The present application relates to methods for leaching and extraction of precious metals. For example, the present application relates to methods of leaching gold, palladium and/or platinum from a substance comprising gold, palladium and/or platinum (such as a gold-containing ore or a platinum group metal (PGM) concentrate) using an organic solvent that is water-miscible or partially water-miscible.

A recyclable, non-toxic solvent media and methods for precious metal leaching and extraction, in particular platinum group metals (PGMs), are described. The solvent media comprises 3-methoxy-3-methyl-1-butanol (MMB), an oxidizing agent such as lithium bromate, and a halogen salt such as lithium bromide. A precious metal leaching process comprises preparing the solvent media, adding precious metal-containing substance to the solvent media and agitation to leach the precious metal from the substance into the solvent. Agitation may be performed for several hours to days at relatively low temperature. After leaching, filtration is performed to separate the solvent-soluble precious metals from insoluble residues. The method may further comprise refinement of the precious metal and purification of the solvent. Purified solvent may be recycled/reused in solvent media for leaching and extraction of precious metals.

Methods and compositions are described in which amine-based compounds are utilized in the recovery of rare earth elements from solution. The rare earth elements are recovered selectively and sequentially.

Hydrometallurgical compositions are described in which organic amine-based lixiviants and organic amine-based pre-lixiviants are utilized in the selective recovery of rare earth elements. The lixiviant species can be regenerated in situ, permitting the organic amine to be used in substoichiometric amounts.

A process for obtaining rare earth (RE) oxides from a starting material including one or more RE compounds of formula REFeB is provided. The process includes the following steps: comminuting the starting material by hydrogen hydrogenation (HPMS); treating the comminuted starting material with an aqueous solution of a carboxylic acid or a mixture of multiple carboxylic acids; precipitating the RE oxides from the carboxylic acid solution by addition of a precipitant that includes an alcohol or a mixture of multiple alcohols. The RE oxides themselves and the use thereof are also provided.

The present invention pertains to a sustainable and efficient method for recycling lithium-ion batteries (LIBs) and producing lithium-ion battery precursor (pCAM) cathode precursors. In the recycling aspect, the invention introduces a green solvent mixture comprising Ethylene glycol phosphite (2-hydroxyethyl dihydrogen phosphite) and water, and not limited to the mixture Ethylene glycol, H.sub.3PO.sub.4 and water (H.sub.2O) or a mixture of Ethylene glycol, H.sub.2SO.sub.4 and water H2O, for leaching valuable metal ions from spent cathodes and ore minerals. This method exhibits outstanding extraction efficiency, with 99.9% recovery rates for nickel, cobalt, manganese, and 99.5% for lithium. In the pCAM synthesis aspect, a novel method that produces pCAM in the spherical hydroxide form using ammonium metal (ii) sulfate hexahydrate (NH4).sub.2M(SO4).sub.2.Math.6H2O, where M represents nickel(II), manganese(II), and cobalt(II), or combinations thereof.

In a method for recovering an active metal of a lithium secondary battery, a preliminary cathode active material mixture is prepared from a cathode of a waste lithium secondary battery, the preliminary cathode active material mixture is fluidized through oxygen-containing gas within a fluidized bed reactor to form a cathode active material mixture, reductive gas is injected into the fluidized bed reactor to form a preliminary precursor mixture from the cathode active material mixture, and a lithium precursor is recovered from the preliminary precursor mixture.