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This paper examines key features of the preparation of high-purity Ga from electronic and electrical engineering industry waste. The decrease in the melting point of impurity-containing Ga is assessed thermodynamically in the ideal solution approximation. It is proposed that the purity of gallium in the final crystallization purification step can be monitored via precision measurement of the temperature of the melt with a pyrometer. [ABSTRACT FROM AUTHOR]

This paper describes a detailed study aimed at developing technological principles of the preparation of 99.99995%-pure Cd, Zn, and Te by crystallization purification methods. We have analyzed the thermophysical properties of Cd, Zn, Te, and structural materials of the equipment involved; substantiated the choice of graphite as a crucible material; and determined its engineering features. We have studied impurity distributions in Cd, Zn, and Te in crystallization processes and determined effective performance parameters of the materials refining process in horizontal directional solidification and zone melting steps. The results have allowed us to obtain 99.99995 to 99.99999%-pure Cd, Zn, and Te in terms of 30 major impurities, with a maximum product yield of up to 85%. [ABSTRACT FROM AUTHOR]

We have proposed and tested a combined process for ultrapurification of monoisotopic S and S sulfur, which comprises thermochemical treatment of sulfur vapor on silica and ceria packing, melting with aluminum, and distillation. The impurity composition of the purified sulfur has been determined by atomic emission and IR spectroscopy. We have obtained monoisotopic S and S sulfur samples comparable in chemical purity to high-purity sulfur of natural isotopic composition. [ABSTRACT FROM AUTHOR]

We have studied the wetting behavior of molten germanium on silica ceramics and amorphous silica coatings in vacuum at a pressure of 1 Pa and a temperature of 1273 K. The results demonstrate that the wetting of rough surfaces of ceramic samples and coatings by liquid Ge is significantly poorer than that of the smooth surface of quartz glass. The contact angle of polished glass is ~100°, and that of the ceramics and coatings increases from 112° to 137° as the total impurity content of the material decreases from 0.120 to 1 × 10 wt %. Using experimental contact angle data, we calculated the work of adhesion of molten Ge to the materials studied. Its value for the surface of the ceramics and coatings decreases from 0.45 to 0.20 J/m with decreasing impurity content, whereas the work of adhesion to a smooth glass surface is 0.55 J/m. We have fabricated fused silica test containers coated with high-purity amorphous silica. Using horizontal zone refining, we obtained germanium samples with a carrier concentration difference on the order of 10 cm. [ABSTRACT FROM AUTHOR]

This paper addresses the preparation, purification (removal of oxygen-containing impurities), and applications of fluoride glasses, with particular attention to the preparation of modified glasses for extending their transmission window. [ABSTRACT FROM AUTHOR]

This paper describes ultrapurification of isotopically enriched calcium and molybdenum compounds and CaMoO calcium molybdate growth charge in order to remove radioactive uranium, thorium, and radium impurities. CaMoO single crystals grown from such charges are needed for the fabrication of scintillator elements of the cryogenic detector for the AMoRE project: a search for Mo neutrino-less double-beta decay. [ABSTRACT FROM AUTHOR]

Using computer simulation, we have studied the effects of principal process parameters on the yield of a substance being purified to the desired purity level in a middle-vessel packed batch distillation column, with examples for isotopically pure silane. The results indicate that there are the optimal column height, reflux rate, and charge weight, which minimize the loss of the substance being purified. [ABSTRACT FROM AUTHOR]

Dense boron samples with a glassy structure have been prepared for the first time by high-pressure sintering of amorphous boron powder at temperatures from 750 to 1100 K. Analysis of the mechanical properties of boron samples sintered at pressures from 2 to 8 GPa and different temperatures indicates that sintering proceeds most effectively near 750 K. Purification of amorphous boron in water is shown to be effective in removing products of boron oxidation in air. [ABSTRACT FROM AUTHOR]

It is shown that the modular technology of high-purity hycirofluoric acid can be optimized along two lines: replacement of the module for the chemical treatment of the acid by a more efficient one and the introduction of a hydroionic convection module for reducing the concentration of ionic impurities. [ABSTRACT FROM AUTHOR]

A process is described for removing carbon-containing impurities from hydrogen with the use of an electrical discharge. Hydrogen purified by this process contains no more than 0.1 ppm carbon. [ABSTRACT FROM AUTHOR]