本研究為針對廢發光二極管下腳料中鎵、銦資源再生技術開發，實驗採用冶金技術進行金屬的資源再生，主要可以分為以下五個部分，化學特性分析、前處理、酸溶浸漬、分離純化與金屬析出，最終產物得以回到產業端使用。
第一部分為廢棄氮化鎵粉末的特性分析，此步驟藉由化學組成分析做為後續本研究規劃的依據，並於第二部分選取合適的前處理技術-鹼焙燒，以改變氮化鎵的晶體結構使其轉變為氧化鎵鈉以利後續的浸漬溶出，在此主要成份為鎵、銦、鋁三種元素，目標金屬鎵與銦溶出率分別可達98.63%與98.31%
完成浸漬溶出後將所得浸出液進行第三部分-目標金屬鎵、銦的分離純化，主要方法為透過溶媒萃取進行金屬分離，並使用分離係數β(Separation factor)、分配比D(Distribution ratio)及萃取效率做為指標數據。本研究利用Cyanex272對於鎵、銦在不同pH值下萃取效率的差異進行兩階段萃取。第一階段萃取銦被選擇性萃取至有機相中，鎵、鋁則留在水相中，有機相中銦離子再藉由鹽酸反萃取至水溶液中，由實驗結果顯示，此階段銦的萃取率為99.08%；反萃取率則為99.9%。而第二階段萃取仍使用Cyanex272及鹽酸進行鎵之萃取與反萃取，將鎵與鋁進行分離，由結果顯示。鎵之一階萃取率為90.8%，以McCabe-Thiele理論顯示鎵之理論萃取階數為2階，而鎵之二階萃取率可達99.13%，最後反萃取率則為99.9%。
第四部分-金屬析出使用化學沉澱法與高溫煅燒方式回收金屬，可得到氧化鎵與氧化銦的產物。最終藉由儀器分析產品純度，氧化鎵與氧化銦之純度分別可達99.46%與99.17%。

With the expansion of LEDs markets, LEDs will contribute to a large stream of solid wastes along with abundant waste electric and electronic equipment (WEEE).Due to the importance and scarcity of gallium and indium, we develop the effective recycling processes of recovering gallium and indium from waste gallium nitride-containing waste LED dust. The procedure was divided into the following steps, alkaline roasting, leaching, separation and purification. In the pretreatment part, owing to the stable chemically properties of gallium nitride, the process would concentrate on bonding rupture. Hence, the gallium nitride was reacted into sodium gallium oxide by alkaline roasting. And the next, the leaching and separation part, which is mainly to dissolve the targets and separate the gallium and indium from each other, including leaching and solvent extraction. The optimal condition of leaching procedures and the optimal parameters including pH value, concentration of Cyanex272, A/O ratio and extraction time were investigated in this study.
In the final purification step, Ga2O3 and In2O3 were obtained by means of chemical precipitation and calcination. With the optimal conditions, the recovery rate of gallium and indium could reach to 99%, and the purity of Ga2O3 and In2O3 are over 99%. The process which was provided in this study can provide an effective method to treat the related waste light emitting diodes dust.

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