In order to observe the impurity behavior during a hydrometallurgical copper recycling process using ammoniacal solution and cuprous ions, copper was recovered from wasted printed circuit boards, where the solution was recycled after adjustment of the solution volume and composition by addition of copper-free solution and oxygen gas. It was confirmed that zinc, nickel and manganese accumulate in the solution, although the accumulation showed no significant impact on the copper purity. It was also found that the accumulation of zinc in the solution increases the risk of copper oxide or hydroxide precipitation during the process, because of the consumption of ammonia. The lead content in the copper deposit was around 20ppmw, 4 times higher than that of LME grade A standard, regardless of the number of the solution recycle. Thus, lead removal using a column filled with an adsorbent was further investigated, and sintered calcium phosphate (hydroxyapatite) was found to be a potential candidate as the lead adsorbent for this process.
