Concentration of Iron Ores. No. 3. [Volume: 8, Issue: 3, 1889, pp. 188-195]

188

UNITED STATES ASSOCIATION OF

[VOL. 8

Concentration of Iron Ores. No. 3.
In continuing the discussion of concentrating iron ores, we may
properly take occasion to call attention to the increasing interest
in sorting ores, pickling out the rich from the lean, thus bringing
up the average units of iron in an ore, and consequently enhancing
its value. This interest has been developed by the demand of the
blast furnaces for richer ores, by the competition in iron mining,
and by the transportation charges, which are the same for a ton
of lean as for a ton of rich ore. This hand-sorting has also attracted attention to the possibility of recovering good ore which
was formerly wasted by being thrown on dump piles, and as a consequence considerable work is now being done by hand to secure
richer or more uniform grades of ore.
For much of the following data concerning hand-sorting, we are
indebted to Mr. Richard A. Parker, M. E., of Marquette. It is
offered to our readers in the hope of encouraging some to improve their product, or to recover from the waste dumps valuable
material.
HAND-SORTING.
The dump pile at the Republic mine in the Marquette region
is now being hand-sorted, and is estimated to contain 2,000,000
tons of ore. 21,000 tons of merchantable ore were separated fromn
this mass in 1888, which after paying 30 cents royalty, and $1.85
freight, netted the operators a profit of 50 cents a ton. The ore as
shipped yielded 62 per cent. of iron, and was Bessemer in quality. A-bout two-thirds was specular and one-third magnetic. The
contractors expect to ship 40,000 tons from this pile in 1889, and
it is estimated that an equal quantity can be obtained for many
years to come. A similar plan of cobbing the piles in other Marquette mines is also being carried out, nearly 30,000 tons of handpicked ore being shipped by one company formed for that purpose
in the last three years. At the Champion mine in the Marquette
region hand separation has been carried on for some time, but
within the last eighteen months a complete system has been
adopted which is giving very satisfactory results. The ore raised
from the mine is either No. 1, No. 2, rock, dump 'or waste. The
No. 1 is mine sorted and must be absolutely clean, usually carry