摘要
废弃稀土荧光粉的回收利用对我国稀土资源的可持续发展和环境保护有重要意义。目前的回收工艺主要有直接回用和从其中回收稀土元素。直接回用以制造新的荧光粉是最理想的方案,但废弃荧光粉中杂质较多,需提纯分离,然而目前的风力分选和离心分离效率低,直接萃取法步骤多,污染严重。从废弃稀土荧光粉中回收稀土元素主要包括超临界CO2萃取和浸出后回收。前者反应迅速,回收率高,但对反应设备要求高,投资大;后者成本低,市场前景好,难点是荧光粉中的铝镁尖晶石结构难以破坏,导致Ce和Tb浸出率低,且浸出液难以循环使用。已有研究表明碱熔可破坏铝镁尖晶石结构,但由于后期采用酸浸,酸耗会增大。综上所述,今后研究应在浸出后回收工艺的优化方面引起重视,集中于寻找可经济高效破坏铝镁尖晶石结构的试剂,同时解决浸出液的循环使用,以实现废弃三基色荧光粉的绿色高效回收。
It is important to recycle rare earth elements from the phosphors for sustainable development and envi-ronment protection. The present recovery processes mainlyinclude direct reuse of the waste phosphor and recyclingrare earth elements of them. Direct reuse of the waste phosphor is the best way of recycling while the separation andpurification is needed for the impurities. However, wind separation and centrifugal separation are inefficient for theirexcessive steps and severe pollution. The methods of recycling of rare earth elements from waste phosphor are ex-tracting using supercritical C02 and recycling after leaching. The advantages of extracting using supercritical C02are high reaction rate and high recovery, while the disadvantages are strict requirements of the reaction equipmentand large investment. The recycling process after leaching has a good prospect in application on account of the lowcost, while the leaching rate of Ce and Te is low according to the difficulty of the unbreakable construction of mag-nesium aluminate spinel which makes the recycling of the leachate hard to realize. It was found that the constructionof magnesium aluminate spinel could be broken by molten alkali though the consumption of an amount of acid dueto the acid-leaching in end-process. In summary, the further research should focus on the fields of optimization ofrecycling process after extracting, developing of the low-cost leachate, and be able to break the construction ofmagnesium aluminate spinel, solving the problem of the recycling of leaching reagent, in order to realize the eco-nomic and efficient recycling of waste trichromatic
出处
《中国稀土学报》
CAS
CSCD
北大核心
2015年第6期641-649,共9页
Journal of the Chinese Society of Rare Earths
关键词
废弃稀土荧光灯
三基色荧光粉
稀土元素
循环使用
rare earth fluorescent
tricolor phosphor
rarephosphors.earth elements
recycling
