Provided are a selective recovery method of vanadium and cesium from a waste sulfuric acid vanadium catalyst by a hydrometallurgical method including water leaching, solid-liquid separation, vanadium solvent extraction, vanadium selective stripping, and cesium alum production, and a high-quality vanadium aqueous solution and cesium alum produced thereby.

A method of separating actinium and/or radium from proton-irradiated thorium metal. The thorium metal is irradiated to produce isotopes including thorium, actinium and/or radium. The resultant product is dissolved in solution and a selective precipitant is used to precipitate a bulk portion of the thorium. The precipitated thorium can be recovered. Chromatography is carried out on the remaining solution to remove residual thorium and to separate the actinium from the radium.

A method of separating actinium and/or radium from proton-irradiated thorium metal. The thorium metal is irradiated to produce isotopes including thorium, actinium and/or radium. The resultant product is dissolved in solution and a selective precipitant is used to precipitate a bulk portion of the thorium. The precipitated thorium can be recovered. Chromatography is carried out on the remaining solution to remove residual thorium and to separate the actinium from the radium.

A composite extractant-enhanced polymer resist comprising an extractant and a polymer resin for direct extraction of valuable metals such as rare earth metals, and more specifically, scandium, Born 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.

A composite extractant-enhanced polymer resist comprising an extractant and a polymer resin for direct extraction of valuable metals such as rare earth metals, and more specifically, scandium, Born 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.

The present invention related to the use of compounds of general formula (I) for separations of rare earth elements (lanthanides) by precipitation, wherein R is selected from the group consisting of H; —CH2COOH; R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 areindependently selected from the group consisting of H; OH; —NO2; —COOH; phenyl; and/or R.sup.2 and R.sup.3 or R.sup.3 and R.sup.4 or R.sup.4 and R.sup.5 or R.sup.5 and R.sup.6 The invention further relates to a method of separation of rare earth elements by precipitation. together with two neighbouring carbon atoms of the aromatic ring form a six-membered aromatic ring.

##STR00001##

The present invention related to the use of compounds of general formula (I) for separations of rare earth elements (lanthanides) by precipitation, wherein R is selected from the group consisting of H; —CH2COOH; R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 areindependently selected from the group consisting of H; OH; —NO2; —COOH; phenyl; and/or R.sup.2 and R.sup.3 or R.sup.3 and R.sup.4 or R.sup.4 and R.sup.5 or R.sup.5 and R.sup.6 The invention further relates to a method of separation of rare earth elements by precipitation. together with two neighbouring carbon atoms of the aromatic ring form a six-membered aromatic ring.

##STR00001##

Provided are a selective recovery method of vanadium and cesium from a waste sulfuric acid vanadium catalyst by a hydrometallurgical method including water leaching, solid-liquid separation, vanadium solvent extraction, vanadium selective stripping, and cesium alum production, and a high-quality vanadium aqueous solution and cesium alum produced thereby.

Provided are a selective recovery method of vanadium and cesium from a waste sulfuric acid vanadium catalyst by a hydrometallurgical method including water leaching, solid-liquid separation, vanadium solvent extraction, vanadium selective stripping, and cesium alum production, and a high-quality vanadium aqueous solution and cesium alum produced thereby.

Provided is a method for producing, from scandium oxalate crystals obtained through an oxalate conversion process, a readily-soluble scandium compound that dissolves easily in an aqueous solution such as an acid. This method for producing a scandium compound involves carrying out an oxalate conversion process using oxalic acid in a solution containing scandium, separating the product obtained through the oxalate conversion process into a liquid and scandium oxalate crystals, and obtaining a scandium compound by roasting the obtained scandium oxalate crystals at a temperature of 400° C. to 800° C., preferably 400° C. to 600° C.