[MEDIA] Grades versus scale Operating copper mines currently...

Grades versus scale

Operating copper mines currently have an average grade of 0.53%.

Copper projects under development now have an average grade of 0.39% or less, according to Mining Intelligence.


Economies of scale, depth and width

60% of the world’s copper comes from porphyry deposits. These deposits are generally lower grade than volcanogenic massive sulphide and sediment hosted deposits.

However porphyry deposits usually offer greater economies of scale and support lower mining costs.

If the zone is close enough to the surface and large enough to be mined in bulk, huge trucks can process large volumes of ore at a relatively low mining cost and capital development.

Open pits are generally less than 300 metres deep and are several hundred metres in diameter.


Ore body geometry

The geometry of the ore body is another very important factor that can have an impact on the cost of extraction.

If the ore body is in a ‘pillow-like’ cross-section that lends itself easily to open pit mining, it will be much cheaper to extract than an ore body that is pivoted on the diagonal.

How the ore body lies will also affect the waste to ore ratio, with a horizontal ore body involving less waste than a diagonal one of equal grade.

Cheers

These are only my thoughts and it does not constitute investment advice. Before acting on any information you read and before making any financial or investment decisions, you should always consult your advisor(s) or other relevant professional experts.