Solvent extraction (SX) and separation of Sn/ Pb from the leach liquor of waste solder material and effluents

Abstract

R & D efforts have been made to develop a suitable process for extraction and separation of tin (Sn) and lead (Pb) metals from the chloride leach liquor of waste solder material and effluents using solvent extraction (SX) process. The studies were carried out for the extraction of tin from the leach liquor of solder materials containing 24.71 g/L Sn and 3.54 g/L Pb using tris 2-ethylhexyl amine (TEHA) diluted in kerosene and isodecanol was used as a modifier. The percentage extraction of Sn from leach liquor was found to be increased with increase in the concentration of extractant (TEHA). The 98.58% recovery of Sn was found using 20% TEHA in contact time 15 min and phase ratio (O/A) 1. Mc-Cabe Thiele diagram was also plotted to determine the stage requirement for the selective extraction of Sn using 20% tris 2-ethylhexyl amine and it was found that at O/A 0.5 in 2-stages of counter current extraction, Sn can be completely recovered from the leach liquor. After the stripping of Sn from loaded organic, the pure solution of tin is obtained. The pure lead solution is obtained as raffinate. From the purified solutions, lead and tin the salts/ metals could be obtained using crystallization/ electrolysis.