Abstract: A process is disclosed for recovering cyanide used to leach gold or silver from ore. In the course of leaching gold or silver from ore, a barren solution is generated. A portion of the barren solution containing sodium cyanide is recycled to the cyanidation process while blowdown from the barren solution is subjected to pre-treatment, UV photodissociation and pH adjustment. Ultimately, a volatile hydrocyanic acid is formed and is absorbed into a sodium hydroxide solution through the employment of a gas-filled membrane. This forms sodium cyanide that can be recycled and used in the cyanidation process to leach gold or silver from ore.

Abstract: A method or process is provided for removing selenate from an ion-exchange or an adsorption media regenerant stream. The regenerant stream is processed in a nanofiltration membrane which produces a permeate and a reject stream containing the selenate. A reducing agent, such as iron, is mixed with the reject stream and this gives rise to an oxidation-reduction reaction that reduces the selenate to selenite. Thereafter, the method includes adsorbing the selenate onto an adsorbent, such as hydrous iron oxide. The adsorbent and adsorbed selenite is removed from the reject stream via a solids-liquid separation process.

Abstract: A process is disclosed for recovering cyanide used to leach gold or silver from ore. In the course of leaching gold or silver from ore, a barren solution is generated. A portion of the barren solution containing sodium cyanide is recycled to the cyanidation process while blowdown from the barren solution is subjected to pre-treatment, UV photodissociation and pH adjustment. Ultimately, a volatile hydrocyanic acid is formed and is absorbed into a sodium hydroxide solution through the employment of a gas-filled membrane. This forms sodium cyanide that can be recycled and used in the cyanidation process to leach gold or silver from ore.

Abstract: A fan rotor for an airplane turbojet including locking blade roots in the respective grooves of an airplane turbojet fan rotor. Each blade root is housed in a groove that is closed by a main latch and by an additional latch that is distinct from the main latch and that is spaced apart therefrom by a predetermined distance.

Abstract: A rotary disc filter is provided with a system for inhibiting biological fouling from biological growth on filters that form a part of the rotary disc filter. A biocide is pumped from a biocide supply tank to a manifold and mixed with a backwash to form a backwash-biocide solution. The backwash-biocide solution is sprayed onto filter media during a backwashing operation and the presence of the biocide inhibits and eliminates biological growth on the filter media.

Abstract: A fan rotor for an airplane turbojet including locking blade roots in the respective grooves of an airplane turbojet fan rotor. Each blade root is housed in a groove that is closed by a main latch and by an additional latch that is distinct from the main latch and that is spaced apart therefrom by a predetermined distance.

Abstract: The invention relates to a process for treating water in an installation comprising a plurality of filtration units, said process comprising at least one step of filtration of said water in said filtration units under initial filtration conditions, and an optional step of modification of the value of at least one controlled parameter within a tolerance interval.

Abstract: A restraining device for a fan blade root, in which a packing member is constituted by a metal structure having hollowed out portions filed in by overmolding with a semi-rigid elastomer material, in particular on a lateral edge concave side between an upstream end zone and a downstream end zone, which end zones are entirely of metal structure, on a lateral edge convex side between the end zones and a central zone that is essentially of metal structure, and on two top portions of the packing member that extend between the elastomer lateral edges on either side of the metal central zone. The metal structure also includes a bottom recess extending over its entire surface between the upstream end zone and the downstream end zone. Hence, the metal structure behaves like a spring blade when the blade turns following a violent impact.

Abstract: A restraining device for a fan blade root, in which a packing member is constituted by a metal structure having hollowed out portions filed in by overmolding with a semi-rigid elastomer material, in particular on a lateral edge concave side between an upstream end zone and a downstream end zone, which end zones are entirely of metal structure, on a lateral edge convex side between the end zones and a central zone that is essentially of metal structure, and on two top portions of the packing member that extend between the elastomer lateral edges on either side of the metal central zone. The metal structure also includes a bottom recess extending over its entire surface between the upstream end zone and the downstream end zone. Hence, the metal structure behaves like a spring blade when the blade turns following a violent impact.

Abstract: A single tank submerged membrane bioreactor for treating feed water having unacceptable levels of ammonia or total nitrogen has both a membrane scouring bubble supply and an oxygenating bubble supply. The membrane scouring bubble supply continuously provides large scouring bubbles to clean the membranes. Permeate is continuously withdrawn from the membranes at a high rate but the large scouring bubbles do not transfer sufficient oxygen to the mixed liquor to create aerobic conditions in the reactor. The oxygenating bubble supply is operated to provide small bubbles of air or oxygen that intermittently produce aerobic conditions in a significant part of the mixed liquor. Alternating aerobic and anoxic conditions occur in a significant portion of the tank suitable for nitrification and denitrification.