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Mechanism of Pb Removal from Brass Scrap by Compound Separation Using Ca and NaF

¹ Graduate School of Science and Engineering, Kagoshima University, Kagoshima, Japan
² Kyushu Tabuchi Co. Ltd., Kirishima, Japan
³ San-Etsu Metals Co. Ltd., Tonami, Japan
⁴ San-Etsu Metals Co. Ltd., Tonami, Japan
⁵ San-Etsu Metals Co. Ltd., Tonami, Japan
⁶ San-Etsu Metals Co. Ltd., Tonami, Japan

International Journal of Nonferrous Metallurgy·Volume 07 (2018)·Pages 1–7·Published 30 January 2018·DOI10.4236/ijnm.2018.71001

Abstract

The Mechanism of Pb removal from brass scrap by compound separation using Ca and NaF addition was investigated. Because large Ca-Pb compound particles formed by Ca addition ris e to the surface of the molten brass, they can be skimmed off from the molten brass. However, fine Ca-Pb compound particles remain in the molten brass because of low buoyancy. By subsequent NaF addition, the reaction between Ca-Pb compound and NaF takes place at their contact regions, resulting in the formation of solid CaF 2 , liquid Pb and Na gas. Pb is mainly present at the Ca-Pb compound-CaF 2 interface. CaF 2 acts as a binder for aggregation of fine Ca-Pb compound particles, resulting in the formation of light and large composite compounds, which rise to the surface of the molten brass. A high Pb removal rate is achieved by skimming off.

KeywordsLead RemovalBrass ScrapCalciumSodium FluorideCompound Separation

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Mechanism of Pb Removal from Brass Scrap by Compound Separation Using Ca and NaF

Abstract

References (14)