In the search for an environmentally friendly, efficient technology of calcium addition to lead alloys a study of calcium oxide electrolysis in molten salts was performed. The research showed that calcium can be electrowon into a liquid lead cathode at temperatures less than 650°C. Alloys containing up to 2 wt% Ca were synthesized from a CaCl2-NaCl-CaO fused mixture with a current efficiency of 40-60%. The sodium impurity obtained was as little as one-tenth of the calcium content. The impact of such factors as temperature, current density and duration of electrolysis on the performance of the cell and quality of the alloys was investigated, as was the anodic process on the graphite electrode.
Get full access to this article
View all access options for this article.
References
1.
DaveyT. R. A. The physical chemistry of lead refining. In Cigan J. M., MacKay T. S. and O'Keefe T. J. eds Lead—zinc—tin ‘80 (Warrendale, PA: The Metallurgical Society of AIME, 1979), 477–507.
2.
AlabyshevA. F. Electrolytical production of alloys of calcium with lead. In Collected works on the electrochemistry of fused salts. GIPKh, 108, 1940, 116-24.
3.
Maslanka-OrmanovaZ. Production of lead—calcium alloys. Prace Inst. Ministerstwa Hutnic., 5, 1953, 89-104.
4.
SongR. Y.Preparation of Pb—Ca—Na master alloy using molten chloride salt electrolysis. Trans. Nonferrous Metals Society China, 6, 2, 1996, 18–25.
5.
BonomiA.Electrowinning of calcium metal by electrolysis of molten salt solution in calcium carbide. In Molten salt electrolysis in metal production (London: IMM, 1977), 14–20.
6.
FreidinaE. B. and FrayD. J. CaCO3 as a source of calcium for electrochemical synthesis of Pb—Ca alloys. InMishraB. ed. EPD con-gress 1999, San Diego, CA (Warrendale: TMS, 1999), 169–80.
7.
FreidinaE. B. and FrayD. J. Study of the ternary system CaC12—NaC1—Ca0 by DSC. Thernzochim. Acta, 356, 2000, 97-100.
8.
AlabyshevA. F., LantratovM. F. and MorachevskiiA. G. Reference electrodes for molten salts (Moscow: Metallurgiia, 1965), 87–9.
9.
HansenM. and AnderkoK. Constitution of binary alloys (New York: McGraw-Hill1958), 405.
10.
LevinE. M., RobbinsC. R. and McMurdieH. F. Phase dia-grams for ceramists, 1969 supplement (Columbus, Ohio: The American Ceramists Soc., 1969), 443.
