Calcium hexaboride (CaB 6 ) crystals with high melting point (2,235°C) have been conveniently synthesized at low temperature (900°C) from molten salt electrolysis. The synthesis was carried out using CaO-B 2 O 3 -LiF melt under argon atmosphere. Electrochemical experiments were carried out in an inconel reactor to having a high purity graphite crucible, which served as an electrolyte holding vessel as well as the anode. An electropolished molybdenum rod was employed as the cathode. The electrolysis was performed at 900°C under argon atmosphere at current densities ranging from 0.5 to 1.5 A/cm 2 at 1:6 M ratios of calcium and boron content. After the electrolysis, the cathode product was removed and cleaned using dilute HCl solution followed by triple distilled water. Characterization of the crystalline product by TG/DTA, XRD, CHNS, EDAX, XPS, EPR, and SEM were reported. From the studies, it has been observed that CaB 6 can be synthesized at all current densities and the products have some impurities.

Liquidus behavior, alumina solubility, electrical conductivity, and decomposition potential of Al2O3 in various compositions of molten fluoride‐chloride salt mixture, normalNaF‐normalKCl , have been studied to find out the suitability of the system as a candidate bath electrolyte for an alternative process of low temperature aluminum electrolysis using composite anodes. Composite anodes, consisting of a mixture of Al2O3 and carbon, of different compositions were prepared and characterized by determining their properties such as apparent density, porosity, and resistivity. A laboratory scale experimental cell of about 30 A capacity was run with the composite anodes and 50:50 mole percent false(normalm/normalofalse) mixture of normalNaF and normalKCl as the bath electrolyte at ∼750°C. The composite anodes with 50 normalw/o Al2O3 were consumed readily during electrolysis, and aluminum metal was obtained. Material and charge balances of the electrolysis experiment show 99.7% anodic and 64.5% cathodic efficiencies.

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The present study reports the results of investigation on the effects of impressed d.c. current on the growth of FeO layer on iron. The atmosphere and the temperature range of study chosen were CO-CO2 gas mixtures and from 973 to 1123K. Except for the initial part, the kinetics of FeO layer growth under normal oxidation, under impressed current of both the polarities and under short-circuited condition followed the parabolic growth law. Under cathodic condition of the sample as well as under short-circuited condition, the rates were found to be more than that under normal oxidation condition. Decrease in oxidation rate was observed during the later part of oxidation, when the iron sample was made anodic. However, at lower temperatures, 973K and 1023K, the rates were found to be more than that under normal oxidation condition. The results have been qualitatively interpreted on the basis of expected changes in situations with regard to defect concentrations at the metal/oxide and oxide/gas interfaces as well as on the basis of changed transport coefficient of defects through the FeO layer. A thermogravimetric method was employed for following up the kinetics. A new method of field application was used.

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