AXIOS mAX -MINERALS
WROXI – synthetic wide-range
oxide standards for fused bead
major and minor element
analysis
Introduction
X-ray fluorescence spectrometry (XRF) is
used extensively for the analysis of a
very wide range of oxide materials and
over a range of concentrations from
0 - 100 wt% oxide. Simple sample
preparation, high accuracy and
precision, and when required, good to
excellent detection limits across large
parts of the periodic table are the
principal reasons for this choice.
Accurate analysis is becoming
increasingly important for many
reasons: for superior production, process
and grade control with associated cost
savings; minimizing and controlling
contamination and environmental
pollution during manufacture; quality
control of products; and pure research.
Accurate quantification requires
accurate, spectrally clean net peak
intensities, accurate corrections for
inter-element matrix effects and good
standards with a wide range of
concentrations.
WROXI is a set of synthetic standards,
together with an application setup for
the AxiosmAX-Minerals sequential
WDXRF spectrometer, which enables
calibrations for twenty-one major
elements in the analysis of oxide
materials based on fused beads. WROXI
can be used either as a primary fused
bead calibration or to verify customer
in-house standards for pressed powder
applications. WROXI is not a precalibration.
The AxiosmAX-Minerals WDXRF
sequential spectrometer with WROXI
standards and the SuperQ software FP
algorithm makes up a unique system
that consistently produces very highquality major and minor element
analyses, e.g. Mg, Al, Si, Ti, Fe, Mn, V, Cr,
Ni, Cu, Zn, Sr, Zr, Ba and Pb, in a wide
variety of oxides, silicates, carbonates,
sulphates, phosphates, rocks and soils
and similar raw materials used in many
different industries, such as cement,
gypsum, iron and manganese ores,
ceramics, bricks, glass, and some heavy
mineral ores.
AxiosmAX-Minerals
AxiosmAX-Minerals is a fully
integrated wavelengthdispersive
XRF spectrometer, complete with
X-Y sample handler and stateof-the-art software. Engineered
for excellence in terms of both
analytical and operational
performance, it has been
configured specifically to meet the
needs of users in the mining and
minerals industries.
Easily integrated into automated
laboratory systems and with a
small footprint, AxiosmAX-Minerals
provides consistent high-quality
data across the full elemental
range, from fluorine to uranium, in
concentrations ranging from ppm
to 100 wt%. It is ideal for mediumto-high-throughput applications in
both production control and R & D
environments.
AxiosmAX-Minerals comes complete
with a set of 20 synthetic multielement wide-range oxides (WROXI)
standards and an application
setup for the handling of fused
bead major element analyses.
Using PANalytical’s unique SuperQ
software FP algorithm, the
WROXI application can determine
concentrations of up to 21 common
oxides in a wide range of rocks, ores
and minerals.
The Analytical X-ray Company
WROXI
Specifications:
1.Elements and their concentration
ranges (wt %):
0 − 58
Na2O
MgO
0 – 78
0 – 78
Al2O3
0 – 80
SiO2
0 – 40
P2O3
0 – 59
SO3
0 – 40
K2O
CaO
0 – 80
0 – 40
TiO2
0 – 10
V2O5
0 – 10
Cr2O3
0 – 80
Mn3O4
0 – 81
Fe2O3
NiO
0 – 12
CuO
0 –
8
ZnO
0 – 10
SrO
0 – 20
0 – 43
ZrO2
BaO
0 – 43
0 – 10
HfO2
PbO
0 – 10
2.Presentation:
• Robust aluminium carrying case containing standards plus user information and concentrations on CD-ROM
• 19 standards
- Supplied as powders; 5 g each
- Supplied in air-tight plastic bottles, packed under nitrogen
- Drift monitors (x2)
- Fusion bead containers
Acknowledgement
The WROXI application and
standards were conceived and
developed in collaboration with
M.N. Ingham and the XRFS Section
of the British Geological Survey
Analytical Geochemistry
Laboratories.
Preparation of standards and samples
For the AxiosmAX-Minerals - WROXI
configuration to operate correctly,
high-purity blanks (the customer’s flux),
and single- or multi-element
concentration standards are essential.
