X射线荧光光谱法测定以钨和钼为主的多金属矿中主次成分

Determination of major and minor components in tungsten and molybdenum polymetallic ore by X-ray fluorescence spectrometry

建立了以钨、钼为主的多金属矿中主成分(SiO2,Al2O3,TFe2O3,CaO,MgO,K2O,Na2O,TiO2,P2O5,MnO)及矿化元素(W,Mo)的X射线荧光光谱分析方法。以四硼酸锂和偏硼酸锂混合物作为熔融试剂,硝酸锂作为样品在熔融过程中防止钨、钼挥发的氧化剂,在700～720℃温度下对样品进行预氧化,然后在1 100～1 200℃下高温熔融,得到的熔片成分均匀,表面光滑,无气孔,符合测定的要求。样品的组成和含量变化对分析线强度造成吸收、增强以及谱线重叠的影响而产生的基体效应采用理论α系数和经验系数相结合的方法校正。方法对生产样品中上述12种成分进行测定,结果表明:SiO2的测定值与重量法的测定值相符,TFe2O3、CaO、Al2O3的测定值与滴定法的测定值相符,MgO、K2O、Na2O、MnO、W、Mo的测定值与ICP-AES法的测定值相符,TiO2、P2O5的测定值与分光光度法的测定值相符。

The X-ray fluorescent spectrometric analysis method of main components （SiO2, Al203, TFe203, CaO, MgO, K20, Na20, TiO2 , P2O5 and MnO） and mineralization elements （W and Mo） in tungsten and molybdenum polymetallie ore was established. The lithium tetraborate and lithium metaborate mixture was used as melting reagent. The lithium nitrate was use as oxidizing agent to prevent the volatilization of tungsten and molybdenum in sample during melting. The sample was pre- oxidized at 700--720 ℃ and then melted at 1 100--1 200 ℃. The prepared sample exhibited uniform composition and smooth surface without air hole, which could meet the determination requirements. The matrix effect, which was caused by adsorption enhancement and spectral overlapping due to the effect of sample composition and content change on analytical intensity, was corrected by theoretical coefficient and empirical coefficient methods. Twelve components in production samples were deter- mined by the proposed method. The results showed that, the results of SiO2 were consistent with those obtained by gravimetric method; the results of TFe203, CaO and A12O3 were consistent with those obtained by titration method; the results of MgO, K2O, Na20, MnO, W and Mo were consist- ent with those obtained by ICP-AES; the results of TiO2 and P2Os were consistent with those obtained by spectrophotometry.