Ball Mill in Action: How a Chilean Copper Mine Achieved 20% Energy Savings
Mar 29,2025

Ball mills are critical for liberating metals from ores.  We dissect their engineering and present a success story from Codelco’s Radomiro Tomic mine.

 

‌Technical Specifications‌

‌Capacity‌: 5-200 tons/hour (depending on ore hardness).

‌Grinding Media‌: Forged steel balls (Φ30mm-Φ120mm) or ceramic beads.

‌Power Consumption‌: 15-30 kWh/ton for copper ore.

‌Applications‌

‌Gold Cyanidation‌: Grinding to 75μm for optimal gold recovery.

‌Iron Ore Pelletizing‌: Produces ultra-fine magnetite concentrate.

‌Lithium Extraction‌: Reduces spodumene ore to 150μm for acid leaching.

 

‌Case Study: Codelco’s Energy-Efficiency Overhaul‌

‌Client Background‌

Chile’s state-owned Codelco aimed to reduce energy costs at their 100,000 tpd copper concentrator.

 

‌Challenges‌

Ball mills consumed 40% of the plant’s total energy.

Overgrinding caused slimes (<10μm) that hampered flotation.

Liners required replacement every 6 months ($25k per mill).

‌Solution‌

 

We retrofitted two ‌Φ4.5×7m Overflow Ball Mills‌ with:

‌High-Efficiency Motors‌: IE4-class motors cut energy use by 12%.

‌Composite Liners‌: Rubber-metal hybrids extended lifespan to 18 months.

‌Advanced Process Control‌: AI algorithms optimized ball charge and slurry density.

 

‌Results‌

‌Energy Savings‌: 20.3% reduction (from 28.7 to 22.9 kWh/ton).

‌Throughput Boost‌: 8% increase in copper recovery due to precise particle size control.

‌ROI‌: $600K  annual savings per mill.

‌Maintenance Checklist‌

‌Monthly‌: Check gear alignment and lubricant viscosity.

‌Quarterly‌: Measure liner thickness with ultrasonic testers.

‌Annually‌: Rebalance the mill trunnion bearings.

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