Abstract: Waste light emitting diode (LED) contains a variety of valuable metal elements, and the recycling of these elements has attracted wide attention. In this work, the distribution characteristics of valuable elements in LED from bulb lamps (L-LED) and SMD 2835 LED (S-LED) were systematically analyzed. XRD, FTIR, ICP-OES, and SEM-EDS methods were used to study the mass composition, phase composition, types of packaging resin and distribution characteristics of valuable metals in the two LEDs. Based on these results, the pre-enrichment and separation of valuable elements in LED using mechanical crushing and screening methods was proposed. The results showed that the lead frames of L-LED and S-LED were pure copper and brass material, respectively. The packaging resins of the two kinds of LED were phenyl methyl silicone resin containing hydroxyl group. The main ingredients of the phosphor in the packaging resin of L-LED and S-LED were Y3Al3.08Ga1.92O12: Ce3+ and Y3Al5O12: Ce3+, respectively. Rare earth elements such as Y, Ce, and Eu existed in the packaging resins, and metal elements such as Cu, Zn, Ni, W, and Ag existed on the metal substrates of lead frames. The scattered element Ga was present only in the chips in S-LED, while it was distributed in both the packaging resin and the chips in L-LED. The components of LED were effectively separated by the processes of mechanical crushing and screening. After crushing and screening, elements Cu, Zn, Ni, W, and Ag were enriched in the screening products with particle size >0.6 mm, and elements Ga, Y, Ce were concentrated in the screening products with particle size <0.6 mm. The pre-treatment process used physical means to enrich and separate valuable elements, which was conducive to the subsequent recovery and utilization of valuable elements.

Key words: LED, valuable elements, enrichment and separation, crushing, screening

摘要： 废弃发光二极管(LED)中含有多种有价金属元素，这些元素的回收利用引起学者们的广泛关注。本研究系统分析了球泡灯灯珠(L-LED)和SMD 2835 LED (S-LED)中有价元素的分布特点。在探明LED各组件质量组成的同时，采用XRD、ICP-OES和SEM-EDS等分析手段研究了有价元素在LED各组件中的分布特征，并据此提出采用机械破碎-筛分预处理技术，对LED中的有价元素进行预富集分离。结果表明，L-LED和S-LED的支架分别为纯铜和黄铜材质。两种LED的封装树脂均为含羟基的苯基甲基有机硅树脂。L-LED和S-LED封装树脂中荧光粉的主要成分分别为Y3Al3.08Ga1.92O12:Ce3+和Y3Al5O12:Ce3+。稀土元素Y, Ce和Eu主要存在于有机硅树脂中；金属元素Cu, Zn, Ni, W和Ag主要分布于支架的金属基板；对于S-LED，稀散元素Ga仅存在于LED芯片中，而L-LED的Ga在硅树脂和芯片中均有分布。通过机械破碎和筛分处理，有效实现了LED各组件的分离。经破碎筛分后，Cu, Zn, Ni, Ag和W元素富集于粒径大于0.6 mm的筛分产物中，而Ga, Y和Ce元素则富集于粒径小于0.6 mm的筛分产物中。该预处理工艺通过物理手段对有价元素进行预富集分离，有利于有价元素后续的回收利用。

关键词: LED, 有价元素, 富集分离, 破碎, 筛分