| Removal of antimoy, arsenic, tin and bismuth in the system of molten cryolite and lead has been investigated in order to develop a new pyrometallurgical lead refining process. Experiments were carried out in an argon atmosphere using 300g of molten lead containing metal elements, such as Sb, As, Sn and Bi, and oxygen. The temperature for this experiments was fixed at 700℃ to satisfy conditions for both the fluidity of flux and the stability of magnesia crucible. The antimony, tin and arsenic contents in molten lead were reduced rapidly from approximately 1,000 to 40 ppm, 30 ppm and 35 ppm, respectively at added oxygen of 0.2wt%, However, the cryolite flux had little effect on the removal of bismuth. A brief thermodynamic analysis was carried out to estimate the solubility products of impurity oxides in molten lead and experimental results were discussed according to the analysis. |
|
