1. LIMESTONE CRUSHING PLANT LOAD MANAGEMENT Jaco Snyman 2012-08-15

2. CEMENT MANUFACTURING

3. ENERGY USAGE OF THE CEMENT MANUFACTURING INDUSTRY Industry consume 30 – 70% of total energy Malaysia & Iran: 12 – 15% of industrial energy used for cement manufacturing Energy source: 75% Fossil fuel, 25% Electrical

4. ELECTRICAL ENERGY USAGE OF CEMENT PLANTS Typical 110 – 120 kWh per ton of cement produced

5. ENERGY SAVINGS – PREVIOUS STUDIES No comprehensive review on energy usage & savings up to 2012 Recent studies estimate: Grinding energy can be reduced with 10 – 20% by increasing mill efficiency & schedules. Waste heat from pyro processing can be used to increase efficiency with 2 - 10%.

6. ENERGY SAVINGS – CRUSHING PLANTS Why? Global cement production of 3.5 Gtons (2011) translates to estimated global crusher energy consumption of 12 282 GWh. 10% saving = 102 MW Daily energy efficiency Very limited studies on crushing plants

7. CASE STUDY - OVERVIEW OF THE CRUSHING PLANT Operate according to production requirements 2x 50kton Stock piles, one loaded and one reclaimed

8. REDUCING ENERGY COST OF THE CRUSHING PLANT 1. Determine required stock-pile levels using: Present stock levels (raw meal, clinker & cement) Sales forecast 2. Optimise crusher running schedule to: Avoid running during Eskom peak periods Maintain minimum required stock Accommodate optimised maintenance schedules 3. Update proposed daily, weekly and monthly schedules on a daily basis

9. RESULTS - ENERGY Proposed and actual baseline for April 2012

10. RESULTS - STOCK

11. CONCLUSION Savings not realised due to: Unexpected equipment failure Unexpected sales & lack of confidence in proposed schedules Negative attitude from personnel Average peak time saving of 1.2 MW possible in this study Global saving of 102MW possible, 50% in China Address challenges to realise potential savings

12. QUESTIONS ?