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Wednesday, October 25, 2017

What Size Classifier Should I Buy?

There's a common misunderstanding about classifiers, and it's to be expected.

Most people pick up a classifier for the first time in the field, and use it to screen out larger gravel before panning or sluicing, and for that job most people will settle on one size that meets twin goals, speed of screening and efficiency of processing the screened material. For me, that size was a number four, or 4 mesh. #4 means four openings in a linear inch, so it's essentially a quarter inch minus the diameter of the wire.

So if your question is, "What size classifier should I take panning?" I have a ready answer for you, but, and this may surprise some people, that's not what they're made for.

Think about the root of the word, "classify," which is just another word for "sort." Classifiers are made for sorting. It just so happens that a #4 is great for sorting between 4+ (includes a lot of waste rock) and 4- (a good size for panning and sluicing), so they're handy in the field.

4 Mesh Classifier

Meanwhile, back at the ranch, you've just picked up a brand new Blue Bowl to process your cons and you automatically think, now what size do I need? Your sluice works great with a #4, so the Blue Bowl must have a magic number too, right?


This is where I break out my golf balls and bowling bowls example. You have a gold nugget the size of a golf ball and a hunk of magnetite the size of a bowling ball, and a big old valve to turn up the water. If you turn the water up high enough to wash away the bowling ball, what happens to the golf ball?

Yep, it washes away.

Gold is only about four times as heavy as your average black sands, so when there's a big enough size disparity, the gold can be lighter. If you had two golf balls, one gold and one iron, the iron would wash away first. That's why we classify.

That Blue Bowl, or any other piece of equipment that relies on gravity to separate the heavier gold particles from the rest of your concentrates, works best when all of the material is the same size, or as close to it as you can get, so we use classifiers to sort the material before we run it.

The common plastic and stainless steel mesh classifiers you find at most prospecting shops generally come in 2, 4, 8, 12, 20, 30, 50, 70, and 100, nines sizes to choose from for a total of ten classifications! That's a lot.

Thankfully, you don't need them all right away, but you do need a few. A selection of smaller sizes will improve your efficiency, say 30, 50, 70 for the Blue Bowl, or 12, 20, 30 for your spiral wheel. Either would give you four classifications to work with. Run each size separate, adjusting in between, and you'll see far better recovery than without.

As for which brand, I like these classifiers (the same pictured above) because they're durable and relatively inexpensive.

Monday, June 20, 2011

Wednesday, October 13, 2010

Gold In Ireland

It's nice to know that just about anywhere you go, there's potential gold to be found.

Read the article: belfasttelegraph.co.uk

Tuesday, October 27, 2009

Kulongoski Calls for Mineral Withdrawal

Release Date: Oct. 15, 2009

Governor calls for greater protections of the Siskiyou Wild Rivers area

(Salem) – In letters to U.S. Secretary of Agriculture Tom Vilsack and U.S. Secretary of the Interior Ken Salazar, Governor Ted Kulongoski today called for greater protections of the Siskiyou Wild Rivers area in southwest Oregon. Specifically, the Governor called for the reinstatement of the withdrawal of mining, first proposed by the Clinton administration in 2001.

“The Siskiyou Wild Rivers area is the most unique and biologically diverse region of our state, and without greater protections, we could lose what makes this area so special,” Governor Kulongoski said. “The first step should be to withdraw mining, and the second should be a wilderness designation – the greatest protection federal law provides.”

In January 2001, the Clinton administration proposed a mining withdrawal for the area. However, the withdrawal was not finalized by the Bush administration. Without the withdrawal, the area is subject to the 1872 federal mining law which does not reflect modern environmental protections or assure adequate royalties to public coffers.

In his letter, Governor Kulongoski also repeated his call for updating of the 1872 law and for permanent protection of the Siskiyou Wild Rivers area by congressional action designating it as a wilderness area. Citing a letter he sent to Oregon’s congressional delegation in 2008, the Governor stressed the significance of the Wild Rivers landscape and ecosystems and his specific concern that a recent ban on dredge mining in California could result in new threats of mining to the Wild Rivers area of Oregon.

The Siskiyou Wild Rivers area is noted for its outstanding scenic and recreational values. It is also nationally recognized for its biological diversity and has been designated an Area of Global Botanical Significance by the World Conservation Union. The area is approximately one million acres in size and spans Bureau of Land Management and national forest lands in Josephine and Curry counties.

In both letters the governor also stated "California recently banned the use of suction dredge mining, the same type of destructive mining that is used in southwest Oregon." Destructive in what way?

Governor Kulongoski,

I believe you have been misinformed, but please feel free to correct me. For the record, would you mind citing any specific study that offers more than a subjective opinion of how dredge mining is "destructive"?

I'll be happy to keep rhetorical commentary about how fish enjoy the food stirred up by dredgers, how dredging improves spawning habitat, how dredgers remove lead and mercury from Oregon waterways, how more sediment is moved during Spring thaws than dredgers could ever hope to move if they all worked 24/7 for life, etc, etc, if you'll do the same.

