Abstract: This invention relates to a take-off assembly for mounting in a spiral separator. The take-off assembly includes an adjustment tongue and a mating member containing a transverse aperture for receiving the adjustment tongue. The mounting member has a surface surrounding the adjustment tongue which is substantially flush with the top surface of the adjustment tongue. There is also provided an undercut for obtaining an undercut of concentrates particles from pulp flowing in the spiral separator whereby tailings and/or middlings contained in an upper portion of the pulp above the concentrates particles may flow across the transverse aperture.There is also provided a spiral separator for gravity separation of minerals containing the take-off assembly and a method of taking undercuts including using the abovementioned take-off assembly in the spiral separator.

Abstract: This invention relates to a spiral separator including an upright column which is supportable with its axis substantially vertically. The spiral separator is adapted to receive at an upper end thereof a plurality of helical turns surrounding the upright column wherein intermediate the height of the separator there is provided an increase in the transverse dimensions or diameter of the separator which provides an initial portion of relatively small transverse dimensions or diameter. By this feature debris or particles of high specific gravity tending to travel in an outer part of the separator adjacent an outer wall thereof entrained with the water in the pulp are caused to travel inwardly toward an inner part of the separator for ultimate separation from particles of low specific gravity.