Search This Blog

Tuesday, December 28, 2010

Sluice box efficiency...

We have in our hands, “Use of Nuclear Tracers to Evaluate Gold Recovery Efficiency,” a bulletin dated April 1994. This bulletin addresses feed rates and water flows for recovery of different types, size and weight of placer gold.

The study was based on gold tracers (irradiated particles) tracked through a large sluicing operation to determine the most efficient means of gold recovery.  A large amount of the information does not apply to the small placer miner, but some interesting facts apply to both large and small scale operations.


In a comparison of expanded metal versus angle iron, the report states, “Flat bar riffles are not recommended for fine gold recovery.” An example of this would be homemade angle iron riffles. “The vortex is launched up to the top of a turbulent slurry column instead of onto the next riffle,” meaning the force of the water (vortex) carries the gold into turbulence rather than onto the next riffle, floating it right out of the sluice box due to bubbling and irregularity of gold particles.

“Regular or modified angle iron riffles should have a 40-60mm. gap and be tilted at 15 degrees upstream of the sluice box‘s vertical in a sluice run, with a slope of 12-15 degrees. Packing and extreme gold loss were often observed when any of the following conditions occurred: Shallow slopes, narrow gaps between riffles, excessive feed rates, insufficient water flow, and riffles larger than 25mm.

“Expanded metal riffles are shallow riffles which are sensitive to scouring and the resulting (which results in) coarse gold losses when they are subjected to surging or excessive water flows and/or steep sluice box gradients.”

We’ve run into this situation many times with our guests… more is better! A high water flow will float finer gold right out of the sluice box. They are amazed that we even watch the ebb and flow of the stream during the day, adjusting for increased water flow.  We try to remove our sluice box if an afternoon rain occurs... the increased flow of the stream might clean it out for us!

Feed rates, as mentioned above, are also critical. Many times a tired prospector starts feeding too much material to the sluice. This will not only dislodge accumulated gold but also float gold across overloaded riffles right back into the stream! We’ve joked about re-running the tailings of someone we know is overloading the sluice box or has too much water flow… but content ourselves with testing our own tailings periodically by pan to adjust for possible loss of gold.

Use of expanded metal or angle iron is stated to, “severely reduces the opportunity for gravels and anything but very coarse gold and nuggets to enter the riffles.”

For those of you wanting to build your own sluice box, a 15 degree upstream angle is needed on riffles, and a slope of 12-15 degrees of your sluice box in the creek.

The article concludes with, “The fine screened sluice boxes had the lowest loss of all… one of the triple run boxes and a single run box lost more gold than they recovered. The fine screen systems with recommended sluice box designs recovered 99% of their placer gold.”

Sunday, December 19, 2010

Claimholders beware!!

We see a lot of claimholders being over staked by overzealous gold prospectors. We’ve been guilty of it once ourselves, but that was an error in BLM records (something every claimholder needs to check). We‘ve made errors and caught multiple BLM errors! One of these days we’ll discuss in depth how to use LR2000 on the BLM website, or maybe I’ll write one of those “LR2000 for greenhorns” manuals!

The history of one of our claims is a composite example of what anyone who owns a claim might expect from those who don’t know, have been misinformed or just plain don’t care!

We became the proud grandparents of our first grandson in 2001. We hadn’t been all that active prospecting… things like getting four teenagers through high school, holding down full-time jobs to support that effort, and developing a rural property into a home had all contributed to little free time and opportunity.

Bob did, by his continued research, find a claim that was “just too good to pass up.” We knew the area was in high demand, so Bob and a friend walked the creek looking for a location certificate or claim posts, then found discovery. The following day we prepared a location certificate in the name of our grandson and returned to hang paper that day.

We were so excited to be claimholders again! Sunday morning dawned and we grabbed some shovels and a sluice box, our trusty pans and some boots. Our excitement made an hour drive seem like minutes, planning and speculating on what we might find!

Well, what we found wasn’t quite what we had anticipated. As we rounded the last curve to our new claim, we spotted a vehicle parked exactly where we had hung one day before.

Now Bob is a pretty mellow guy, but not too tolerant of people who flagrantly abuse a clear-cut legal issue. He did maintain his composure and approached the party (I followed with a camera). As I snapped photos of them hanging a location certificate over the top of ours, Bob queried them as to what they were doing?

Here’s lesson no. 1 on what not to do while staking a claim… The party proceeded to tell Bob they had prepared a claim certificate and driven to the Billings BLM (Bureau of Land Management) office to file the claim. They had been turned away at BLM, being informed they had to find discovery, post a location certificate on the property and file at the county level before filing at BLM. The sequence of events is critical: find discovery, post location certificate, file at county, file at BLM.

They knew the process now, but didn’t seem to notice that there was already a location certificate on the property!  Lesson no. 2: Always look for location certificates, affidavit of assessment or any indication that a claim is staked!

The day wasn’t entirely ruined, but it was a little disappointing to find claim jumpers rather than gold!

The story doesn’t end here… there’s not a happily ever after to this story, just a year-by-year challenge!

