Monday, March 9, 2015

All About Shaker Tables (Conclusion)

 (A basic rectangular shaker table.)

Shaker tables are to gold concentrates what bees are to honey. They go hand-in-hand. Any miner worth his or her salt who has an ongoing need for processing large amounts of concentrates knows what I'm talking about here and is probably using a shaker table to rattle the last bit of gold out of those black sands.

In my previous post on shaker tables, I gave you the basic rundown on what shakers are and how they're configured. In this post I'm going to provide you with the operating specifications for a couple of shaker table models, all manufactured and sold by the Holman-Wilfey Company. Holman-Wilfey is a concern based in the United Kingdom (UK) and their wet table concentrators are in use throughout the world, including the United States, Australia, Canada, South America, Asia, and Africa. That's a pretty good chunk of the world folks, so I suspect Homan-Wilfey shaker tables are pretty damn good.

Holman 8000

Of the three Holman-Wilfey shakers I'm covering here, the Holman 8000 has the largest concentrate capacity and is used mostly in small-scale or commercial mining and precious metal recovery operations. This model is driven using a head motion with stroke adjustment between 8 millimeters (mm) and 16 mm (nominal). The head or shaking motion is self-lubricating and is pretty simple in its engineering design so it's easy to use and requires little maintenance over the long haul. The motor for the 8000 is a fitted 1.5 kilowatt (kW) IP56 electric job.

(Here's a simple graphic of the Holman 8000.)

The 8000's deck shakes diagonally along its entire length and is supported by 42 separate carriers. Construction of the Holman 8000 is wood covered by rubber that's 5 mm in thickness. The decks only come in white and black which I find a bit surprising. I can see the potential for black sands to show up well on a white background but not so much on a black background...duh. Gold will show up OK on black or white, but dark green is (in my humble view) the very best color background for spotting gold. Wouldn't hurt Holman-Wilfey to give that a try methinks. That said however, if the shaker unit works properly in terms of gravity separation, then the background color is a moot point, don't you think?

Various riffle patterns can be employed on the Holman 8000, which is true of most manufactured shaker tables, UK-made or otherwise. The table itself can be tilted and easily adjusted using a small hand wheel even when the machine is doing its thing and shaking away like crazy. Well maybe not crazy but you get the idea methinks. The entire unit is mounted on either steel base mountings or, get this...a solid concrete plinth. Huh? Not likely to use haul that puppy around quickly and easily, so I'd settle on the galvanized steel brace mount.

Wilfey 7000

The Wilfey 7000 shaker table has many of the same specs as the Holman 8000. The differences are the motor, which is a 2.2 kW affair and the motion (shaking) stroke adjustment includes 18 mm and 36 mm settings. Other than these points the Wilfey shaker table is pretty much the same as its Holman counterpart. The 7000 is most often found in larger placer mining operations and industrial recovery environments.

(A Wilfey 7000 shaker table set up to recover precious metal from industrial and manufacturing operations.)

Unless you're a crew member on one of those TV reality gold shows, a full-on commercial placer miner, or the boss of a larger mining concern you probably aren't going to need a Holman 8000 or a Wilfey 7000 or anything close to those two shaker tables. Even in my best days as a small-scale placer miner (dredging included) I don't think I ever generated enough gold-bearing concentrates to validate my acquisition of one of these large wet tables.

Laboratory Shaker Tables

Laboratory shaker tables are small, portable variants of larger tables like the Holman 8000 and the Wilfey 7000. These sorts of shakers are typically found in lab-type situations where sample testing of gold-bearing concentrates is taking place. Commercial mining operators (the smart ones, anyway) will drill samples BEFORE buying and running all sorts of expensive gear and then process those sample concentrates via a lab shaker to get a drift on how much gold per yard can be expected once mining operations are given the go ahead.

 (Here's an example of a laboratory sized shaker table. Courtesy GSI Inc.)

Contrast this professional approach to some of what you've seen on those TV gold reality shows and you'll get an idea as to why I still maintain that I could take certain individuals from those shows, give them a shovel and a gold pan, plop their asses in any given gold-bearing dry wash or running stream and they wouldn't be able to find a speck o' color. Not one single grain. What's that you say? Oh sure, seat them behind the controls of a D-8, a rock truck, a massive wash plant all safe and secure on good Yukon gold ground and they'll find plenty. Therein, brothers and sisters, lies the difference between real small-scale miners, wannabes, and commercial miners.

Don't Make Me Go Postal!

While I'm on this rant track, here's one more thing that burns my aging ass about the most popular gold reality show on TV. It's ALL ABOUT MACHINERY! Machinery breakdowns, machinery operation, driving machinery, fixing machinery, lusting over machinery, plopping down enormous sums of cash for machinery, and on and on and on. Yes, I know machinery is important to commercial mining operations. But here's the deal. I'm a small-scale gold miner tried and true. Always was and always will be. When I watch a show about gold mining or prospecting, I WANT TO SEE GOLD BEING FOUND AND RECOVERED THE OLD FASHIONED WAY! I don't want to watch 60 minutes of TV boneheads obsessing over machinery. If I got my rocks off watching heavy machinery there are plenty of construction sites around here I can go to, so don't make me go postal on your idiotic, overblown, melodramatic TV asses!

(Enough with the heavy machinery already!)

OK, back to the task at hand. Interestingly enough, brand-new shaker tables like those described in this post aren't all that expensive. I've seen highs range from $10,000.00 (USD) for large industrial models down to $1,500.00 for used ones. I imagine a decent laboratory version shaker could be had for somewhere around $500.00 or less. But please don't quote my price quotes here! I've never purchased a shaker table nor am I an expert on their pricing. So do your homework before buying one if that's the direction you're headed with your small-scale mining activities.

Peace to one all!

(c) Jim Rocha (J.R.) 2015

Questions? E-mail me at jr872vt90@yahoo.com

2 comments:

  1. Hello Jim, I wondered what happened to part 2 of this. There wasn't anything there before....damn computers I'll guess!
    I hadn't thought about those TV gold shows before. You are right, it is mostly about machinery, very little about the actual gold. More than that, it is about fighting among themselves and other problems. Entertainment I suppose....
    Now there is the new one "Legend of the Superstition Mountains" about the Lost Dutchman mine. So far, it's a pretty stupid show. I've been watching it hoping it might get better, but not so far. I was surprised to see a guy I know as the "geologist expert" on it. Not impressed.....

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  2. Hey, one more thing, CONGRATS NORCAL RON!!!! Still looking for it's sister here......

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