Hey Cazisme:
Arizona's motto is the Copper State and they are reasonably friendly toward hard rock mining as long as you stay away from the heavily populated areas. Having a patented mining claim is even better as it will reduce your involvement with BLM.
In the past, I ran a small 60 TPD hard rock project in AZ and recommend you visit both the Mining/Minerals Museum and the State Mine Inspector offices located in PHX. You will get a lot of useful/helpful info from both places. Small patent mines require a minimum of permits with the possible exception of an ESA and water. The state water agency can be very picky about surface and underground water usage.
The state mine inspectors follow the MSHA regulations closely, so be aware that everyone entering the mine/mill site must have an up-to-date miners certificate. In the past, the inspector's office give classes for the “40-hr New Miner” and “8-hr refresher” courses on a monthly basis. If needed, check with them.
As Dave said, “underground mining is expensive and dangerous”, and I wouldn't recommend it to anyone without the proper training and experience. Cost wise, driving a drift (tunnel) large enough to handle a small LHD can easily run several $100/LFt, and sinking shafts will cost even more.
I don't think assay dates are as important when compared to “what was assayed”, and do you have a vein structure (ore body) large enough to support the high cost of mining. You mentioned a “6 to 70% for lead per ton”. Was that a typo? At 60/70% Pb/ton you don't have a gold/silver mine, you have a galena mine and more problems. Separating gold/silver from galena can be a metallurgy challenge. If you mine on a commercial scale, sending your concentrates off for processing makes more sense, but adds to the cost.
For now I would recommend a few of things; 1. Make sure your friend pays the taxes on the patent mining claim. If not, the property will revert back to public domain and be lost forever. 2. A “boots on the ground” visit to the site to determine the current mine condition. Take/hire an experienced person to go underground. Safety first. 3. Lots of additional assays and drilling/sampling program. How big is the vein structure (width/depth)? Based on your your early assay, if it's galena and the vein width is less than 3' across and doesn't go to depth, the mine won't come close to paying for itself.
I didn't mean to write a book, but the permitting side of hard rock mining will be the least of your problems. Everyday will be a battle, but with the right ore it could be interesting. Don't be blinded by the gold numbers, $30 to $600 is a huge spread, and you don't have enough silver to pay for fuel. You need more assays and a complete mine evaluation before making an economical business decision.
Good luck and let us know what happens.
John
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