The WROXI standards set is comprised of
20 synthetic multiple-oxide standards.
One advantage of using synthetic
standards made from traceable
compounds, is that the method is
brought significantly closer to being a
primary rather than a comparative
method. The standards are delivered as
powders to be prepared as fused beads
by the customer, using the customer’s
flux, dilution ratios and methodology.
They are therefore suited and applicable
to every ‘oxide’ laboratory.
The standards are made from pure
chemicals, pre-conditioned, weighed,
ground and packaged under nitrogen.
Detailed instructions on the use and
handling of the WROXI standards are
included with the application package.
The WROXI standards and certified
reference materials illustrated in the
figures and tables below were prepared
Measurement conditions
40 mm fused beads were measured in
37 mm sample holders using a 37 mm
collimator mask. Single unshared
backgrounds were used for all channels
except Zn, Cu, Ni, Mg and Na for which
two background positions were used.
One of the Na background positions was
shared with Mg. Kα lines were
measured for all elements except
Pb (L β1), Ba, Zr and Sr (L α1).
The SuperQ software for AxiosmAXMinerals contains an application
template for the WROXI application and
setup only requires the measurement of
the standards. The measurement
program takes approximately nine
minutes. Measurement times for the
individual elements used to obtain the
data presented are given in Table 1.
using 1.0 g of sample fused in 10.0 g
flux (66 % lithium tetraborate, 34 %
lithium metaborate) and cast into
40 mm diameter fused beads. Pure
lithium tetraborate can be used for
routine samples, depending on the
sample type, although the mixed flux is
preferred for preparing the WROXI
standards. Also, depending on the type
of sample, 0.5 or 1.0 g NH4NO3 can be
added as an oxidizer. The excess
NH4NO3 disappears completely during
the fusion process and so has no effect
on the sample dilution. 15-200 mg of
LiBr or LiI can be used as a releasing
agent. The fusion temperature was
1150 °C using the LiT/LiM flux mixture.
For the accurate analysis of sulfur, for
example in cements and gypsum, it is
advisable to lower the fusion
temperature to 1050 °C to avoid the loss
of sulfur during the fusion process.
Many of the oxide samples contain H2O,
carbonates and other volatile
compounds, which are lost during the
fusion process as loss on ignition (L.O.I.).
L.O.I. was used as a balance compound
in this application.
Compound
Na2O
Total time (s)
72
MgO
42
Al2O3
36
SiO2
36
P2O5
12
SO3
24
K2O
16
CaO
20
TiO2
16
V2O5
16
Cr2O3
16
Mn3O4
16
Fe2O2
16
NiO
12
CuO
12
ZnO
12
SrO
56
ZrO2
28
BaO
48
HfO2
26
PbO
Total Application
8
540
Table 1. Total measurement time (peak +
backgrounds)
CRM
Type
100
y = 1.004x0.006
R2 = 0.9999
90
80
WROXI (wt%)
Accuracy
The accuracy of the AxiosmAX-Minerals
spectrometer using WROXI standards
and SuperQ (FP) calibration model for
major and minor element analyses in
oxides and related materials is excellent.
This is illustrated in an accuracy
overview plot for a number of oxides
(Figure 1), in plots for individual oxides;
Al2O3, P2O5, K2O, TiO2, Mn3O4, and
Fe2O3, (Figures 2 - 7), and in a
comparison of certified and measured
values for 14 Certified Reference
Materials (CRMs) of widely varying
composition (Table 2). The absolute and
relative accuracy of the WROXI method
is also shown for a range of oxides in
Table 3. For all comparisons between
certified and measured values, the CRMs
were measured as routine samples
against the WROXI calibration. The
combination of WROXI standards and
the PANalytical FP calibration model
enables accurate extrapolation of
calibrations outside the range in the
standards. For example, high Al2O3 and
high Fe2O3 CRMs have been analysed
successfully with WROXI (Figures 2
and 7).
70
Theory
60
Na2O
50
MgO
Al2O3
40
SiO2
30
CaO
20
TiO2
10
Fe2O3
0
Mn3O4
0
10
20
30
40
50
60
70
80
90
100
Certified (wt%)
Figure 1. Accuracy overview: comparison of certified and measured values for 8 oxides in
the wide variety of CRMs listed in Table 2
Na2O (wt %)
Cert. Meas.
