Apparatus and method for separating materials of different densities

An apparatus for separating materials of different densities, the apparatus comprising:

• a separation cup having an internal cavity configured to hold media and comprising a bottom region, an opening, and a shoulder trap between the bottom region and the opening, the separation cup comprising
• an inner wall defining a central body region with an upper and a lower ends and forming therein the internal cavity of a substantially conical shape having a diameter tapering downward toward the lower end of the central body region, an interior shoulder circumscribing the upper end and defining of the central body region, the shoulder trap circumscribing the internal cavity and a neck region above the central body region, and further comprising
• one or more passages formed through from the lower end of the central body region to the upper end of the central body region;
• and the one or more passages each define a flow path from the lower end to the upper end of the central body region of the separation cup,
• wherein the diameter of the internal cavity increases in a downward direction through the shoulder trap;
• and reduces in a downward direction through the neck region,
• wherein the shoulder trap is configured such that when the separation cup is spun about a central axis, relatively more dense material in the media is collected in the shoulder trap, and relatively less dense material in the media is expelled from the separation cup through the opening;
• and
• a rotary actuator coupled to the separation cup and configured to spin the separation cup about a central axis of the separation cup.