Basically, they mine the ore and put it in stockpiles of assigned grades. 10g/t, 40g/t, 100g/t etc etc. They then have an optimal feed grade. They basically calculate how many "scoops" from each stockpile they need to achieve that grade, and to be left with no low grade ore at the end of the job.
Only problem is, they need to go over the whole process with a fine tooth comb to find where the discrepancy lies.
CCU gets pushed around on low volume - both up and down. So imagine the momentum you can generate when you have some negative news that can be misconstrued as "the Silver's not there"
I used to subscribe to ASCI and the low volume, big moves element was highlighted as a risk, and also potential winning element, of holding this stock. It certainly can test your nerves though.
CCU Price at posting:
31.5¢ Sentiment: Buy Disclosure: Held