1. John Kline johnpkline1@gmail.com
Cement Mill Study
John Kline

3. Operating Power of Main Components
On Average 90.5% of Mill Motor Power Consumed

4. Total Shop Power Compared with Mill Motor Power
Red Dots are Vertical Mills
Total Shop Power = ~110% of Mill Power

5. Mill Throughput Compared with Mill Motor Power
Mill Throughput TPH =
Mill Motor kW *

6. Reasonable Correlations
Mill motor consumed power = 90% of mill motor installed power (r2 = )
Mill shop power = 110% of mill motor installed power (r2 = )
Mill throughput = * mill motor installed power (r2 = )
Indicating a mean power consumption of 36.7 kWh/t for the mill and 44.7 kWh/t for the shop
Larger mills are seen to be approximately 5.8% more productive (r2 = )
The above were all with forced intercepts of zero
TPH2 kW2*1.058
TPH kW1 =

7. Equipment Impacts

8. Motor Power Comparison

9. Power Consumption Auxiliares

10. Blaine impact on power consumption

11. Power Consumption Relationships

12. No apparent relationship to grinding aid

13. Appendix

14. PCA/ENERGY STAR Finish Mill Energy Survey
IEEE West Coast Conference
San Antonio, TX
October 30, 2015
Steve Coppinger, P.E. (VP, Engineering Services)
CalPortland Company

15. ENERGY STAR Plant Energy Performance Indicator (EPI)
Benchmarking tool that compares plant energy efficiency to comparable plants in the industry.
Based on PCA Energy & Labor Survey
Certification requires plant efficiency to be in top quartile.
27 Cement Plants are certified

16. The Cement Industry Curve Has Shifted
The distribution of energy performance has shifted
1) Low performers improved the most
2) 61 trillion Btu saved
3) 13% reduction
4) Based on 2011 Duke Study baseline to 2008

17. Finish Mill Benchmarking Survey
Industry wanted to drill down to plant area energy efficiency
Finish mills were identified as large energy consumers
Survey developed by PCA Energy Subcommittee and ENERGY STAR Cement Focus group
Intended to measure finish mill process energy efficiencies
Surveys collected from 19 companies, 61 plants, and 170 mills

18. Composition of Reporting Mills
Circuit Type
Mill Type
Vertical (5.9%)
Open (2.5%)
Ball
93.5%
Closed
97.5%
Type of Separator
Number of Compartments
Static (15.2%)
Three (2.3%)
One (17.4%)
Dynamic
84.8%
Two
80.3%

19. Production Characteristics
Average Blaine of Cement Produced
Percent of Plants Primarily Producing Cement Types
Additive Composition of Cement Produced

20. Operating Statistics
Mill Motor

21. Fan

22. Separator

23. Auxiliaries
Roll Press

24. Average Operating kWh per Ton

25. Energy Efficiency by Mill Capacity
Average kWh per Ton
Average Tons per Hour

26. Energy Efficiency by Average Blaine
Average kWh per Ton
Average Blaine

27. Energy Efficiency by Average Blaine Less Than 5000
Average kWh per Ton
Average Blaine

28. Energy Efficiency by Average Blaine Greater Than 5000
Average kWh per Ton
Average Blaine

29. Next Steps ENERGY STAR will review data and provide further analysis
Final report will be issued
Possibility of evaluating other plant areas if requested