應用置換法於實廠處理醫療電子印刷電路板硫酸銅廢液

Application of Cementation Technology in Treating Copper-Bearing Waste from Micro-etching Processes of Medical Electronics Printed Circuit Board

吳南明(Nan-Min Wu) ； 陳文欽(Wen-Chin Chen) ； 林建光(Chien-Kuang Lin)

《健康管理學刊》 12卷2期 (2014/12) Pp. 77-87

摘要

本研究針對醫療電子印刷電路板微蝕刻製程所產出的硫酸銅廢液，應用銅-鐵置換技術進行資源化處理，評估初始銅濃度和pH值對反應速率的影響。結果發現銅初始濃度值分別是15、23、30 g/L時，反應循一階動力式進行，但反應速率均隨銅離子的初始濃度增加而遞減。另以四組pH值（pH=1~4）進行試驗，發現pH=4之銅離子置換率較其他3組降低約40%，推測當溶液pH增加時，鐵片表面因氫氧化銅大量沉積而形成鈍化現象，鐵片表面活性面積減少，導致置換反應減緩且因無法有效釋出電子，以離子型態進入電雙層往外擴散，置換率因此受到化學反應所限制。本試驗以三組pH值（pH=1~3）進行質量平衡估算，結果發現總投入量和總產出量之合計相等，符合實驗預期，不過資源轉換率平均值僅58.7%，建議未來應於製程上進行改善，藉由減少置換槽的清洗耗水量或藉由廢水回收再利用於製程中，以提升資源轉換率。

關鍵字

醫療電子 ； 置換技術 ； 鈍化 ； 質量平衡 ； 資源轉換率

並列摘要

A copper-bearing waste generated from the micro-etching process of medical electronics printed circuit board (PCB) was studied by iron cementation technology in a practical chemical plant. Operation parameters include initial copper ion concentrations (15, 23, 30 g/L) and pH values (pH=1, 2, 3, 4) were assessed. Results showed that, within the range from 15 to 30 g/L of copper ion concentration, the reaction rate decreased with increasing the initial concentration. In addition, the higher the pH value the slower the copper cementation rate. And at pH=4, the rate is as low as about 40%, compared to the other pH values. It is attributed that, presumably as the pH of the solution increases, the copper hydroxide may deposit onto the iron surface to form a passivation layer, resulting in the blocking of solid-liquid interface mass transfer. Results of mass balance calculations indicated that the unit operation of the plant was quite in line with expectations. However, the average resource conversion rate was at 58.7%. In order to increase the resource conversion rate, it is suggested that reduce of water consumption and recycling to the process should be taken into consideration.

並列關鍵字

Medical electronics ； Cementation technology ； Passivation ； Mass balance ； Resource conversion rate