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.

Abstract: The helical sluice, or spiral, of a mineral separator used for mineral separation, has a series of take-off openings to carry off strata of dense minerals which form when a pulp of water and minerals to be separated pass through the spiral. Each take-off opening is a slot in the spiral bottom, transverse to the flow, and its effective length, or throat gap, may be varied by a tongue slidably engaged in the slot and having a splitter blade extending up from its leading end to deflect dense strata into the throat gap. A second slot is formed in the tongue to take off middlings, and this is also adjustable, by a slide.