A system for recovering rare earth elements from coal ash includes a leaching reactor, an ash dryer downstream of the leaching reactor, and a roaster downstream of the ash dryer that is cooperatively connected to both the leaching reactor and the ash dryer. Coal ash is mixed with an acid stream such that rare earth elements present in the coal ash are dissolved in the acid stream, thereby creating (i) a leachate containing the rare earth elements and (ii) leached ash. The leachate is heated to obtain acid vapor and an acid-soluble rare earth concentrate. Mixing of the coal ash with the acid stream can occur in a leaching reactor and heating of the leachate can occur in a roaster. The acid-soluble rare earth concentrate can be fed to a hydrometallurgical process to separate and purify the rare earth elements.

In a method for recovering a copper sulfide concentrate by froth flotation from an ore containing an iron sulfide, wet grinding of the ore with grinding media made of high chromium cast iron alloy having a chromium content of from 10 to 35% by weight is combined with an addition of hydrogen peroxide to the conditioned mineral pulp before or during flotation in order to improve concentrate grade and recovery of copper sulfides.

In a method for recovering a copper sulfide concentrate by froth flotation from an ore containing an iron sulfide, wet grinding of the ore with grinding media made of high chromium cast iron alloy having a chromium content of from 10 to 35% by weight is combined with an addition of hydrogen peroxide to the conditioned mineral pulp before or during flotation in order to improve concentrate grade and recovery of copper sulfides.

Methods for recovering gold from a refractory gold ore and concentrate are described. The method can include leaching the refractory gold ore and concentrate with the alkaline reagent under ambient or near-ambient conditions and a subsequent gold complexation. The method can optionally include separating a gold-containing leachate from a gold-unlocked solid residue obtained during the leaching step and performing a subsequent complexation on the gold-unlocked solid residue and optionally gold complexation on the gold-containing leachate. These methods can increase the gold recovery compared to conventional methods.

Methods for recovering gold from a refractory gold ore and concentrate are described. The method can include leaching the refractory gold ore and concentrate with the alkaline reagent under ambient or near-ambient conditions and a subsequent gold complexation. The method can optionally include separating a gold-containing leachate from a gold-unlocked solid residue obtained during the leaching step and performing a subsequent complexation on the gold-unlocked solid residue and optionally gold complexation on the gold-containing leachate. These methods can increase the gold recovery compared to conventional methods.

Apparatuses and methods for extracting desired chemical species and/or impurities from input material. An aspect of the present disclosure comprises a continuous flow system using solvents and other reactants to assist in conversion and extraction of the desired output material and/or removal of specific impurities from the input material through pressure, temperature, and volume control within the extraction system.

A hydrometallurgical process is provided for the selective extraction of one or more target metals from ore, concentrates, tailings, slags or other metal bearing solids, by combining simultaneously leaching with sorption in the state of wet solids. The sorption is performed by means of sorbents such as ion exchange resins, activated carbon, zeolites, among others, and mixtures thereof. The process comprises the steps of: (a) blending the metal bearing solids with acidic or basic leaching agents, one or more sorbents, and a sufficient amount of an aqueous solution to wet substantially both the metal bearing solids and the sorbent without formation of a slurry, thereby obtaining wet solids; (b) performing sorption leaching in wet solids; (c) diluting the wet solids and preparing a pulp by adding an aqueous solution; (d) separating the loaded sorbent from the pulp; (e) eluting (desorbing) target metals from the loaded sorbent with an eluent to an eluate, returning thereafter the sorbent back to the blending step (a); and (f) recovering target metals from the eluate to obtain one or more final metal products, returning the eluent back to the elution step (e). The invention has the main advantage of improving metal recoveries at a reduced consumption rate of leaching agents.

A method is provided for recycling lithium-ion batteries containing plastics, electrolyte, carbon, metals, and lithium. The method includes: Lithium-ion batteries are ground to form ground battery material which is then pyrolyzed at a temperature between about 100° C. and 700° C. for a time sufficient to vaporize about 80 wt % to 100 wt % of electrolytes present in the ground battery material. The resulting material is further ground and screen classified to produce a screen oversize and a screen undersize. The screen oversize comprises metals and plastics, while the screen undersize comprises a black mass material. Lithium dissolution, triboelectric charging and electrostatic separation of the black mass material (not necessarily in that order) produces a liquid comprising dissolved lithium, a graphite product, and a concentrated metal fines product. Lithium is precipitated from the liquid comprising dissolved lithium, and the concentrated metal fines can be further treated by hydrometallurgy or pyrometallurgy processes.

A method and system are provided in which a gold and/or silver-collecting resin-in-leach circuit comprises both co-current and counter-current sections.

A method and system are provided in which a gold and/or silver-collecting resin-in-leach circuit comprises both co-current and counter-current sections.