that would be the
of trouble in the mil. Two O-mm rommes then divide the
feed into two products % that between 30 and 10 which
goes to the buig and 0 the 10 mm and finer which goes
directly to the classifying jigs.
The gs of the Haz type but are OF special design
evolved Bunker plant the result OF an extensive series
Of experiments The bugs have four and the classifying g
FIVE compartments. Such a number OF compartments IS
called for by necessity Of making five different products the
colrse iigs anu nine on the classifying gs.
The bujigs separate the following products ~ rst-cup
aayng from so SIS cent Pb shipped directly
the seter ~ secondcup concentrate assayng from 20 TO Az
Ler cent P This could be shipped direct but owing the ngn
freight and charges is profitable to grind this
concentrate in Huntington mills and to its grade by emn'
ang large part the iron carbonate on Gard tables
Tas third an fourthcup discharges are middng which is
crashed b rolls to sz and is regged on two cassl-
flying gs that work exclusively mddng 4) Hutch product
returned middng ig @ failing assayng from to To-
The classifying gs separate the feed into nine products "
Slime carrying nothing than 20Omesh ~ Fstcup con-
centrate assayng cent shipped smeter
@ Secondcup assayng cent sent grading
department N Third and fourth discharge mddng as
saying per lead and 30 cent ron This either
shipped eadron treated with fifth product 5 The
fifth cup discharges mdng assaying from to per cent which
is crushed rolls goes 6 The hutches OF
the third fifth compartments that have passed through
the 3m jig go the sandros and then to No. ee
vao ~ The first compartment assaying about 81
per cent flows the sand plant where passed through n.y.