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

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

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

Mill Throughput Compared with Mill Motor Power Mill Throughput TPH = Mill Motor kW * 0.0245

Reasonable Correlations Mill motor consumed power = 90% of mill motor installed power (r2 = 0.9646) Mill shop power = 110% of mill motor installed power (r2 = 0.8957) Mill throughput = 0.0245 * mill motor installed power (r2 = 0.7781) 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 = 0.8452) The above were all with forced intercepts of zero TPH2 kW2*1.058 TPH1 kW1 =

Equipment Impacts

Motor Power Comparison

Power Consumption Auxiliares

Blaine impact on power consumption

Power Consumption Relationships

No apparent relationship to grinding aid

Appendix

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

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

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 - 1997 baseline to 2008

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

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%

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

Operating Statistics Mill Motor

Fan

Separator

Auxiliaries Roll Press

Average Operating kWh per Ton

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

Energy Efficiency by Average Blaine Average kWh per Ton Average Blaine

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

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

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