MgO (wt %)
Al2O3 (wt %)
SiO2 (wt %)
P2O5 (wt %)
Cert. Meas. Cert. Meas. Cert. Meas. Cert. Meas.
SO3 (wt %)
Cert. Meas.
BCR32
Phosphate
0.77
0.4
0.39
0.55
0.52
2.09
2.09
32.98
32.71
1.84
1.85
BCS174/1
Slag
0.17
7.13
7.04
1.72
1.73
14.69
14.37
12.30
12.40
0.40
0.40
2.59
0.20
BCS176/2
Manganese ore
0.11
0.13
0.04
0.03
5.20
5.29
2.53
0.20
0.04
0.14
BCS276
Silica brick
0.06
0.06
0.06
0.04
0.85
0.89
95.90
96.08
0.03
0.01
0.14
50.91
0.08
BCS348
Ball clay
0.34
0.34
BCS370
Magnesite
0.06
0.02
0.31
61.8
0.29
31.59
31.44
51.13
62.48
12.3
12.38
3.01
0.07
BCS393
Limestone
0.05
0.00
0.15
0.15
0.12
0.16
0.70
0.68
0.01
0.01
BCS394
Bauxite
0.02
0.04
0.12
0.13
88.80
88.74
4.98
4.94
0.22
0.23
16.84
2.44
FER-1
Iron ore
0.01
0.01
0.28
0.25
0.50
0.54
16.92
GBW03109
Gypsum
0.018
0.011
1.02
1.04
0.016
0.071
0.27
0.13
2.96
0.24
2.45
0.02
0.10
0.13
0.62
0.51
0.036 55.63
55.17
GSS-7
Soil
0.07
0.07
0.26
0.20
29.26
29.40
32.69
32.56
0.26
0.27
0.06
0.14
MRG-1
Gabbro
0.74
0.73
13.55
13.84
8.47
8.41
39.12
39.14
0.08
0.07
0.15
0.21
NBS89
Lead-barium glass
5.70
5.85
0.03
0.04
0.18
0.17
65.15
65.12
0.23
0.23
0.03
0.03
NIST1880a
Cement
0.19
0.19
1.72
1.69
5.18
5.12
20.31
20.38
0.22
0.22
3.25
3.18
CRM
Type
K2O (wt %)
Cert. Meas.
CaO (wt %)
TiO2 (wt %)
Cr2O3 (wt %)
Mn3O4 (wt %)
Cert. Meas. Cert. Meas. Cert. Meas. Cert. Meas.
Fe2O3 (wt %)
Cert. Meas.
BCR32
Phosphate
0.08
51.76
51.46
0.03
0.03
0.04
0.04
0.00
0.01
0.23
0.24
BCS174/1
Slag
0.03
44.83
44.52
0.70
0.69
0.26
0.24
5.49
5.31
12.10
12.04
10.06
BCS176/2
Manganese ore
1.30
1.26
0.09
0.13
0.30
0.28
0.01
0.01
65.91
65.84
9.81
BCS276
Silica brick
0.14
0.12
1.75
1.70
0.17
0.16
0.02
0.02
0.16
0.16
0.79
0.78
BCS348
Ball clay
2.33
2.23
0.17
0.18
1.08
1.08
0.16
0.01
0.00
1.04
1.05
BCS370
Magnesite
0.03
0.02
1.54
1.59
0.13
0.11
13.40
13.53
0.12
0.12
7.23
7.18
BCS393
Limestone
0.02
0.01
55.40
56.13
0.01
0.01
0.00
0.00
0.01
0.01
0.05
0.06
BCS394
Bauxite
0.02
0.02
0.08
0.10
3.11
3.09
0.08
0.08
0.00
1.90
1.92
FER-1
Iron 0re
0.01
0.01
3.31
3.27
0.03
0.02
0.00
0.00
0.23
75.72
75.65
0.23
GBW03109
Gypsum
0.02
0.01
40.70
41.95
0.00
0.00
0.00
0.00
0.02
0.03
GSS-7
Soil
0.20
0.19
0.16
0.14
3.37
3.36
0.06
0.06
0.26
18.76
19.02
0.06
18.14
0.25
MRG-1
Gabbro
0.18
0.18
14.70
14.83
3.77
3.77
0.07
0.18
0.19
17.94
NBS89
Lead-barium glass
8.40
8.49
0.21
0.23
0.01
0.01
0.01
0.10
0.09
0.05
0.06
NIST1880a
Cement
0.92
0.92
63.83
64.23
0.25
0.26
0.00
0.12
0.12
2.81
2.80
0.01
Table 2. Analytical accuracy: comparison of certified and measured values for twelve major and minor oxides in fourteen CRMs of various
types
40
2
y = 1.001x-0.009
