The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1932-03-04

strength and decrease weight, are find
ing thei rway into general use and sheet
steel stampings are replacing iron or
steel castings for many uses. The
tendency of all these chronological adj
vances is in the direction of less steel
tonnage in proportion to the dollar
value of the manufactured goods, and
this tendency will of course have its
effect on the question of the length
of life of ore reserves.
The second factor which will vitality
affect the length of the period during
which the great iron and steel in
dnstry of the middle west can look
to Lake Superior for its supplies OF
iron ore is the existence of unknown
quantities of low grade ore which
would have to be treated before it
would be disable by the iron furnaces
Economically this low grade ore does
not figure largely in the present pic
ture, because the costs of the benefi-
ciating processes, added to the other
costs of production and shipping, make
the unlimited use of low grade ores i'm
possible at present ore markets.
Roughly speaking iron ore which con-
tains more than SO per cent metallic
iron and Is free from Objectionable
quantities of undesirable minerals is
known as high grade ore. Fairly ac-
curate records of the high grade ore
are kept by the states of Minnesota and
Michigan, but the Minnesota records
probably are more complete for the
reason, chiefly, that the ore lies closer
to the surface in Minnesota and is more
easily located and Unidentified. 1t is
probable that the hope for future dis
coveries of high grade ore is stronger
in Michigan than in Minnesota, be-
cause most of the ore lies deep under
ground in the Michigan ranges and
what may remain to be discovered is
more of a mystery than it is in Mime
sofa where comparatively shallow test
borings tell the ore story quickly.
How extensive the deposits of low
grade ore may be has never been de-
termined. Mine operators know that
there are vast supplies although they
do not know accurately either the ex-
tent or the quality of these ores and
further extensive exploration would not
be justified under present conditions
Lower operating costs or new dis
coveries in beneficiating processes would
be necessary to bring this low grade
ore out.
The processes required for benefci-
ating low grade ore vary widely. Some
Of it must be washed to remove chemi-
cal elements which would prove in
furious in blast furnace operation
Some contains too nigh percentage
Of moisture and must be dried. Some
requires crushing to free the iron par
ticles from the rock in which it is en-
bedded. and some requires sintering, q
heat process by which the ore is ag-
glomerated.
OF the efficacy of these beneficiatine
processes there is no doubt. In fac,
some of the beneficiated ore, particu-
larry that which has been sintered, has
a higher content of metallic iron than
any Of the high grade ores which are
being used. This of course would pro-
duce some economies of handling
shipping and transporting from the
mines to the furnaces.
Taking such economies as might be
affected as an offset, however, the cost
of the beneficiating process would still
increase the cost of iron ore beyond
the Level of the present ore market
Naturally the ore producers cannot af-
ford to go through the processes OF
beneficiating the low grade ore if they
cannot sell it for what it would cost
them.
One situation which puts the mine
operators under the necessity of going
on in the working of the high grade
ore deposits even to the point of their
serious depletion before making any
definite effort to use the low grade ore
is the taxing policy of the re-produc-
ing states, particularly the state OF
Minnesota, where the best possibilities
for developing the use of low grade
ores exist. It must be borne in mind
that Of the total known reserves of high
grade ore considerably less than is pei
cent is in. Michigan and only a neg
ligible quantity in Wisconsin. AS Of
the beginning of this year Michigan
reserves were placed at 168, 349, 1923 tons
and the reserves of Wisconsin at but
q, 100000 tons, exclusive of low grade
ores. OF last years total shipment OF
Al, 1851 tons of Lake Superior ore
1,157, 480 came from Michigan mines
1.14s.171 from Wisconsin, and the re-
manning 34.881 ,010 tons from Minnesota
The state of Minnesota taxes known
deposits Of ore on an ad valorem basis
the basis of assessment being the
highest on any class of property in the
state, SO per cent of the actual value
masmuch as this assessment is levied
yearly as long as the iron in the ground
gives the land its taxing value it is
evident that the mine operators cam
not well afford to leave high grade
deposits unworked and subject to almost
confiscatory taxation while they de-
vote themselves to beneficiating low
grade ore which will not pay profit
Taxation in Minnesota is really the
barrier which stands in the way of
utilization Of the vast low grade ore
deposits Of the Minnesota ranges. The
interests Of the ore producers them
selves andthe vast industrial districts
Of the middle west call for conserva-
ton Of the high grade deposits by mix
ing In with the shipments of high grade
ore constantly increasing percentage