The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1923-06-22
AVERAGE ANALYSIS
SUPERIOR ORES.
VERMlLION RANGE HAS HIGH.
EST GRADE OF IRON ORE
IN EVERY WAY.
(From Skillings' Review


The variation from year to year,
and over periods Of years. in the
average analyses of Lake Superior
iron ores tells one of the most in
teresting and important stories that
can be imagined. The current an
nual report of the Lake Superior
Iron Ore Association (1922) is ac-
companied by graphic charts showing
the range in average analyses from
1902 to 1922. Comparisons are thus
obtainable between the different
iron ranges, and the variation year
by year for each range. 1t is OBJ
served that the performance of each
iron range has been singularly con-
sistent year after year, and there
has been less variation than one
would expect.
A noticeable fact is that the aver
age iron for all grades FOR the
Mesabi range, and for the total of
all ranges, has in recent years been
increasing. From 1902 to 1911
there was a consistent DECREASE in
average iron analyses, and then a
period of little variation followed by
a pronounced increase, from 1917
to 1922.
The average natural iron on the
Mesabi range increased from SOFT
to 51.99 during the last ten years
The average PHOSPHORUS has re-
manned practically the same, while
the average moisture has decreased
from 1851 to 11.39 during the same
period. The decreased moisture
content accounts in a large measure
for the increase in the natural iron.
Probably a large factor in raising
the average iron content has been
the large shipments Of concentrates,
the product of the washing plants
of the western Mesabi, which aver
age, after treatment, considerably
higher in iron and lower moisture
than the average direct shipping ore.
1t Is also true that to maintain a
high average grade of ore, careful
mining and careful grading are rec
essary, and the fact that the grade
has been increasing is a credit to
the operators engaged in the iron
mining industry. Study of the fig
ures appears to indicate also that in
the heavy shipping years the grade
was heavy, lower grade ores could be
disposed of. In lean year like
1921, only the best grades Of ore
were wanted. The variations in the
Mesabi range analyses are reflected
pretty closely in the average for all
ranges, as the big Minnesota range
contributes about two-thirds Of the
total.
The Lake Superior Iron Ore Asso-
citation lists the ores as Bessemer,
Non-Bessemer phosphorus .180 and
under), Non-Bessemer phosphorus
above 1907, Manganiferous, and Sill
iceous torres containing 1900
silica and over). Analyses on all
these grades for all ranges are list
ed in their pamphlet.
1t is noted that the Bessemer
ores predominant on the Vermilion
range only where they amount to
800 Of the total. The grade of
the Bessemer ores of this range ex-
coed in large measure any other
range. The Gogebic range pro-
duces a large percentage Of Bes-
semer ore OF good grade. The av-
erage Bessemer ore from all ranges
last year ran 54.57% natural iron
and .040% phos., and made up
1850 of the total tonnage. It is
of interest to note that in 1918 the
average grade was $685. natural
iron, .043 phos., and Bessemer ores
made up 38.4% of the total, show
ing quite a decrease in ten years
in the amount of Bessemer ore
available.
Of the low phos. Nom Besscmer
ores we find the highest grade on
the Vermilion, with the Marquette
next. Of the Mesabi and Mar
quette range ore about two-thirds
is of this class. The highest phos.
ores are on the Vermilion and
Guyana, the highest moisture on
the Mesabi and Marquette. The
Non-Bessemer low phos., ores are
the most important group listed,
making 57.46 of the total, and in
1877 the group averaged 51.35s5