Lead chloride, molten

It was an adaptation of the Castner cell to sodium chloride for fused caustic electrolysis. A mixture of sodium chloride and other chlorides, molten at 620°C, was electroly2ed ia rectangular or oval cells heated only by the current. Several cells have been patented for the electrolysis of fused salt ia cells with molten lead cathodes (65). However, it is difficult to separate the lead from the sodium (see Electrochemical processing). 

This bismuth—calcium—magnesium dross also contains lead that must be removed. The dross is heated in a ketde to free any entrapped lead that melts and forms a pool under the dross. This lead is cast and returned to the bismuth separation cycle. The dross is then melted and treated with chlorine and/or lead chloride to remove the calcium and magnesium. The resulting molten metal is an alloy of bismuth and lead, high in bismuth which is then treated to produce refined bismuth metal. 

The removal of silver from lead is accomplished by die addition of zinc to the molten lead, and slowly cooling to a temperature just above the melting point of lead (600 K). A crust of zinc containing the silver can be separated from the liquid, and the zinc can be removed from tlris product by distillation. The residual zinc in the lead can be removed eitlrer by distillation of the zinc, or by pumping chlorine tluough the metal to form a zinc-lead chloride slag. 

Violent reaction or incandescent reaction with ammonia, hydrogen, lead chloride, mercury, phosphorus(V) oxide, silicon, sulfur, titanium dioxide in the presence of heat. Contact with hydroxylamine forms a heat-sensitive explosive. Molten calcium reacts explosively with asbestos cement. 

Kerosene Lacquer solvents Lacquers Lactic acid, cold Lactic acid, hot Laurie acid Lead, molten Lead acetate Lead arsenate Lead bromide Lead carbonate Lead chloride Lead chromate Lead dioxide Lead nitrate Lead oxide Lime bleach Lime sulfur Linoleic acid Linseed oil Lithium carbonate Lithium chloride Lithium hydroxide Lithium nitrate Lithium nitrite... 

Molten lead and molten sodium are combined in a ratio of 9 1 by weight, and the resultant alloy is solidified and flaked. The flaked alloy is passed to an autoclave which is charged with ethyl chloride for a period of 1 h or more. The reaction takes place in the presence of an acetone catalyst at a temperature of 70-75° C and a pressure of 350-420 kPa. 

The simplest form consists of a flat cathode located just above and electrically connected to a pool of molten lead, which collects in the base of the cell. This in turn is connected through a steel bar to the power supply. The anodes are graphite plates held above the cathode using ceramic spacers and provide for the escape of chlorine gas to collect in the upper sealed space of the cell. The cell is fed with dry lead chloride, which is controlled by the density of the electrolyte, and lead metal is periodically tapped from the cell via a siphon. 

US Bureau of Mines work indicated that only copper, silver and zinc (to a minor extent) appeared to co-deposit with lead. Copper and silver could be removed by prior treatment of the melt with lead before electrolysis. Elements less noble than lead can build up in the electrolyte, such as calcium, magnesium, sodium, iron and zinc. These effects necessitate the feeding of relatively pure lead chloride as well as the ability to bleed or purge the electrolyte periodically to maintain impurities at a low level. These aspects of prolonged operation of a molten lead chloride cell have yet to be fully resolved. 

The essential lesson from past attempts to develop processes for the production of lead by molten chloride electrolysis was that the electrolyte must be of high purity. Chlorination of lead concentrates and feeding of the resulting lead chloride directly to an electrolytic cell was unsuccessful. 

Egan, J.J. (1961) A Polarographic Study of Excess Lead Dissolved in Molten Lead Chloride. J. Phys. Chem., 65C, 2222. 

Haarberg, G.M., Stpre, T., Bprresen, B., and Tunold, R. (1994) Electrochemical Studies of Lead Deposition from Pure Molten Lead Chloride. Electrochemical Society Proceedings, 94-13,463-467. 

McLaughlin, D.R and Stoltz, R.A. (1988) Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride lead chloride solvent. US Patent 4737 244. 

Bichloride of mercury (see Mercuric chloride) Bichromates (dichromates) - 663 Biocide -185 Biological solutions - 884 Bismuth carbonate - 28,54,114,124,149,152, 154.156, 253, 264, 393, 398,811,824 Bismuth-lead eutectic, molten - 642, 673, 736 Bismuth, molten - 642, 646, 732, 736 Bismuth nitrate - 613 Bismuth oxycarbonate - 824 Bismuth subcarbonate - 824 Bisulfite in scrubber -109 Bitter almond, oil (see Essential oils)... 

Molten Salts Thallous formate Lead chloride+zinc chloride Silver nitrate+potassium nitrate... 

Williams, F. A., 1961. Separation of heavy minerals with molten lead chloride. Trans. Inst. Mining and Met. 70 69. 

Nonporous electrodes were prepared by impregnating ordinary graphite with molten polyethylene, silver chloride, or lead chloride. High-temperature treatment apparently resulted in a certain chemical... 

The lead and 2inc are separated into two molten phases by progressive cooling. Following ammonium chloride treatment to remove dross, the lead is returned to the condenser. Zinc is cast into ingots after dissolved lead is removed by cooling. 

These facts would suggest that die electrolysis of molten alkali metal salts could lead to the inuoduction of mobile elecU ons which can diffuse rapidly through a melt, and any chemical reduction process resulting from a high chemical potential of the alkali metal could occur in the body of the melt, rather than being conhned to the cathode volume. This probably explains the failure of attempts to produce tire refractoty elements, such as titanium, by elecU olysis of a molten sodium chloride-titanium chloride melt, in which a metal dust is formed in the bulk of the elecU olyte. 

Increasing the concentration of potassium chloride, KCI, in the molten system K2TaF7 - KCI leads to the spectral transformation (Fig. 78, a), which is similar to that observed in the case of K2TaF7 - KF. The intensity of the band at 600 cm 1 decreases while the intensity of the band at 540 cm 1 increases. When KCI concentration is equal to, or greater than 0.8 mol fractions, the band at 600 cm 1 disappears and the only band observed is at 540 cm 1. The above behavior of the system can be explained by the following interaction between hexafluorotantalate ions, TaF6 and chloride ions, CF ... 

The molten salt, sodium aluminum chloride, fulfills two other tasks in the cell system. The ceramic electrolyte "-alumina is sensitive to high-current spots. The inner surface of the ceramic electrolyte tube is completely covered with molten salt, leading to uniform current distribution over the ceramic surface. This uniform current flow is one reason for the excellent cycle life of ZEBRA batteries. 

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