Abstract: A process is disclosed for the separation and recovery of L-phenylalanine from an impure aqueous solution by ultrafiltering and/or centrifuging to remove cellular material and large proteins, contacting the filtered solution with activated carbon to adsorb L-phenylalanine, eluting adsorbed L-phenylalanine, passing the eluate through an ion exchanger, and recovering substantially pure L-phenylalanine from the ion exchange eluate.

Abstract: The known method of removing heavy metal and cyanide ions from plating waste solutions wherein the solution is passed through flow-through, high surface area electrodes to precipitate heavy metal ions and to oxidize cyanide is improved through the use of a novel stationary bed dual electrode capable of reducing heavy metal and cyanide ion concentration. The process promotes economical electrolytic purification because it can be accomplished at relatively high current efficiencies. The metals removed from the solutions are recovered in a concentrated form suitable for purification.

Abstract: Disclosed is an easily assembled and disassembled stationary particulate bed dual electrode for recovering metal values from electrolytic solutions. The electrode comprises two assemblies adapted for mating with one another. Each assembly has a perforated flow distributing plate and a basket-like compartment for holding carbonaceous, conductive particles onto which the metal values deposit. This compartment is quickly and easily disassembled for removal of the metal-clad particulate bed.

Abstract: A process for the direct electrochemical recovery of copper values from dilute ammoniacal leach liquors.

Abstract: Recovery of copper and/or other metal values from pregnant, highly dilute liquors and conversion of the barren liquor to a suitable lixiviant; for recovery of copper or other metal values from leaching systems, such as acid treatment of mine waste dumps, vat or heap leaching and insitu mining as part of an overall copper recovery process.