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

• 作者: Hidekazu Sueyoshi Kousaku Yamada Masashi Miyazaki Nobuyuki Ashie Takuya Okada Yoshiharu Kousaka
• 来源期刊: 有色冶金(英文)
• 学科: 化学
• 关键词: Lead REMOVAL BRASS SCRAP Calcium Sodium Fluoride COMPOUND SEPARATION
• 年，卷（期）: 2018,（1）
• 页码范围: 1-7
• 页数: 7页
• 分类号: O6

摘要

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 rise 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 CaF2, liquid Pb and Na gas. Pb is mainly present at the Ca-Pb compound-CaF2 interface. CaF2 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.