A process may involve treating calcium sulfate separated from phosphoric acid with acid to obtain a suspension comprising purified calcium sulfate, separating the purified calcium sulfate in solid form from a liquid phase of the suspension, treating the purified calcium sulfate with water or with a salt- and/or chelate ligand-containing aqueous solution to leach rare earths out of the calcium sulfate, separating the further-purified calcium sulfate in solid form from the liquid phase of the suspension, mixing the purified calcium sulfate that is separated off with admixtures and reducing agents to obtain a raw meal mixture for cement clinker production, burning the raw meal mixture to obtain the cement clinker and thereby forming sulfur dioxide as offgas, and feeding the sulfur dioxide as raw material to sulfuric acid production to produce the sulfuric acid.

Recovery of noble metals (including the recovery of gold and/or silver from gold and/or silver containing material) is generally described. The gold and/or silver can be recovered selectively, in some cases, such that gold and/or silver are at least partially separated from non-silver and/or non-gold material. Gold and/or silver may be recovered from material using mixtures of acids, in some instances. In some cases, the mixture can comprise nitric acid and at least one supplemental acid, such as sulfuric acid, phosphoric acid, and/or a sulfonic acid. The amount of nitric acid within the mixture can be, in some instances, relatively small compared to the amount of sulfuric acid or phosphoric acid within the mixture. In some cases, the recovery of gold and/or silver using the acid mixtures can be enhanced by transporting an electric current between an electrode and the gold and/or silver of the material. In some cases, acid mixtures can be used to recover silver from particular types of materials, such as material comprising silver metal and cadmium oxide and/or material comprising silver metal and tungsten metal.

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.

The present invention refers to an improved process for recovering zinc from primary and secondary raw materials, said process comprising a first leaching step wherein the ratio between the zinc weight contained in the raw material and the volume of the leaching solution is at least 20 kg zinc per m.sup.3 of acid aqueous solution; a neutralization step; and a solvent extraction stage in the presence of organic extractant, wherein the temperature is maintained from 47 to 52° C.

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

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.

A method of processing a gold-containing ore that contains reactive sulphide minerals that includes selecting processing conditions to optimize liberating gold in reactive sulphide minerals and processing the ore in accordance with the selected processing conditions and liberating gold in the reactive sulphide minerals. In other words, when there are reactive sulphide minerals and “barren” minerals in an ore, the invention focuses on liberating gold in the reactive sulphide minerals only.

A method of recovering substantially rare earth elements (REEs) from magnets, including first dissolving a magnet to yield a solution containing Nd, Pr, and Dy, and then equilibrating a first column with Cu2+ solution to yield a first equilibrated column, introducing the solution to the first equilibrated column, and introducing a ligand solution to the first equilibrated column to establish three bands of different liquid compositions in the column, wherein the three bands comprise a Dy/Nd mixed band, a first pure Nd band, and a Nd/Pr mixed band. Next, sending the Dy/Nd mixed band to a second column containing a Cu2+ solution and introducing a ligand solution to the second column to establish a pure Dy band and a second pure Nd band in the second column, and sending the Nd/Pr mixed band to a third column containing a Cu2+ solution and introducing a ligand solution to the third column to establish a third pure Nd band and a pure Pr band in the third column. Finally, eluting the respective pure Nd bands to recover Nd, eluting the pure Dy band to recover Dy, and eluting the pure Pr band to recover Pr.

The invention relates to a method for recovering precious metals from electronic waste utilising biometallurgical techniques. In one aspect, a method of recovering one or more target metals from electronic waste, includes (a) removing at least a portion of non-target material from the electronic waste or grinding to a preselected size particle to give pre-processed electronic waste; (b) contacting the pre-processed electronic waste with a lixiviant such that at least a portion of the target metal(s) dissolve into the lixiviant to produce a pregnant solution; (c) contacting a microorganism with the pregnant solution such that at least a portion of the target metal(s) ions biosorb to the microorganism wherein the microorganism becomes metal laden and the pregnant solution becomes barren; (d) substantially separating the metal laden microorganism from the barren solution; and (e) recovery of the target metal(s) from the metal laden microorganism.

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.