Small Mining Operations
Hard Rock 101: Mechanical Techniques
June 2020 by John Norman
Since we know that the secret to breaking rock is applying force from the inside out (putting tension on the rock), we will be looking at ways we can generate force using human and machine power.
The 10-Ton Boulder: Expanding Grout Demolition
Imagine you have located a source of virgin placer ore containing immense gold value. Now imagine that there is a 10-ton monolith of extremely hard gneiss in between you and payday.
Gold Recovery with Centrifugal Bowls
Centrifugal bowls are very efficient, and with proper operation they can consistently achieve gold recoveries above 95% with gold of about 50 mesh size.
Ask The Experts
Any good books on mineralized faults and contacts?
Conductive Minerals and Your Metal Detector
...most prospectors don't even think about the conductivity of minerals, but there are some that do conduct electricity to a certain degree, so metal detectors will respond to them.
Papa's Got A Brand New Dredge!
It was time to prime the pump and start the engine! Dan’s priming method is to use a small, submersible, 12-volt pump. My priming method is to use a hand-operated diaphragm pump.
Hard Rock Milling: A Matter of Scale
Most 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.
The Underground Mining Adventure Continues
Our group of independent miners have been busy crafting a uniquely designed ladder/ore cart track from the bottom of an 85-foot mine shaft in a historical hard rock mine.
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The Bawl Mill
• Our Readers Say Re: It's Time to Get the Heck Out of China
• Ask The Experts - What’s the status of suction gold dredge permitting in California?
• Ask The Experts - How do I properly and safely dispose of blasting caps?
• Ask The Experts - How much silver per ton does it take to make a mine profitable?
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• Ask The Experts - What is the name and model of the old jaw crusher pictured in last month’s issue?
• Dredging Tips and Tricks: T-80 Air Compressor Maintenance
• Clearing the Nugget Trap with a Detector
• Resurrecting an Old Hard Rock Mine—Setting Up the Millsite
• Desert Prospecting Yields More Than Just Gold
• Memories of Shirttail Creek, Northern California
• Indictments Pile Up for Gold Traders
• Melman on Gold & Silver
• Mining Stock Quotes and Mineral & Metal Prices
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Seeking The Truth—A Letter From the Editor
• Legislative and Regulatory Update
• PLP Update: The Path for Legally Re-Starting Suction Gold Dredge Mining in 2021
