The Wallace miner. [volume] (Wallace, Idaho) 1907-current, 1922-02-23
THE ASBESTOS INDUSTRY
IMPORTANT TO-ANERICA
WHERE THE MINERAL FIBER
COMES FROM, AND SOME OF
ITS APPLICATIONS.
(by Robert q. skerrett in Scientific

Today. however this unique minera
figures Importantly in many OF oul
daily activities. and we shall probably
yet learn OF more ways in which ii
may be made to serve us adNantag
eously.
Asbestos is OF divers kinds Some
have short filaments. others have long
nbers, and there is a sort that has a
strictly crystalline structure. Until
recently the manufacturer insisted
upon asbestos OF silky texture and
would have nothing TO do with the
type that was marked by longer but
less flexible nlaments AS might be
expected. necessity has given indus
trial value to some of the hitherto I'M
favored varieties. but. even So the
preference still prevails for an ashes
tos which will lend itself readily to
weaving or telling because of its plant
fibers. Canada supplies the world with
the largest quantity of this particular
kind of asbestos, known as chrysotile,
and the United States utlizes by far
the biggest share of this output.
According to the latest figures
available. the asbestos mines of our
neighbor to the north yielded. in 1919
total of 1853 tons of marketable
asbestos. valued at slO9S22S9, and of
that amount we took quite SO per cent.
In other words we are in the lead as
manufacturers of this material It is
true that asbestos has been found in
Arizona California. Georgia, Mary
land. Oregon and Idaho Georgia is
the biggest producer but it furnishes
only fiber of the lowest grade Cali |
fOrnia ranks next and. together with |
Maryland is a source Of good quality !
of so-called mill fiber Arizona at
present is third in output its asbestos |
being chiefly spinning fiber with a
considerable proportion of the mill |
sort; but recent discoveries of ashes |
tos of unusually long and silky texture |
promise to give that state preemi-
hence.
Whatever may be the future devel-
Opment of our own resources the sys-
TEN of mining the stuff will probably |
be much akin to that practiced in I'M
covering the famous deposits which lie |
in the province of Quebec and run. in
the form of veins through massive
lodges of serpentine rock Merely be
cause the flament of this asbestos
may be separated from one another by
the unaided fingers is no warrant for
the assumption that the raw material
can be recovered with anything like
that ease from its prehistoric bed in
the earths crust The mining of as
bestos in Canada is. indeed "A toilsome
undertaking; and for every ton of
marketable asbestos great many tons
of enveloping and superposed rock
must be removed. This can be appre-
ciated when il is recalled that during
1919 matter of 3,O61,690 tons of rock
was mined and taken out of the pits,
from which was realized an average
of only zoos pounds of asbestos per I
ton Of serpentine
Broadly stated asbestos has hereto
fore been mined in open pits or quar- {
ries, and this procedure will predom- I
mate in the province OF Quebec AT
the start after eXplatOry borings have 7
brought to light underlying veins of S
the mineral the superposed soil must Il
be cleared away and this not infre- O
Quently calls for the digging by steam a
shovels of earth to a depth of 25 feet. t
With the asbestos bearing serpentine IL
thus exposed. then comes the actual b
excavation of the productive pit, and b
it is customary to cut and blast the a
rock in series of benches, Slopes etc. c
which are dimensioned agreeably to il
the magnitude Of the pit and the b
depth to which the work is carried. el
The rock so detached is then hoisted W
out of the pits by derricks or overhead re
cl
This serpentine is attacked 10y pow
sr-driven drills and the holes are next VI
charged with dynamite containing 40 Sc
per cent of nitroglycerne The opera II
lions demand wide experience and II
pretty comprehensive knowledge of the is
rend of strata and sheeting planes SC
otherwise much time and money can til
De squandered in Ruthless efforts The p;
Thetford district of the province ia
> here most of the mining is done. is m
divided off into numerous claims and en-
enterprises are often close al
,eighbors. This situation has been OF
latterly for some variation II,
n the general practice of getting our is
he desired asbestos ca
For instance. at one mine. situated M
n narrow strip between thanking
laims open-pit excavation had to be p,
alted because the clearing had gone pr
own to a depth where there was fear aa
f the steep sides yielding and start as
lg rock slides. Accordingly the own lin
rs offset this hazard by sinking 4 st
cries Of shafts. and from these, some di
undreds OF feet below they develop IN
4 system of drifts galleries glory tr
oles. etc. similar to hard rock min it,
g for copper tin. gold. silver. etc IN
ormally. open-cut methods answer if
st and are the most economical for pr