We Need Discontinuous Improvements in Mineral Liberation Energy Efficiency

Noko PhalaCEEC Short TalkJune 2012

We face several sustainability challenges ….

Environmental and social responsibilities – reputational risks

Skills availability and retention

Employee safety – conditions (e.g. seismicity) and practices

Inflationary cost pressures – energy price, mining inputs, wages

There is scope for technology and innovation to steer the tankers

=+

$/t

Hard ores(energy cost)

High consumables demand and costs inflation

Low grades

Refractoryores

Margin contractionOz Rec/t

..and this has in turn led to a broad technology development spectrum

The most common grinding method – tumbling mill – is inherently energy inefficient. Whilst continuous optimization is necessary, we believe the sustainability challenges require radical breakthroughs in energy utilization

Tromans (2008) analysis:

Considering energy of resultant surface

The base energy requirement is a grinding method independent analysis;The challenge to obtaining it is overcoming the kinetic barriers;

Discontinuous improvements in energy utilization – encouraging directions

Pre-upgrading

Pre-treatment

•Electric pulses•Ultrasound•Microwaves•…etc ?

$/t cost savings directly related to % waste rejection

•Sensor-based sorting : exploration of other attributes ?•Ore dilution can be ~ 200 % in a deep level mine

Is a HPGR just an efficient crusher ?VRM for finish grinding ?VSI potential?Explore other mechanisms …

New ComminutionMechanisms

$/t energy saving related to degree of ore softening

Complete elimination of a tumbling mill should be the goal

Just how close to the thermodynamic limit can we get ?

Are we aggressive enough in pushing ideas through the development systems?

Can we comminute based on a new set of rules ?

Destruction of a solid – define optimal breakage mechanism, then design a fitting device…we feel like we are stuck with optimising existing devices

Multiple Impacts on Multiple ParticlesMisdirected impacts (misses), mismatched energies

Compression of Multiple ParticlesDirected energy application, mismatched energies

Step-wise Compression of a Particle andits Daughters IndividuallyDirected energy application, energy matching

Shocking of Multiple ParticlesDirected energy application, mismatched energies

Step-wise Shocking of a Particle andits Daughters IndividuallyDirected energy application, energy matching

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Step-wise Tension to a Particle and its Daughters IndividuallyAs above or better ?

What about shear and torsion ?

Going Forward

The nature of the sustainability challenges we face make an innovative mindset a business imperative - wild ideas are becoming normal part of project trade-offs;

From policy and industry “statements” to radical approaches and executable industry roadmaps: how do we become more aggressive in pursuit of the goals ?

Being more open, and reaching out more to fields outside ours for solutions to our problems;

Open innovation – Creativity on demand, access the global brainpower