熔融制样-X射线荧光光谱法测定锰矿石中的14种组分

Determination of fourteen components in manganese ores by X-ray fluorescence spectrometry with fusion sample preparation

采用熔融制样,以X射线荧光光谱法(XRF)实现了同时测定锰矿石中Mn、TFe、SiO_2、Al_2O_3、K_2O、Na_2O、CaO、MgO、BaO、TiO_2、P、Cu、Zn、Ni等14种主次量组分。选择锰矿石国家标准物质、人工合成混合标样以及化学定值样品,通过灼烧减量校正建立校准曲线,解决了各类锰矿石中的多种组分的测定问题。探讨和分析了影响熔融条件的各种因素,获得了最佳的制备条件:样品与Li_2B_4O_7-LiBO_2混合熔剂稀释比例为1∶20,加入0. 10 g NH_4Br作脱模剂,0. 30 g NH_4NO_3作氧化剂,于700℃预氧化5min,1 100℃熔融时间8 min制备玻璃熔片。对锰矿石样品进行精密度考察,除了低含量的Na_2O的相对标准偏差(RSD,n=12)为8. 93%外,其他各组分测定结果的相对标准偏差均小于5%。将本文方法用于锰矿石样品的测定,结果与样品湿法测定值相一致。

Fourteen major and minor components in manganese ores,including Mn,TFe,SiO 2,Al 2O 3,K 2O,Na 2O,CaO,MgO,BaO,TiO 2,P,Cu,Zn and Ni,can be determined simultaneously by X-Ray Fluorescence Spectrometry(XRF)with fusion sample preparation.From the Chinese National Standard Materials of manganese ores,artificial synthesis of mixed standards and stoichiometric samples,the calibration curves are established via loss-on-ignition method.This can be applied to solve the problem of determining various components in manganese ores.The optimal preparation conditions are obtained after various affecting factors of the fusing conditions.A glass fuse piece can be prepared by mixing the sample with Li 2B 4O 7-LiBO 2 at a dilution ratio of 1∶20,adding 0.10 g of NH 4Br as a release agent and 0.30 g of NH 4NO 3 as an oxidant,pre-oxidizing at 700°C for 5 min,and subsequent fusing at 1 100°C for 8 min.Through the precision investigation of manganese ore samples,the result of the relative standard deviation of the determination is less than 5%,but the low content of Na 2O is 8.93%(RSD,n=12).The proposed method can be applied to determine the components of various manganese ore samples,the results are consistent with those obtained by wet method.