Processing schemes for the extraction and/or separation of rare earth elements (REEs) from rare earth containing products such as rare earth mineral ore bodies and intermediate products derived from rare earth mineral ore bodies. The processing schemes may be applied independently or in various combinations to produce end-products that have a very high purity with respect to REEs, including high value critical REEs. The processes may include acid digestion, formation of rare earth oxalate compounds, metathesizing of rare earth oxalate compounds, selective precipitation and/or solvent extraction to form the high purity REE end products.

Methods for recovering metals from metal-containing materials are provided. The metal-containing material comprises either Co and Li (e.g., an electrode material from a spent lithium ion battery) or Fe and Al (e.g., bauxite). The metal-containing material is exposed to a leaching solution comprising ammonium hydrogen oxalate, oxalic acid, or both, to provide a solid composed of either cobalt oxalate or iron oxalate, and a solution of either lithium oxalate or aluminum oxalate. The solid is processed to provide either cobalt oxide or iron oxide; the solution is processed to provide either a lithium precipitate or an aluminum precipitate, and a filtrate comprising an oxalate; and the filtrate comprising the oxalate is processed to recover ammonium hydrogen oxalate, oxalic acid, or both. The method further comprises repeating the digestion step with the recovered ammonium hydrogen oxalate, the recovered oxalic acid, or both.

Disclosed are leaching aids and methods of using the leaching aids. The leaching aids can include one or a combination of compounds. The methods of using the leaching aids can include a process of recovering metal from ore, for example, a process involving leaching, concentration and purification unit operations.

The present invention relates to a method for dissolving metals by photocatalysis. A metal-containing material to be dissolved is dispersed in a mixed solution of photocatalyst-containing cyanide and organic chloride; then, a photocatalyst is added; next, an oxygen-containing gas or a substance which is capable of generating oxygen is introduced; and irradiation is applied for a period of time to dissolve metals. Compared with the prior method, the present invention is advantageous in moderate reaction condition, energy conservation, environmental protection, low cost, and convenient operation, and is suitable for mass industrial treatment on metal dissolution.

The present invention relates to a method for dissolving metals by photocatalysis. A metal-containing material to be dissolved is dispersed in a mixed solution of photocatalyst-containing cyanide and organic chloride; then, a photocatalyst is added; next, an oxygen-containing gas or a substance which is capable of generating oxygen is introduced; and irradiation is applied for a period of time to dissolve metals. Compared with the prior method, the present invention is advantageous in moderate reaction condition, energy conservation, environmental protection, low cost, and convenient operation, and is suitable for mass industrial treatment on metal dissolution.

Processing schemes for the extraction and/or separation of rare earth elements (REEs) from rare earth containing products such as rare earth mineral ore bodies and intermediate products derived from rare earth mineral ore bodies. The processing schemes may be applied independently or in various combinations to produce end-products that have a very high purity with respect to REEs, including high value critical REEs. The processes may include acid digestion, formation of rare earth oxalate compounds, metathesizing of rare earth oxalate compounds, selective precipitation and/or solvent extraction to form the high purity REE end products.

A method for recovering rare earth elements (REE) from a leach solution. The method includes determining the concentration of a first plurality of contaminates in the leach solution, adding a first amount of oxalic acid to the leach solution and allowing it to react for a first period of time to form a first precipitant and a first liquor, maintaining the pH of the first liquor between 1.5 and 3 by the addition of an alkali base, removing the first precipitant, adding a second amount of oxalic acid to the first liquor and allowing it to react for a second period of time to form a second precipitant and a second liquor, maintaining the pH of the second liquor between 1.5 and 3 by the addition of the alkali base, and removing the second precipitant.

Provided is a method for leaching nickel from a nickel oxide ore that enables a nickel sulfate production method which is easily carried out with a small amount of waste generation. The method for leaching nickel into an organic phase disclosed here includes the step of bringing a nickel ore into contact with an organic phase. The organic phase contains a hydrophobic deep eutectic solvent including a hydrogen bond donor and a hydrogen bond acceptor, and an organic acid. The hydrogen bond donor is an acidic hydrogen bond donor. The organic acid is a strong acid.

Provided is a method for leaching nickel from a nickel oxide ore that enables a nickel sulfate production method which is easily carried out with a small amount of waste generation. The method for leaching nickel into an organic phase disclosed here includes the step of bringing a nickel ore into contact with an organic phase. The organic phase contains a hydrophobic deep eutectic solvent including a hydrogen bond donor and a hydrogen bond acceptor, and an organic acid. The hydrogen bond donor is an acidic hydrogen bond donor. The organic acid is a strong acid.

The present disclosure refers to a method of obtaining metal ions from a battery, the method comprising adding a crushed battery to a leaching solution comprising fruit and organic acid, thereby obtaining a leachate comprising metal ions, wherein the method is performed at a temperature above 80° C.