Determination of Twelve Major, Minor and Trace Components in Phosphate Ores by X-ray Fluorescence Spectrometry with a Lower-dilution Ratio of Fused Bead Sample Preparation
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摘要: 当前应用X射线荧光光谱熔片制样技术分析测定较低含量、低荧光产额氟组分时,准确度较低,精密度较差、检出限较高。本文运用5∶1较低稀释比熔样制片技术,采用波长色散X射线荧光光谱法测定磷矿石中12个主次量组分(F、Na2O、MgO、Al2O3、SiO2、P2O5、K2O、CaO、TiO2、MnO、TFe2O3和痕量SrO)。采用磷矿石、岩石国家一级标准物质、磷矿石管理样品和人工配制标准样品校准,经验系数法进行基体校正,结果表明12个组分分析方法的精密度和准确度较好,检出限较低,未知样品的分析结果比较满意;氟的精密度、准确度和检出限均好于文献中10∶1熔样稀释比得出的结果。该方法解决了压片制样测定氟组分,熔片制样测定其他主次量组分的技术问题,同时也降低了熔片制样技术测定氟的检出限。Abstract: The accuracy and precision are lower, and the detection limit is higher for the determination of F with low content and low fluorescence yield by using X-ray Fluorescence Spectrometry combined with lower dilution ratio fused bead samples preparation. In this paper a method has been reported for the determination of 12 major, minor and trace elements in phosphate ores by wavelength dispersive X-ray Fluorescence Spectrometry. A lower-dilution ratio (5∶1 reagent to sample) fused bead sample preparation mix was used for measurements. Chinese National Standard Materials with similar matrix elemental compositions to the samples were used to calibrate the matrix effect with the experience coefficient method. Results show that precision and accuracy of the method are greatly improved for 12 components, with lower detection limits and satisfactory results for unknown samples. Especially, precision, accuracy and detection limit of F were better than the analytical results in literature and were obtained by using a 10∶1 fused dilution ratio. Meanwhile, this method solved the technological problem by determining the F component using a pressed pellet sample, and other major and minor components by using fused bead pellet samples. The detection limit of F was also lowered by using this method.
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表 1 分析元素的测量条件
Table 1. Measurement conditions of the elements by XRF
元素 分析线 分析晶体 探测器 电压U/kV 电流i/mA 2θ/(°) 测量时间 t/s PHA范围 峰值 背景 峰值 背景 F Kα RX-35 F-PC 30 120 39.50 41.00 60 30 100~300 Na Kα RX-35 F-PC 30 120 25.52 26.85 30 10 140~278 Mg Kα RX-35 F-PC 30 120 21.14 23.00 30 10 130~340 Al Kα PET F-PC 30 120 144.85 140.00 20 10 100~300 Si Kα PET F-PC 30 120 109.25 111.00 20 10 100~300 P Kα Ge F-PC 30 120 141.20 143.00 20 10 100~300 K Kα LiF3 F-PC 30 120 136.60 140.70 20 10 100~300 Ca Kα LiF3 F-PC 30 120 113.15 110.90 10 5 100~300 Ti Kα LiF1 SC 50 50 86.12 84.20 20 10 100~300 Sr Kα LiF1 SC 50 70 25.12 27.27 20 10 100~300 Mn Kα LiF1 SC 50 70 62.96 64.60 20 10 100~300 Fe Kα LiF1 SC 50 70 57.50 55.18 10 5 89~372 表 2 校准样品中各组分的含量范围
Table 2. Concentration ranges of elements in calibration samples
