黄钠铁矾和硫化锰分步去除硫酸锰溶液中铁钴镍

采用黄钠铁矾和硫化锰沉淀法从软锰矿硫酸浸出液中分步去除Fe^(3+)、Co^(2+)、Ni^(2+)。先采用黄钠铁矾法沉淀去除Fe^(3+),再采用硫化锰沉淀去除Co^(2+)、Ni^(2+)。单因素试验最佳工艺条件为:隔氧环境下,MnS添加量10g/L、反应温度75℃、反应时间30min、转速120r/min,此条件下,Co^(2+)去除率达99.2%,Ni^(2+)去除率达99.81%。

Size influence on the fluorescence decay time of ZnS:Mn^(2+) nanocrystals

ZnS:Mn2+ nanocrystals(NCs) with particle size from 1.9 nm to 3.2 nm are synthesized via chemical precipitation method with different [S2-]/[Zn2+] ratios.The size-dependent decay for Mn emission exhibits a double exponential behavior.And two lifetime values,in millisecond time domain,can both be shortened with size increasing,which is attributed to enhanced interaction between host and Mn2+ impurity.A molecular structure model is proposed to interpret the tendency of two lifetime components,which is correlated to the number of S vacancy(Vs) defects around Mn2+.