R2 = 1.000
n = 113
80
P2O5 (measured wt %)
Al2O3 (measured wt %)
100
60
40
20
30
20
10
0
0
0
20
40
60
80
0
100
10
20
30
40
P2O5 (certified wt %)
Al2O3 (certified wt %)
5
20
4
15
10
5
5
y = 0.998x-0.010
R2 = 0.999
n = 112
4
3
20
2
TiO2 (measured wt %)
y = 1.002x-0.001
R2 = 1.000
n = 102
TiO2 (measured wt %)
K2O (measured wt %)
3
y = 1.003x-0.004
R2 = 1.000
n = 106
1
15
10
5
0
0
5
10
15
20
TiO2 (certified wt %)
0
0
0
5
10
15
0
20
1
3
4
5
100
100
6
y = 0.994x-0.001
R2 = 1.000
n = 110
80
Fe2O3 (measured wt %)
Mn3O4 (measured wt %)
2
TiO2 (certified wt %)
K2O (certified wt %)
60
40
7
y = 1.011x-0.052
R2 = 1.000
n = 114
80
60
40
20
20
0
0
0
20
40
60
80
0
100
20
Figures 2 - 7. Accuracy verification: comparison of certified and measured values for the WROXI standards (
CRMs (
). The regression values y, x and R2 are for the CRMs only.
Concentration Na2O
Av abs diff
(wt %)
Av rel diff
(%)
No of samples (n)
Av abs diff
(wt %)
Av rel diff
(%)
No. of samples (n)
40
60
80
100
Fe2O3 (certified wt %)
Mn3O4 (certified wt %)
) and a large number (n) of
MgO
Al2O3
SiO2
P2O5
*SO3
K2O
CaO
TiO2
Cr2O3
Mn3O4
Fe2O3
0.069
0.222
0.147
0.473
0.063
0.107
0.051
0.284
0.022
0.136
0.107
0.210
2.49
3.85
1.49
1.50
1.25
1.10
1.54
1.95
1.43
2.51
2.15
1.76
39
71
90
109
17
38
46
85
17
2
19
94
range
>1 wt%
0.024
0.1-1.0 wt% 0.043
0.042
0.044
0.012
0.013
0.017
0.055
0.016
0.013
0.006
0.022
10.3
10.2
18.2
9.30
5.60
12.5
4.84
6.55
4.44
4.04
3.01
3.69
32
29
22
7
50
10
19
22
70
15
46
12
Table 3. Absolute and relative errors for a selection of oxides calculated from a large number (n) of CRMs. Data are presented for two concentration
ranges, > 1 wt% and 0.1 – 1.0 wt%. *Data for SO3 are from a series of cement and gypsum samples specially prepared at a lower (1050 °C) fusion
temperature to prevent the loss of sulfur.
Precision and instrument stability
The precision, repeatability and
reproducibility of the AxiosmAX-Minerals
system are excellent, not only for
short-term measurements (15
consecutive measurements, Table 4), but
also for longer-term measurements
(measurements carried out over a period
of fourteen days).
For comparison, the counting statistical
error (CSE) expressed in concentration
units is also shown in Table 4.
Fifteen consecutive measurements of a
single sample (fusion disk of a basalt
rock GBW07105) demonstrate relative
standard deviations better than
0.1-0.7 % at typical concentration levels
greater than 0.2 wt% for many of the
elements commonly analysed in
wide-range oxide samples, e.g. Na2O,
MgO, Al2O3, SiO2, P2O5, TiO2, K2O, CaO
and Fe2O3.