组分 wB/% F 0.07~3.54 Na2O 0.059~3.38 MgO 0.21~8.19 Al2O3 0.58~18.82 SiO2 1.25~59.23 P2O5 0.16~38.45 K2O 0.17~4.16 CaO 0.60~52.58 TiO2 0.037~2.37 MnO 0.015~0.17 TFe2O3 0.78~13.4 SrO 0.0106~0.16 注:TFe2O3表示样品中的Fe全部以Fe2O3表示。 表 3 稀释比为5∶1时氟组分的X射线荧光强度
Table 3. X-ray fluorescence intensities of F with the ratio 5∶1 for reagent to sample
测量次数 测量强度/kcps 210 211 212 CHPG CHPZH EPG HUI1 HUI2 QPG R3 R5 1-JHQ 0.1616 0.1004 0.0247 0.1485 0.1121 0.0948 0.0855 0.0315 0.1782 0.0047 0.0047 2-JHQ 0.1719 0.1100 0.0318 0.1561 0.1148 0.0981 0.0904 0.0357 0.1926 0.0109 0.0069 3-JHQ 0.1836 0.1206 0.0384 0.1638 0.1251 0.1165 0.1013 0.0396 0.1901 0.0133 0.0157 4-JHQ 0.1814 0.1174 0.0404 0.1617 0.1259 0.1176 0.0971 0.0435 0.1917 0.0100 0.0153 5-JHQ 0.1853 0.1174 0.0435 0.1689 0.1244 0.1215 0.1029 0.0484 0.1862 0.0200 0.0212 6-JHQ 0.1862 0.1170 0.0432 0.1647 0.1268 0.1210 0.1024 0.0449 0.2012 0.0195 0.0192 7-JHQ 0.1907 0.1261 0.0469 0.1711 0.1359 0.1188 0.1060 0.0507 0.2064 0.0229 0.0206 8-JHQ 0.1878 0.1254 0.0490 0.1737 0.1338 0.1262 0.1078 0.0583 0.1970 0.0286 0.0194 9-JHQ 0.1940 0.1232 0.0492 0.1719 0.1312 0.1203 0.1048 0.0558 0.2047 0.0261 0.0266 10-JHQ 0.1983 0.1311 0.0491 0.1726 0.1380 0.1259 0.1116 0.0572 0.2041 0.0300 0.0240 11-JHQ 0.1988 0.1275 0.0508 0.1814 0.1378 0.1295 0.1132 0.0576 0.2028 0.0311 0.0259 12-JHQ 0.1992 0.1265 0.0514 0.1782 0.1404 0.1227 0.1178 0.0579 0.2045 0.0288 0.0293 13-JHQ 0.1965 0.1243 0.0494 0.1764 0.1359 0.1240 0.1165 0.0567 0.2019 0.0365 0.0293 14-JHQ 0.1987 0.1287 0.0571 0.1747 0.1313 0.1303 0.1184 0.0645 0.2044 0.0328 0.0334 15-JHQ 0.2010 0.1245 0.0579 0.1778 0.1393 0.1273 0.1170 0.0596 0.2045 0.0310 0.0336 1-GZQ 0.1651 0.1022 0.0215 0.1409 0.1147 0.1048 0.0860 0.0337 0.1763 0.0046 0.0078 2-GZQ 0.1709 0.1031 0.0259 0.1457 0.1106 0.0995 0.0888 0.0271 0.1745 0.0051 0.0077 3-GZQ 0.1731 0.1027 0.0299 0.1519 0.1089 0.1002 0.0918 0.0333 0.1772 0.0058 0.0074 4-GZQ 0.1636 0.1096 0.0319 0.1537 0.1143 0.0971 0.0930 0.0308 0.1702 0.0086 0.0144 5-GZQ 0.1671 0.1065 0.0288 0.1464 0.1151 0.0975 0.0921 0.0329 0.1779 0.0092 0.0080 6-GZQ 0.1713 0.1083 0.0308 0.1496 0.1163 0.1034 0.0937 0.0363 0.1730 0.0088 0.0081 7-GZQ 0.1745 0.1061 0.0329 0.1482 0.1159 0.1075 0.0935 0.0319 0.1776 0.0082 0.0112 8-GZQ 0.1651 0.1028 0.0273 0.1523 0.1175 0.1010 0.0925 0.0346 0.1788 0.0070 0.0134 9-GZQ 0.1693 0.1090 0.0270 0.1518 0.1093 0.0995 0.0906 0.0321 0.1771 0.0112 0.0101 10-GZQ 0.1741 0.1107 0.0255 0.1521 0.1172 0.1071 0.0965 0.0370 0.1770 0.0132 0.0193 11-GZQ 0.1692 0.1092 0.0289 0.1558 0.1203 0.1043 0.0959 0.0366 0.1777 0.0108 0.0158 12-GZQ 0.1731 0.1074 0.0294 0.1445 0.1123 0.1030 0.0958 0.0346 0.1741 0.0173 0.0153 13-GZQ 0.1712 0.1111 0.0278 0.1493 0.1142 0.0951 0.0953 0.0366 0.1792 0.0144 0.0104 