The rapid and precise determination of the elemental composition of materials used in cement production is key for successful process control and product quality. Immediate feedback permits close control of all process parameters. Routine analysis requires extremely short measurement times and this makes the same instruments available for other tasks such as alternative fuels analysis or analysis of non-routine samples such as hot meal and filter dust.
Sequential wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry is an established technique for all the above- said tasks. This report illustrates the extraordinary analytical performance of the S8 TIGER in terms of analytical speed, precision, sample throughput and time-to-result. The technique also offers analytical flexibility for modern day tasks.
Instrument
The S8 TIGER spectrometer is easy to use by virtue of its unique TouchControl and SampleCare features having superior analytical performance. SampleCare offers reliable operation and high instrument uptime of the S8 TIGER by means of the advanced 4x protection of all spectrometer components against contamination and damage caused by dust and liquids. The spectrometer features the high intensity 4 kW Rhodium X-ray tube, five analyzer crystals, and two collimators (0.23° and 0.46°) and also offers highly flexible and compact beampath, which gives highest intensity and analytical speed. Sodium and magnesium analysis benefits from the use of the intensity- optimized XS-55 crystal. The curved germanium crystal XS-GE-C offers 20-40% more intensity for the elements P, S and Cl. The multilayer XS-CEM crystal guarantees long-term stability for Al and Si.
Sample Preparation
About 10 g of raw meal was finely ground with three grinding aid tablets and pressed with a pressure of 20 tons. This process formed highly stable samples and can be used for both manual and automated preparation of sample.
Measurement
Measurements were carried out on the S8 TIGER using 4 kW Rh excitation. The total time-to result which includes loading, evacuation, analysis and reporting of the results was 113 s. Two samples were measured 50 times one after the other to illustrate the analytical performance under real conditions. Na, Mg, Al, Si, P, S, K, Ca, Mn and Fe were measured and the concentrations were determined as oxides. This test aimed at demonstrating extraordinary quality of analytical data or reproducibility under real conditions. The precision test was performed 20 times a second day to demonstrate analytical stability.
Results
The calibration data and the maximum difference between certified and measured data are summarized in Table 1. Precision data for CaO, Al2O3 and SiO2 are shown in the process control chart depicted in the following figures.
.jpg)
.jpg)
.jpg)
The same has been summarized in Tables 2 and 3. The S8 TIGER spectrometer’s precision and accuracy apparently exceeded the requirements of ASTM C114. The statistical error in counting is only minimal, thus making preparation of sample a key factor for successful process control.
| Element |
Concentration Range [%] |
ASTM Max. Diff |
S8 TIGER Max. Diff |
| Na2O |
0.08 - 0.45 |
0.05 |
0.02 |
| MgO |
1.2 - 4.2 |
0.2 |
0.1 |
| Al2O3 |
3.1 - 5.8 |
0.2 |
0.1 |
| Si02 |
17.6 - 25.2 |
0.2 |
0.1 |
| P2O5 |
0.02 - 0.2 |
0.03 |
0.03 |
| SO3 |
1.9 - 3.2 |
0.1 |
0.1 |
| K2O |
0.1 - 1.5 |
0.05 |
0.04 |
| CaO |
61.5 - 68.2 |
0.3 |
0.15 |
| Mn3O4 |
0.08 - 0.6 |
0.03 |
0.01 |
| Fe2O3 |
0.3 - 4.4 |
0.10 |
0.03 |
Conclusions
The extraordinary precision achieved shows that the S8 TIGER has superior analytical performance. The S8 TIGER’s beampath design offers the best intensity for each element. Specific analyzer crystals such as the XS-CEM are optimized for a maximum of intensity and stability, which guarantees long-term precision. Immediate feedback helps in ensuring best product quality. Extremely high analytical speed and shortest time-to-result makes the system available for other tasks.
| Time |
Na2O [%] |
MgO [%] |
Al2O3 [%] |
SiO2 [%] |
P2O5 [%] |
SO3 [%] |
K2O [%] |
CaO [%] |
Mn3O4 [%] |
Fe2O3 [%] |
| 18:35:36 |
0.141 |
2.188 |
6.300 |
22.72 |
0.121 |
4.075 |
1.021 |
60.80 |
0.130 |
2.248 |
| 18:40:41 |
0.144 |
2.189 |
6.320 |
22.73 |
0.120 |
4.082 |
1.020 |
60.77 |
0.128 |
2.246 |
| |
... |
... |
... |
... |
... |
... |
... |
... |
... |
... |
| 20:37:23 |
0.143 |
2.192 |
6.300 |
22.77 |
0.119 |
4.094 |
1.015 |
60.87 |
0.128 |
2.248 |
| 20:42:28 |
0.144 |
2.191 |
6.290 |
22.79 |
0.120 |
4.087 |
1.018 |
60.76 |
0.129 |
2.245 |
| 22:39:09 |
0.144 |
2.191 |
6.280 |
22.77 |
0.120 |
4.088 |
1.024 |
60.87 |
0.129 |
2.249 |
| 22:44:13 |
0.144 |
2.186 |
6.300 |
22.79 |
0.121 |
4.092 |
1.019 |
60.80 |
0.129 |
2.254 |
| |
... |
... |
... |
... |
... |
... |
... |
... |
... |
... |
| Mean Value |
0.143 |
2.189 |
6.300 |
22.77 |
0.120 |
4.084 |
1.021 |
60.78 |
0.128 |
2.248 |
| Std.Dev. |
0.001 |
0.006 |
0.016 |
0.02 |
0.001 |
0.006 |
0.002 |
0.05 |
0.001 |
0.004 |
| RSD. |
1.03 |
0.27 |
0.25 |
0.10 |
0.62 |
0.14 |
0.22 |
0.08 |
0.74 |
0.19 |
| Time |
Na2O [%] |
MgO [%] |
Al2O3 [%] |
SiO2 [%] |
P2O5 [%] |
SO3 [%] |
K2O [%] |
CaO [%] |
Mn3O4 [%] |
Fe2O3 [%] |
| 08:42:25 |
0.140 |
2.164 |
6.310 |
22.77 |
0.120 |
4.076 |
1.014 |
60.78 |
0.123 |
2.228 |
| 08:47:29 |
0.143 |
2.179 |
6.330 |
22.83 |
0.120 |
4.078 |
1.014 |
60.73 |
0.129 |
2.224 |
| |
... |
... |
... |
... |
... |
... |
... |
... |
... |
... |
| 10:13:45 |
0.142 |
2.199 |
6.310 |
22.79 |
0.121 |
4.095 |
1.018 |
60.76 |
0.129 |
2.243 |
| 10:18:49 |
0.141 |
2.181 |
6.310 |
22.81 |
0.121 |
4.089 |
1.017 |
60.76 |
0.126 |
2.239 |
| Mean Value |
0.141 |
2.187 |
6.303 |
22.78 |
0.121 |
4.085 |
1.017 |
60.79 |
0.128 |
2.240 |
| Std.Dev. |
0.001 |
0.009 |
0.018 |
0.02 |
0.001 |
0.007 |
0.002 |
0.04 |
0.001 |
0.007 |
| RSD. |
0.94 |
0.39 |
0.28 |
0.10 |
0.67 |
0.17 |
0.23 |
0.07 |
1.15 |
0.33 |
This information has been sourced, reviewed and adapted from materials provided by Bruker X-Ray Analysis.
For more information on this source, please visit Bruker X-Ray Analysis.