Abstract: A method for separating gold from copper in a gold ore processing system. Gold ore containing elemental gold and elemental copper is treated with an aqueous cyanide solution to produce a liquid product containing a gold-cyanide complex and a copper-cyanide complex. The liquid product is then delivered to a nanofiltration membrane which prevents the copper-cyanide complex from passing therethrough while allowing passage of the gold-cyanide complex. Nanofiltration of the liquid product specifically produces (1) a retentate which contains the copper-cyanide complex; and (2) a permeate which contains the gold-cyanide complex. In this manner, the gold-cyanide complex is effectively separated from the copper-cyanide complex. The permeate is then treated (e.g. with activated carbon or elemental zinc) to ultimately obtain elemental gold therefrom. The copper-cyanide complex may either be discarded or treated to recover elemental copper from the complex.

Abstract: A bone particle collecting unit (30) has first (32) and second (34) interfitting housing members capturing a cylindrical screen basket assembly (64). Bone particle containing effluent from a surgical site is received through a port (40) in the first housing member (32) into the screen basket assembly (64). Suction is applied from a port (56) in the second housing member (34) to remove liquid which passes through the screen basket assembly. The screen basket assembly (64) includes a disc (66) which frictionally receives one end of a cylindrical screen (70) with the other end o the screen received about a rib (42) formed in the first housing member (32). Disc (66) of the screen basket assembly is received on guide ribs (58) to seat the assembly in the second housing member (34).

Abstract: A filtration membrane for micro- or ultra-filtration is formed from a complex of PVDF and calcined .alpha.-alumina (".alpha.-Al") particles, in which complex the particles are reacted and dispersed. The suspended complex is then mixed with a hydrophilic polymer such as polyvinyl alcohol (40%-90% hydrolyzed) referred to herein as HPVA, which reacts with the complex imparting hydrophilicity to the polymer. The novel membrane provides about 50% higher specific flux than a membrane made with the same polymer but without the .alpha.-Al particles. Unexpectedly, the net flux is improved by treating the membrane with a solution of sodium hypochlorite which fails to remove the HPVA from the novel membrane but does remove it from the prior art membrane which does not contain the .alpha.-Al. The preferred membrane comprises a macroporous support coated on its outer surface with a thin tubular asymmetric semipermeable film of polymer containing less than about 50% by is weight of .alpha.-A1 particles.