電氣鍍鋅線廢水價值創造與再利用技術

中鋼電氣鍍鋅線核心製程為濕式電鍍，因為電鍍前需要潤濕鋼帶，而電鍍後則需沖洗鋼帶避免電鍍液殘留，所以純水耗用量大，且使用後純水如無法再利用，則只能當成廢水處理。本篇研究利用分析產線各區水質參數及適用性，將廢水可利用性提升為4次、轉向輥盛盤廢水回收再利用，以減少轉向輥潤濕槽之純水耗用，且還可幫助增加電鍍液之補充來源、而冷凝水雜質經沉澱過濾槽攔截後，有效提升廢水回收系統產水率。廢水價值再創造及再利用效益內容包含減少廢水處理、減少純水耗用、增加回收純水、減少電鍍液成本等。

關鍵字

電氣鍍鋅線；濕式電鍍製程；廢水回收系統

並列摘要

The core process on the Electrolytic Galvanizing Line (EGL) in China Steel Corporation (CSC) is wet electroplating. The steel strips need to be rinsed before electroplating, while flushed after electroplating to avoid electrolyte residual, resulting in substantial De-mineralized Water (DMW) consumption. Besides, used DMW would be discharged to wastewater treatment plant if it cannot be recycled. In this research, process water parameters and applicability in each line section were analyzed to elevate reuse frequency of wastewater to 4 times, recycle pan wastewater of the deflector rolls with a reduction in DMW consumption of the deflector-roll rinsing tank and an increase in electrolyte supply, and remove impurity solids of the condensed water in the deposit-and-filter tank to effectively enhance Waste Water Recovery (WWR) yield. The benefits of DMW reuse and value-creation include reductions of wastewater treatment, DMW consumption, and electrolyte cost, along with increase in De-mineralized Water Returned (DWR).