Melting with fluxes

The crude metal obtained by electrolysis contains xqj to 2.7% Cl, besides other impurities (Fe, Al, Si, N). Purification is effected by melting with fluxing agents or, better, by repeated filtration. This may be done simply by pushing a sheet iron screen downward through the melt. This reduces the chlorine content considerably (final content 0.003% Cl). 

Refractory samples are often only present as granulates and are hard to grind. Indeed, here the abrasion of the mills (be it even a hard material such as WC) is high and this leads to contamination and consequently to interferences in the AAS determination. In this case, melting with fluxes is the only method of digestion. 

Gl ss-Ionomers. Glass-ionomers show fluoride release at levels that are usually higher than those found in composite materials. The fluoride is found within the aluminosihcate glass, which is melted with fluoride fluxes and ground to form powder filler. The fluoride is added as calcium fluoride [7789-75-5] aluminum fluoride [15098-87-0] and sodium fluoride [7681-49-4] in a combined proportion of approximately 20% by weight in the final powder (284,285). 

Single crystals of the 1223 thallium monolayer phase were grown from a copper-rich melt with molar composition 1 2 2 4 (Tl Ba Ca Cu) the mixture was heated to 925°C, soaked 6 h, and cooled at l°C/min (57). Magnetic flux exclusion experiments indicated a sharp Tc onset of 110 K. 

Up to now the so-called catalytic process is the only way to produce c-BN on an industrial scale. However, catalytic is not the correct scientific term, because the activation energy for transformation is not decreased by these substances. The substances which are used have the function of a solvent, and are responsible for the formation of c-BN. This method is successful because of the different solubilities of c-BN and h-BN in the flux. The precursor substances form a eutectic melt with the h-BN [152]. If the reaction conditions are in the domain of stable c-BN, spontaneous crystallization takes place and the c-BN growth rate is relatively high. 

Fluorine occurs in nature in minerals such as fluorite, Cap2 fluor-apatite, Ca.(PO )3F, which is a constituent of bones and teeth and cryolite, Na3AlF<. and in small quantities in sea water. Its name fluorine, from Latin finere, to flow, refers to the use of fluorite as a flux (a material which forms a melt with metal oxides). 

Dehydration, or more generally, devolatilization of the oceanic crust is a process that combines continuous and discontinuous reactions in a variety of heterogeneous bulk compositions. In addition, within a vertical column—the sedimentary, mafic, and serpentinized peridotite layers— each experience a significant thermal gradient. The result is a continuous, but not constant, production of a fluid or melt, with the rate of mobile phase production generally decreasing with depth. Peaks in the volatile flux result from significant discontinuous reactions. However, despite the continuous fluid flux, trace elements may not necessarily be released continuously. 

The compound K20 A1203 Si02 described by Weyberg [26] was prepared from melts with the aid of a flux (kaolin with K2Cr04). Bowen [22] in 1917 obtained this same compound while preparing the orthorhombic form of KAlSi04 with the aid of fluxes. The compound was present in the sample in small amounts as octahedra. 

The specific volume of calcine will be about 40 liters/MT of heavy metal for combined HLW and MLW, corresponding to that to be expected from the AGNS plant. For final disposal, the product from the fluidized-bed calcination will have to be consolidated by melting with a glass flux. If it is to be stored for extended periods directly in sealed canisters, the calcined solid will have to be stabilized (denitrated, dehydrated) at approximately 900 C. 

The early model of Flux [2] and Flood and Forland and Motzfeld [3] describes the sulfate melt as a melt with oxyanions. According to this model, the S04 -anion dissociates, giving SO3 and 0 -ions (Eq. 1) ... 

---