We ran into this same party several weeks later when they approached us to say they had “bought into” an adjacent claim and they were putting in boundary posts. Bob asked to see their claim map because they seemed to be confused about the boundaries. He noticed that the claim had been re-located and asked why? He was informed that BLM had said they needed the location certificate amended and misconstrued that as needing re-location. The party was upset, frustrated when given a fly-over of our claim boundaries to show exactly how it laid, and stated he would assign his own MMC (mining mineral claim) number and didn’t want to deal with BLM! He proceeded to put in posts (PVC at that, you might know how we feel about (PVC!) at least 100 feet within our claim boundaries.

Now lesson #3 on what constitutes amendment of a claim and what constitutes re-location… I took this information directly from the BLM website so I didn’t misrepresent the issue:
AMENDMENTS/RELOCATIONS:
“An amendment to a location for an active mining claim or site can be made at any time and must be filed with the appropriate State Recorder’s Office before filing in the proper BLM State Office within 90 days of recording. It can be made on the same type of form as was used for the original location with “Amended” added to the title of the location notice. An amended location relates back to the original date that the mining claim or site was located. (Info on filing fees left out.)
“Amendments are used to:
1. Correct or clarify omissions or defects in the original location certification;
2. Correct legal descriptions, due to an error made on the original certificate (the location on the ground cannot be changed); and
3. Change the claim name.
“A relocation, on the other hand, is treated as a new original location which essentially covers the same land as a prior mining claim/site. As such, a relocation will be issued a new serial number and date stamp. A processing fee… is required. A relocation does not relate back to the date of any prior location and is adverse to any prior location.
“A relocation may not be established by the use of an ‘amended location notice,’ but requires a new, original notice or certificate as prescribed by state law.
This ‘relocation’ usually occurs when a miner fails to timely file the required annual filings and the claim was on federal land that is open for mineral entry so the miner wants to “re-stake” the same claim.“The major difference between an amendment and a relocation is an amendment cannot take in new acreage, but a relocation can.”

The fact was, since they had re-located the claim, our claim location pre-dated them. We had used the original boundaries of the adjacent claim as our adjoining claim line. Their re-location adjusted boundaries into our existing claim. We pretty much let that go, pointing out the discrepancy. Since that day, an annual replacement of adjacent posts has been necessary because they are moved or removed!

Again through research, we see that this same adjacent claim is not showing up on LR2000 in the township, range and section where it was located. We prepare a location certificate and proceed to the claim to determine if the location has been abandoned. A claim certificate is posted, but the MMC number is not uniform with those found in the Black Hills. We returned home (pre-cell phone days) and called BLM. They did not show a claim by that name or by that claimholders’ name, or MMC # in South Dakota. We assumed that the party had done just as they said, assigned their own MMC #.
We returned to the claim (now this is an hour’s drive to and fro each time) and proceeded to nail up our location certificate. A vehicle screeches to a halt on this dusty gravel road, and a man identifiable to us as the former claimholder proceeds to rant and rave that we have over staked him and we are claim jumping! We removed our location certificate and left, but not before showing him that his claim does not show on the BLM printout that we have.

We returned home, called BLM again! The adjacent claimholder had already called and we got a lecture from BLM about claim jumping, stating they had made an entry error, the MMC # was in Montana, but the claim was valid. We restate: always check your claim with BLM!
So that was a lesson learned… check, double check, then re-check!

This same plaeer claim, located in 2001, was in 2005 blanketed by a mining company with lode claims. Lesson no. 4 -- you cannot locate a lode or placer claim over an existing claim. Mining companies do this… they blanket a section with claims regardless of existing claims. Individuals do this… at least once a year someone tries to overstake our placer claim(s) regardless of what paperwork is hanging, how many signs we post, how much time we spend on the claim(s). If you’re not there 24/7 and you’ve got a good claim, they will come!

This leaves an interesting situation, however. Our 2001 claim is valid. It pre-dates the lode claims. Our adjacent claimholder, however, re-located once again in 2008, which forfeited all his rights to the placer claim because of a lode claim dated 2005.  We don't think he is aware of that, but seriously doubt he would appreciate any input from us!

This is a lot of information. It is also some of the worst-case scenario(s) all encompassed on one individual claim. The lesson(s) learned would be to keep track of your claim, ask the right questions of the right people, and always preserve the integrity of your original claim if possible.

Wednesday, December 15, 2010

Overlooked cache of gold...

Driving through the Iron Creek region of the Northern Black Hills this week, we see claims on every creek, one of which we own.

Family, friends and acquaintances constantly approach us about “where to find gold“. Our Iron Creek claim is an excellent example of both stream and bench gravel containing gold. The stream is intermittent, usually running water only until the drier months of July or August. The lack of water these months would discourage the average prospector.

Throughout the Black Hills, there are huge reserves of un-worked gravel benches. The old-timers often spoke of stranded dry placers in small valleys and ravines. Oftentimes a ditch was dug to divert water to the workings. That practice now requires a lot of paperwork, and the dry placers have all but been forgotten due to lack of water.

