S2 RANGER Slag-Analyzer Solution

Alexander Seyfarth

BRUKER AXS

May 2008

EAF Slag Requirements

� Compatibility with the refractories - MgO saturated since most slag lines consistof magnesia-carbon refractories

� Good foaming properties - Foam at the right time and long enough

� Lower Energy consumption and metal loss

� Controlling additive (Dolomite, Lime , Coal, ProSlag™) amounts therefore cost!

Why slag analysis?

� New furnace refractory linings enable more heats between maintenance intervals

• E.g. dry monolithic bottom material instead of brick

• Specialized zone based lining with customized bricks

� Slag is used to protect refractory material

• Less repair and downtime

• More heats in combination with refractory optimization

� Slag properties impact energy consumption

� Selection of additives to create effective slag

• Additives for Mg and Ca

• Additives for C

• Additives for Al, Si flux

� Slag optimization for better alloy control

Courtesy of BAKER Refractories

Pay back of slag control

� Use of monolithic patching material decreased from 7.0 to 5.5 lb. per ton of steel produced.

� Gunning material consumption decreased from 2.4 to 0.7 lb. per ton.

� Furnace brick life doubled

� The energy consumption per heat decreased from 339 to 323 kWh/ton.

� Tons per hour increased from 113 to 119.5

With the RIGHT slag control this WOULD have been your

PAYBACK

EAF Slag compositionAnalytical requirements

% MgO 8% CaO 43% FeO 26% MnO 6% Al2O3 4% SiO2 13

Fluxing Oxides

Refractory Oxides

New Challenges!

�Number of heats / shift increased

�Time per heat lower

�Accuracy for Al, Si, Mg important!

5 10 15 20 25 30 35 40 45 50

2

4

6

8

10

12

14

16

% M

gO

L

C2S+

MW+L

MW + L

C2S+L

B3 = 1.61600°C (2912°F)

What is needed ?

� Time to result from sample to result < 20 min!

• Get the data while heat is still ON!

� Repeatable and fit for purpose results

• Accuracy for Mg and Al, Si important

• Rations to be calculated with analysis

� Results transmittable into Level 2 system

• Metallurgist needs data to calculate next heat!

� Rugged all in one design

• One plug! No cables! No PC

� Easy to use

• 3rd shift capable ☺

Analytical Technology

� Metal analysis now only done by OES

• Slag analysis via OES not effective and problematic

• Metal analysis including N and C!

� Slag analysis by XRF very effective !

• Used since 1970’s

• WD and ED XRF techniques available

� WD XRF had sensitivity AND resolution for Mg Al and Si

• WD XRF is used since the 70’s

XRF X-ray Fluorescence AnalysisCharacteristic X-rays

Energy of X-ray photons

� element

� qualitative analysis

Number of X-ray photons at a given energy

� concentration

� quantitative analysis

X-ray

tube

Sample

E , N

X-ray Fluorescence AnalysisWavelength-dispersive XRF (WD-XRF)

� an analyzer crystal separates the various wavelengths λ (energies)

� the detector records only the number N of X-ray photons at a given wavelength (energy)

X-ray

tube

Sample

DetectorN

λλλλ

WD XRF technology

� Process grade WDXRF

• LAB setting -> smaller unit

• less demand on infrastructure

• Direct loading for uptime

• Auto samplers…

• Backup for OES (steel!)

� BUT not in the control room…

• Too big!

X-ray Fluorescence AnalysisEnergy-dispersive XRF (EDX , ED-XRF)

The detector is used to record both

� the energy E and

� the number N

of X-ray photons

X-ray

tube

Sample

Detector

E , N

ResolutionSDD vs. Si Pin

� SDD (145 eV) compared to Si-PIN (250 eV)

Cl K αααα

S KααααCa Kαααα

Resolution is not all!Standard Detector vs. Bruker XFlash®410

Energy resolution of Cu Kα at different count rates.

XFlash SDD in S2 Ranger 4th Generation

standard detector (SDD)

010

020

030

040

050

060

070

080

090

010

00

110

012

00

130

014

00

Cps

Si

KA

1

Si K

B1

Al K

A1

Al K

B1

Mg

KA

1

Mg

KB

1

1.11.21.31.41.51.61.71.8

KeV

Separation and sensitivity at 100.000 cps

Si

AlMg

Sample – taken manual or by robot

Crush to ensure homogeneity

BEFORE

AFTER

Sample preparation in 3 steps Dose – Grind – Press

�Crush sample

�Grind sample

�Press powder into tablet

Remove “iron” from powder

� Second quick removal by magnet

Sample preparation repeatability10 pellets from crushed material

Accuracy and stability (EAF) (n=10 on same sample)

E A F Compound

Avg. error of calibration

(SEC) (wt%)

Stability as Std. Dev.

(wt%) Al2O3 0.12 0.03 CaO 0.58 0.04 Cr2O3 0.04 0.01 FeO 0.13 0.05 MgO 0.23 0.13 MnO 0.12 0.01 P2O5 0.15 0.01 S 0.005 0.00 SiO2 0.71 0.05 TiO2 0.05 0.01

Long term stability ….

S2 SLAG-ANALYZER ED XRF with XFlash™

� All in ONE design

� Pd X-Ray tube operated up to 50Watts, air cooled

� Silicon Drift Detector 4th generation XFlash with 145 eV at 100.000 cps (MnKA1)

� Integrated Vacuum pump

� Direct Access Sample compartment

� TOUCHCONTROL™

� Built in Printer

Direct Access for samplecleaning no problem!

Accuracy and Repeatability

E A F Compound

Avg. error of calibration

(SEC) (wt%)

Stability as Std. Dev.

(wt%) Al2O3 0.12 0.03 CaO 0.58 0.04 Cr2O3 0.04 0.01 FeO 0.13 0.05 MgO 0.23 0.13 MnO 0.12 0.01 P2O5 0.15 0.01 S 0.005 0.00 SiO2 0.71 0.05 TiO2 0.05 0.01

Connectivity..Networked via TCP/IP

On Demand via WEBEXOn Demand via WEBEX

All in one Design

S2 RANGER SLAG-ANALYZER

� Time to result from sample to result < 20 min?

� Repeatable and fit for purpose results

� Easy to use

� Results transmittable into Level 2 system

� Rugged all in one design

�Together we can make it happen in your plant!

www.bruker-axs.com

Together we can make it happen in your plant!