More importantly, this level of precision
is maintained for measurements carried
out over a period of 14 days, illustrating
the long-term stability of the system.
Compound Na2O
MgO
Al2O3
SiO2
P2O5
SO3
wt %
wt %
wt %
wt %
wt %
wt %
Certified conc.
3.38
7.77
13.83
44.64
0.946
0.02
REPEATABILITY (15 consecutive measurements)
Mean conc.
3.36
7.69
13.96
44.47
0.991
0.019
Min. conc.
3.33
7.66
13.92
44.4
0.979
0.017
Max. conc.
3.39
7.71
13.99
44.54
0.999
0.02
RMS conc.
0.01
0.01
0.02
0.04
0.005
0.001
RMS relative (%) 0.42
0.17
0.12
0.09
0.51
4.69
REPRODUCIBILITY (14 days)
Mean conc.
3.36
7.69
13.95
44.44
0.998
0.02
Min. conc.
3.34
7.65
13.92
44.34
0.973
0.017
Max. conc.
3.39
7.72
13.97
44.54
0.999
0.024
RMS conc.
0.02
0.02
0.02
0.06
0.007
0.002
RMS relative (%) 0.44
0.23
0.11
0.13
0.72
10.18
COUNTING STATISTICAL ERROR
CSE in wt % conc.
0.01
0.015
0.019
0.035
0.005
0.001
CSE rel (%)
0.3
0.19
0.14
0.08
0.53
5
Compound K2O
CaO
TiO2
Cr2O3
Mn3O4
Fe2O3
wt %
wt %
wt %
wt %
wt %
wt %
Certified conc.
2.32
8.81
2.37
0.02
0.182
13.4
What is the FP
algorithm?
The intensity of X-rays measured for
a given concentration of an element
depends on the bulk composition or
matrix of the sample being
analysed.
For accurate quantification we need
to make so-called matrix corrections
to account for the differences in
bulk composition that occur from
sample to sample.
PANalytical’s FP or Fundamental
Parameters algorithm used in the
SuperQ software calculates matrix
corrections from the theoretical
laws governing the physics of
X-rays. As such, FP models have a
significant advantage over more
traditional influence coefficientbased matrix corrections (e.g.
theoretical alphas).
Unlike theoretical alphas
calculations, the FP model calculates
matrix corrections that are specific
to each sample. This enables
accurate analyses over very wide
ranges in concentration and in very
different types of sample. In
addition, accurate analysis can be
made outside the range of
concentrations bracketed by the
standards.
REPEATABILITY (15 consecutive measurements)
Mean conc.
2.34
9.02
2.37
0.022
0.185
13.35
Min. conc.
2.33
9
2.35
0.02
0.182
13.32
Max. conc.
2.36
9.03
2.38
0.026
0.189
13.39
RMS conc.
0.01
0.01
0.01
0.002
0.002
0.02
RMS relative (%)
0.35
0.1
0.34
7.83
1.18
0.14
REPRODUCIBILITY (14 days)
Mean conc.
2.34
9.02
2.37
0.023
0.184
13.35
Min. conc.
2.33
9
2.35
0.02
0.181
13.31
Max. conc.
2.36
9.03
2.38
0.026
0.188
13.39
RMS conc.
0.01
0.01
0.01
0.002
0.002
0.03
RMS relative (%)
0.37
0.14
0.31
7.59
1.22
0.19
COUNTING STATISTICAL ERROR
CSE in wt % conc.
0.008
0.014
0.008
0.002
0.003
0.017
CSE rel (%)
0.34
0.16
0.34
10
1.65
0.13
Table 4. Analytical precision for WROXI fusions of GBW07105 (basalt)
Pro-Trace software
and standards
The AxiosmAX-Minerals can be
supplied with the unique Pro-Trace
software and standards. Pro-Trace
provides the highest quality trace
element analysis (Sc to U) and
targets a wide range of materials of
geological and environmental
significance, including rocks, soils,
sediments, ores, minerals, mineral
soils and fly ash.
