Melt extraction mineral residues

At each step, a fraction of fluid f is added to the mantle wedge from the slab. The bulk partition coefficients used for fluid dehydration can be derived from published mineral/fluid partition coefficients (see Tables Al and A2). The composition of the residual slab is estimated as follows after At which is the time step between two melt extractions (similar equation for Th and Pa) ... 

In this chapter the mineral-melt phase equilibria that control the compositions of partial melts are examined on the basis of experimental and thermodynamic databases, and this information is used to predict the effects of partial melt extraction from fertile upper mantle on residual mineralogy and major-element chemistry. 

Figure 4 Normative spinel Iherzolite mineral abundances (wt.%) in batch partial melt extraction residues (0-25%) from fertile peridotite (composition 8, Table 1) as a function of Mg (molar Mg/(Fe + Mg)) at 0.5 GPa, 1 GPa, and 2 GPa, based on the melting model of Kinzler and Grove (1992a, 1993). Normative mineral compositions are calculated using the spinel Iherzolite normative algorithm of Kelemen et ai, (1992).

On-line SFE-pSFC-FTIR was used to identify extractable components (additives and monomers) from a variety of nylons [392]. SFE-SFC-FID with 100% C02 and methanol-modified scC02 were used to quantitate the amount of residual caprolactam in a PA6/PA6.6 copolymer. Similarly, the more permeable PS showed various additives (Irganox 1076, phosphite AO, stearic acid - ex Zn-stearate - and mineral oil as a melt flow controller) and low-MW linear and cyclic oligomers in relatively mild SCF extraction conditions [392]. Also, antioxidants in PE have been analysed by means of coupling of SFE-SFC with IR detection [121]. Yang [393] has described SFE-SFC-FTIR for the analysis of polar compounds deposited on polymeric matrices, whereas Ikushima et al. [394] monitored the extraction of higher fatty acid esters. Despite the expectations, SFE-SFC-FTIR hyphenation in on-line additive analysis of polymers has not found widespread industrial use. While applications of SFC-FTIR and SFC-MS to the analysis of additives in polymeric matrices are not abundant, these techniques find wide application in the analysis of food and natural product components [395]. 

To a suspension of 3-(4-bromo-2-fluorobenzyl)-7-chloro-l,2,3,4-tetrahydro-2,4-dioxoquinazoline in N,N-dimethylformamide was added sodium hydride (60% in mineral oil) with stirring at 0°C and the mixture was stirred for 15 min at the same temperature. To this mixture was added ethyl bromoacetate and the mixture was stirred for 1 h at room temperature. The reaction mixture was poured into diluted hydrochloric acid and extracted with ethyl acetate. The extract was washed with brine, dried and evaporated to give a residue. Thus obtained product was purified by recrystallization from isopropyl ether to give 2-[3-(4-bromo-2-fluorobenzyl)-7-chloro-l,2,3,4-tetrahydro-2,4-dioxoquinazolin-l-yl]acetic acid melting point 223°-224°C. 

Osmium isotopes currently provide the strongest case for mineral-to-mineral disequilibrium, and for mineral-melt disequilibrium available from observations on natural rocks. Thus, both osmium alloys and sulfides from ophiolites and mantle xenoliths have yielded strongly heterogeneous osmium isotope ratios (Alard et al., 2002 Meibom et al., 2002). The most remarkable aspect of these results is that these ophiolites were emplaced in Phanerozoic times, yet they contain osmiumbearing phases that have retained model ages in excess of 2 Ga in some cases. The melts that were extracted from these ophiolitic peridotites contained almost certainly much more radiogenic osmium and could, in any case, not have been in osmium-isotopic equilibrium with all of these isotopically diverse residual phases. 

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