A green chemistry hydrometallurgical process for recovering one or more metals from a metal-containing material includes leaching the metal-containing material with formic acid, obtaining a leachate comprising the one or more metals as one or more metal formates, and precipitating at least one of the one or more metal formates. The metal-containing material may be a lithium-ion battery cathode material, resulting in Li formate remaining in solution and precipitation of salts including one or more of Ni, Co, and Mn formates. Steps may include filtration of the leachate, sulphurization of retained metal formate salts to produce metal sulphate salts, purification of filtered leachate by adding lithium carbonate and filtering, dewatering of the purified leachate, and thermal decomposition of resulting lithium salts to produce battery grade lithium carbonate. Carbon dioxide, water, and formic acid may be recovered and reused, without liquid or solid waste produced.

Disclosed is a method for processing ash, particularly fly ash, in which method several elements are separated from the ash. In the method both noble metals and rare earth elements are separated.

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.

The present invention is a CO.sub.2 based hydrometallurgical multistage reaction and separation system comprising: a pre-washing device configured to fully mix the feedstock, such as industrial solid waste, mineral and mine tailings with auxiliary reagents and water at specific ratio, a reactor configured to treat the washed slurry with CO.sub.2 bubbling and discharge the treated slurry to the next stage, multistage separators configured to separate solid particles from treated slurry and recycle the unreacted solids back into the pre-washing device, a by-product preparation device configured to generate calcium and magnesium based products from filtrate containing target elements, a water recirculating device configured to recycle the remaining liquor back to the system. The present invention ensures the whole system is able to continuously and consistently react at maximum capacity through continuous slurry feeding and CO.sub.2 bubbling into the reactors which also enables multistage circulating reaction.

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.

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.

The invention relates to a method for extracting rare earth elements contained in permanent magnets, which includes the steps of thermal treatment of the permanent magnet, crushing at the end of the thermal treatment in order to obtain particles with a size smaller than 2 mm, treatment by agitation of the particles in a solution containing an organic acid, and separation of the liquid phase from the solid phase.

Embodiments of the present disclosure generally relate to the recovery and extraction of rare earth elements. More specifically, embodiments of the disclosure relate to methods for separating rare earth elements from coal, coal by-product(s), and/or coal-derived product(s). In an embodiment, a method of removing rare earth elements from a coal-derived product is provided. The method generally includes introducing supercritical CO.sub.2 to the coal ash to form a first mixture, introducing a first acid to the first mixture to form a second mixture, and removing a first composition from the second mixture, the first composition comprising the one or more rare earth elements.

Discloses a hydrometallurgical process and system for the recovery of precious metals; specifically palladium, rhodium, and platinum metals, at high purity and with limited waste and environmental fouling.

Weak acid lixiviants are used to selectively extract calcium from various sources (e.g., steel slag, impure lime, dolomite). Preferably, non-amine weak acids (e.g., weak acids that do not include an amine) as lixiviants are used. Such lixiviants can be used in stoichiometric quantities relative to calcium content of the calcium source material.