A mill having vertical rollers running in a circular enclosure with a
stone or iron base or die. There are two classes: (1) those in which the
rollers gyrate around a central axis, rolling upon the die as they go (the
true Chile mill), and (2) those in which the enclosure or pan revolves,
and the rollers, placed on a fixed axis, are in turn revolved by the pan.
It was formerly used as a coarse grinder, but is now used for fine
Dictionary of Mining, Mineral, and Related Terms