Alkaline complexes

Extraction of hemiceUulose is a complex process that alters or degrades hemiceUulose in some manner (11,138). Alkaline reagents that break hydrogen bonds are the most effective solvents but they de-estetify and initiate -elimination reactions. Polar solvents such as DMSO and dimethylformamide are more specific and are used to extract partiaUy acetylated polymers from milled wood or holoceUulose (11,139). Solvent mixtures of increasing solvent power are employed in a sequential manner (138) and advantage is taken of the different behavior of various alkaUes and alkaline complexes under different experimental conditions of extraction, concentration, and temperature (4,140). Some sequences for these elaborate extraction schemes have been summarized (138,139) and an experimenter should optimize them for the material involved and the desired end product (102). 

Petersen, O.V., Giester, G., Brandstatter, F., and Niedermayr, G. (2002) Nabesite, Na2BeSi4O10-4H2O, a new mineral species from the lllmaussaq alkaline complex. South Greenland. Can. 

Syenite, lamprophyre, and carbonatite dykes of the Moose Creek Valley, Ice River Alkaline Complex, southeastern British Columbia, Canada ... 

Currie, K.L. 1975. The geology and petrology of the Ice River Alkaline Complex, British Columbia. Geological Survey of Canada Bulletin 245, Ottawa, ON. 

Fig. 3. SEM backscattered electron image of alteration in zirconolite from the Afrikanda alkaline complex, Kola Peninsula, Russia. This crystal exhibits complex magmatic zoning, late-stage replacement by an unknown Ba-Zr-Ti-silicate phase, and preferential alteration along cracks and Th-U-rich zones.

Perovskites also exhibit reaction relationships with phosphate minerals and exotic alkali-titanium-silicate minerals under late-stage magmatic conditions. In a systematic study of loparite mineral chemistry in the Lovozero alkaline complex, Russia, Kogarko et al. (2002) have... 

Mitchell, R. H. Chakhmouradian, A. R. 1998a. Th-rich loparite from the Khibina alkaline complex, Kola Peninsula isomorphism and para-genesis. Mineralogical Magazine, 62, 341-353. 

Kvanefjeld Plateau, northwest Ilimaussaq alkaline complex, S. Greenland. 

Humic acid I (symbol H) retained the sorbed material to a slightly greater extent in acid media, but released marginally greater amounts to the complexing agents. The alkaline complexing solutions (i.e., citrate, pyrophosphate, EDTA, DTPA) appeared to dissolve or colloidally disperse the humic acids, but there was a residual > 0.45 pm fraction which retained a measurable amount of the sorbed ion (this observation is consistent with the adsorption/pH trends observed in earlier studies). 

As in the alkaline complexes, for the group II cation complexes, the pyramidal isomer is always harder than the square (Table 6 and Figure 7). In Figure 7, it can be seen that in both isomers, the Be complex (both isomers) is somewhat softer (than expected from the general trend). This may imply that its aromatic character is decreased due to the strong interaction-induced distortion of the A1 unit. 

Ce -REE energy transfer is strong for any REE ion that has transitions in the UV, such as Eu, Pr, Tm and Tb. Therefore in CL or photoluminescence spectra of apatites (and other minerals), Ce emission may be quenched by energy transfer to these and other REE species, even with their concentration levels substantially lower than that of the Ce. An example is given by the spectra of two fluorescent apatites from the Col dwell alkaline complex in Ontario (Mitchell et al. 1997). Both of these apatites have dominant Ce but only very weak emission in the general area of the Ce bands. 

Warren RW (1970) EPR of Mn in calcium fluorophosphates. 1. The Ca (11) site. Phys Rev B 2 4383-4388 Waychunas G (1989) Luminescence, X-ray emission and new spectroscopies. Rev Mineral 18 638-698 Wright AO, Seltzer MD, Graber JB, Zandi B, Merkle LD, Chai BHT (1996) Spectroscopic investigation of Pr in fluorapatite crystals. JPhys Chem Solids 57 1337-1350 Xiong J (1995) Cathodoluminescence studies of feldspars and apatites from the Coldwell alkaline complex. MSc thesis, Lakehead Univ, Thunder Bay, Ontario... 

It is a vein type deposit, which is hosted within, and is genetically related to, a carbonatitic alkaline complex. The deposit is very similar to the Californian Mountain Pass deposit. The similarities are the high concentrations of bastnaesite and barite, low niobium content, and the presence of sulphides (Wang et al. 2001). It has proven reserves of 0.4 million tons of ore grading at 2 % REE oxides. The discovery of the deposit was described by Pu (1988). The age of the carbonatites related to the deposit is 27.8-40.3 Ma (Cheng et al. 2003 Mindat.Org 2015). 

Cemy P, Tmeman DL (1985) Polylithionite from the rare-metal deposits of the Blachfoid Lake alkaline complex, N.W.T, Canada Am. Mineral 70 1127-1134... 

Steenfelt A (2012) Rare earth elements in Greenland known and new targets identified and characterised by regional stream sediment data. Geochem Expl Environ Anal 12 313-326 Stoltz NB, Meyer EM (2012) Economie potential of rare earth elements in apatite of the Khibina Alkaline complex. Kola Peninsula, Russia. In 4th International Geologica Belgica Meeting, 2012... 

ABSTRACT The obtention of (tetradecachloro-4-oxidotriphenylmethyl)" M" " (M=Li, Na, K, n-BU4N) salts in ethereal solution and the isolation of some alkaline complexed salts (M= Li-12C4, Na-18C6, K-18C6, K (THF)- (H2O) 3 4, n-BU4N) are described and discussed. The association phenomena of these salts has been studied by electronic spectroscopy, osmometry and electron spin resonance. Linear correlations between radii counterions and the position maxima of the electronic spectra bands permit the study of the species present in solution (free ions, ion pairs and quadrupolar aggregates). 

Mirkina, S. L., Gerling, E. K., Shukolyukov, Y. A. Determination of the absolute age of the alkaline complexes of the Middle Urals with the aid of the lead-isotopic and the potassium-argon methods. Geokhimiya, no. 8, 643—648 (1962). 

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