碱焙烧气氛对废稀土荧光粉铈铽提取的研究  

Extraction of Waste Rare Earth Phosphors Cerium and Terbium in Alkali-Roasting Atmosphere

作　　者：徐略渭 何秉轩 胡皓东 雷鑫 邵龙彬 梁勇[1] 廖春发[1] 刘德刚[1] Xu Luewei;He Bingxuan;Hu Haodong;Lei Xin;Shao Longbin;Liang Yong;Liao Chunfa;Liu Degang(Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technolo-gy,Ganzhou 341000,China)

机构地区：[1]江西理工大学材料冶金化学学部,江西赣州341000

出　　处：《中国稀土学报》2022年第2期268-275,共8页Journal of the Chinese Society of Rare Earths

基　　金：江西理工大学清江青年英才支持计划项目(JXUSTQJBJ2017004);江西理工大学大学生创新创业训练计划项目(DC2019-036)资助;江西省离子型稀土资源绿色开发与高值利用国家重点实验室培育计划项目(20194AFD44003);广东省放射性与三稀资源利用重点实验室开放基金项目(2018B030322009)。

摘　　要：废稀土荧光粉是重要的稀土二次资源,目前从废稀土荧光粉中回收稀土存在铈铽提取率低的问题。为了解决该问题,通过热力学计算,绘制了铈、铽氧化物的离解-生成反应吉布斯自由能图与离解-生成反应平衡图,表明在1000 K条件下碱焙烧废稀土荧光粉,且氧分压低于1.5×10^(-42)Pa时,铈,铽能以Ce_(2)O_(3),Tb_(2)O_(3)形式稳定存在。通过研究O_(2)浓度对废稀土荧光粉碱焙烧过程中抑制Ce,Tb氧化的影响,结果表明:先在O_(2)浓度低于0.4%,温度973 K碱焙烧3 h,后通过液固比10∶1,温度60℃,HCl浓度8 mol·L^(-1),浸出1 h,Ce,Tb提取率分别高达99.11%,99.18%,克服了传统废稀土荧光粉碱焙烧-HCl浸出工艺中Ce,Tb提取率低的难题,从而提出了低氧碱焙烧废稀土荧光粉抑制铈铽氧化的新思路。Waste rare earth phosphor is an important rare earth secondary resource.At present,the recovery of rare earth from waste rare earth phosphor has the problem of low extraction rate of cerium and terbium.In order to solve this problem,this paper draws the dissociation-formation reaction Gibbs free energy diagram and the dissociation-formation reaction equilibrium diagram of cerium and terbium oxides through thermodynamic calcula⁃tions,indicating that the waste rare-earth phosphors are alkali roasted at 1000 K,and when the oxygen partial pressure is lower than 1.5×10^(-42)Pa,Ce^(3+)and Tb^(3+) can exist stably in the form of Ce_(2)O_(3)and Tb_(2)O_(3).By studying the influence of oxygen concentration on the inhibition of Ce and Tb oxidation during the alkali-roasting process of waste rare earth phosphors,the results showed that,firstly,the oxygen concentration was lower than 0.4%,the temperature was 973 K,alkali-roasting time was for 3 h,and then the liquid-solid ratio was 10∶1,the tem⁃perature is 60℃,the hydrochloric acid concentration is 8 mol·L^(-1),and the leaching is 1 h,the extraction rates of Ce and Tb are respectively as high as 99.11%and 99.18%,overcoming the problem of low extraction rate of Ce and Tb in the traditional alkali roasting-hydrochloric acid leaching process of waste rare-earth phosphors,and a new idea of low-oxygen alkali roasting waste rare-earth phosphors to inhibit the oxidation of cerium and terbium was put forward.

关 键 词：废稀土荧光粉 低氧 碱焙烧 热力学 铈 铽 

分 类 号：TF845[冶金工程—有色金属冶金]