利用薄片樹脂電去離子技術進行蝕刻廢液中鹽酸回收及銦分離的效能評估

Abstract

本研究為利用樹脂薄片電去離子技術回收模擬氧化銦錫蝕刻廢液中鹽酸以及分離銦的效能評估。研究中使用的樹脂薄片為將傳統電去離子技術中的樹脂固定化，配合雙極膜以及陰離子交換膜達到陰、陽離子分離的效果；在實驗過程採批次性實驗，將每次處裡的水質到達一定程度後才利用分析儀器定量，再利用渴望度方程式計算出三因子實驗對於最大化氯產率和最小化特徵能耗的操作條件。最後以生命週期評估軟體算出各因子對環境的衝擊。 以統計軟體Design-Expert 8.0 中渴望度方程式算出最大氯產率為每小時每平方公尺有效面積0.197公斤，操作電壓為10福特，進流速度每分鐘240毫升，樹脂配比中陽離子交換能力比陰離子交換能力等於1:1.05特徵能耗為每公斤氯2.58度電；同時追求高產率低能耗時的操作條件為9.1伏特，每分鐘進流240毫升，樹脂配比中陽離子交換能力比陰離子交換能力約1:1.8，此時氯的產率約每小時每平方公尺有效面積0.169公斤的氯，相當於4M鹽酸。 以生命週期評估軟體Umberto 5.5計算出追求產率和能耗平衡點的操作條件對於減少用水消耗的效果較差，而對於減緩全球暖化潛勢較明顯，最終整體環境衝擊是減少了十七個百分比。

A test was conducted to simultaneously recover indium and hydrochloric acid from synthesized waste ITO etching water discharge by using two compartment electrodeionization (EDI) with bipolar and anion exchange membranes. Then a 3-factor experiment was performed, and the system was optimized to achieve the highest productivity of chloride and lowest specific energy consumption (SEC) by using a desirability function. The results indicated that the most hydrochloric acid was successfully recovered by EDI when the optimized condition for maximum productivity of chloride was 10 volts and a 240 ml/min feed flowrate using a commercialized configuration of resin wafer. For minimum SEC the voltage was set to 7 volts with a 240ml/min feed flowrate, with the resin wafer containing 75.54% anion capacity. Finally, when recovery and SEC are balanced, voltage is calculated to be 9.1 and 240 ml/min of feed flowrate using a wafer with 64.31% anion capacity. The process produces 0.12M hydrochloride, has an operating time of 39 - 256 minutes, and the specific energy consumption ranges from 0.55 to 5.6 kWh/kg. Nearly all the indium was retained on the resin during the batch wise experiment for the following treatment.