Abstract: An oxidation process uses an inclined raceway which has a plurality of longitudinally spaced transverse riffles across the raceway so that a slurry of water and particles to be oxidized runs over the raceway in turbulent flow to a catchment tank at the bottom end of the raceway. The material is recirculated over the raceway every two to three minutes for a period of two to six hours. The oxidation process can be used in conjunction with heating and vibration of the raceway to oxidize the particles. The oxidation process is particularly used in the separation of metals from ores in which after oxidation leaching agents including bromide and chlorine compounds are added to the mixture during the recirculation over the raceway to leach the metals in soluble salts from the particles. Ion exchange systems are used using known resins to extract the metals from the liquid after the recirculation system is complete.

Abstract: Method for separating materials of different specific gravities using a centrifugal separator of the type comprising a bowl having a base and a peripheral wall surrounding a vertical axis about which the bowl rotates and a jacket having a base plate under the base of the bowl and a sleeve surrounding the peripheral wall includes a central bottom discharge for the concentrate. The bowl is mounted on the shaft with a hub connecting the shaft to the base plate of the jacket. Water is supplied through the shaft and into the area of the base of the bowl. Tubular discharge ducts extend from holes in the base plate across the space under the bowl to the base of the bowl. These remain open during processing of feed materials supplied to the bowl through a vertical tube feeding onto an imperforate plate carried by the bowl above the tubular ducts, and allow the concentrate washed down from the wall of the bowl to discharge when the feed and the centrifugal action of the bowl are halted.

Abstract: A centrifugal separator of the type comprising a bowl having a base and a peripheral wall surrounding a vertical axis about which the bowl rotates and a jacket having a base plate under the base of the bowl and a sleeve surrounding the peripheral wall includes a central bottom discharge for the concentrate. The bowl is mounted on the shaft with a hub connecting the shaft to the base plate of the jacket. Water is supplied through the shaft and into the area of the base of the bowl. Tubular discharge ducts extend from holes in the base plate across the space under the bowl to the base plate of the jacket. These remain open during processing of feed materials supplied to the bowl through a vertical tube feeding onto a base plate carried by the bowl above the tubular ducts, and allow the concentrate washed down from the wall of the bowl to discharge when the feed and the centrifugal action of the bowl are halted.

Abstract: A centrifugal separator of the type comprising a bowl having a base and a peripheral wall surrounding a vertical axis about which the bowl rotates and a jacket having a base plate under the base of the bowl and a sleeve surrounding the peripheral wall includes a central bottom discharge for the concentrate. The bowl is mounted on the shaft with a hub connecting the shaft to the base plate of the jacket. Water is supplied through the shaft and through a pair of ducts passing through the hub and into the area of the base of the bowl. The discharge also extends through the hub through a pair of ducts which diverge from the central discharge opening outwardly and downwardly into a collection chamber. The discharge duct portions through the hub are angularly offset from the water supply duct portions through the hub so that both can be formed in the hub.