Global Cement and Raw Materials Fusion/XRF Analytical Solution

Transcription

1 263 Global Cement and Raw Materials Fusion/XRF Analytical Solution Mathieu Bouchard, John Anzelmo, and Sebastien Rivard Corporation Scientifique Claisse, Quebec, Canada Alexander Seyfarth and Larry Arias Bruker-AXS, Madison, WI Kai Behrens and Soodabeh Durali-M Bruker-AXS GmbH, Karlsruhe, Germany ABSTRACT A robust analytical method using an automated fusion machine as sample preparation tool and a wavelength-dispersive X-ray fluorescence spectrometer for the determination of all the elements of interest for the cement industry has been developed. This method was used to prepare all cements, all process materials, and a very large range of raw materials. The choice of all fusion parameters and all XRF analysis conditions, including calibration corrections, are shown. Two sets of reference materials (RM) from two different sources were used to verify that this fusion method allows a matrix match for cement from different origins. One set is from the National Institute of Standards and Technology (NIST) and the other set is from the Japan Cement Association (JCA). A critical evaluation of precision and accuracy has been performed against standard methods from two well known international reference organizations: The American Society for Testing and Materials International (ASTM) and the International Organization for Standardization (ISO). The two standard methods for analysis of cement by X-ray fluorescence are known as: ASTM C 114 [1] and ISO/DIS [2]. Qualification of reference materials not included in the calibration is also investigated. INTRODUCTION For the last five decades, X-ray fluorescence spectrometry has been widely accepted as the standard method for quantitative chemical analysis of cement industry samples. In the past, sample preparation by both pressed powder and fusion were accepted for those analyses [3]. The 21 st century reality of the cement industry with the increase of production of cements with alternative raw materials and additives involving secondary fuels, and the use of reference materials from various sources in the world, make the use of pressed powder more complicated because of the necessity for matrix matching to increase or optimize the accuracy with this analytical technique. The use of the fusion preparation technique requires less calibration curves because this method removes particle size and mineralogy effects [3, 4]. For those reasons a global and unique fusion method for the preparation of all cements, all process materials, and a very large range of raw materials is desirable, when combined with wavelength-dispersive X-ray fluorescence (WDXRF), to allow compliance with the ASTM C 114 and ISO/DIS specifications of precision and accuracy.

2 This document was presented at the Denver X-ray Conference (DXC) on Applications of X-ray Analysis. Sponsored by the International Centre for Diffraction Data (ICDD). This document is provided by ICDD in cooperation with the authors and presenters of the DXC for the express purpose of educating the scientific community. All copyrights for the document are retained by ICDD. Usage is restricted for the purposes of education and scientific research. DXC Website ICDD Website -

3 264 To develop a fusion method for sample preparation, with such a wide range of different materials with various compositions, many parameters were evaluated. The list of materials that were investigated were the following: cement, blended cement, cements with additions, aluminate cement, clinker, kiln feed, raw mix, limestone, gypsum, sand, clay, bauxite, silica fume, slag, fly ash, iron ore and others. Because the fusion process has a history of more than 50 years, some of the parameters are well known. Parameters such as type of material for crucible and molds, composition of flux, type and amount of non-wetting agent to use, and maximum fusion temperature are well known, and incorporated with an automated fusion machine for excellent precision and stability over time. Nevertheless, a global solution still requires refinement of the various parameters. The list of all parameters that were evaluated for this project was: - Calcinations and/or lost on ignition (LOI)) at various temperatures - Effective way to prepare the mix in the crucible - Fusion time - Agitation speed at various stages of the process - Best sample to flux ratio - Dry oxidation process and selection of oxidizer - Cooling speed and time EXPERIMENTAL -Apparatus and instrumental conditions A Claisse M4 propane fired automatic fluxer was used to generate all fusion beads. A Fisher Scientific Isotemp for the LOI determinations and preparation of ignited samples. The LOI method used for all cement types and clinker included ignition at 950 in a clean Pt crucible for 60 minutes. This first method meets ASTM and ISO requirements for LOI determination. Because material which contained under oxidized compounds could destroy platinum ware, a second LOI method for those materials was incorporated called LOI until constant weigh. The sample was weighed precisely in a clean and ignited ceramic crucible, then ignited at 950, then cooled and weighed. Thereafter, the sample is ignited by sequences of 15 minutes in the furnace at the same temperature, 30 minutes of cooling and weighing. A constant weigh is considered when two successive weighings give a result with a difference of less than g. A Bruker-AXS S4 Explorer sequential wavelength-dispersive X-ray spectrometer with an 82 position automatic sample changer and a rhodium end-window X-ray tube was used for data generation. Spectrometer analytical conditions, peak-line, background measurements, background position, pulse-height, counting time and others were selected and optimized by wavelength step-scanning of selected standard disks. The ISO validation test for repeatability of the spectrometer was used to verify proper spectrometer operation and to optimize the counting time for the peaks. The

