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.

Provided is a method for obtaining high-purity scandium oxide efficiently from a solution containing scandium. The method for producing high-purity scandium oxide of the present invention has a first firing step S12 for subjecting a solution containing scandium to oxalation treatment using oxalic acid and firing the obtained crystals of scandium oxalate at a temperature of 400 to 600 C., inclusive, a dissolution step S13 for dissolving the scandium compound obtained by firing in one or more solutions selected from hydrochloric acid and nitric acid to obtain a solution, a reprecipitation step S14 for subjecting the solution to oxalation treatment using oxalic acid and generating a reprecipitate of scandium oxalate, and a second firing step S15 for firing the reprecipitate of obtained scandium oxalate to obtain scandium oxide.

A method for recovery of precious metals from copper anode slime may include leaching a leach liquor out of the copper anode slime by mixing the copper anode slime with a mixture of nitric acid and sulfuric acid, separating silver from the leach liquor by forming a silver chloride precipitate in the leach liquor by mixing a supersaturated sodium chloride solution with the leach liquor at room temperature and obtaining a first filtrate by filtering the silver chloride precipitate out of the leach liquor. Copper may be separated from the first filtrate by forming a copper hydroxide precipitate in the first filtrate by adjusting pH of the first filtrate at 9 and obtaining a second filtrate by filtering the copper hydroxide precipitate out of the first filtrate. Metallic selenium may be recovered from the second filtrate by reducing the metallic selenium via a chemical reduction utilizing L-ascorbic acid (LAA) as a reducing agent.

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.

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.

A process and system are disclosed for recovering lithium from a lithium-containing silicate mineral. The process and system comprise mixing the silicate mineral with nitric acid. The process and system also comprise subjecting the mixture to a leaching process having conditions such that lithium values in the silicate mineral are leached from the silicate mineral as lithium nitrate. The nitric acid can be in aqueous, gaseous or precursor gaseous form.

Disclosed is a method for clean metallurgy of molybdenum, including steps: 1) roasting molybdenite with calcium to obtain calcified molybdenum calcine, and leaching the calcified molybdenum calcine with an inorganic acid to obtain a molybdenum-containing inorganic acid leachate; 2) extracting molybdenum in the leachate with a cationic extractant to obtain an organic phase loaded with molybdyl cations and a raffinate; 3) using a hydrogen peroxide solution as a stripping agent to obtain a molybdenum stripping liquor; and 4) heating the molybdenum stripping liquor to dissociate peroxymolybdic acid therein so as to form a molybdic acid precipitate, and then calcining to obtain a molybdenum trioxide product. The method solves the problem of ammonia nitrogen wastewater production and can also be used for the enrichment and recovery of rhenium.

A method for separating a light rare earth element and a heavy rare earth element includes at least the steps of: (1) 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) dissolving the obtained composite oxide or mixture of oxides in hydrochloric acid and/or nitric acid; (3) adding a precipitant to the obtained solution to give a precipitate; (4) calcining the obtained precipitate; (5) 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) 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.

A method of making a zeolite comprises: adding a zeolite seed to a leach solution containing silicon and aluminum; and heating the leach solution to obtain the zeolite. The leach solution can be made by mixing coal ash with a basic stream, thereby creating (i) a leach solution containing silicon and aluminum, and (ii) leached ash; and separating the leach solution from the leached ash.

A process for 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 including a plurality of caustic extractions of coal ash at an elevated temperature, followed by an acidic treatment to dissolve aluminum silicate and REEs. 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 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.