Small Mine Selective Blasting
January 2000 by Dr. Ralph E. PrayDrill holes in a mineralized vein often penetrate hidden layers of poor ore which, after blasting, end up diluting the production quality. Disseminated gold ores carrying two ounces per ton may be identical in appearance to adjacent vein material...
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.
I had never run an impact mill before, but anything involving rocks, water and a big electric motor sounded great.
San Marino, California—"Boys, I believe I have found a gold mine!" With these simple words, an obscure New Jersey carpenter and mechanic named James W. Marshall set in motion a global cascade of events that dramatically shaped the social and economic life of California and the American West.
For those who rarely nuggetshoot, or are thinking about doing a little occasional nugget hunting, to buy a specialized gold detector may not be financially practical. Fortunately, a coin shooter with do-all capabilities, while it may not be as sensitive to sub-grain flakes, is satisfactory for many nugget hunting situations, especially if a smaller accessory coil is used.
Excerpts from California Mining Journal, our original title, published 50 years ago this month.
• Training to be greener...but still unemployed
• By the Numbers
• Notable Quotes
The Bureau of Land Management (BLM) has added some useful tools to their website. The Land and Mineral Use Records system has been meshed with a map viewer that allows users to obtain mining claim information in a useful format.
The Bawl Mill • Over the Divide • Our Readers Say • Letter from the Editor to our Readers and Advertisers • Administration Considers Bypassing Congress • First Woman to Draw Mining Pension • Mohave Mountain Placers, Arizona • High Court to Reconsider Wilderness Water Rights • Sixteen to One Takes on MSHA • Picks & Pans: Gold Mining on Joie Osgood Ranch • Gold • Company Notes • Millie's Tailings • Placer PGMs in Alaska • Mogollon—New Mexico's Remote Gold Camp • ICMJ 9th Annual Photo Contest Results • The Other Minerals of Mt. Diablo • Melman on Gold & Silver • Mining Stock Quotes and Mineral & Metal Prices • Looking Back