14-GZQ 0.1669 0.1091 0.0288 0.1525 0.1144 0.1042 0.0930 0.0328 0.1773 0.0149 0.0154 15-GZQ 0.1705 0.1054 0.0287 0.1500 0.1126 0.1034 0.0923 0.0331 0.1716 0.0130 0.0149 RSD-JQD/% 1.59 2.52 9.40 1.77 2.29 2.60 2.98 7.18 1.55 50.3 50.3 RSD-JHQ/% 4.49 4.64 15.0 4.18 5.54 6.55 7.90 16.3 3.32 34.8 32.7 RSD-GZQ/% 2.04 2.85 9.80 2.63 2.74 3.59 3.01 7.78 1.52 37.7 31.8 注:210、211、212为磷矿石国家一级标准物质;CHPG、CHPZH、EPG、QPG为磷矿石管理样品;HUI1为样品GBW 07210与GBW 07105(质量比1∶1)的混合物,HUN2为样品GBW 07211与GBW 07107的混合物(质量比1∶3);R3、R5为岩石国家一级标准物质。1-JHQ为置于交换器上的一组样品的第1次测量结果,其余类似编号以此类推;1-GZQ为测完后保存在干燥器中的一组样品的第1次测量结果,其余类似编号以此类推;RSD-JQD、RSD-JHQ、RSD-GZQ分别表示扣除本底后的净强度、保存在交换器中的测量强度(15次)、保存在干燥器中测量强度(15次)的相对标准偏差。 表 4 方法检出限
Table 4. Detection limits of the method
组分 检出限/(μg·g-1 ) F 1121 Na2O 97 MgO 283 Al2O3 154 SiO2 150 P2O5 67 K2O 35 CaO 181 TiO2 61 MnO 4 TFe2O3 250 SrO 6 表 5 方法精密度和仪器精密度
Table 5. Precision tests of the method and the instrument
组分 GBW 07210 (n=10) HUN2 (n=10) 标准值/% 方法精密度RSD/% 仪器精密度RSD/% 标准值/% 方法精密度RSD/% 仪器精密度RSD/% F 3.54 1.96 1.56 0.61 4.11 5.25 Na2O 0.33 1.07 1.48 0.28 1.50 1.39 MgO 0.43 0.81 0.49 3.56 0.24 0.16 Al2O3 0.58 0.98 0.58 14.76 0.38 0.06 SiO2 3.26 0.51 0.27 45.33 0.32 0.09 TFe2O3 1.04 0.44 0.24 5.97 0.23 0.12 P2O5 36.89 0.11 0.06 5.34 0.26 0.13 MnO 0.024 3.17 3.08 0.019 3.39 2.65 SrO 0.077 0.66 0.17 0.048 0.32 0.23 K2O 0.17 0.89 0.48 3.19 0.30 0.07 CaO 51.32 0.10 0.05 10.63 0.16 0.07 TiO2 0.037 4.99 4.28 0.53 0.82 0.53 表 6 方法准确度
Table 6. Accuracy tests of the methodwB/%
样品 项目 F Na2O MgO Al2O3 SiO2 TFe2O3 P2O5 MnO SrO K2O CaO TiO2 GBW 07210 标准值 3.54 0.33 0.43 0.58 3.26 1.04 36.89 0.024 0.077 0.17 51.32 0.037 本法 3.50 0.31 0.52 0.62 3.16 1.09 36.86 0.021 0.077 0.15 51.87 0.043 GBW 07212 标准值 0.51 0.14 7.12 4.06 38.80 3.08 6.06 0.026 0.055 2.63 19.42 0.48 本法 0.48 0.13 7.24 4.07 38.96 3.09 6.31 0.028 0.055 2.58 19.58 0.50 EG 推荐值 2.07* 0.17 1.65 3.51 12.87 1.61 29.44 ** ** 0.99 42.55 0.24 本法 2.13 0.23 1.64 3.50 12.86 1.63 29.57 0.03 0.082 0.97 42.60 0.24 HUN2 推荐值 0.61 0.28 3.56 14.76 45.33 5.97 5.34 0.019 0.048 3.19 10.63 0.53 本法 0.51 0.24 3.81 14.74 45.24 5.97 5.37 0.021 0.048 3.16 10.55 0.53 QG 推荐值 3.69* ** 0.21 1.04 1.25 0.78 38.45 ** ** ** 52.58 0.07 本法 3.45 0.28 0.26 0.98 1.29 0.81 38.36 0.13 0.08 0.21 53.08 0.06 GBW 07105 标准值 0.07 3.38 7.77 13.83 44.64 13.40 0.95 0.17 0.13 2.32 8.81 2.37 本法 0.08 3.46 7.57 13.80 44.68 13.40 0.85 0.17 0.13 2.37 8.95 2.38 未知样品1 推荐值 - - 1.10 - - - 30.18 - - - - - 本法 2.95 0.20 1.36 1.00 15.52 0.88 30.16 0.024 0.074 0.29 44.02 0.052 未知样品2 推荐值 - - 0.58 - - - 29.21 - - - - - 本法 2.69 0.15 0.65 1.18 21.23 1.03 28.98 0.042 0.091 0.27 41.42 0.085 注:带“*”的数据为电化学分析方法的测量值;“**”表示管理样品没有给出该组分的推荐值; “-”表示云南磷化集团研发中心没有提供未知样品相应组分的分析值。 -
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