melbourne continuous on-line measurement of process mineralogy for quality control and optimisation...
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Melbourne
Continuous On-line Measurement of Process Mineralogy for Quality
Control and Optimisation using X-ray Diffraction
Dr Peter Storer
Principle Scientist,
FCT-ACTech Pty Ltd
Melbourne
Continuous On-Stream Mineral Analyser►For Real time Industrial Process Control
►Automatic Mineral Phase Analysis
►In Plant On-Stream Location
►Linked to Plant Control System
►Continuous Analysis
►Data Trending
►Calculated Elemental Analysis
COSMA
Melbourne
Cement Plant, Utah USA – October 2001
Cement Mill building
Product conveyor
tube
Analyser room
Melbourne
Auger sampling from mill product
Cement conveyor at
100-150 tph
Melbourne
Sample Handling Schematic
1
2
3
4
COSMA
Melbourne
Cement Sampling – Multiple lines
Three sample lines
COSMA
Melbourne
Automatic and Continuous Sample Presentation
Feedscrew Turntable
Moving sample maximizes number of particles analyzed
Melbourne
X-ray tube, sample stage and detector
Etc.
Melbourne
Diffraction Pattern – analysed by Reitveld analysis
0
20000
40000
60000
80000
100000
120000
600 1100 1600 2100 2600
Two theta
Co
un
ts
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Particle Statistics are Important! We cannot use Stationary Samples to Analyse “As Received”
Material
0
500
1000
1500
2000
2500
33 34 35 36 37 38 39 40 41 42
Angle Two Theta (degrees)
Inte
ns
ity
(Co
un
ts)
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Particle Statistics are Important! Rotating Turntable
0
300
600
900
1200
1500
33 34 35 36 37 38 39 40 41 42
Two Theta Angle (degrees)
Inte
nsi
ty (
Co
un
ts)
MelbourneNickel Concentrate Samples
Melbourne
Sudbury Nickel Concentrate - Static sample measurements
0
1000
2000
3000
4000
5000
6000
10 20 30 40 50 60 70 80 90 100 110
Two theta
Co
un
ts
Loading 1
Loading 2
Loading 3
Loading 4
Melbourne
Sudbury Nickel Concentrate - Static sample measurements
0
1000
2000
3000
4000
5000
6000
50 55 60 65 70 75
Two theta
Co
un
ts
Loading 1
Loading 2
Loading 3
Loading 4
Melbourne
Sudbury Nickel Concentrate - Rotating Sample
0
1000
2000
3000
4000
5000
6000
50 55 60 65 70 75
Two theta
Co
un
ts
Rotate1
Rotate2
Melbourne
Raw Materials processed to Cement Minerals
Melbourne
Mineral Analysis – as it happens!
MelbourneFree Lime
• Free lime is monitored in the clinker to ensure it is below the maximum limit.
• Excess free lime may indicate under burnt clinker or excess CaO in the raw meal.
• XRD provides the opportunity to clearly identify the cause of excess free lime.
Melbourne
Free Lime Excursion.
10
20
30
40
50
60
26 Jan 27 Jan 28 Jan
Pe
rce
nt A
lite
, Be
lite
0.0
0.5
1.0
1.5
2.0
2.5
Pe
rce
nt F
ree
Lim
e
Alite Beliteb Lime
Underburning…
Melbourne
0
10
20
30
40
50
60
70
20 Nov 21 Nov 22 Nov
Per
cent
Alit
e, B
elite
0.0
0.5
1.0
1.5
2.0
2.5
Per
cent
Fre
e Li
me
Alite Bogue C3S Beliteb Bogue C2S Lime
Free Lime Excursion – Excess free lime in Kiln Feed
Melbourne
Gypsum – CaSO4. 2H2O
• Gypsum is added to clinker in the grinding stage to control the cement setting time.
• During the grinding process some of the gypsum is dehydrated to plaster of paris.
• XRD provides the opportunity to monitor the gypsum/hemihydrate ratio.
Melbourne
Trend of gypsum states after mill stoppage
0
0.5
1
1.5
2
2.5
3
3.5
4
20:16 21:16 22:16 23:16
Time
Wei
gh
t p
erc
ent
Hemihydrate
Gypsum
Mill Restart
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Trend of gypsum states for constant mill exit temperature
0
1
2
3
4
5
6
7
3:00 24-Feb
11:00 24-Feb
19:00 24-Feb
3:00 25-Feb
11:00 25-Feb
19:00 25-Feb
Date/Time
Per
cen
t o
f m
ate
rial
60
70
80
90
100
110
120Gypsum DihydrateHemihydrateMill Feed GypsumXRD Derived SO3Mill Exit Temp.
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Showing the clinker temperature when hemihydrate increased
30
40
50
60
70
80
90
100
110
120
3:00 24-Feb
11:00 24-Feb
19:00 24-Feb
3:00 25-Feb
11:00 25-Feb
19:00 25-Feb
Date/Time
Tem
per
atu
re (
Deg
C)
Mill Exit CementTemperature
Mill Feed ClinkerTemperature
Melbourne
Limestone – CaCO3
• Limestone is added to the cement mill to control the cement cost and minimise greenhouse emissions.
• Different cement types and regulatory standards exist for additions.
• XRD provides the opportunity to monitor limestone addition.
Melbourne
Trend of Production Type change showing limestone addition
Melbourne
0
0.5
1
1.5
2
2.5
3
3.5
25-Oct-05 14-Dec-05 02-Feb-06 24-Mar-06 13-May-06 02-Jul-06 21-Aug-06
Date
Lo
ss (
%)
Trend of Loss results on Finished Cement
Limit
Number of Cases
0 10 20 30 40 50
1.59
Number of Cases10 20 30 40
Melbourne
Conclusion
►Continuous On-Stream XRD Analysis for
material streams – direct on powder or crushed and ground for coarse samples
►Control based on mineralogical information – allows timing and direction of control action►Kiln operation and burner settings
►Cement Mill and Separator operation
►Feed rate control and monitoring
►Direction of Product to Silos
Melbourne
Conclusion
►Raw Material monitoring/control at the Product
stage allows optimum additive control.►Limestone, Gypsum
►Dynamic sample presentation allows coarser sample analysis.►Ease of sample prep, minimum wear on equipment.
►Excellent Quality Monitor
“Like having my best lab guy working 24/7!”
Melbourne
Thank you! … Questions?