摘要: | 印刷電路板製程繁瑣印,是一個集合光學、電學、化學、機械及管理的綜合工業。2007 年全球印刷電路板產業的產值達到44,277 百萬美元。印刷電路板製造業於濕式製程電鍍單元大量使用金屬鹽類作為原物料使用,所排放之廢液含有高度回收價值的銅、鉛、鎳、金及鈀等重金屬及貴金屬,國內印刷電路板製造業95 年度含重金屬廢棄物申報總量約為322,907 公噸,此類廢棄物若不妥善處理,對於環境之影響,生態之衝擊將日益嚴重,亦造成企業及社會成本之增加。 本論文主要以北區某一印刷電路板廠A 為研究對象,研究內容包含金之廢棄物資源化方式、電解機與離子交換樹脂回收效率及操作成本之探討。研究結果顯示: 1.離子交換樹脂單獨使用時回收金的效能大於電解機單獨使用之效 能。 2.離子交換樹脂搭配使用於回收金的效能優於電解機配合離子交換 樹脂之使用方式,與文獻資料說明其效能理應相等而有所差異, 建議採相同回收方式的廠商,應針對電解機後端樹脂塔之設計操 作參數是否最佳化進行了解,以減少黃金的流失。 3.針對北區印刷電路板A 廠所提供的離子交換樹脂進行效率分析, 發現實際金回收效率到達96 %,樹脂並於第三天試驗過程已達操 作容量,此時若不更換樹脂將造成樹脂貫穿情形發生。建議採離 子交換方式回收的印刷電路板業者,可針對自廠離子交換樹脂的 貫穿水量及時間點進行了解,以降低黃金的流失。 4.由金鹽投入量與回收黃金的比例中發現,半成品板所佔的黃金量 最多,其後續所產生的廢棄物問題若不建立一套有效之回收體系 ,勢必對於環境造成污染,資源形成浪費。 關鍵字:印刷電路板、黃金、離子交換、電解、回收效率 PCB (printed circuit board) is an integrated industry of optics, electricity,chemistry, machinery, and management. In year 2007, the total industry revenuealready reached 44.2 billion USD. The wet processes for plating of PCB industry use large amount of metal salts. Therefore, their waste liquids usually contain high valuable metals, such as copper, lead, nickel, gold and palladium.In 2006, the reported amount of waste with heavy metals in Taiwan PCB industry was around 322,907 ton. If these wastes are not well treated, their impact to environment and ecologic system will be serious and also will costenterprises and society more. This thesis takes a PCB plant in northern Taiwan as an example to discuss theefficiency and operating cost, for recovering gold from waste liquid usingelectrolysis and ion exchange. This study shows the following results: 1. The efficiency of ion exchange is better than that of electrolysis in gold recycle. 2. The efficiency of combination of ion resins is better than that of the combination of ion resin and electrolysis in gold recycle. This finding is different from literatures. Therefore, it is suggested that the recycling facility should be optimized to reduce the loss of gold. 3. It was found that gold recycling efficiency was 96%. Resin of ion resin for a PCB plant located in northern Taiwan reached the capacity limit in the third day of test. If the resin is not replaced, then breakthrough will occur. Therefore, this study suggests the PCB plants using ion resin for gold recycling must understand the breakthrough point for flow and time to avoid loss of gold. 4. The analysis indicates that semi-finished product is of the highest percentage of the gold input. An efficient recycling system is needed to properly deal with the subsequent waste problem and avoid resource waste and environmental pollution. Key words : printed circuit board, gold, ion exchange, electrolysis, recycling efficiency. |