Dust removal
device
The AxiosmAX-Minerals is equipped
with a dust collection device, to
protect the instrument from dusty
samples and reducing cross
contamination and wear on critical
components. This is particularly
useful and important when pressed
powder samples are used for
routine analysis.
Conclusions
Elemental analysis with XRF is already the key to the control of quality and
production processes in the many industries analysing a wide range of oxide
materials.
The AxiosmAX-Minerals – WROXI – SuperQ (FP) system further extends the
advantages of XRF as the best analytical method for oxides analysis, and is
capable of measuring all elements required to control the production and
manufacture of materials such as cement, gypsum, iron and manganese ores,
ceramics, bricks, glass and some heavy mineral ores. It has been demonstrated
that analyses are accurate and precise and the method benefits from a simple
fusion sample preparation. Furthermore, the stability of the system is such
that individual calibrations can be used for months. Time-consuming restandardizations are unnecessary and the resulting data are highly consistent
over time. Although the AxiosmAX-Minerals has been configured to meet
industry requirements (see below), it can be upgraded easily with features
such as increased power, continuous loading for extra speed of analysis,
Omnian for complete standardless analysis and Pro-Trace for high-quality
trace element analysis.
The use of synthetic WROXI standards made from traceable compounds brings
this method close to being a primary analytical method, rather than the
strictly comparative method using CRMs as standards, which is commonly
used in the XRF analysis of wide-range oxides.
Standard configuration
Optionally configured items
X-ray tube
Rh-anode SST-mAX with
ZETA Technology
Cr-anode, other anodes on request
Generator
2.4 kW
3.0 kW, 4.0 kW
Tube filters
Brass 400 µm, Al 750 µm,
Al 200 µm + 1 free choice
Beam stop, brass 100, 300 µm, Be tube
protection filter
Fixed collimator
mask
27, 30, 35 or 37 mm
Programmable mask: 3 position (27, 30, 37
mm) or 6 position (6, 10, 20, 27, 30, 37 mm)
Primary collimators
150 µm, 300 µm
100, 550, 700, 4000 µm (max. 3 in total)
Crystals
LiF200, LiF220, Ge111, PE002,
PX1
LiF420, Ge111 curved, PE002 curved, InSb (flat/
curved), TLAP coated, PX4, PX5, PX6, PX7,
PX8, PX10 (max. 8)
Detectors
Flow, scintillation
Sealed Xe (duplex with flow), Hi-Per Scint
Fixed channels
Hi-Per channels, max. 2, for B to Mg
Loading
Single
Continuous: 30 s/sample less instrument
overhead
Direct: up to 10 s/sample less instrument
overhead
Analysis medium
Vacuum
He (N2) path
Dust removal device Included
Global and near
Spinner
Included
Sample changer
Included
Standards
WROXI for 21 oxides (Na, Mg,
Al, Si, P, S, K, Ca, Ti, V, Cr, Mn,
Fe, Ni, Cu, Zn, Sr, Zr, Ba, Hf, Pb)
(5 g/standard)
Software
SuperQ
Omnian, Pro-Trace, FP Multi, SPC, UAI,
Enhanced Data Security, Type Standardization
Industry-specific
modules
WROXI minerals module
CEMOXI cement module
Oil-Trace setup standards
ADPOL and TOXEL polymer modules
PANalytical B.V.
Lelyweg 1, 7602 EA Almelo
P.O. Box 13, 7600 AA Almelo
The Netherlands
T +31 (0) 546 534 444
F +31 (0) 546 534 598
[email protected]
www.panalytical.com
High-capacity changer up to 209 samples
(32 mm) or 140 samples (40 mm)
Regional sales offices
Americas
T +1 508 647 1100
F +1 508 647 1115
Europe, Middle East, Africa
T +31 (0) 546 834 444
F +31 (0) 546 834 499
Asia Pacific
T +65 6741 2868
F +65 6741 2166
Although diligent care has been used to ensure that the information herein is accurate, nothing contained herein can be construed to imply any
representation or warrantee as to the accuracy, currency or completeness of this information. The content hereof is subject to change without
further notice.Please contact us for the latest version of this document or further information. © PANalytical B.V. [2009]. 9498 707 32612 PN7224
AxiosmAX-Minerals