With the expansion of light emitting diode (LED) markets, LED will contribute to a large stream of solid wastes along with abundant waste electric and electronic equipment (WEEE) 1) , The demands for multiple LED lighting have rapidly increased during the previous decades 2) , and so do the waste light emitting diodes.However, waste dust generated during manufacturing of LED contain significant amounts of gallium and indium, needs suitable treatment and can be an important resource for recovery.According to the U.S. Geological Survey, the global gallium productions (4N) have raised 50 tons, moreover, the high purity gallium productions (9N) was 180 tons in 2017 3) . There are 70 percent of gallium was applicated in semiconductor including gallium nitride and gallium arsenide. Besides, U.S. Geological Survey also predicts the usage of gallium will increase 30% for the application of 5G in the future. However, gallium is one kind of critical raw materials. The recovery of gallium becomes important when the supply cannot meet the market demand. Also, the demand for indium worldwide exceeds 500 tons per year. Due to the abundant natural resources of indium, there is an urgent need for the development of indiumcontaining waste and waste liquid recovery technologies. Alternative sources of indium are focused on the disposal of waste materials containing indium, such as ITO waste, †
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