4 265 spectrometer analytical conditions for the measurement of all elements are listed in Table 1. A 28 mm collimator mask and vacuum were used for all measurements. Table 1. Spectrometer Operation Parameters Element kv ma Crystal Collimator Detector a Peak Peak Time Low bkd b High bkd b Bkd Time ( ( (Ao) (s) ( ( (s) Al K PET 0.46 FPC Ca K LiF FPC Cr K LiF SC Fe K LiF SC KK LiF FPC Mg K XS FPC Mn K LiF SC Na K XS FPC PK Ge 0.46 FPC SK Ge 0.46 FPC Si K PET 0.46 FPC Sr K LiF SC Ti K LiF FPC Zn K LiF SC a FPC = gas flow proportional counter; SC = scintillation counter b Low bkd and high bkd = value for lower and higher background when used -Fusion method development To develop this global fusion method both ignited and non ignited materials were fused. Different dry oxidation processes on the fluxer were tried with different oxidizers. Three ways to prepare the sample and flux mix in the crucible were tried. Different sample to flux ratios were tried (1:6, 1:8 and 1:10). For the preferred ratio which is 1:10 different total amounts of preparation were evaluated. -Global sample preparation method An Optimix * crucible and a 32 mm diameter, 1 mm thick mold was used to eliminate the curvature effect, which can occur after multiple heating cycles. Pure grade pre-fused flux * composition of 49.75% lithium tetraborate (LiT), 49.75% lithium metaborate (LiM), containing integrated 0.50% LiBr non-wetting agent was selected to increase the homogeneity and make stable glass disks. The maximum fusion temperature used for this fusion is 1050 ritical temperature, flux begins to volatilize without consistency which changes the sample to flux ratio [5]. Other compounds like SO 3 begin to volatilize without consistency as well [4]. -Results of fusion method development It was determined that ignition of the sample is absolutely necessary in the analytical process for a global fusion method. This critical step allows fusion of the raw materials and cements with additions, which are difficult or impossible to fuse in the non-ignited state. A preparation with a ratio of 1:10 with 6.600g of total mass takes a fusion program * Available at Corporation Scientifique Claisse

5 266 of 13 minutes heating at 1025 to prepare stable glass disks with high alumina and/or high silica samples. The mold is automatically heated in the flame before the pouring step. The cooling process is done with forced air for 5 minutes. -Step by step procedure First g of ignited sample is weigh with in a clean and dry Optimix Pt/Au crucible. Then, g of Claisse LiT/LiM/LiBr: 49.75/49.75/0.50, Pure Grade Flux is weighed with g precision on top of the sample. A mini-vortex mixer is used to mix the sample with the flux. The mini-vortex mixer speed was controlled so as not to lose material, because variance from the ratio of flux to sample weight causes error in the results [6]. All parameters set for this fusion program on the M4 fluxer are shown in table 2. Table 2. Automatic fusion program parameters Step F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 F13 Heating Heating Heating Heating Heating Heating Heating Heating Pouring Cooling Cooling Cooling Cooling Cooling Gas Crucible Speed Time (mm:ss) 00:05 00:05 00:05 00:05 04:30 07:00 00:15 00:30 00:35 00:05 00:10 00:10 00:10 04:15 Arm Position Mold Arm Position Fan Speed

6 267 -Robustness of the fusion method More than 200 different samples from the 20 material types were fused with the global fusion method. The materials are listed in table 3. This list included materials not commonly used as raw materials, but sometimes found in waste materials used as fuel, to test the limits of the global nature of the method. Table 3. List of Materials used in this experiment Material Types Fused with Sucess Fusion Failed Total Number with the Method of Sample Tried Cement Cement with Additions a Aluminate Cement Clinker Kiln Feed/Raw Mix Limestone Gypsum Sand Clay Bauxite Silica Fume Slag b Fly Ash Coal Ash Iron Ore c Basalt Chalcopyrite d Jarosite e Soil and Sediment Unknown Total a Only the cements with known additions are listed here; the cement category probably included some cements with additions b The two slag samples that failed contained copper c The iron ore samples that failed contained magnetite and/or high iron concentration d Chalcopyrite is an iron ore containing copper e Jarosite is an iron ore containing potassium The Global Fusion Method showed good efficiency to prepare homogenous and stable lithium borate glass disks with all of the materials except three: chalcopyrite, high iron ore and copper slag.

