Abstract: A solids separator (10) is provided for separating solid particulates according to the density of individual particles. The separator (10) includes a cylindrical container (12) having a container bottom (22) carrying a drive shaft member (28). A cylindrical perforated liner (62) is releasably mounted concentrically within the container (12) on an elevated plate member (70) with an annular liquid jacket (80) being defined by the interior surface of the container and the exterior of the liner. An opening into the top of the container is used to introduce solids into the liner. Provision is made for injecting a liquid under pressure into the container which comprising a liquid source connected with a liquid conduit (46) received in a coaxial passageway (30) in the drive shaft member. A vacuum source, including a vacuum tube (82) mounted independently of the container and extending into the liner, is provided to extract the solid particulates of a specific density from preselected locations within the container.