Hard Rock Milling: A Matter of Scale
April 2013 by Chris RalphMost prospectors understand placer mining a lot better than hard rock mining and don’t realize the amount of work that goes into processing different types of hard rock ore.
Pumps can be set up quite a distance away horizontally from the sluice, even hundreds of feet. It will work so long as there is sufficient water at the source where the pump is located. Vertical distance is more of a problem than horizontal distance; 30 to 40 feet is the maximum vertical climb for most pumps.
Lots of prospectors are trying out nugget detecting for the first time and finding out that it isn’t all that easy. In fact, in my opinion, metal detecting for nuggets is perhaps the most difficult form of prospecting that one can take on.
Back in October I read with great interest Chris Ralph’s article on the use of a metal detector while drywashing, and I wholeheartedly agree—I wouldn’t even consider going drywashing without using a metal detector in conjunction...
As I started walking down to the river one chilly morning, the mist was hanging over the calm portions of the water like a white cotton blanket. This scene got me to thinking about why the river was like that—the deep pools, boulder fields, gravel bars, the effects of how much water was moving at any given time along the watercourse—and most of all the relationship all these things have on where I will be able to find gold.
The right speed accumulates only the heavy materials and allows all of the lighter stuff to flow through. This optimum speed is dependent on the size of the gravel you need to move through the system.
They must have assumed the paystreak was spotty and had been mined out, so they never mined as close to the side of the valley as they should have.
This is just the type of specimen that could have been easily ignored by the old-time miners. It felt a little heavier in my hand than a chunk of quartz of that size ought to have been.
The Bawl Mill • Ask the Experts - processing plants that can extract rare earth metals • Ask the Experts - what does MDB&M stand for? • Ask the Experts - proper mining claim procedures • The Hughes Creek Placers, Montana • Benefits of a Detecting Partner • Excavator Testing Wet Placer Ground • Paperwork Guy—A Cautionary Tale • ICMJ Online Forum Now Available • Detecting For Gold—Are You Up For It? • A Trip Down the Yukon River • Selenium, Mercury and Suction Dredging—Studies Contradict CA State Water Resources Board • Melman on Gold & Silver • Mining Stock Quotes and Mineral & Metal Prices