从某钾长石尾矿中提取稀土和铌工艺研究

Study on Extraction of Rare Earth and Niobium from Potash Feldspar Tailings

某钾长石选矿尾矿中稀土矿物主要由独居石、氟碳钙铈矿、褐帘石和氟碳铈矿等组成,铌矿物主要由铌铁矿和铌铁金红石组成,稀土和铌矿物矿物粒度细,且多与其他矿物紧密共生,REO含量0.52%,Nb2O5含量0.19%。采用硫酸焙烧—水浸工艺提取选矿尾矿中稀土和铌,研究了酸用量、焙烧时间和温度、浸出温度和时间等对稀土和铌浸出率的影响。结果表明,最佳工艺参数为:硫酸与尾矿质量比2∶1、300℃焙烧2 h、浸出液固比L/S=3、80℃水浸出2 h,稀土和铌浸出率分别达到83.3%和75.9%。

Rare earth minerals in potash feldspar tailings are mainly composed of allanite,monazite,bastnaesite and parasite,while niobium minerals in tailings are mainly composed of niobite and rutile,and rare earth and niobium minerals have fine grain size and are closely associated with other minerals.Content of REO and Nb2O5 is 0.52%and 0.19%respectively.Rare earth and niobium were extracted by sulfuric acid roasting-water immersion.Effects of acid addition,roasting time and temperature,leaching temperature and time on leaching rate of rare earth and niobium were studied.The results show that leaching rate of rare earth and niobium is 83.3%and 75.9%respectively under the optimum conditions including mass ratio of sulfuric acid to tailings of 2∶1,roasting at 300℃for 2 h,and leaching at 80℃for 2 h with L/S=3.