XRF Analysis and Preparation of Fly Ash Fused Beads

One of the residual waste products obtained from the combustion of coal is fly ash, which is formed from the particles that rise with flue gases. Employed as a component in certain cement mixes, recovered fly ash enhances the strength and durability of concrete.

In this study, a fly ash sample was fused to form two glass bead sets after it was pulverized and blended. A Katanax K1 electric fusion fluxer (Figure 1) was used to perform the fusion.

Ten beads were created using two lithium borate fusion fluxes (five beads each) from SPEX CertiPrep. Energy dispersive X-ray flourescence spectroscopy (ED-XRF) was used to analyze the beads.

The results were compared between the sets and also within them to determine how flux composition affects XRF measurements and to determine the consistency of the K1-produced beads.

Katanax K1 electric fusion fluxer

Figure 1. Katanax K1 electric fusion fluxer

Fusion Method

In order to remove the approx. -0.2% remaining carbon, the fly ash was roasted at 750°C in a porcelain crucible for a duration of two hours. Flux and fly ash, weighing 6.40 g and 0.80 g, respectively were mixed at a ratio of 8:1 in a Pt/Au crucible.

The mixture prepared by hand using a plastic lab spatula, after which it was fused into a glass bead measuring 32 mm, using the Katanax K1 electric fusion fluxer. K1’s OXIDE program was modified and employed for this process and the step 4, the important fusion stage, was set at 1035°C for a duration of 15 minutes.

Five beads were prepared following this method using SPEX CertiPrep FFB-5005-02 with lithium tetraborate:lithium metaborate at 1:1 ratio and 0.5% lithium bromide as a non-wetting agent. Another set of five beads were prepared using FFB-6705-02 with lithium tetraborate:lithium metaborate at 2:1 ratio and 0.5% lithium bromide.

Analysis

ED-XRF was used to analyze both sets of beads. Ten measurements were taken on each bead and the results were averaged. Tables 1 and 2 show the composition percentage for all analytes. The main components of the fly ash were alumina and silica, while oxides of calcium, iron, phosphorus, sodium, titanium, sulfur, and magnesium constituted the remaining fly ash.

Table 1. Fly Ash Composition (%) using FFB-5005-02

Analyte Average Bead 1 Bead 2 Bead 3 Bead 4 Bead 5
SiO2 52.08 52.11 52.07 52.11 52.08 52.06
AI2O3 26.75 26.74 26.76 26.74 26.74 26.76
Fe2O3 6.52 6.52 6.52 6.52 6.52 6.52
K2O 4.14 4.14 4.13 4.14 4.14 4.15
CaO 3.46 3.45 3.46 3.46 3.46 3.46
MgO 2.04 2.04 2.04 2.04 2.04 2.05
P2O5 1.42 1.42 1.43 1.42 1.43 1.43
TiO2 1.26 1.26 1.25 1.26 1.26 1.26
Na2O 1.23 1.22 1.25 1.22 1.24 1.23
SO3 0.16 0.16 0.16 0.16 0.16 0.16

 

Table 2. Fly Ash Composition (%) using FFB-6705-02

Analyte Average Bead 1 Bead 2 Bead 3 Bead 4 Bead 5
SiO2 52.07 52.05 52.12 52.09 52.09 52.02
AI2O3 26.75 26.75 26.79 26.75 26.69 26.76
Fe2O3 6.49 6.50 6.47 6.50 6.50 6.50
K2O 4.15 4.15 4.15 4.15 4.16 4.16
CaO 3.47 3.48 3.45 3.48 3.48 3.47
MgO 2.05 2.06 2.02 2.06 2.06 2.06
P2O5 1.42 1.41 1.41 1.41 1.42 1.42
TiO2 1.26 1.26 1.25 1.26 1.26 1.26
Na2O 1.24 1.24 1.23 1.24 1.24 1.25
SO3 0.16 0.16 0.16 0.16 0.16 0.16

 

The XRF results show that there is very good consistency within the set. This shows that the K1 produces beads that have a high degree of productivity and that the sample was homogenous. Tables 1 and 2 show also equal overall average.

The flux composition does not affect the XRF results. Both of the fluxes produce clear glass beads and are suitable for use with fly ash.

The ten scans conducted on each bead also yielded consistent results. Table 3 shows an example of one bead, which is representative of the results of the scans of the other nine beads.

Table 3. Fly Ash results for 10 successive XRF scans of Bead 4 prepared using FFB-5005-02

Analyte SiO2 AI2O3 Fe2O3 K2O CaO
Scan 1 52.09 26.81 6.52 4.14 3.47
Scan 2 52.05 26.81 6.51 4.13 3.46
Scan 3 52.14 26.71 6.52 4.15 3.45
Scan 4 52.04 26.71 6.51 4.15 3.47
Scan 5 52.07 26.80 6.51 4.14 3.48
Scan 6 52.11 26.76 6.53 4.12 3.46
Scan 7 52.04 26.71 6.53 4.15 3.47
Scan 8 52.05 26.75 6.51 4.16 3.42
Scan 9 52.14 26.67 6.52 4.15 3.48
Scan 10 52.07 26.67 6.52 4.15 3.46
Average 52.08 26.74 6.52 4.14 3.46

 

Analyte MgO P2O5 TiO2 Na2O S03
Scan 1 2.04 1.42 1.26 1.18 0.16
Scan 2 2.02 1.42 1.26 1.24 0.16
Scan 3 2.04 1.42 1.27 1.21 0.16
Scan 4 2.05 1.45 1.26 1.29 0.16
Scan 5 2.02 1.42 1.26 1.23 0.16
Scan 6 2.03 1.42 1.26 1.20 0.16
Scan 7 2.07 1.46 1.26 1.24 0.16
Scan 8 2.05 1.46 1.26 1.27 0.16
Scan 9 2.07 1.42 1.27 1.21 0.16
Scan 10 2.03 1.42 1.25 1.31 0.16
Average 2.04 1.43 1.26 1.24 0.16

 

Conclusion

The easy-to-use Katanax K1 electric fusion fluxer is efficient in creating reproducible, high quality beads. The XRF results of the two fluxes employed in this study show that the choice of flux has no effect on the analysis.

The high level of bead consistency within a set shows that the flux’s elemental composition is uniform.

This information has been sourced, reviewed and adapted from materials provided by SPEX SamplePrep.

For more information on this source, please visit SPEX SamplePrep.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    SPEX SamplePrep. (2019, January 02). XRF Analysis and Preparation of Fly Ash Fused Beads. AZoM. Retrieved on June 18, 2019 from https://www.azom.com/article.aspx?ArticleID=13170.

  • MLA

    SPEX SamplePrep. "XRF Analysis and Preparation of Fly Ash Fused Beads". AZoM. 18 June 2019. <https://www.azom.com/article.aspx?ArticleID=13170>.

  • Chicago

    SPEX SamplePrep. "XRF Analysis and Preparation of Fly Ash Fused Beads". AZoM. https://www.azom.com/article.aspx?ArticleID=13170. (accessed June 18, 2019).

  • Harvard

    SPEX SamplePrep. 2019. XRF Analysis and Preparation of Fly Ash Fused Beads. AZoM, viewed 18 June 2019, https://www.azom.com/article.aspx?ArticleID=13170.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit