Abstract No. 37. Progress in Analytical Chemistry and Material Characterisation in the Steel and Metals Industry Düsseldorf, May 19-21, 2015

Size: px

Start display at page:

Download "Abstract No. 37. Progress in Analytical Chemistry and Material Characterisation in the Steel and Metals Industry Düsseldorf, May 19-21, 2015"

Kelly Hancock
6 years ago
Views:

1 Abstract No. 7 Progress in Analytical Chemistry and Material Characterisation in the Steel and Metals Industry Düsseldorf, May 19-1, 015 Combined XRF-XRD analysis for magnetite and Fe determination in iron ores and processed materials. A.S.Kozlov 1,, P.S.Chizhov,, V.A.Filichkina 1 1. National University of Science and Technology MISIS. Leninskiy pr., Moscow, Russia.. Moscow State University, Chemistry Department. Leninskie gory 1-, Moscow, Russia. Thermo Techno LLC, Kolpachny per. 9a, Moscow, Russia The control of iron ores enrichment and processing (sintering, pelletizing) normally involves magnetite (in case of magnetic separation usage) and/or Fe determination. Standard wet chemistry methods take time and are difficult to automate especially for magnetite determination. Fe analysis by direct determination of Fe -containing phases (magnetite, wuestite, pyroxene, etc.) via X-ray diffraction (XRD) calibration curve is subject to errors due to the variance of absorption coefficient, and, moreover, can t be used for Fe determination in amorphous phase (up to 60% in sinters). We developed a new method which uses X-ray Fluorescence (XRF) data for absorption correction and, in some cases, for accounting the additional signal related to total Fe content by XRF intensity ratio. The method fully exploits the combination of XRF and XRD on the same sample to significantly improve the accuracy and reliability of quantification of iron containing phases in ores and sinters. The results from this new phase quantification method are compared with standard wet chemistry approaches for iron ores, pellets and sinters revealing good correctness and stability. Methods and comparison with wet chemistry data will be presented and discussed. CETAS 015

of magnetite Determination of Fe in pellets

2 Outline Fe analysis as a part of analytical control Instrumental methods for Fe oxidation state determination Determination of magnetite Determination of Fe in pellets and sinters Summary Acknowledgements Chizhov P.S., Kozlov A.S., Filichkina A.V. Combined XRF-XRD analysis of magnetite and Fe in ores and processed materials CETAS 015

Analytical control of iron ore mining/processing - technology Chemical composition Fe Analytical control of iron

ISO 597, GOST 581.18 Manganese (usually as MnO) ISO 968, GOST 5659 Aluminium (Al O ) ISO 688, GOST 581.

16 Sulfur (S) ISO 689, GOST 581.0 Phosphorus (P) ISO 599, GOST 581.

) Additional tasks (deposit and technology-dependent) Alkalis (K O &Na O) ISO 11, ISO 11, GOST 581.

3 Analytical control of iron ore mining/processing - technology Chemical composition Fe Analytical control of iron ore mining/processing Chemical composition reference methods Common analytical tasks Total iron content (Fe tot ) ISO 597, GOST Manganese (usually as MnO) ISO 968, GOST 5659 Aluminium (Al O ) ISO 688, GOST Silicon (SiO ) ISO 598, GOST Calcium (CaO) ISO 100, GOST Magnesium (MgO) ISO 100, GOST Sulfur (S) ISO 689, GOST Phosphorus (P) ISO 599, GOST Fe (Fe II O) ISO 905, GOST 5657 Chemical composition Phase composition (Fe O?) Additional tasks (deposit and technology-dependent) Alkalis (K O &Na O) ISO 11, ISO 11, GOST Copper (Cu) ISO 518, GOST 5658 Zinc (Zn) ISO 110, GOST Lead (Pb) ISO 111, GOST Titanium (TiO ) ISO 691, GOST 50 Vanadium (V O 5 ) ISO 968, GOST 581. Chromium (Cr O ) ISO 156, GOST Chemical composition Fe? CETAS 015

4 Analytical control of iron ore mining/processing Chemical composition laboratory practice Common analytical tasks Total iron content (Fe tot ) ISO 597, GOST Manganese (usually as MnO) ISO 968, GOST 5659 Aluminium (Al O ) ISO 688, GOST Silicon (SiO ) ISO 598, GOST Calcium (CaO) ISO 100, GOST Magnesium (MgO) ISO 100, GOST Sulfur (S) ISO 689, GOST Phosphorus (P) ISO 599, GOST Fe (Fe II O) ISO 905, GOST 5657 Additional tasks (deposit and technology-dependent) Alkalis (K O &Na O) ISO 11, ISO 11, GOST Copper (Cu) ISO 518, GOST 5658 Zinc (Zn) ISO 110, GOST Lead (Pb) ISO 111, GOST Titanium (TiO ) ISO 691, GOST 50 Vanadium (V O 5 ) ISO 968, GOST 581. Chromium (Cr O ) ISO 156, GOST HCl 6HCl FeCl 8HCl FeCl 1HCl 1NH FeS HCl FeCl FeS Instrumental methods for oxidation state determination Fe O Fe O Requirements and restrictions Compatibility with existing reference methods CaFeSi O 6 Fe HCl FeCl H H H O FeCl F CaCl S H O FeCl Simple sample preparation, low costs, automated XPS Short analysis time (max min in total) ( NH ) XRF (ISO 9516) wet chemistry ICP XRF wet chemistry ICP SiF 6H O 8NH Cl Phase composition accounting! CETAS 015 Moessbauer Automated wet chemistry? Magnetometry? 6

Instrumental methods for oxidation state determination: XRF Principles and problems Chemical shift (energy and/or intensity shift for characteristic lines)

.. [Fe S 6 ] [Fe (S ) 6 ] [Fe O ] [Fe O 6 ] Wet chemistry not: 6 Fe Cr O 1H 6Fe Cr 7HO Works well for stable coordination (S - vs. SO -, etc.

, Analytika i kontrol, 1(010), 1 Instrumental methods for oxidation state determination: XRD Principles and problems 7 Direct determination of crystalline

5 Instrumental methods for oxidation state determination: XRF Principles and problems Chemical shift (energy and/or intensity shift for characteristic lines) Chemical shift is structure-specific,... [Fe S 6 ] [Fe (S ) 6 ] [Fe O ] [Fe O 6 ] Wet chemistry not: 6 Fe Cr O 1H 6Fe Cr 7HO Works well for stable coordination (S - vs. SO -, etc.) Might be used for Fe in case of constant phase composition Chubarov et. al., Analytika i kontrol, 1(010), 1 Instrumental methods for oxidation state determination: XRD Principles and problems 7 Direct determination of crystalline phase contents - Corresponds to solution composition (Fe O Fe Fe ) The ratio phase/fe varies if - solid solution forms (Fe O Fe TiO, FeCO CaCO MgCO, Fe 1-x O, etc ) To ensure the results: - calculate absolute phase fractions (and amorphous phase fraction up to 60% in sinters) - account for Fe in amorphous phase Combined XRF-XRD methods give a solution! CETAS 015

$T P (θ θ ) h, k, l External standard method: absolute phase fractions calculated I calc Finally: w ρ 1 1 ZiM ivi ki wi = ZiM ivi ki ( θ ) = B( θ ) Φ V p LPG F T P( θ θ ) ρ 1 k = Φ V ρ phase 0 0 V c =$

6 Dealing with amorphous phase - SQAmorph I External standard method for Rietveld refinement Siroquant add-on Classic Rietveld: normalized up to 100% of crystalline phases calc ( θ ) = B(θ ) k p F LPG T P (θ θ ) h, k, l External standard method: absolute phase fractions calculated I calc Finally: w ρ 1 1 ZiM ivi ki wi = ZiM ivi ki ( θ ) = B( θ ) Φ V p LPG F T P( θ θ ) ρ 1 k = Φ V ρ phase 0 0 V c = k phase Φ 0 ρ0 Vc μ h, k, l 1 μ XRD data ZMV 0 S beam c Instrumental constant Experimental part The algorithm XRF data w el μel ρ el Studying the phase composition of the sample with Rietveldexternal standard - Determining Fe -containing phases - Calculating Fe content in crystalline part of the sample - Assuming the MVR type Creating the routine method: - Measure I int of selected reflections of the phases of interest - Calculating MVR in AI approach - Making additional corrections for absorption coefficient, solid solutions formation, etc. (from XRF data) - Checking accuracy repeatability CETAS 015 i

$Combined XRF-XRD methods: instruments ARL 9900 Workstation WDXRF spectrometer θ θ diffractometer XRF: Be-U,$ to combine XRF and XRD Combined XRF-XRD methods Fe O content determination Karelsky okatysh (Severstal),

to combine XRF and XRD Combined XRF-XRD methods Fe O content determination Karelsky okatysh (Severstal),

59 8.9.9 9 5.70 6.1 Р.61.1 Р..56 Tails 8 1.0 1.1 17.9.9 9.67.6 1 1.5 1.

