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.

A method of making a polycrystalline diamond compact includes forming a first layer of polycrystalline diamond precursor materials comprising diamond particles and a first concentration of catalyst, forming a second layer of polycrystalline diamond precursor materials comprising diamond particles and a second concentration of catalyst, and placing a layer of an infiltrant material in the proximity of the first or the second layer of polycrystalline diamond precursor materials. The second concentration of catalyst is greater than the first concentration of catalyst. The infiltrant material is a catalyst. The first layer and the second layer are sintered under high-pressure high-temperature conditions in the presence of the infiltrant material to form the polycrystalline diamond compact. At least a portion of the catalyst is leached from the polycrystalline diamond compact.

A process for removal of aluminium and iron in the recycling of rechargeable batteries comprising providing a leachate from black mass, adding phosphoric acid (H.sub.3PO.sub.4) to said leachate and adjusting the pH to form iron phosphate (FePO.sub.4) and aluminium phosphate (AlPO.sub.4), precipitating and removing the formed FePO.sub.4 and AlPO.sub.4, and forming a filtrate for further recovery of cathode metals, mainly NMC-metals and lithium.

A process for bio-oxidation of sulfides in mineral ore having a metal such as gold occluded or dispersed within the ore as a sulfide is disclosed. The first step comminutes the ore into particles with a size distribution having a P80 of less than 0.25 inch with minus 106 micron particles in the range of 15% to 40% by weight. Agglomerates are formed by adding to the comminuted ore particles an acidic inoculate solution including water, with the solution further including microorganisms capable of bio-oxidizing the sulfides. The agglomerates are then placed in at least one bio-reactor containment vessel to form an ore bed. The process continues by bio-oxidizing the sulfides in the ore bed; then re-circulating the solution through the ore bed, and continuing the bio-oxidation until a desired bio-oxidation level is achieved. Thereafter, the metal is recovered from the ore.

Systems and methods for direct recycling and upcycling of spent cathode materials using Flame-Assisted Spray Pyrolysis Technology (FAST). In illustrative embodiments, cathode layers are separated and collected from spent battery cells. The cathode laminate is ground to a powdered form and treated to remove contaminants by sifting into a hot stream of air which heats the powders, burning off contaminants. After cooling and particle collection, the powders may be dispersed into leaching solution to dissolve metal oxides and create an acid metal solution or ground into nano-sized primary particles and mixed with dispersing liquids to form a solution. The solution may be mixed with glycerol and additional metal salts to create a final precursor solution, which may undergo spray pyrolysis followed by drying and calcination to create cathode materials with high consistency and repeatability, or mixed with an alkaline metal salt solution and undergo electrodeposition to recover desired metal salts.

A cone valve of the present invention enables to extend a lifespan more than a conventional cone valve even if it is used as a check valve when feeding slurry containing highly abrasive coarse particles. A cone valve (1) used as a check valve when feeding slurry, comprising at least a valve body (11), a valve seat (13), and a spring (14) incorporated to make the valve body (11) contact the valve seat (14), wherein an entire length of the spring (14) is at least shorter than a stroke length of the valve body (11).

Provided is a hydrometallurgical process of recovering Ni from nickel oxide ore using a high pressure acid leaching, in which abrasion of the facilities caused by an ore slurry is suppressed, the amount of a final neutralized residue is reduced, and impurity components are separated and recovered for recycling. The hydrometallurgical process includes, as steps of the high pressure acid leaching, at least one step selected from step (A): separating and recovering chromite particles in the ore slurry; step (B-1): through leaching step and a solid-liquid separation step, performing neutralization of a leachate obtained after the solid-liquid separation step using a Mg-based alkali such as Mg(OH).sub.2; and step (B-2): through leaching step and a solid-liquid separation step, performing neutralization of a leachate obtained after the solid-liquid separation step using a Mg-based alkali such as Mg(OH).sub.2, and then recovering hematite particles.

Provided is a production method for refining iron oxide (hematite), which has such a low sulfur content as to be used as an iron-making raw material, from a leach residue containing iron oxide produced by a high pressure acid leach (HPAL) process. In the method for refining iron oxide for ironmaking by a process of adding sulfuric acid to nickel oxide ore and then leaching nickel from the nickel oxide ore using a pressure vessel, an amount of the sulfuric acid added is 150 kg or more and 220 kg or less per ton of nickel oxide ore.

A method is provided for leaching the metals while granulating molten matte, comprising the steps of feeding a molten matte as a falling stream into a granulation chamber, spraying a liquid jet on the stream of molten matte to atomize the matte, and cooling the matte particles thus formed. The liquid jet comprises an acid solution containing water and sulfuric acid so that the acid solution starts leaching metals from the molten matte when the liquid jet contacts the molten matte. Part of product solution from granulation can be circulated to liquid jets to increase the metal content in the solution and to reduce its acid con-tent.

Hydrometallurgical solvent extraction processes for recovering value metal ion species such as any of manganese, cobalt, nickel, and/or lithium from solutions derived from recycled electronics and/or batteries and containing mixed-metal ions by separating the value metal ions using selective stripping techniques as herein described, are provided.