The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1918-10-24
LEAD AND ZINC MINING
IN MISSISSIPPI VALLEY
VARIOUS USES OF THE METALS
IN TIMES OF PEACE AND
WAR.
&c. T. Lednum and r. H. Summer in
Dupont Magazine)

(E. L. Lednum ana II. II. SuHlHleI Al
Dupont Magazine)
The story of the development in the
past few years reads almost like ic-
ton. Under normal conditions the
greatest demand for zinc products
has been in the peaceful pursuits of
industry, in the making of preserve
jar tops. waste pipes and chemical
apparatus After the outbreak of hos
tilties the demand for these metals
changed from domestic uses to the
more serious business of war, AMI the
present demand for these products is
largely for military purposes.
Both Of these metals are found in
enormous quantities buried in the
ground in the form of ores, with no
Indication on the surface to sho"
their location. The ore bodies of the
Gated by drilling from the surface by
means of we'll drills. The powdered
rock and ore brought up by these
outfits are carefully tested and
when there is enough of the desired
minerals to pay for mining, shafts
are sunk to the levels of the ore bod
les. Tunnels called drifts are driven
from these shafts to permit of the
mining of the ores, which are the
minerals together with the rock in the
natural bed, Zinc and lead ores gen.
orally occur together combined with
sulphur as sulphides. AS these ores
of zinc and lead are so similar, many
complex and difficult problems are
often encountered by the mill oper-
ators in separating them, and by the
smelters in finally reducing them to
pure metal.
In addition to these simple zinc
lead ores, called sulphides, of the Mis-
sissippi valley, other sources of zinc
are from franklinite, a very complex
ore containing iron and manganese;
smithsonite, carbonate of zinc; will
emite, a silicate of zinc; zincite, an
oAiue VI ZiHc, anu tttldiHlne, dllOtuei
carbonate of zinc. Lead also occurs
associated with silver gold, copper
and sulphur likewise as an oxide,
sulphate, chromate, phosphate and
carbonate. In all of these ores the
minerals are associated with many
other substances from which they
must be separated
In the Missouri district the drifts
ordinarily strike the deposits Of pay
ore" at the top After considerable
amount of worthless rock Is removed
by blasting, the ore itself is drilled by
means of power drills and the hole
loaded with dynamite The blasts
break the ore loose and shatter it in
to fragments that are loaded into the
buckets or small mine cars and hoist
ed to the surface
The ore is then crushed to the fine
ness of sand and sent to the jgs,
where it is mixed with water and
subjected to a pulsating or jigging
motion, The desired ore is separated
by gravity from the lighter and
worthless rock called "gangue" This
also separates the zinc and lead ores,
which are now called Concentrates"
and each is collected in troughs or
chutes and carried to bins until need
ed The refuse or gangue Is passed
out as waste to the spoil pile or the
dump.
Some of the very fine material can
not be separated by the jigs and
passes to concentrating tables, where,
carried in partial suspension in wa
ter, it is passed over tables that
shake the material in such a way as
to separate not only the valuable ore
from the gangue but the zinc from
the lead ore as well, These concen-
trates are then placed in the bins
with those from the jigs.
In smelling, the zinc ore is placed
in sealed clay retorts or furnaces and
heated. This drives the metallic zinc
off in the form of vapor, which is
and is then known as
"spelter," of which there are several
grades, based on the purity or the
of zinc contained.
Different smelling equipment is
needed for the lead, which is melted
out of the ore in large furnaces. The
heavy molten lead sinks to the bot
tom and is drawn off there, while
the lighter Stag" or waste, which is
much lighter rises to the top of the
mass and is drawn off through
higher set of openings and is sent to
the Stag dump.
The uses of spelter, both in times !
Of peace and of war, are many. Some
times it is used alone: sometimes it is |
associated with copper lead and var
Gus other substances.
1t is not necessary to go out of |
he home to find these uses, for
when the visitor pushes the button
It the door the bell rings-the battery /
which supplies the power to ring the
,ell contains zinc. The ringing of the
,ell may result in one or all of the
GLOWING events in the household:
rhe washboard of zinc may be aban-
oned temporarily; baby may splash
water out of his little tub of zinc;
nupu CON NAV find on nnnDrtnpity |