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I continue to hear
from most mining companies in the U.S. and Canada how impossible it is
to mine in Montana. On the contrary, the facts are just the opposite,
for smaller operations. Let's go thru the scenarios of mining permits
one by one:
Open Pits and/or
underground mines can fall under or do fall under a Small Miner
Exclusion (SME), which allows an entity to mine on 5 acres or less
without a bond and no tonnage limit. An entity can have 2 Small Miners
Exclusions as long as they are more than 1 mile appart.
Thou shall not use
any cyanide process on any ores mined from an open pit mine in Montana
as instituted by I-137 in 1998. Ores from underground mines are not
included in the 1998 cyanide ban, ie. lower grade ores from underground
mines can be heap leached, and/or milled with agitation tank leach ie.
carbon in pulp, carbon in leach or Merrill Crowe cyanide systems. These
cyanide processes would require additional permitting and bonding
through the state.
To give an
example, we have a permitted underground mine where vein widths vary
from 30-150 feet. Our mill capacity is 150-280 tons per day. The mineis
8 miles from our mill. So considering the economics, what is the cost
of mining, trucking and milling?
This establishes
the cut-off grade of the ore to be shipped to the mill. Let's assume
25% of the shear zone is mill feed and the other is sub-economic for
the mill. Since the ore is amenable to heap leaching, it can legally go
on a pad. Grade control will become the controlling factor of all
second class ores. This would eliminate most of the dumps with the
exception of country rock obtained from cross cuts or other development
work done off the ore body.
Open pits are
allowed under I-137 so long as the ore is milled with gravity and/or
flotation. We asked the State of Montana's DEQ in 1999-2000 when we
were open pitting the shear zone mentioned previously; "Is it legal to
cyanide leach our flotation concentrates with our in-house Merrill
Crowe Cyanide circuit?". After several months, the DEQ replied, "No."
This can be challenged and will be in the near future.
When I look at
strip ratios of open pits on some of our own ground, I believe it is
cheaper to bulk mine the vein systems from underground anyway.
Since the closure
of Assarco's Smelter at Helena, Montana the processing of concentrates
has become an issue....where do we ship them? Our philosophy is, do it
all in-house, and we can and do. We smelt the free milling gold and
cyanide leach our float cons with great success and high recoveries
from our underground mines.
I must admit some
of our ores, in the district, would yield higher recoveries with a
cyanide circuit on gravity flotation tails. However, the long term
liability and infra structure costs were not within my budget when I
built my mill.
PLACER
MINES
We permitted the
Brown's Gulch Placer in early 2002 under a SME (5 acres or less). Under
this permit there was no limit to the amount of ore or waste we could
move as long as we did not disturb more then 5 acres.
In placer mining,
unlike hard rock, there is a bond that must be posted with the state
for an SME. The amount of the bond does not exceed $10,000. Likewise a
MPDES permit is required (discharge permit) if any waters will be
discharged from the operation. In Brown's Gulch only one field visit
from the DEQ was required before our reclamation and mining plan was
approved. We then submitted our bond.
Placer mines in
most cases have a larger visual impact and generally disturb more
ground then small hard rock mines. Likewise they are usually located
along active streams. This most likely accounts for the bond
requirement.
EXPLORATION
PERMITS
(as they apply to road construct,
drilling and bulk sampling)
In 1997 our
Prospect Mine needed to be trenched and drilled. After posting a bond
of less then $5,000 we completed the trenching and 13 diamond drill
holes. We also collected a 1000 ton bulk sample for metallurgical
purposes. The program was completed and reclaimed.
We then developed
a short haul road 200' long to the south of the Prospect Vein and
drilled indicated reserves. We then proceeded with an 800' 10'X10'
underground haulage ramp. We did this under our exploration permit
since you can extract up to 10,000 tons per project under the permit.
Smaller vein and
high grade ore deposits fit very well with this type of permitting for
development purposes and moderate production that fall under what would
be considered a bulk sample.
Our mill will only
process up to 70,000 ton per annum so we are only small miners in the
eyes of the mining industry anyway.
The continual
stories I keep hearing about mining in Montana aren't true. I wish
before industry and people talk about Montana, they would stop and
collect the facts.
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