A composite extractant-enhanced polymer resin comprising an extractant and a polymer resin for direct extraction of valuable metals such as rare earth metals, and more specifically, scandium, from an acid-leaching slurry and/or acid-leaching solution in which ferric ions are not required to be reduced into ferrous ions. The extractant may be cationic, non-ionic, or anionic. More specifically, the extractant di(2-ethylhexyl)phosphoric acid may be used. The polymer resin may be non-functional or have functional groups of sulfonic acid, carboxylic acid, iminodiacetic acid, phosphoric acid, or amines. The composite extractant-enhanced polymer resin may be used for extraction of rare earth metals from acid-leaching slurries or solutions.

Provided is a method for recovering scandium, with which it is possible to easily and efficiently recover high-purity scandium from nickel oxide ores. This method for recovering scandium involves passing a solution containing scandium through an ion exchange resin, then subjecting the eluant eluted from the ion exchange resin to solvent extraction and separating the extraction residual liquid and the extraction agent after extraction, then performing an oxalation process on the extraction residual liquid to obtain a scandium oxalate precipitate, and roasting the precipitate to obtain scandium oxide, wherein the method is characterized in that an amine-based extraction agent is used as the extraction agent for solvent extraction.

A method for recycling rare earth from a wastewater from rare earth mining or from rare earth smelting, includes the steps of: removing oil from the wastewater to obtain a degreased wastewater; purifying the degreased wastewater to obtain a purified wastewater using a pretreatment system; recycling rare earth from the purified wastewater to obtain a rare earth slurry and a low rare earth wastewater using a rare earth recycling tank; treating the low rare earth wastewater to obtain ammonia gas using an ammonium degassing device; and converting the ammonia gas to obtain aqueous ammonia using an aqueous ammonium preparing system.

Methods for removing, reducing or treating the trace metal contaminants and the smaller fine sized cerium oxide particles from cerium oxide particles, cerium oxide slurry or chemical mechanical polishing (CMP) compositions for Shallow Trench Isolation (STI) process are applied. The treated chemical mechanical polishing (CMP) compositions, or the CMP polishing compositions prepared by using the treated cerium oxide particles or the treated cerium oxide slurry are used to polish substrate that contains at least a surface comprising silicon dioxide film for STI (Shallow trench isolation) processing and applications. The reduced nano-sized particle related defects have been observed due to the reduced trace metal ion contaminants and reduced very smaller fine cerium oxide particles in the Shallow Trench Isolation (STI) CMP polishing.

The present invention relates to a process, method and plant for recovering scandium and ions containing scandium using an ion exchange resin from a feed stream. The feed stream may be, but is by no means limited to, a leach liquor or leach pulp.

A method for producing a solid scandium-containing material comprises providing an aqueous solution containing carbonate ions, carbamate ions, hydrogen carbonate (HCO.sub.3.sup.+) ions, or mixtures thereof, contacting the aqueous solution with a scandium containing material containing one or more impurities to produce a scandium-loaded solution and a depleted scandium containing material, separating the depleted scandium containing material from the scandium loaded solution, treating the scandium loaded solution to cause precipitation of a solid scandium-containing material while avoiding or minimizing precipitation of impurities present in the aqueous solution, and separating the solid scandium-containing material from the solution. In another embodiment, a high purity scandium containing is produced by contacting a solid material containing scandium with an acid to form a scandium loaded solution, separating the scandium loaded solution from any solids, adding additional acid to the scandium loaded solution to reduce the pH and precipitating a high purity scandium oxalate material by adding oxalic acid to the solution.

The present disclosure provides a process for polishing at least one metal contaminant from a stock solution comprising Sc comprising the steps of a) contacting the stock solution with an ion exchange resin capturing Sc and the at least one metal contaminate so as to produce a metal ion exchange resin complex, and b) scrubbing the metal resin complex with a scrubbing solution comprising a carboxylate ion, so as to produce a Sc ion exchange resin complex and a spent carboxylate solution, which can be treated by electrodialysis to regenerate the carboxylate ion required for scrubbing.

The present disclosure provides a process for polishing at least one metal contaminant from a stock solution comprising Sc comprising the steps of a) contacting the stock solution with an ion exchange resin capturing Sc and the at least one metal contaminate so as to produce a metal ion exchange resin complex, and b) scrubbing the metal resin complex with a scrubbing solution comprising a carboxylate ion, so as to produce a Sc ion exchange resin complex and a spent carboxylate solution, which can be treated by electrodialysis to regenerate the carboxylate ion required for scrubbing.

According to this method for recovering scandium, an acidic solution containing scandium is used and a scandium dissolution liquid after purification is obtained by a double sulfate precipitation step, and scandium is recovered from the obtained scandium dissolution liquid, as follows: [A] A precipitation step wherein sodium sulfate is added into the acidic solution containing scandium, so that a precipitate of a scandium double sulfate is obtained; [B] A neutralization step wherein pure water is added to the precipitate of a scandium double sulfate obtained in the precipitation step to dissolve the precipitate of a scandium double sulfate therein, and scandium hydroxide is obtained by adding a neutralizing agent into the obtained dissolution liquid; and [C] A re-dissolution step wherein an acid is added to the scandium hydroxide obtained in the neutralization step, so that a scandium dissolution after purification, in which the scandium hydroxide is dissolved, is obtained.

In alternative embodiments, the invention provides processes and methods for extracting and recovering rare earth materials from a wet-process phosphoric acid using one or more continuous ion exchange resin systems. In alternative embodiments, the method is particularly suited for use in extracting and recovering multiple rare earth materials present in low concentrations contained in wet-process phosphoric acid.