Abstract: A spiral separator includes an upright column supported with its axis substantially vertical and adapted to receive at an upper end thereof a pulp of water and particles to be separated. The spiral separator also includes a plurality of helical turns mounted to said upright column wherein at least in a top portion of the separator there is provided a channel located on an outer part of the separator. The channel is initially narrow and deep and becomes progressively wider to enable the particles to obtain or maintain an initial velocity so as to maintain the flow of pulp without the coarser and/or less dense particles becoming stationary or stranding and wherein the coarser and/or less dense particles may be retained in an outer section of the channel and the finer and/or denser particles may move toward an inner section of the channel and be retained in said inner section.

Abstract: A spiral separator for the wet gravity separation of solids of different specific gravities has a number of helical sluices or spirals mounted about a vertical column, the bottom of each spiral being substantially straight in cross-section and inclining upwards from inside to outside of the spiral, the pitch of the outside of the spiral being substantially uniform, but the angle of the spiral bottom to horizontal, and therefore the pitch of the inside part of the spiral, varying, this angle and the inside pitch of the spiral being greater in the upper part of the spiral than in the lower part.

Abstract: A spiral separator for the wet gravity separation of solids of different specific gravities has a number of helical sluices or spirals mounted about a vertical column, the bottom of each spiral being substantially straight in cross-section and inclining upwards from inside to outside of the spiral, the pitch of the outside of the spiral being substantially uniform, but the angle of the spiral bottom to horizontal, and therefore the pitch of the inside part of the spiral, varying, this angle and the inside pitch of the spiral being greater in the upper part of the spiral than in the lower part.