Melting salt effect

Anode effect — refers to the sudden increase in voltage and decrease in current that happens when a gas film forms on the anode during electrolysis in melted salts. It is of special importance in -> aluminum production (-> Hall-Herault process). 

Both this melt temperature and the glass transition of the resultant material are highly susceptible to the presence of plasticizers. The dominant species is water, but small sugars and salts may also have an influence (see Chapter 5). Nonetheless, it is clear that whereas the processes in the extruder barrel should be related to the effect of plasticizers on gelatinisation or melting, their effect on final product properties should be related to the glass transition of the amorphous molten extrudate. 

Nakajima, I., Kawaniski, G., and Furuichi, E. (1975). Reaction of melting salts upon micelles and their effects on caldum, phosphorus and bound water. Agric. Biol. Chem. 39,979-987. 

Tatsumi, K., Ohba, S., Nakajima, I., Shinohara, K., and Kawanishi, G. (1975). The effects of melting salts on the state of dispersion of casein. 3. The effect of melting salts on the texture of process cheese. J. Agric. Ghent. Soc. Jpn. 49, 481-489. 

The most direct effect of defects on tire properties of a material usually derive from altered ionic conductivity and diffusion properties. So-called superionic conductors materials which have an ionic conductivity comparable to that of molten salts. This h conductivity is due to the presence of defects, which can be introduced thermally or the presence of impurities. Diffusion affects important processes such as corrosion z catalysis. The specific heat capacity is also affected near the melting temperature the h capacity of a defective material is higher than for the equivalent ideal crystal. This refle the fact that the creation of defects is enthalpically unfavourable but is more than comp sated for by the increase in entropy, so leading to an overall decrease in the free energy... 

Highway. Rock salt, solar salt, and in some cases in Europe, evaporated salt are used to maintain traffic safety and mobiUty during snow and ice conditions in snowbelt regions throughout the world. Sodium chloride melts ice at temperatures down to its eutectic point of —21.12°C. Most snowstorms occur when the temperature is near 0°C, where salt is very effective. More than 40% of dry salt produced in the United States is used for highway deicing. 

Processing at Sead.es Lake, California, by North American Chemical is similar to that of Texas brines. Brine is cooled to 16°C to remove borax crystals, then cooled to 4°C which precipitates Glauber s salt. This salt is then separated from its mother Hquor, melted in multi-effect vacuum crystallizers to form anhydrous sodium sulfate, and dried. Both processes produce crystals that are 99.3—99.7% pure (9). 

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