7 Combined XRF-XRD methods: instruments ARL 9900 Workstation WDXRF spectrometer θ θ diffractometer XRF: Be-U, Sim/Seq XRD: 8-80 θ, CoKα (CuKα) Constant sample shape High stability, high intensity Single OXSAS software easy to combine XRF and XRD Combined XRF-XRD methods Fe O content determination Karelsky okatysh (Severstal), Kostomuksha, Karelia Fe O in ores and tails Sample w(fe magn ), % Given Found Ores Р.61.1 Р..56 Tails ( Fe ) = A A Fe O net C magn 0 1 No need to account for amorphous phase The reproducibility fulfills GOST CETAS 015 XRF-like sample preparation Measurement time 0s

8 Combined XRF-XRD methods Fe content in pellets 1 Karelsky okatysh (Severstal), Kostomuksha, Karelia Fe O in ores and tails C( FeO) = A0 A1 I int ( FeO (0)) ( Fe O (0)) α I ( CaKα ) α I ( AlKα ) α I ( SiKα ) α I ( Fe O (0) Bg1) α I abs Sample w(feo), % Given Found w, % Combined XRF-XRD methods Fe content in pellets Accuracy and repeatability Amorphous phase content is 10-18% Nearly all Fe is in crystalline phases Soild solutions formation! Measurement time 70s (inc. XRF) 5 # of Sample measurement 1 7 1А А А А B B B B SD CETAS 015

Combined XRF-XRD methods Fe content in sinters α S NLMK case high basicity of sinters 1 Fe O net = I S int C( FeO) = A0 A1 FeO net ( FeO) α I( CaKα ) α I( AlKα ) α I( MgKα ) [ Fe O 111) ] [ Fe O Bg1]

9 Combined XRF-XRD methods Fe content in sinters α S NLMK case high basicity of sinters 1 Fe O net = I S int C( FeO) = A0 A1 FeO net ( FeO) α I( CaKα ) α I( AlKα ) α I( MgKα ) [ Fe O 111) ] [ Fe O Bg1] I[ Fe O Bg] I ( ( FeO) = I( FeKα ) FeKβ FeKβ,5 1, FeKβ FeKβ Combined XRF-XRD methods Fe content in sinters Accuracy and repeatability Sample w(feo), % Given Found w, % фон фон Remarkable Fe content in complex phases Spectral correction (chemical shift) is used Measurement time s (inc.xrf) # of measurement Sample А А А А B B B B SD CETAS 015

10 Combined XRF-XRD methods Fe content in sinters Severstal case high basicity of sinters w, % Phases a Fe O Fe O FeO Amorphous phase ( FeO) = A A Fe O net α S( FeO) α I( CaKα ) α I( AlKα ) α I( SKα ) α I( TiKα ) C Combined XRF-XRD methods Fe content in sinters Severstal case high basicity of sinters SEE R Number of samples 8 Fe in amorphous phase is nearly absent Spectral correction (chemical shift) is not needed Measurement time 60 s (inc. XRF) CETAS 015

11 Summary Novel method of Fe routine analysis is suggested. The method operates with XRF and XRD data, and can be used both for ores and processed materials (sinters, pellets) The method is implemented at Karelsky okatysh, others in process. ARL 9900 Workstation is the most convenient instrumental solution for method implementation. Aknowledgments Maxim Lobanov (MSU), Maxim Voytenko (Thermo Techno) for fruitful discussions Thank you for your attention! CETAS 015

CETAS Iron sinter process control using XRD. Uwe König 1 & Nicholas Norberg 1 1 PANalytical B.V., Almelo, Netherlands

CETAS Iron sinter process control using XRD. Uwe König 1 & Nicholas Norberg 1 1 PANalytical B.V., Almelo, Netherlands Abstract No. 44 Iron sinter process control using XRD Uwe König 1 & Nicholas Norberg 1 1 PANalytical B.V., Almelo, Netherlands The use of high speed detectors made X-ray diffraction (XRD) become an important