Method of copper precipitation in lead-free solder, granulation and separation of (CuX)6Sn5 compounds and recovery of tin

摘要

The purpose of the present invention is to separate excess coppers leached out in a lead-free solder bath and recover tin with high efficiency. An element X for forming a (CuX)6Sn5 compound between copper and tin in molten lead-free solders is added to separate out a (CuX)6Sn5 compound. Tin is recovered by binding the (CuX)6Sn5 compound by passing thereof through a multi-perforated plate, further generating swirling currents to precipitate and separate the bound (CuX)6Sn5 compounds and removing thereof.