Post on 01-Feb-2018
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Reducing the energy required in grinding clinker to cement: some case studies
H. Benzer, N. Aydogan , H. Dundar and A. J. Lynch
HACETTEPE UNIVERSITY Mining Engineering Department
2Reducing the energy required in grinding clinker to cement
1. INTRODUCTION
MetPlant 20118‐9 August 2011, Perth, Western Australia
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500
1,000
1,500
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3,000
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2006 2007 2008 2009 2010
World cement production (million tonnes)
The effect of change in ball size
Optimizing circuits containing HPGRs, ball mills and separators
The use of high intensity grinding
3Reducing the energy required in grinding clinker to cement
2. OUTLINE
MetPlant 20118‐9 August 2011, Perth, Western Australia
4Reducing the energy required in grinding clinker to cement
3. THE EFFECT OF CHANGE IN BALL SIZE
MetPlant 20118‐9 August 2011, Perth, Western Australia
5Reducing the energy required in grinding clinker to cement
3. THE EFFECT OF CHANGE IN BALL SIZE
MetPlant 20118‐9 August 2011, Perth, Western Australia
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weight %
ball size (mm)
1st chamberbefore
after
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17 20 25 30 40 50
weight %
ball size (mm)
2nd chamber
before
after
6Reducing the energy required in grinding clinker to cement
3. THE EFFECT OF CHANGE IN BALL SIZE
MetPlant 20118‐9 August 2011, Perth, Western Australia
Capacity (tph)
Product type Before optimization After optimizationA 155 180B 178 205C 162 195D 142 160
7Reducing the energy required in grinding clinker to cement
4. HPGR APPLICATONS AND ENERGY EFFICIENCY
MetPlant 20118‐9 August 2011, Perth, Western Australia
8Reducing the energy required in grinding clinker to cement
4. HPGR APPLICATONS AND ENERGY EFFICIENCY
MetPlant 20118‐9 August 2011, Perth, Western Australia
(2) (3)
(1)
9Reducing the energy required in grinding clinker to cement
4. HPGR APPLICATONS AND ENERGY EFFICIENCY
MetPlant 20118‐9 August 2011, Perth, Western Australia
Case study 1 2 3
Raw materials fed Clinker (95%) Clinker (74%) Clinker (94)
Capacity (tph) 55.3 71.7 132.0
Specific energy use (kWh/t)HPGR - 8.9 8.02
HPGR-Ball Mill 32.7 29.5 21.6
Final product size (µm) 30 68 28
10Reducing the energy required in grinding clinker to cement
5. VERY FINE GRINDING USING VBM
MetPlant 20118‐9 August 2011, Perth, Western Australia
Vibration frequency (rpm) 1160
Motor power (kW) 50
Internal Diameter (m) 0.78
Internal Length (m) 1.2
Operational ball load % 90
11Reducing the energy required in grinding clinker to cement
5. VERY FINE GRINDING USING VBM
MetPlant 20118‐9 August 2011, Perth, Western Australia
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passing %
p.size (mm)
tot. Feed to VBM‐1
VBM‐1 discharge
VBM‐2 discharge
sp.en.consumption(kWh/t)
28 days strength(MPa)
Finish cement 28 37.6
End-product 35 38.1
12Reducing the energy required in grinding clinker to cement
6. CONCLUSION
MetPlant 20118‐9 August 2011, Perth, Western Australia
• Optimizing the ball size distribution in finish milling of cement using modelling and simulation resulted in higher production rate, reduced overall specific energy consumption and lower cost of metal wear.
• The use of HPGRs in finish milling circuits as pregrinders increases the capacity of the existing circuits by reducing the work done by the downstream ball mills. Closed circuit HPGRs reduce significantly theoverall specific energy consumption of the circuit.
• Vibratory ball mills used after finish cement production to reshape the final product when the additives are increased results in a cost‐effective process. However for high capacity finish milling circuits the application of the Vibratory Ball Mills is not practical due to their low capacity.
13Reducing the energy required in grinding clinker to cement
7. ACKNOWLEDGEMENTS
MetPlant 20118‐9 August 2011, Perth, Western Australia
• Izmır Cement Plant for their permission to present this work
• Hacettepe Comminution Group members for their support in conducting the surveys