View single post by Chriss H
 Posted: Sat Oct 29th, 2016 07:30 am
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Chriss H

Joined: Sat Aug 13th, 2016
Location: Plano, Texas USA
Posts: 91
Salada, the book Keith mentioned and I posted a link here (this thread on Oct, 25) has a lot of this very information. One thing I'm learning is the stamp mills in Gilpin county were slow drop vs. the California method of speedy stamping, the ore in Colorado was amalgamated with a lot of different minerals and hence quite hard to get a good percentage of gold out, until the mining engineers figured out how to slow the stamps down, and use direct quicksilver methods as soon as they crushed the ore finely in the mortar box, to eventually end up with around a 70-74% recovery rate, equaling California's best averages of recovery. In the earlier days of hard rock mining they were stuck at around 40-50% recovery rates, making it almost not worth the effort of digging so deep and hauling the ore out to process.

I'm sure learning a lot about early days of hard rock mining lately.


I'm a Colorado mining district afficianado. Planning a layout in HOn3 based on the Gilpin County area.
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