7 268 -Preparation for calibration, selection of control samples and preparation for validation As discussed previously one objective of this project was to calibrate the WDXRF with two sets of RM from different origins: NIST Standard Reference Material (SRM) Series 1880a, 1881a and 1884a to 1889a, and JCA Reference Materials for X-ray Fluorescence Analysis 601A Series XRF-01 to XRF-15. The second objective was to comply with the requirements of ASTM and ISO standard methods for analysis of cement. Those standard methods have two different philosophies. ASTM uses SRM verify precision and accuracy on two different days [1]. ISO validates repeatability of the method using one or more RM, as control samples that are not included in the calibration over at least two weeks [2]. An important thing to note is that for verification of ASTM requirements, results should include LOI, and for ISO, LOI free results are needed. Table 4 shows the element concentration range as oxide equivalent for both RM sets and for the combination of the two sets. This table also shows the element concentration of the two control samples selected to evaluate the global fusion/xrf method with ISO standard method. Table 4. RM element concentration as oxide equivalent and control samples Elements Concentration Range NIST (LOI Free Base) Concentration Range JCA (LOI Free Base) Concentration Range NIST & JCA (LOI Free Base) ISO Control Samples a (LOI Free Base) JCA XRF-03 JCA XRF-14 SiO 2 (%) Al 2 O 3 (%) Fe 2 O 3 (%) CaO (%) MgO (%) SO 3 (%) N/A Na 2 O(%) K 2 O(%) TiO 2 (%) P 2 O 5 (%) Mn 2 O 3 (%) SrO (%) Cr 2 O 3 (%) N/A - N/A N/A N/A ZnO (%) N/A - N/A N/A N/A a Control samples: One or more certified RM, not used in the calibration and having a composition within the calibration range for each element to be analyzed. When only one validation certified RM is to be used, select a sample in the middle of the concentration ranges. Where several validation certified RM used, select samples covering high and low values [2]. For the calibration of the XRF instrument and for validation of the Global Fusion/XRF method with ASTM Standard Test Method C 114, two set of glass disks were prepared for every RM, one on the first day and the second on the next day, not less than 24 hours apart. For validation of the analytical method with ISO 10 glass disks of every control samples (JCA XRF-03 and JCA XRF-14) were prepared over 15 days (not less then 2 weeks). The control sample glass disks were run on the same day they were prepared.

8 269 RESULTS AND DISCUSSION -Calibration All of the NIST and JCA Reference Materials (except the control samples) were used in the calibration. Table 5 shows for which element inter-element corrections were used and which type. This table also shows the squared correlation coefficients from the calibration curves of all analyzed elements. This tool shows that this sample preparation method eliminates the effect of different matrix from different origins, because all results are very close to 1. These results confirm that the validation of the global fusion/xrf analytical method against the previously mentioned ASTM and ISO standard methods could now proceed. Table 5. Inter-element correction and squared correlation coefficients for all calibration curves Element Inter-element Squared correction Correlation information Coefficient Al K Fixed Alphas Ca K Fixed Alphas Cr K No Correction Fe K Fixed Alphas KK Fixed Alphas Mg K Fixed Alphas Mn K No Correction Na K No Correction PK Fixed Alphas SK Fixed Alphas Si K Fixed Alphas Sr K No Correction Ti K Fixed Alphas Zn K No Correction