The fact is, all of the oposition to suction dredge mining is based on little more than opinion and rhetoric, and quite frankly, families like mine whose livelihoods are dependant on the small-scale mining industry would rather those in government got their facts straight before any more knee-jerk policy making, at our expense.

Thank you...

Thursday, June 25, 2009

Digging for Sunstones

I'm pretty jazzed. My brother and I are planning a trip to do some sunstone mining, though we may decide to go dig up some gold instead if we don't get ourselves organized. The pop up trailer has been checked, and the carpenter ants haven't come back so we should be comfortable wherever we end up. Maybe not super plush, queen size air mattress comfy, but comfortable all the same. I still need to put the hitch on my new rig.

Yep, the old van I posted about in my crevicing post from a while back is gone. I bought an Explorer and sold the van to a jug band to haul their amps and equipment to gigs. Yep, a jug band.

What else is new...? Hmm, nothing much. Guess I better get back to work.

Here are some sunstone sites for those curious:

Dust Devil Mining
Spectrum Sunstone Mines

Thursday, April 2, 2009

Metal Detecting Video

This is the sort of find that makes all that digging in the dirt worth it!

Cabin Fever

It's official. Cabin fever has officially set in. My mind is increasingly wrapped up in thoughts of gold, of mountain streams, rocky canyons and tricky descents into the same. At the Salem Gold Show this weekend one of the vendors dropped 7.5 ozt of fine gold on the floor, and while I felt terrible for them and hoped they could recover it all, part of me spied that jagged crack in the concrete floor under the pile of pretty pretty gold and thought about coming back with some crevicing tools.

I know I won't be able to get out much this season, so how best can I maximize the time I do get? Do I stay local and move some serious material with the dredge? Should I take a highbanker down to the claims and work the old camp site? Or should I load up a pack, a small sluice and some basics and head into the wilderness? No chance my wife will let me get away with all three... Or is there...?

I'll just have to do some more detecting close to home to help scratch the itch. Maybe a little silver will help ease the craving for gold. Digging is digging, right? Or should I slip over to the empty lot next door, where Klondike Kate used to live with her stash of Yukon gold?

The mind wanders. There are so many possibilities and so little time in the day. Why isn't retirement at age 45, or even 40? Who says I can't make it happen early? Who says I have to retire to enjoy more leisure time?

For those of you in the same situation, I feel for you, but at least you can stop wondering. It's official. Cabin fever has indeed set in...

Thursday, March 19, 2009

Gold in Oregon

Today I stumbled upon a really cool resource while trying to find information on gold in Starveout Creek in Southern Oregon. It's a detailed index of Southern Oregon's appearances in the Salt Lake Mining Review published from 1899 to 1929. From there I was able to find my way to an online digital archive of the Mining Review and have spent the last couple hours reading up on creek after creek, mining company after mining company. It's fascinating!

The index makes the paper a really handy tool for researching gold locations in Oregon. It gives the year, issue and page numbers of mentions of creeks, mines, miners, etc. The digital archive itself though, is also a fantastic resource for Utah miners and miners in other states as well. I also noticed sections for Nevada and Montana, and I'm sure Idaho, California and many other states were covered as well.

Prospectors and history buffs should really check it out.

Wednesday, February 4, 2009

Japan Sewage Yields More Gold than Top Mines

TOKYO, Jan 30 (Reuters) - Resource-poor Japan just discovered a new source of mineral wealth -- sewage.

A sewage treatment facility in central Japan has recorded a higher gold yield from sludge than can be found at some of the world's best mines. An official in Nagano prefecture, northwest of Tokyo, said the high percentage of gold found at the Suwa facility was probably due to the large number of precision equipment manufacturers in the vicinity that use the yellow metal. The facility recently recorded finding 1,890 grammes of gold per tonne of ash from incinerated sludge.

That is a far higher gold content than Japan's Hishikari Mine, one of the world's top gold mines, owned by Sumitomo Metal Mining Co Ltd (5713.T), which contains 20-40 grammes of the precious metal per tonne of ore.

The prefecture is so far due to receive 5 million yen ($55,810) for the gold, minus expenses.

It expects to earn about 15 million yen for the fiscal year to the end of March from the gold it has retrieved from the ashes of incinerated sludge.

"How much we actually receive will depend on gold prices at the time," the official said.

Some gold industry officials expect prices this year to top the all-time high above $1,030 per ounce set in 2008, on buying by investors worried about the deepening economic downturn. (Reporting by Miho Yoshikawa; Editing by Hugh Lawson)

Friday, January 23, 2009

Gold Prices in 2009

I'm sitting here looking at gold hovering at $896 an ounce after a $40 jump just today. Last year it topped $1000 and now it's poised to pass $900 again. So where will it end up in 2009?

As the economy contiues to vent ballast in a desperate effort to resurface will people start the serious hoarding that tips supply and demand on its head and pushes gold straight through the roof, or will things settle out sooner than the experts predict? My guess is we see it over $1000 again in '09, maybe even around $1100-$1200, but I wouldn't be shocked if it hit $1500 an ounce.

I'm not a speculator, nor do I actively follow the markets, but I have a hunch it's going to go up again. I wasn't too far off with my predictions last January...