Hydraulic particle separation apparatus for placer mining

A hydraulic particle separator, comprising:

• a main body having a top, a bottom, a cavity extending downward from the top through the bottom, and a wall having an interior surface surrounding the cavity,
• a partition disposed within the cavity, wherein the partition separates the cavity into a lower chamber and an upper chamber, and wherein the partition has at least one opening between the lower chamber and the upper chamber;
• one or more grooves on the interior surface of the wall and extending vertically therealong within the upper chamber, wherein the one or more grooves are substantially aligned with one or more grooves disposed on the upper surface of the partition
• at least one tangential flow inlet port disposed along the wall of the upper chamber above the partition, wherein the tangential flow inlet port is to direct a flow of clear liquid tangentially into the upper chamber to engender spiral flow within the upper chamber;
• and
• at least one feed inlet port disposed on the top of said main body and in fluidic communication with the upper chamber of said cavity, wherein the inlet port is to direct solid particulate-containing fluid stream into the upper chamber.