Abstract: An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

Abstract: An improved putter exhibiting centrifugal balance. Centrifugal balance is defined as the ability of the putter to tend to swing in a straight line, even when deliberately forced to rotate. Centrifugal balance ensures that a golfer will be provided with a club having inherent stability along the intended line of the putt. Centrifugal balance is achieved by providing the putter shaft with a calculated curved section and predetermined angle of attachment such that the straight portion of the shaft is positioned so that a line extended along the axis of the straight portion intercepts on the front face of the head. An axis that is perpendicular to this extended line at the intercept will then pass through the center of gravity of the club. The center of gravity of the head is positioned well aft of the front face of the club and achieved by having a head shape that has two substantial theoretical centers of gravity in the sole and heel portions of the head.