9 270 -ASTM Precision and accuracy The ASTM precision test was applied as it is described in method [1]. The duplicates are the two disks prepared on two different days for every RM. The results shown in tables 6 and 7 are the absolute difference of the results of duplicate for all analyzed element. The maximum difference for all elements is shown and compared to the ASTM precision limit. The maximum values obtained for all elements meet the specifications and well within the limits. Table 6. ASTM C114: Precision Test Results (Part 1) Calibrated SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O RM (%) (%) (%) (%) (%) (%) (%) (%) NIST 1880a NIST 1881a NIST 1884a NIST 1885a NIST 1886a NIST 1887a NIST 1888a NIST 1889a JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF Max Value ASTM Limit Control SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O Samples a (%) (%) (%) (%) (%) (%) (%) (%) JCA-XRF JCA-XRF a Results of control samples are include in the calculation for Max Value

10 271 Table 7. ASTM C114: Precision Test Results (Part 2) Calibrated TiO 2 P 2 O 5 Mn 2 O 3 SrO Cr2O 3 ZnO Sum RM (%) (%) (%) (%) (%) (%) (%) NIST 1880a NIST 1881a NIST 1884a NIST 1885a NIST 1886a NIST 1887a NIST 1888a NIST 1889a JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF Max Value ASTM Limit Control TiO 2 P 2 O 5 Mn 2 O 3 SrO Cr2O 3 ZnO Sum Samples a (%) (%) (%) (%) (%) (%) (%) JCA-XRF JCA-XRF a Results of control samples are include in the calculation for Max Value

11 272 The ASTM accuracy test was applied as it is described in method [1]. The results shown in tables 8 and 9 are the absolute difference of the average of duplicates from the RM certified values for all analyzed elements. The absolute maximum error for all elements is shown and compared to the ASTM accuracy limit. The maximum values obtained for all elements meet the specifications and well within the limits. Table 9. ASTM C114: Accuracy Test Results (Part 1) Calibrated SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O RM (%) (%) (%) (%) (%) (%) (%) (%) NIST 1880a NIST 1881a NIST 1884a NIST 1885a NIST 1886a NIST 1887a NIST 1888a NIST 1889a JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF N/A JCA-XRF N/A JCA-XRF N/A JCA-XRF N/A JCA-XRF N/A Abs. Max Er. a ASTM Limit Control SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O Samples b (%) (%) (%) (%) (%) (%) (%) (%) JCA-XRF JCA-XRF N/A a Abs. Max Er. = Absolute Maximum Error b Results of control samples are include in the calculation for Abs. Max Er.

12 273 Table 10. ASTM C114: Accuracy Test Results (Part 2) Calibrated TiO 2 P 2 O 5 Mn 2 O 3 SrO Cr2O 3 ZnO Sum RM (%) (%) (%) (%) (%) (%) (%) NIST 1880a NIST 1881a NIST 1884a NIST 1885a NIST 1886a NIST 1887a NIST 1888a NIST 1889a JCA-XRF N/A N/A 0.06 JCA-XRF N/A N/A 0.11 JCA-XRF N/A N/A 0.04 JCA-XRF N/A N/A 0.05 JCA-XRF N/A N/A 0.17 JCA-XRF N/A N/A 0.29 JCA-XRF N/A N/A 0.01 JCA-XRF N/A N/A 0.26 JCA-XRF N/A N/A N/A JCA-XRF N/A N/A N/A JCA-XRF N/A N/A N/A JCA-XRF N/A N/A N/A JCA-XRF N/A N/A N/A Abs. Max Er. a ASTM Limit Control TiO 2 P 2 O 5 Mn 2 O 3 SrO Cr2O 3 ZnO Sum Samples b (%) (%) (%) (%) (%) (%) (%) JCA-XRF N/A N/A 0.09 JCA-XRF N/A N/A N/A a Abs. Max Er. = Absolute Maximum Error b Results of control samples are include in the calculation for Abs. Max Er. -ISO Precision and accuracy It is important to note that the ISO limits for precision and accuracy are not a fixed limit as in ASTM C 114. The ISO limits are pending the concentration of the element in the samples analyzed. The ISO precision test was applied as described in the method [2]. The absolute differences shown in tables 11, 12, 13 and 14 were calculated from successive results of the control samples. The maximum absolute difference for all elements is shown and compared to the ISO expert precision limit. The maximum values obtained for all elements meet the specified limits for both control samples.