How we find them… Dry placer workings are hard to see unless you know what to look for. Indications of old workings would be irregular mounding, not necessarily next to the creek. Some of the high bench deposits are stranded at elevations of 5000-6000 feet, but also exist in low lying valleys. If you know your geology and follow the strike of vein deposits close to lode mines, you almost always find stranded placers in the drainages. Bob has found these stranded bench deposits on the side of Richmond Hill above Squaw Creek while running an exploration dozer. They lay in like snowdrifts of red iron-stained gravels, which he was told are very rich. This is private property within a federal mine site, but just one graphic example of the possibilities.

What do you do with such a claim if you stake it! Basic equipment would demand at least a shovel and 5-gallon bucket to transport material to water, either a creek or home. We have spent many hours recovering gold with a household hose and sluice box! Modern-day technology includes recirc systems (buy or build) that contain water which is re-circulated through the sluice box. This would consist of a sluice box, marine pump, a 20-30 gallon rubber tub and a power source. Water would have to be hauled to the location or again, you can use a household garden hose and haul the material home!

Just a reminder, any mechanized mining in South Dakota requires a permit!

Spiral pans might be another option. They are partially submerged in a tub of water, run by a battery and separate the heavy minerals out of concentrates.

Dry washers are commonly used in desert regions and work best on sandy material, almost nonexistent in the Black Hills. Almost all our placers are clay laden and would not dry wash efficiently.

So if you are thinking of obtaining a claim, don’t overlooked these under-worked gold resources!

Check out our website at http:/www.blackhillsgoldmines.com if you want a claim of your own!  A good weekend on any claim we find for you would pay enough to cover our asking price!

Monday, December 6, 2010

Gravel and clay... what to look for!

Snowbound is what we are… not enough to cause travel problems but enough to keep us from trekking through the woods.  It’s a good time to discuss where and how to look for gold…

The Black Hills gold rush was mostly composed of would-be prospectors (we call them Greenhorns) looking for gold nuggets to be plucked out of the creek!  A small minority of those rushers knew their stuff… and generally were the ones who ended up striking it rich!

We project that 25% of the population wants to be gold prospectors… of that 25%, maybe 1% know what to look for!  Most of the claim jumping on our claims is harmless; they don’t know where or what to look for so they just dig in the creek and probably find enough gold to figure out it is hard work for a few flecks of gold!

Gravel bars are a good prospect.  This is rounded rock that has migrated down the creek through multiple flood events.  The gravel is deposited in layers with each successive season.  Gold is heavy, so it quickly settles through the layers to either bedrock or false bedrock. Gold found while digging a bit in the creek was probably deposited recently and it is doubtful you will find paying quantities.

Here’s where it gets tricky!  You’ve found a gravel deposit… where is the gold?

Clay can be false bedrock and will be either your friend or foe.  Clay bands are easily recognizable in an exposed bank.  They can be false bedrock that keeps the gold from settling to bedrock, but they are also what we like to call “a sluice robber.”  Clay in your sluice box will collect gold and carry it back into the stream. 

We’ve encountered a variety of clays, everything from gritty red clay to slimy yellow smectite. 

There are instances in the Black Hills of yellow clay being high-grade clay containing gold.   Historically documented near the modern day Gilt Edge Mine, is a gold rush era article stating, “recent strike at depth of 32 feet proven to be an immense flat body of rich ore resembling yellow mud.”

All clay should be tested before sluicing to determine gold content.  Why??  We have trouble convincing “greenhorns” that the ore can’t be put in the sluice box and end up having visible gold in the box “disappear” with clay-bound ore. 

So before you sluice suspicious ore, break clay balls and rinse ore extensively while panning.  This helps determine the gold content and whether or not the clay becomes water soluble.  There is a product called Clay Gone that will help break down the clay, or a few drops of environmentally-friendly dish detergent might accomplish the same purpose.  We also “clean” the sluice box before attempting to sluice gold-rich clay-bound material.  That way you haven’t lost acquired gold, but might recover gold from the clay.

The Bear Gulch area is said to have a clay band within inches or feet of bedrock.  Between the clay and bedrock the gravel is said to be extremely rich in placer gold.  It would be assumed that the gold was laid down in gravel, some sedimentary event covered it, and eventually decomposed into a clay.  Through the eons other gravel was deposited upon the clay, creating false bedrock.

We’ve also found, at another location nearby, a gold-rich iron-stained band above a grayish-silver clay, the clay band from 6 inches to 3 feet deep.  The clay looks like a decomposed bedrock.  We’ve never found what is below the clay band because penetration of the clay brings in water.

In another region quite geographically distant, gold tends to be concentrated closer to the surface.  Some bands are completely barren of gold and others are low-grade.  We’ve found gray clay, more than likely decomposed porphrey, which seems to carry a lot of nice flour and small nuggets.  If  bedrock can be reached, very nice pockets of nuggets exist in a red clay zone which is blackish-red sand carrying small, rounded hematite nodules in abundance.

Clay, therefore, is your friend because it may help collect gold to a specific layer.  It is your foe because it absorbs and carries the gold you are trying to recover!

We can’t emphasize strongly enough… look for clay bands to test, but don’t run clays through your sluice box if it already carries gold!