Provided are a method for crushing hard tungsten carbide (WC) scraps which is a pre-step of alkaline leaching and acid leaching processes for recycling of tungsten and cobalt, the method including mixing hard tungsten carbide (WC) scraps such as chips, wires, bolts, drills, etc., that are metalworking tools to be discarded after being used, with aluminum, followed by heating to a high temperature, to form an intermetallic compound, metal oxides, or mixtures thereof in a sponge form, and crushing the intermetallic compound, the metal oxides, or the mixtures thereof in a sponge form. Further, provided is a method for recovering tungsten and cobalt from hard tungsten carbide (WC) scrap powder through alkaline leaching and acid leaching methods.

In one aspect, the disclosure relates to a continuous process for treating acid mine drainage while simultaneously recovering a high-grade rare earth preconcentrate suitable for extraction of commercially valuable rare earth oxides. In a further aspect, the preconcentrate is from about 0.1% to 5% rare earth elements on a dry weight basis. In another aspect, the disclosure relates to a method for processing the preconcentrate to generate a pregnant leach solution that does not form gels or emulsions and is suitable for processing via solvent extraction. In another aspect, the disclosure relates to a system and plant for carrying out the disclosed process. In still another aspect, the disclosure relates to a composition containing rare earth elements produced by the process disclosed herein. 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 discloses a method for recycling a spent lithium-ion battery, including the following steps: sandwiching a cathode of the spent lithium-ion battery with a conductive acid-resistant material as a cathode of a primary battery system; sandwiching an anode of the spent lithium-ion battery with a conductive acid-resistant material as an anode of the primary battery system; injecting an acid solution into a chamber of the primary battery system; and carrying out, after an electrochemical reaction is completed, solid-liquid separation on a mixed liquor in the chamber. The present invention further discloses an electrochemical system for recycling a spent lithium-ion battery. The method for recycling a spent lithium-ion battery in the present invention requires only dismantlement of cathode and anode materials, without a series of complex pretreatment operations on the cathode materials of the spent lithium-ion battery. In addition, by the method, the cathodes and anodes of the spent lithium-ion battery can be recycled at the same time, and valuable elements can be separated, which is greatly improved compared with the electrolytic leaching method. Moreover, there is no need to add an external power supply, which saves energy and can also output electricity.

A process disclosed herein is related to the isolation and purification of substantially pure chemicals, including silica gel, sodium silicate, aluminum silicate, iron oxide, and rare earth elements (or rare earth metals, REEs), from massive industrial waste coal ash. In one embodiment, the process includes a plurality of caustic extractions of coal ash at an elevated temperature, followed by an acidic treatment to dissolve aluminum silicate and REEs. The dissolved aluminum silicate is precipitated out by pH adjustment as a solid product while REEs remain in the solution. REEs are captured and enriched using an ion exchange column. Alternatively, the solution containing aluminum silicate and REEs is heated to produce silica gel, which is easily separated from the enriched REEs solution. REEs are then isolated and purified from the enriched solution to afford substantially pure individual REE by a ligand-assisted chromatography. Additionally, a simplified process using one caustic extraction and one acidic extraction with an ion exchange process was also investigated and optimized to afford a comparable efficiency.

A process is disclosed for recovering lithium from a lithium-containing silicate mineral. The process comprises mixing the silicate mineral with nitric acid. The process also comprises subjecting the mixture to a leaching process having conditions such that lithium values in the silicate mineral are leached into an aqueous phase as lithium nitrate. The leaching process conditions may be controlled such that non-lithium values in the silicate mineral tend not to be leached into the aqueous phase.

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

In a method of recovering an active metal of a lithium secondary battery, an acidic leaching liquid is added to a material to be recovered which contains a lithium metal oxide to form a mixture including a first active metal solution and a leached residue. The formed mixture is subjected to solid-liquid separation for separating the first active metal solution from the leached residue to form a second active metal solution. A lithium hydroxide aqueous solution containing an iron salt is added to the second active metal solution to form a third active metal solution from which impurities are removed or reduced. A lithium precursor is recovered from the third active metal solution.

An improved beta(?)-spodumene (?LiAlSi.sub.2O.sub.6) nitric acid conversion process produces discrete lithium (Li), aluminum (Al) and silica (SiO.sub.2) materials by: (i) converting lithium nitrate, LiNO.sub.3, to lithium carbonate, Li.sub.2CO.sub.3; (ii) creating a Al-rich precipitate either by thermally decomposing aluminum nitrate, Al(NO.sub.3).sub.3, or by reacting Al(NO.sub.3).sub.3 with aqueous and/or solid ammonium carbonate, (NH.sub.4).sub.2CO.sub.3; and (iii) forming a solid SiO.sub.2-rich aluminosilicate residue by selectively leaching Li and Al from ?-spodumene. Three key reactants consumed during processingnitric acid (HNO.sub.3), ammonia (NH.sub.3), and magnesium oxide (MgO)may be regenerated internally by closed-loop chemical cycles, this feature of the process greatly improving its economics in commercial applications.

The present invention relates to use of an amino-containing neutral phosphine extractant of Formula I in extraction and separation of thorium, and a process of extracting and separating thorium using the amino-containing neutral phosphine extractant of Formula I, ##STR00001##
wherein, R.sub.1 and R.sub.2 are each independently selected from the group consisting of C.sub.1-C.sub.12 alkyl, R.sub.3 and R.sub.4 are each independently selected from the group consisting of C.sub.1-16 alkyl and hydrogen, and n is an integer of 1 to 8.

An object of the present invention is to provide a method useful for separating a light rare earth element and a heavy rare earth element, which, for example, when a light rare earth element and a heavy rare earth element are separated from a workpiece containing a light rare earth element and a heavy rare earth element by a solvent extraction method, makes it possible to reduce the amount of extractant or organic solvent used or downsize the apparatus, or makes it possible to reduce the work burden on the process, such as the analysis of the content ratio between the light rare earth element and the heavy rare earth element contained in the workpiece. The method of the present invention as a means for resolution is characterized by including at least: (1) a step of obtaining, from a workpiece containing a light rare earth element and a heavy rare earth element, a composite oxide or mixture of oxides of the two; (2) a step of dissolving the obtained composite oxide or mixture of oxides of a light rare earth element and a heavy rare earth element in hydrochloric acid and/or nitric acid; (3) a step of adding a precipitant to the obtained solution to give a precipitate; (4) a step of calcining the obtained precipitate; (5) a step of adding the obtained calcine in an amount of 1.1 times to 3.0 times the upper solubility limit to hydrochloric acid and/or nitric acid having a concentration of 0.7 mol/L or more to give a solution and a residue; and (6) a step of separating the obtained solution and residue, thereby giving the solution as a light rare earth element-rich inclusion and the residue as a heavy rare earth element-rich inclusion (here, the term rich means that the content ratio of the concerned rare earth element to the other rare earth element is higher than the content ratio in the workpiece).