Etchant Regeneration & Copper Recovery
蚀刻废液铜回收与再生配方
标签：废液再生, 铜回收, 电解, 环保合规
FeCl3 蚀刻液含铜 30 g/L 后蚀速骤降，电解再生（石墨阴极、电流密度 1–2 A/dm²、槽压 2.5–3.5 V）可电解沉积回收铜粉并再生氯化亚铁为三氯化铁，再生后蚀速恢复 80–90%。废液含铜 >8 g/L 即属危废（HW22），委托处置费约 3000 元/吨——自建 20 L 电解再生槽年省处置费数千元。回收铜粉压块后可回炉铸造，实现闭环。
FeCl3 slows sharply above 30 g/L copper; electrolytic regeneration (graphite cathode, 1–2 A/dm², 2.5–3.5 V) plates out copper powder and re-oxidizes FeCl2 to FeCl3, restoring 80–90% etch rate. Spent bath above 8 g/L Cu is hazardous waste (HW22, ~¥3000/t disposal)—a 20 L regen tank saves thousands per year. Recovered copper powder can be pressed and remelted: a closed loop. ---