The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1919-02-27
Lead and Zinc Mining and Milling in
the Joplin Diftrict

cent metallic lead for the galena con-
centrates. The base price depends
largely upon the state of the spelter
market and is determined during the
latter part of each week.
"As the different grades of concen-
trates produced from the many mines
throughout the district vary, the price
received per ton of concentrates, dry
weight, are determined by the grade
of concentrates and the content of i'm
purities. Thus for zinc blende con-
centrates, if the assay varies from the
basis, 81 is added to or deducted from
the base price for each l per cent of
zinc above or below 60 per cent. Pen
alties are imposed for certain impur-
tiles if present. Usually for each per
cent of iron above ! per cent, 81 is de-
Quoted from the base price. Where
the percentage of iron is high this
! imposed at all Lead and lime are
penalized, usually by deducting a cer-
tain amount from the base price per
| ton of concentrates. This results in
two or three different grades of zinc
concentrates, each with its base price.
For example, a zinc blende concen-
trate containing 0.5 per cent or more
/ lead would no longer be classed under
the standard grade, but under a grade
with a lower base price.
! Because of the great demand for
the better grades of spelter since the
war began, the smelters have been
somewhat more exacting as to impuri-
ties in zinc concentrates and have low
cred the allowable percentages of i'm
purities for the different grades. 9th
er undesirable impurities in zinc con-
centrates are barite, fluorspar and hi
tumen, but these are not frequently
found with the ores of the Joplin dis
trict. Sorted ore, such as lump ga
lena ore and the oxide ore of zinc is
usually sold on flat bid the ore buy
er inspecting the ore and making an
offer of so much per ton for it."
Labor Conditions.
Mr.. Wright finds nearly all en-
ployes of the mines and mills are Am
erican born, a condition that is espe-
cially to be commended in these trou-
blesome times. He says:
Nearly all the miners and surface
men in the Joplin district are Ameri.
can-born. AS a rule they are efficient
and intelligent, and readily pick uT
new ideas whenever they are given tn,
opportunity.
"The shift for underground work II
the mines is hours, whereas the mil
, shifts are 10 hours each. When {
mine has been well developed a sin
; gle underground shift can often breal
, enough ore to keep the mill runnin
during two 10-hour shifts. A few o
! the larger companies are now runnin
e their mills three S-hour shifts rathe
than two 10-hour shifts. 1t is believ
: ed that this plan. If followed, will i
many cases make for greater efficien
h cy in both mining and milling.
e "In 1916 the average scale of wage
n paid to the miners in this district wa
: based on a sliding scale basis of
: 25-cent increase or decrease for ever
e $40 increase or decrease in the aver
G age base price for 60 per cent zin
concentrates covering a period Of on
h month"
: Under this system when the price {
r so per cent zinc concentrates is bt
), tween $50 and $90|per ton drill me
: receive $3.75 per day and helper
n fContinued on Page a.