Patent application number | Description | Published |
20100319491 | METHOD FOR EXTRACTING AND SEPARATING RARE EARTH ELEMENTS - Solvent extraction from an aqueous phase containing first and second rare earth elements is carried out by contacting an organic phase containing a diglycolamic acid as an extractant and a hydrocarbon or a low-polar alcohol as a solvent, with the aqueous phase below pH 3 for extracting the first rare earth element into the organic phase, back-extracting from the organic phase with an aqueous acid solution for recovering the first rare earth element, and recovering the second rare earth element which has not been extracted into the organic phase and has remained in the aqueous phase. | 12-23-2010 |
20120004458 | SYNTHESIS OF RARE EARTH METAL EXTRACTANT - A rare earth metal extractant in the form of a dialkyl diglycol amic acid is synthesized by reacting diglycolic anhydride with a dialkylamine in a synthesis medium. A molar ratio (B/A) of dialkylamine (B) to diglycolic anhydride (A) is at least 1.0. A non-polar or low-polar solvent in which the dialkyl diglycol amic acid is dissolvable is used as the synthesis medium. | 01-05-2012 |
20120004459 | SYNTHESIS OF RARE EARTH METAL EXTRACTANT - A rare earth metal extractant in the form of a dialkyl diglycol amic acid is synthesized by reacting diglycolic anhydride with a dialkylamine in an aprotic polar solvent, with a molar ratio of dialkylamine to diglycolic anhydride being at least 1.0, and removing the aprotic polar solvent. | 01-05-2012 |
20120328493 | METHOD FOR EXTRACTING AND SEPARATING LIGHT RARE EARTH ELEMENT - A target light rare earth element is separated from an aqueous solution containing two or more of La, Ce, Pr and Nd by contacting an organic phase containing an extractant with the aqueous solution in a counter-current flow multistage mixer-settler while adding an alkaline solution thereto, and contacting the organic phase with an acid aqueous solution for back-extracting the target element. The extractant is a dialkyl diglycol amic acid having formula: R | 12-27-2012 |
20130102806 | METHOD FOR SYNTHESIZING RARE EARTH METAL EXTRACTANT - A rare earth metal extractant containing, as the extractant component, dialkyldiglycol amide acid which is excellent in breaking down light rare earth elements is reacted in diglycolic acid (X mol) and an esterification agent (Y mol) at a reaction temperature of 70° C. or more and for a reaction time of one hour or more such that the mol ratio of Y/X is 2.5 or more, and is subjected to vacuum concentration. Subsequently, a reaction intermediate product is obtained by removing unreacted products and reaction residue, and an aprotic polar solvent is added as the reaction solvent. Then, the reaction intermediate product is reacted with dialkyl amine (Z mol) such that the mol ratio of Z/X is 0.9 or more and the aprotic polar solvent is removed. As a consequence, a rare earth metal extractant is efficiently synthesized at a low cost and at a high yield without having to use expensive diglycolic acid anhydride and harmful dichloromethane. | 04-25-2013 |
20130123534 | METHOD FOR SYNTHESIZING RARE EARTH METAL EXTRACTANT - A rare earth metal extractant containing, as the extractant component, dialkyldiglycol amide acid which is excellent in breaking down light rare earth elements is reacted in diglycolic acid (X mol) and an esterification agent (Y mol) at a reaction temperature of 70° C. or more and for a reaction time of one hour or more such that the mol ratio of Y/X is 2.5 or more, and is subjected to vacuum concentration. Subsequently, a reaction intermediate product is obtained by removing unreacted products and reaction residue. Then a nonpolar or low-polar solvent which is an organic solvent for forming an organic phase during solvent extraction of the rare earth metal and which is capable of dissolving dialkyldiglycol amide acid is added as the reaction solvent, and the reaction intermediate product is reacted with dialkyl amine (Z mol) such that the mol ratio of Z/X is 0.9 or more. | 05-16-2013 |
20130271248 | RARE EARTH SINTERED MAGNET AND MAKING METHOD - A rare earth sintered magnet as an anisotropic sintered body comprising Nd | 10-17-2013 |
20150179336 | METHOD AND APPARATUS FOR PREPARING RARE EARTH SINTERED MAGNET - A mold comprising a die, an upper punch, and a lower punch, the pressure surface of one or both of the upper and lower punches being shaped non-planar, a cavity being defined between the die and the lower punch, is combined with a feeder including a shooter provided with a main sieve at its lower end port, the main sieve having a sifting surface of substantially the same non-planar shape as the pressure surface. A rare earth sintered magnet is prepared by feeding an alloy powder into the cavity through the shooter and sieve while applying weak vibration and vertical reciprocation to the shooter, applying a uniaxial pressure to the alloy powder fill in the cavity under a magnetic field to form a precursor, and heat treating the precursor. | 06-25-2015 |
20150179337 | METHOD AND APPARATUS FOR PREPARING RARE EARTH SINTERED MAGNET - A mold comprising a die, an upper punch, and a lower punch, the pressure surface of one or both of the upper and lower punches being shaped non-planar, a cavity being defined between the die and the lower punch, is combined with a feeder including a shooter provided with a main sieve at its lower end port, the main sieve having a sifting surface of substantially the same non-planar shape as the pressure surface. A rare earth sintered magnet is prepared by feeding an alloy powder into the cavity through the shooter and sieve while applying weak vibration to the shooter, applying a uniaxial pressure to the alloy powder fill in the cavity under a magnetic field to form a precursor, and heat treating the precursor. | 06-25-2015 |