Iron Ore Concentration No. 2. [Volume: 8, Issue: 2, 1888, pp. 97-111]

100

UNITED STATES ASSOCIATION OF

[VOL 8r

privilege of working over the waste piles from one of our large
mines is considered worthy of the payment of a considerable bonus
in, addition to the per ton rate on ore won, indicates the importance
which is attached to the utilization of what was considered of
minor importance. Another enterprise is about being started in
the 'Marquette range of the Lake Superior region, where magneticseparation will be attempted, reference to which will appear in this
article.
Comparatively few of those who are acquainted in a general
way with our iron ore resources are aware of the extent of the
deposits of magnetic iron ores within a rAdius of fifty miles of
New York city, but in this territory is included most of the New
Jersey ores, and the deposits in Putnam county, New York. At
two'of the latter active work in concentrating magnetites is now
carried on, viz: at the Theall or Croton Mine and at the Tillv
Foster Mine.
The plant which we illustrate on plate VIII and which will be
described in detail later, was erected at the Croton Mines. near
Brewster, New York, to treat by water plunger jigs the leaner
ore removed from. the workings of this mine. A scarcity of water
and confidence in magnetic separation has lately encouraged the
proprietor to substitute the' Buchanan Magnetic rolls which are
now being operated there.
At the Tilly Foster Mine, two miles from the Croton Mines, a
new concentrating plant is now in operation, in which Ball stamps
and rotary water jigs (the Conkling pattern shown on pages 8 and
10, Vol. VIII) are used. This plant is too new as yet to offer
any fair indication of the results obtained and reference to it will
be deferred until a future issue.
THE EDISON MAGNETIC SEPARATOR, which is illustrated by
plate V, was described in the Iron Age, and we shall use the
text from our contemporary with additions.
" The principle upon which it is based is extremely simple, consisting, as it does, of deflecting by a powerful magnet. those
particles in a mixture of ore and gangue which are magnetic, in
their fall by its field. The quartz or other gangue falling by the
magnet are not affected by its attraction. The particles of mag