Melbourne Continuous On-line Measurement of Process Mineralogy for Quality Control and Optimisation...

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

Melbourne

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)

Melbourne

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

Melbourne

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.

Melbourne

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?