Abstract: LiFePO4 or LiMnxFe(1-x)PO4-containing black mass or a material that is derived from LiFePO4 or LiMnxFe(1-x)PO4-containing black mass is acid baked or salt baked and leached with water to extract Li+, one or more types of non-lithium cations, and SO42?. A basic reagent is added to the acidic leachate to precipitate salts of the non-lithium cation(s) to form solid leachate tailings. After separating the lithium-enriched liquor from the solid leachate tailings to produce a product liquor, the product liquor is optionally contacted with a precipitation agent in order to precipitate product Li2CO3 or LiOH.

Abstract: In described embodiments, a process for recovery of a metal from a grounded ore comprises leaching the grounded ore with a leaching reagent, an oxidant and an oxygen vector. In particular, a process for recovery of gold from a grounded gold ore, comprises leaching the grounded gold ore with a cyanide salt, an oxidant and an oxygen vector. The oxygen vector is selected from dodecane, decane, hexadecane, or the like.

Abstract: A low-temperature leaching operation employs a raw, red mud slurry directly from aluminum production for an oxalic acid leaching of ferric oxalate. Residual calcium, titanium, aluminum and other rare earths are also recoverable in a secondary stream. Monitoring and control of the pH of the leach solution yields soluble ferric oxalate without high temperatures or specific radiation or light sources. Addition of iron powder results in precipitation of ferrous oxalate, isolated by magnetic separation from the iron powder which recirculates in the solution. Magnetite may then be produced by heating the ferrous oxalate in low pO2 conditions.

Abstract: A low-temperature leaching operation employs a raw, red mud slurry directly from aluminum production for an oxalic acid leaching of ferric oxalate. Residual calcium, titanium, aluminum and other rare earths are also recoverable in a secondary stream. Monitoring and control of the pH of the leach solution yields soluble ferric oxalate without high temperatures or specific radiation or light sources. Addition of iron powder results in precipitation of ferrous oxalate, isolated by magnetic separation from the iron powder which recirculates in the solution. Magnetite may then be produced by heating the ferrous oxalate in low pO2 conditions.