Yttrium -sulfate

Yttrium sulfate is used in making many yttrium salts. 

Yttrium sulfate is produced as an intermediate in recovering yttrium from monazite or xenotime (see Yttrium, Recovery). Rare earth sulfates are separated on a cation exchange resin bed. Yttrium fraction is purified by fractional crystallization. Alternatively, yttrium sulfate may be prepared by reacting yttrium oxide with sulfuric acid. 

Y(OH)3 (c). Thomsen15 measured the heat of reaction of aqueous yttrium sulfate with aqueous barium hydroxide. 

Ethyl Ethyl Malonate Ethyl Yttrium Sulfate a 221-0936... 

FD y C amarillo yogurt, yoghurt ytterbium oxide yttrium sulfate... 

Figure 48 (Imanaka et al. 1985a) shows one of the representative aT-T relationships for sodium sulfate and sodium sulfate doped with various amounts of yttrium sulfate with silicon dioxide. The Si02 addition prevents the sodium sulfate from becoming ductile. By doping a rare earth in the form of yttrium sulfate into sodium sulfate, the conductivity is greatly enhanced and the phase transition which causes the decline in the oT-T curve disappears except at the lowest 2(804)3 mixing of 4.9 mol%. This result indicates that the rare-earth mixing in sulfate with silicon dioxide contributes greatly to suppressing the phase transition in sodium sulfate as well as increasing the ionic conductivity.

III) nitrate 4-water (III) oxide (III) sulfate 8-water Yttrium chloride fluoride... 

Fra.ctiona.1 Precipituition. A preliminary enrichment of certain lanthanides can be carried out by selective precipitation of the hydroxides or double salts. The lighter lanthanides (La, Ce, Pr, Nd, Sm) do not easily form soluble double sulfates, whereas those of the heavier lanthanides (Ho, Er, Tm, Yb, Lu) and yttrium are soluble. Generally, the use of this method has been confined to cmde separation of the rare-earth mixture into three groups light, medium, and heavy. 

Bismuth Trisulfate. Bismuth(III) sulfate [7787-68-0], Bi2(S0 3, is a colorless, very hygroscopic compound that decomposes above 405°C to yield bismuthyl salts and Bi202. The compound hydrolyzes slowly in cold water and rapidly in hot water to the yellow bismuthyl sulfate [12010-64-9], (Bi0)2S04. The normal sulfate is isomorphous with the sulfates of yttrium, lanthanum, and praseodymium. 

However, solubility, depending as it does on the rather small difference between solvation energy and lattice energy (both large quantities which themselves increase as cation size decreases) and on entropy effects, cannot be simply related to cation radius. No consistent trends are apparent in aqueous, or for that matter nonaqueous, solutions but an empirical distinction can often be made between the lighter cerium lanthanides and the heavier yttrium lanthanides. Thus oxalates, double sulfates and double nitrates of the former are rather less soluble and basic nitrates more soluble than those of the latter. The differences are by no means sharp, but classical separation procedures depended on them. 

Yttrium oxide is produced as an intermediate in recovery of yttrium from xenotime and monazite (See Yttrium, Recovery). The oxide is produced after separation of rare earth sulfates obtained from digesting the mineral with sulfuric acid on a cation exchange bed, precipitating yttrium fraction as oxalate, and igniting the oxalate at 750°C. 

One important aspect of such coating processes is the generality of the procedure. It would appear that specific surface characteristics of the preformed particles are not necessarily essential for the successful deposition of the new layer. For example, yttrium basic carbonate coatings were produced on zirconium basic sulfate... 

On heating, all of the anhydrous sulfates of the trivalent rare-earth elements and yttrium, type formula R2(S04)3 decompose, without first melting, to basic salts (oxysulfates) of the type R203.S03, then to an oxide. The oxide final product is R203 for all the elements except cerium, praesodymium,... 

Classical methods of separation [7] are (1) fractional crystallization, (2) precipitation and (3) thermal reactions. Fractional crystallization is an effective method for lanthanides at the lower end of the series, which differ in cation radius to a large extent. The separation of lanthanum as a double nitrate, La(N03)3-2NH4N03-4H20, from praseodymium and other trivalent lanthanide with prior removal of cerium as Ce4+ is quite a rapid process and is of commercial significance. Other examples are separation of yttrium earths as bromates, RE(Br03>9H20 and use of simple nitrates, sulfates and double sulfate and alkali metal rare earth ethylenediamine tetraacetate complex salts in fractional crystallization separation. 

Fractional precipitation is similar to fractional crystallization technique but takes advantage of basicity differences and solubility differences. Separation of yttrium from yttrium earths by fractional precipitation is an example of differences in basicity. Separation of yttrium earths from cerium earths by double alkali sulfate precipitation in the form of double sulfates is an example of fractional precipitation. 

When rare earth oxides, hydroxides, or carbonates react with dilute sulfuric acid, rare earth sulfate hydrates are obtained and they have the formula RE2(S04)3 H20 where = 3,4,5, 6,8, and 9. The most common is = 9 for lanthanum and cerium and = 8 for praseodymium to lutetium and yttrium. Anhydrous compounds may be obtained by heating the respective rare earth sulfate hydrate at 155-260 °C, however, they easily absorb water to become hydrated again. 

UH609S uranyl sulfate trihydrate 20910-28-J 5 25.00 3 2800 1 1 4981 YH12N3015 yttrium nitrate hexahydrate 13494-98-J J 25.00 2.680C 1... 

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