For those who don't know the difference in feed grade vs average...

For those who don't know the difference in feed grade vs average grade.

A Mineral Resource is the size of the current deposit when you consider it to be a single ore body. In this case, when you look at the nickel and cobalt as a single zone. That means there are parts within this ore body zone that has high cobalt, for example, and lower cobalt. As a result we end up with a grade of less than 0.1% cobalt.


But you don’t mine an ore body as a single deposit. Instead, you put the waste to the side and only treat the mineralised ore. Thus you process the higher grade cobalt and nickel material and stock pile the lower grade dirt. As a result, the actual grade of the material you feed into the plant is much higher than the overall Mineral Resource grade.


At Sconi, the ratio of waste to ore is 0.6 : 1.0


So we move 600kg of low grade material to extract 1 tonne of high grade material.


A 0.6 : 1.0 ratio is extremely good.


CLQ, for example, has a 0.8 : 1.0 strip ratio.


Ardea has a strip ratio of 2.68 : 1.0. So they have to move almost 3 tonnes of barren dirt to be about to extract 1 tonne of ore. That means that only 25% of the earth they move is mineralised. Hence their mining costs would be significantly higher than AUZ or CLQ.