Abstract: A method of separating solids, the method comprising: •adding said solids to a suspension of particulate material comprising magnetic, or magnetized, particles in a liquid, •locating the combined solids and suspension in a separation vessel such that rotation is imparted to the combined solids and suspension around a space bounded by an outer wall of the vessel to impart a centrifugal force on the solids; and •applying, during operation of said separation vessel, a magnetic field to said combined solids and suspension in said separation vessel to impart a magnetic biasing force on the particles of said particulate material in an inwards direction away from the outer wall of the vessel at least in a lower region of the vessel, •wherein said particulate material has a coarseness (particle size) that is determined by at least one of the size of said separation vessel, the particulate material shape and type, the solids particle size and type, the feed pressure of the combined solids and suspension, and a desired

Abstract: A method of separating solids, the method comprising: •adding said solids to a suspension of particulate material comprising magnetic, or magnetised, particles in a liquid, •locating the combined solids and suspension in a separation vessel such that rotation is imparted to the combined solids and suspension around a space bounded by an outer wall of the vessel to impart a centrifugal force on the solids; and •applying, during operation of said separation vessel, a magnetic field to said combined solids and suspension in said separation vessel to impart a magnetic biasing force on the particles of said particulate material in an inwards direction away from the outer wall of the vessel at least in a lower region of the vessel, •wherein said particulate material has a coarseness (particle size) that is determined by at least one of the size of said separation vessel, the particulate material shape and type, the solids particle size and type, the feed pressure of the combined solids and suspension, and a desired

Abstract: Methods for removing, or leaching, cobalt or other diamond-diamond bonding catalysts from polycrystalline diamond compacts (PDCs) or other structures formed from polycrystalline diamond include leaching under conditions that simulate use of PDCs in a hot hole drilling environment. A leaching agent may be formulated, when used under appropriate conditions, to remove or substantially remove cobalt or another catalyst from polycrystalline diamond without dissolving, degrading or otherwise attacking a substrate that supports or carries the polycrystalline diamond. The leaching agent may include one or more components that mimick the chemicals or conditions to which a PDC would be exposed in a hot hole drilling environment. Polycrystalline diamond structures from which cobalt or another diamond-diamond bonding catalyst has been removed or substantially removed are also disclosed, as are systems for leaching cobalt or other diamond-diamond bonding catalysts from polycrystalline diamond.

Abstract: Methods for removing, or leaching, cobalt or other diamond-diamond bonding catalysts from polycrystalline diamond compacts (PDCs) or other structures formed from polycrystalline diamond include leaching under conditions that simulate use of PDCs in a hot hole drilling environment. A leaching agent may be formulated, when used under appropriate conditions, to remove or substantially remove cobalt or another catalyst from polycrystalline diamond without dissolving, degrading or otherwise attacking a substrate that supports or carries the polycrystalline diamond. The leaching agent may include one or more components that mimick the chemicals or conditions to which a PDC would be exposed in a hot hole drilling environment. Polycrystalline diamond structures from which cobalt or another diamond-diamond bonding catalyst has been removed or substantially removed are also disclosed, as are systems for leaching cobalt or other diamond-diamond bonding catalysts from polycrystalline diamond.