Medinah Minerals (MDMN)

[easymillion]

Not an Extensive Search
but low grade ores of sufficient tonnage are routinely pre-processed before sending to the smelter:
Low-grade materials containing as little as 0.03 ounce of gold per ton, providing sufficient tonnage is available, are now being field tested for precious-metal recovery. The Bureau of Mines and several mining companies have conducted extensive hydrometallurgical studies to exploit low-grade ores and mine waste material.
... and that's from a Bureau of Mines Information Circular/l978!
Better pre-processing methods are continually under development, and a lot has changed in the past 30 years!

As stated in my previous post:

In the past, gold explorers would shy away from a deposit with less than 1g/t of gold, common in Nevada. However, those who saw the total picture were willing to take a risk in mining for gold in the state. To date, the low grade deposits in Nevada have become one of the largest sources of gold in the world. Total recorded gold production from 1835 to 2008 totaled 152 million ounces, worth about US$180 billion at 2010 prices with the majority coming from low grade/high tonnage deposits in the last 30 years.

For anyone that is math challenged, 0.03 ounces is less than 1 gm/ton, and look at the date on the Bureau of Mines report - 1978. As stated above, the majority coming from low grade/high tonnage deposits in the last 30 years. Also, that's only for the gold recovery, not CU which Chile is considered an important leader of in mining circles and certainly knows how to refine and extract. A little in depth DD goes a long way to showing economic valuation, IMO.

If You're In, You're In
Invested in the Mountain
...and That's What Counts!
easy
***************************
The world needs dreamers and the world needs doers. But above all, the world needs dreamers who do.
Sarah Ban Breathnach