13 274 Table 11. ISO: Precision Test Results of control sample JCA-XRF-03 (Part 1) Precision SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O (%) (%) (%) (%) (%) (%) (%) (%) Difference Difference Difference Difference Difference Difference Difference Difference Difference Max Difference ISO Expert Limit Table 12. ISO: Precision Test Results of control sample JCA-XRF-03 (Part 2) Precision TiO 2 P 2 O 5 Mn 2 O 3 SrO Cr2O 3 ZnO Sum (%) (%) (%) (%) (%) (%) (%) Difference Difference Difference Difference Difference Difference Difference Difference Difference Max Difference ISO Expert Limit N/A Table 13. ISO: Precision Test Results of control sample JCA-XRF-14 (Part 1) Precision SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O (%) (%) (%) (%) (%) (%) (%) (%) Difference N/A Difference N/A Difference N/A Difference N/A Difference N/A Difference N/A Difference N/A Difference N/A Difference N/A Max Difference N/A ISO Expert Limit N/A

14 275 Table 14. ISO: Precision Test Results of control sample JCA-XRF-14 (Part 2) Precision TiO 2 P 2 O 5 Mn 2 O 3 SrO Cr2O 3 ZnO Sum (%) (%) (%) (%) (%) (%) (%) Difference Difference Difference Difference Difference Difference Difference Difference Difference Max Difference ISO Expert Limit N/A The ISO accuracy test was applied as described in the method [2]. The accuracy values shown in tables 15, 16, 17 and 18 were calculated as difference of the results from the 10 preparations over 15 days against the certified values. The absolute maximum error for all elements is shown and compared to the ISO expert accuracy limit. The maximum values obtained for all elements are in the requirement limits for both control samples. Table 15. ISO: Accuracy Test Results of control sample JCA-XRF-03 (Part 1) Accuracy SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O (%) (%) (%) (%) (%) (%) (%) (%) Accuracy Accuracy Accuracy Accuracy Accuracy Accuracy Accuracy Accuracy Accuracy Accuracy Abs. Max Error ISO Expert Limit

15 276 Table 16. ISO: Accuracy Test Results of control sample JCA-XRF-03 (Part 2) Accuracy TiO 2 P 2 O 5 Mn 2 O 3 SrO Cr2O 3 ZnO Sum (%) (%) (%) (%) (%) (%) (%) Accuracy N/A N/A 0.12 Accuracy N/A N/A 0.06 Accuracy N/A N/A 0.11 Accuracy N/A N/A 0.00 Accuracy N/A N/A 0.01 Accuracy N/A N/A 0.02 Accuracy N/A N/A 0.02 Accuracy N/A N/A 0.07 Accuracy N/A N/A 0.01 Accuracy N/A N/A 0.00 Abs. Max Error N/A N/A 0.12 ISO Expert Limit N/A N/A N/A Table 17. ISO: Accuracy Test Results of control sample JCA-XRF-14 (Part 1) Accuracy SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O (%) (%) (%) (%) (%) (%) (%) (%) Accuracy N/A Accuracy N/A Accuracy N/A Accuracy N/A Accuracy N/A Accuracy N/A Accuracy N/A Accuracy N/A Accuracy N/A Accuracy N/A Abs. Max Error N/A ISO Expert Limit N/A Table 18. ISO: Accuracy Test Results of control sample JCA-XRF-14 (Part 2) Accuracy TiO 2 P 2 O 5 Mn 2 O 3 SrO Cr2O 3 ZnO Sum (%) (%) (%) (%) (%) (%) (%) Accuracy N/A N/A N/A Accuracy N/A N/A N/A Accuracy N/A N/A N/A Accuracy N/A N/A N/A Accuracy N/A N/A N/A Accuracy N/A N/A N/A Accuracy N/A N/A N/A Accuracy N/A N/A N/A Accuracy N/A N/A N/A Accuracy N/A N/A N/A Abs. Max Error N/A N/A N/A ISO Expert Limit N/A N/A N/A

