One or more embodiments relates to a process for extracting Rare Earth Elements (REEs) from REE-bearing underclays, claystones, shales, coal-mining waste, and waste coal. In at least one embodiment the process includes contacting the REE-bearing underclays, claystones, shales, coal-mining waste, and waste coal with an Organic Acid Solution (OAS) comprising at least one organic acid and at least one ionic salt at a predetermined ambient temperature and predetermined pH; and separating the REE from the REE-bearing underclays, claystones, shales, coal-mining waste, and waste coal, forming REE+Yttrium (REY) concentrate.

The present disclosure relates to processes for treating a coal associated material, e.g., acid mine drainage, while simultaneously recovering a high-grade rare earth preconcentrate suitable for extraction of commercially valuable rare earth oxides. Disclosed herein are methods for preparing a hydraulic pre-concentrate enriched in rare earth elements and critical minerals. Also disclosed herein are methods for preparing a pregnant leach solution from the disclosed hydraulic pre-concentrates. The present disclosure also relates to systems and plants for carrying out the disclosed processes. Also disclosed are compositions produced by the process disclosed herein in which the compositions comprise rare earth elements. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

A process for leaching a mineral particulate material comprising the steps of feeding the mineral particulate material to a leaching step (10) in which at least one valuable metal in the mineral particulate material is leached into a leach solution to form a pregnant leach liquor and a solid residue containing undissolved mineral matter, the leaching step being conducted under conditions such that elemental sulphur is formed in the leaching step, wherein beads or particles that take up elemental sulphur are added to the leaching step such that elemental sulphur is taken up by or collects on the beads or particles, and separating the beads or particles from the pregnant leach liquor and the solid residue. The beads or particles may be treated to remove sulphur and the beads or particles are returned to the leaching step. Alternatively the mineral doesn't need to comprise a soluble component and can be a refractory sulphide of iron and/or arsenic containing precious metals that require oxidation before downstream conventional processes such as cyanidation.

A method of removing aluminum from a waste electrode. The method includes comminuting the waste electrode containing a waste current collector and an electrode active material. The method further includes screening the comminuted waste electrode to collect the electrode active material. The method further includes mixing the electrode active material and an alkaline solution to remove aluminum impurities in the electrode active material.

Compositions, systems, and methods for selectively leaching and/or extracting lithium from sedimentary deposits and other resources are generally described.

A method for extracting noble metals from mining tailings and other solids is provided. The method uses a Lewis acid, Brønsted acid, complexing agent and oxygen to provide excellent extraction without the need for chorine gas or cyanide.

Any metal having a low α-ray emission, the metal being any one of tin, silver, copper, zinc, or indium, wherein an emission of an α-ray after heating the metal at 100° C. in an atmosphere for six hours is 0.002 cph/cm.sup.2 or less. Any metal of tin, silver, copper, zinc and indium each including lead as an impurity is dissolved to prepare a hydrosulfate aqueous solution of the metal and lead sulfate is precipitated and removed in the solution. The lead sulfate is precipitated in the hydrosulfate aqueous solution by adding a lead nitrate aqueous solution including lead having an α-ray emission of 10 cph/cm.sup.2 or less to the hydrosulfate aqueous solution, from which the lead sulfate has been removed, and, at the same time, the solution is circulated while removing the lead sulfate to electrowinning the metal using the hydrosulfate aqueous solution as an electrolytic solution.

A method for separating thorium and cerium from a solid concentrate comprising compounds of thorium, cerium and further rare earth metals, comprising: a) contacting the solid concentrate with an acid to achieve an acid composition with a pH of less than 0.5; b) reacting the acid composition obtained in step a) with ozone or heating the acid composition at a temperature ranging from 110° C. to 130° C. for a time period ranging from 1 to 3 hours, thereby oxidizing the cerium ions in the acid composition to an oxidation state of +IV; c) increasing, to at most 2, the pH of the composition obtained in step b), resulting in the precipitation of thorium and cerium compounds; and d) separating the precipitated thorium and cerium compounds from the composition obtained in step c) to obtain an aqueous acidic rare earth solution depleted in thorium and cerium.

Methods for recovering a metal value from a metal-bearing material are provided. The method comprises agglomerating the metal-bearing material with an agglomeration solution comprising a raffinate, an oxidant, and citric acid or salts thereof to form an agglomerated metal-bearing material; leaching the agglomerated metal-bearing material with a leaching solution comprising the raffinate and the citric acid or salts thereof to produce a pregnant leaching solution and a leached material; re-oxidizing the leached material with a curing solution comprising the raffinate and the oxidant; and recovering the metal value from the pregnant leach solution to produce the raffinate.

Methods for recovering a metal value from a metal-bearing material are provided. The method comprises agglomerating the metal-bearing material with an agglomeration solution comprising a raffinate, an oxidant, and citric acid or salts thereof to form an agglomerated metal-bearing material; leaching the agglomerated metal-bearing material with a leaching solution comprising the raffinate and the citric acid or salts thereof to produce a pregnant leaching solution and a leached material; re-oxidizing the leached material with a curing solution comprising the raffinate and the oxidant; and recovering the metal value from the pregnant leach solution to produce the raffinate.