Oxide extractant

Rare earth (RE) is a generic name for 14 metallic elements of the lanthanide series. These elements have similar chemical propenies and are usually supplied as a mixture of oxides extracted from ores such as bastnaesite or monazite. 

In Figure 10, the chromatograms of the precipitates from methylamine and methylamine-nitrous oxide extraction of red spruce, and methylamine extraction of Indulin AT are compared along with the chromatogram of Indulin AT. The lignins obtained from methylamine extraction of red spruce has the broadest apparent MWD. Extraction with methylamine-nitrous... 

Zhu, Y., Song, C. 1992. Recovery of neptunium, plutonium and americium from highly active waste. Tri-alkyl phosphine oxide extraction. In Transuranium Elements A Half Century. Morss, L.R. Fuger, J., Eds. ACS, Washington, DC, pp. 318-330. 

Zhu, Y., Jiao, R. 1994. Chinese experience in the removal of actinides from highly active waste by trialkyl phosphine oxide extraction. Nucl. Technol. 108 361-369. 

All samples stored at 4°C in glass containers protected from light and air oxidation extracted within 7 days of collection and analyzed within 7 days of extraction residual chlorine if present in aqueous samples must be removed by adding Na C ( 100 mg/L sample). 

Figure 1. Sulfur-33 NMR spectra of oxidized extraction residue from floated Herrin No.6 coal.

Titanium cesium alum, 6 50 Titanium (II) chloride from disproportionation of titanium (III) chloride, 6 56, 61 Titanium(III) chloride, 6 52, 57 Titanium (IV) chloride, reduction of, with hydrogen, 6 52, 57 Titanium complex compounds, cations, with acetylacetone, [Ti-(C.H. hTiCl, and [Ti(C6H7-0,),]FeCl , 2 119, 120 Titanium(IV) oxide, extraction of, from ilmenite, 5 79, 81 to titanium powder with calcium, 6 47... 

Salt and metal insoluble impurities, such as Pu02, associated with plutonium metal are taken up by the salt in Stage 1. Stage 2 is essentially free of these impurities. Strickland, et al. (14), reported that plutonium oxide extracts americium from molten plutonium metal in a molten salt media. Because these salt and metal insoluble impurities are present in sizable amounts only in Stage 1, the side reaction between americium and these impurities occurs only in Stage 1. The side reaction term (B) is introduced to quantify the side reaction caused by the presence of impurities such as in Stage 1. 

Tab. 13.1 Quantities of pyrrolizidine alkaloids and their N-oxides extracted from E. vulgare-derived honey.

Reducible fraction of metals bound to iron and manganese oxides (extraction by hydroxylamine hydrochloride)... 

Sediment phosphorus extraction analyses show that hydrous iron oxides (extracted by (NH4)2C204) play a major role in the transport of sediment phosphorus. In northern areas of the Genesee River watershed calcium carbonate formation also appears to be Involved in phosphorus fixation. Ion activity product calculations for water column samples from the Genesee River consistently exhibit subsaturation with respect to the stable calcium phosphate phase, hydroxyapatite. Calcium carbonate, which can serve as a substrate for phosphate mineralization, shows an ion activity product below the solubility product in the Genesee River except during the summer low-rainfall season. 

Hsu, C., and RP. Buxbaum, 1987, Palladium-coated zirconium membranes for oxidative extraction, in Preprint Annual AIChE Meeting, New York. 

El-Reefy, S.A., Selim, Y.T., and Aly, H.F., Equilihrium and kinetic studies on the separation of uranium and thorium from nitric acid medium by liquid emulsion membrane based on trioctylphosphine oxide extractant. Anal. Sci., 1997, 13 333-338. 

Table 19 R-group substituents for various type of phosphine oxide extractants.

Ramirez-Verduzco, L.F., Torres-Garcia, E., Gomez-Quintana, R., Gonzalez-Pena, V., and Murrieta-Guevara, F. Desulfurization of diesel by oxidation/extraction scheme influence of the extraction solvent. Catalysis Today, 2004, 98, 289. 

Extraction of Actinides from Bismuth into Ammonium Chloroaluminate (13, 14, 15). Experiments are being performed to demonstrate the oxidative extraction of the actinides from bismuth into ammonium chloroaluminate (NHi+AlCli ) and product recovery from the latter salt. Initial experiments with uranium dissolved in bismuth showed essentially complete extraction of the uranium into the salt with only a minimum of contact time at 330°C. Extraction of thorium from bismuth took appreciably longer and the solubility of ThCl in NH4AICI4 at 375°C was appreciably less than that of UCli+ at the same temperature, (1.1 wt % ThCl vs. 7.0 wt % UC1I+). 

We have also examined some other methods. Extraction by SnCl2 appeared to be entirely unreliable since it cannot extract Ptn+ out of bulk oxide. Extraction by acetylacetone caused difficulties when the system was rich in chlorine. Therefore, the method as described above was finally adopted. 

The major difference between the bacterial system and photosystem 11 is the source of the electrons that are used to neutralize the positive charge tormed on the special pair, P680, a very strong oxidant, extracts electrons from water molecules bound at the manganese center. d"he structure of this center includes a calcium ion and four manganese ions. Manganese was apparently evolutionarily selected for this role because of its ability to exist in multiple oxidation states (Mn, Mn ", Mn, Mn ) and to form strong... 

The application of liquid emulsion membrane based on trioctylphosphine oxide extractant for the separation of thorium and uranium was described [3]. Thoron I was used to determine Th in aqueous phase. 

A liquid emulsion membrane based on trioctylphosphine oxide extractant was applied for separation of uranium and thorium from Ce, Cu and Cd [2]. Highly selective U02 imprinted polymer (synthesized using uranium vinylbenzoate, divinylbenzene in styrene and 2,2 -azobisisobutyronitrile) was proposed for purification, preconcentration and determination of the uranyl ion [3]. Dibenzoylmethane was used as a colorimetric reagent. The detection limit of 160 ppt was achieved. 

Other data in this ethylene oxide extraction patent provide an independent method to calculate the distribution coefficient. Examples state that the CO2 stream leaving the extractor contains 2.9 wt % ethylene oxide which is in equilibrium with a liquid solution containing 0.24 wt % ethylene oxide. The y/x ratio is 12, a very good independent corroboration of the value calculated from the inverse of the solvent to feed ratio and the assumption that the exu-action was an equilibrium one. 

The study of frozen aqueous solutions of iron(III) compounds is only of limited value because of the tendency to hydrolyse, and the relaxation broadening [63, 128], and little work has been done. A potentially more profitable application is the study of solvent extracts. Frozen nitrobenzene extracts of iron(III) in HCl, HBr, and NaSCN solutions contain respectively the FeCl4 and FeBr4 anions and a 6-coordinate complex Fe(NCS)4X2 (X is either water or nitrobenzene) [129, 130]. The spin-spin relaxation behaviour is dependent on the solvent, and trioctylphosphine oxide extracts show partially resolved hyperfine structure. 

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