16 277 -Qualification of Reference Material not included in the calibration The last step of the project was to use one set of RM's for the calibration and then a different set of RM Qualification. The same glass disks used for the calibration with both RM series were used to investigate this point. It is not interesting to discuss the precision for this part of the experiment, because no parameters were changed in the fusion process and in the XRF analysis. Only calibration parameters have been changed, so only accuracy results will change. The first test was to create a calibration including only NIST SRM, then analyze JCA RM as unknowns and look for ASTM accuracy test results. The results are available in table 19. All absolute maximum errors are within the specified limit except for SiO 2 and Mn 2 O 3 which only one result out of fifteen is out for both elements. Those results of SiO 2 and Mn 2 O 3 for RM JCA-XRF-15 are out of the limits but it is less than the double of the limits. ASTM standard method specifies that when you use more than seven RM's, at least 77% shall be within the prescribed limits, and the remainder by no more than twice the value [1]. JCA RM's therefore were qualified by ASTM method even though they were not included in the calibration. Table 19. ASTM C114: Accuracy Test Results for qualification of JCA using a calibration including only NIST SRM's Reference SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO SO 3 Na 2 O K 2 O TiO 2 P 2 O 5 Mn 2 O 3 SrO Materials (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF JCA-XRF N/A JCA-XRF N/A JCA-XRF N/A JCA-XRF N/A JCA-XRF N/A JCA-XRF N/A Abs. Max Er. a ASTM Limit a : Abs. Max Er. = Absolute Maximum Error The second test was to create a calibration including only JCA RM's, and then analyze NIST SRM's as unknowns, looking to meet ASTM C 114 accuracy specifications. The results are available in table 20. All absolute maximum errors are within the specified limit except for Na 2 O where only one result out of eight is out. This result of Na 2 Ofor RM NIST 1885a is out of the limit but it is less than the double of the limit. As for the previous test, these results meet the ASTM requirements for the same reason. NIST SRM's were qualified by ASTM method even though they were not included in the calibration.

17 278 Table 20. ASTM C114: Accuracy Test Results for qualification of NIST using a calibration including only JCA Reference SiO2 Al2O3 Fe2O3 CaO MgO SO3 Na2O K2O TiO2 P2O5 Mn2O3 SrO Materials (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) NIST 1880a NIST 1881a NIST 1884a NIST 1885a NIST 1886a NIST 1887a NIST 1888a NIST 1889a Abs. Max Er. a ASTM Limit a : Abs. Max Er. = Absolute Maximum Error It is interesting to note that NIST 1885a Na 2 O value is 1.086% on an LOI free basis. If we compare it to the JCA series Na 2 O calibration range in the table 4, it is far beyond the maximum value covered by the JCA series. The same situation occurs for the JCA-XRF- 15, SiO 2 (29.29%) and Mn 2 O 3 (0.53%) values, which are beyond the range covered by the NIST SRM series for SiO 2 and Mn 2 O 3. CONCLUSIONS A global fusion/xrf analytical method for cement industry materials has been described in this paper. This method of preparation by fusion allows fusing cements and all the raw materials normally found in a cement plant. The overall method complies with the precision and accuracy requirements of the international standard methods for cement analysis (ISO/DIS and ASTM C 114). Moreover, qualification by ASTM C 114 of both complete series of reference materials (NIST SRM's and JCA RM's) not included in the calibration was achieved, which is a step forward in quality control for chemical analysis in the cement industry. Acknowledgements The authors thank Luc B support in the project. Finally, the authors have special thanks for M Corporation Scientifique Claisse for her devoted work in the laboratory. She fused more than a 1,000 beads for this project.

18 279 References 1. ASTM, Standard C114-08, s for Chemical Analysis of Hydraulic Cement Annual Book of ASTM Standards, Volume 04.01, ASTM International, West Conshohocken, PA, 2008, pp DIN EN ISO (Draft standard, ), Methods of testing cement - Chemical analysis of cement - Part 2: Analysis by X-ray fluorescence (ISO/DIS :2007), 30 pp. 3. Anzelmo, J.A., "The Role of XRF, Inter-Element Corrections, and Sample Preparation Effects in the 100-Year Evolution of ASTM Standard Test Method C114", Journal of ASTM International, Vol. 6, No. 2, Paper ID JAI101730, available online at , pp Spangenberg, J. and Fontbot, "X-Ray Fluorescence Analysis of Base Metal Sulphide and Iron-Manganese Oxide Ore Samples in Fused Glass Disc", X-Ray Spectrometry, Vol. 23, 1994, pp Loubser, M., Strydom, C., and Potgieter, H., "A Thermogravimetric Analysis Study of Volatilization of Flux Mixtures Used in XRF Sample Preparation", X-Ray Spectrom. 2004; 33: , Published online 29 January 2004 in Wiley InterScience ( DOI: /xrs Berube L., Rivard S., Anzelmo J., "XRF Fusion Precision with TheAnt", International Cement Review, March, 2008, 4 pp.