Properties of punch plate (or Jarvine Riffle) for improving gold capture

[PickaxeCA]

There are plenty of people (Doc from Gold Hog, Vo Gus, etc) who claim that the majority of their gold is caught in the pooling area where water falls into the top end of a highbanker. I have heard some claims of 80-90%+ being caught up there.

With this in mind, what are all the magical properties of a *small section* of punch plate over miner's moss (backed, or unbacked with V matting underneath) that cause such strong gold capture in the area with falling flow?

Here are my thoughts:

1. Friction - coarse gold gets snared in the moss (this is obvious)
2. Additional classification (also obvious)
3. Downward hydraulic pressure - 'pins' gold to the bottom, forcing it to burrow down even further.
4. One way ticket - once gold has sunk under the punch plate, the non-perforated parts (solid sheet) is a vertical barrier. Plus, water falling through holes will not let the gold rise upward again.
5. Diffuses flow - spreads out water, creates a more even flow, reduces surging, reduces turbulence and lifting force
6. Reduces material speed (slows down the gold)
7. Breaks surface tension - gold cannot rise up to ride on the surface tension
8. Creates a fluid bed (elutriation / gravity column) - if a reverse ramp riffle is used on the downstream end

----

What are your thoughts on punch plate or a diffuser at the top of a highbanker or sluice, and its impact on capture rates?

Are there any magical gold-catching properties that I have missed?

Let's talk about all the uses for punch plate when it comes to sluicing / highbanking.

Note - I'm sure many of you have heard about the Jarvie / Jarvine riffle (punch plate folded like an accordion). I wonder if it has unique properties that make it more effective than normal punch plate for capturing gold.

Watch this video on the Dream Mat channel if you haven't seen this technology before (not my channel, no affiliation):
Jarvine Riffle by AIGP & Dream Mat: https://www.youtube.com/watch?v=XKy7tODBf1I

[Joe S (AK)]

All your 8 points seem solid there.

I suspect that all the classified material drops down and the punch plate slows the water flow just enough that the lighter material is slowly washed out from under the plate but that the Gold (possibly even Platinum and maybe even Lead) have just too much heaviness to them to wash along and they give up movement under there, effectively stopped by the moss.

In experimenting with Gold Hog products I have intentionally removed the punch plate and even the moss and initially ran the entire bank run over the then barren plate (OK, you could now sort of call it a 'Slick Plate') and it seemed that the rubber mats/riffles in the main part of the recovery bed still recovered most, if not all, the Gold from the gravel traveling over them. As we all know, certain sizes and shapes of Gold particles are more efficiently captured in uniquely formed "catchment zones" in our equipment where even slight changes in water flow and Gold sizes/shape/weight all combine to be often found in consistent catchers.

The Reverse Riffle does seem to be acting as a nugget trap for not only the larger sizes of Gold but also some of the fines and that dead zone under the material grabs certain shapes of that Gold while other Gold and the lights continue onward to the riffles.

Good observations there!

Joe

[PickaxeCA]

@Joe - with something as simple as some miner's moss +/- punch plate +/- Jarvie Riffle, there is a lot going on in terms of physics and hydrodynamics that aid in gold capture. I like the analogy of a 3D gauntlet that once gold enters it cannot escape.

Slowing the water 'just enough' seems to be a common theme in capturing as much fine gold as possible (but not slowing down so much as to affect production speed).

I'm always in interested in learning more about increasing fine gold capture with *high flow and feed rates* (slow feed/flow is much easier, and is much more foolproof).

[Joe S (AK)]

Doc, over at Gold Hog, had a few tutorial videos addressing fine tuning a box with mats to maximize recovering many different Gold sizes all the way down to fly poop. Slowing and / or flattening the water and sluice, it turns out, isn't as critical as controlling by pitch the water speed over certain shapes and combinations of mats.

We all started out hearing the mantra "to get the small Gold go flat, long and slow" from the old guys (who had heard that from the really, really, really old guys) but it turns out that unless you want to catch ALL the black sand for some convoluted reason that goal is just chasing a fool's mission.

It turns out a better system is to just start with a WAY too steep box (blowing everything out) and then incrementally dropping the head of the box until you capture all the Gold as well as just some of the heavies. Everything lighter just goes through with the aggressive water flow and marches to the sea. Of course, other things such as particle size ("The Rule of Four") has to be addressed. By washing lighter material through the box and only retaining some of the black sands, all the targeted Gold and Platinum stays behind in the mats.

Joe

[Geowizard]

Those "Old guys";

"We all started out hearing the mantra "to get the small Gold go flat, long and slow" from the old guys (who had heard that from the really, really, really old guys) but it turns out that unless you want to catch ALL the black sand for some convoluted reason that goal is just chasing a fool's mission."

I offer homage to those that precede us.

Most, if not all of what we know and understand about capture and concentration of fine gold today is based on the body of knowledge that precedes us. I read all about how much smarter we are today than those "old guys" without any tangible measure to support the claims. We don't know what their input "heads" were. We have a sense of what the tails were because we have the ignominious distinction of sifting through their left-over scraps!

All of the modern marvels are NOT getting more GOLD. We know this because there is no side-by-side comparison offered between the "old guys" method and the latest Gold HOG, Gold Cube or any other that proves it. I can offer a guess why.

Be smart. Do a side-by-side comparison. Measure the input. Measure the output. Real-time. No camera cuts.

Otherwise it's a fussy, unsubstantiated debate over the old guys and the smarter new guys with NO basis in fact.

- Geowizard

[Geowizard]

Punch plate is a screen;

I used punch plate the same as our forefathers did. Not as a "prop" not as a "gimmick" but as a tool.

My story - All that was left after the miners left Ophir was the "twenty minus". All that was left after I left was sub-micron!

The previous mining that took place over the course of 50 years at Ophir involved mining with conventional dozer-sluice-dragline methods. I personally got to touch and feel the sluice box. I got to touch and feel the Hungarian riffles. I got to touch and feel the punch plate. The punch plate was on 1" stand-offs to elevate it. the bottom half was 2" Hungarian to catch nuggets.

The punch plate was used to provide an over-under level of screening. The "over" sized rocks and gravels passed over a more quiet, laminar flow, lower level. I ran 1/4" punch plate down the first half of the 3 ft x 16 ft box. I ran expanded over Astro-turf over the bottom half. I captured micron GOLD too small to recover by any known gravity means that remained in the tails after cleaning the cons. I have "buckets" of cons rejects with ounces of microscopic, visible, micron gold!

I had a "Rock Shop" at Ophir and a Binocular Bosch and Lomb adjustable 7-32X microscope.

I used a microscopic scale called a "Stage Micrometer". It looks like a specimen slide used on a medical microscope. It's an A36CALM1 X ruler 1mm/100 Div x0.01mm P/N106011 Stage Micrometer. The scale has an "electron sputtered" silver line 1 mm long with 100 divisions. You can only see the divisions with a microscope.

Wanna talk about fine GOLD?

- Geowizard

[Geowizard]

Those "NEW" Guys!

In the comments from the video... "Blows my mind!"

As an "old guy", I have years and years of experience watching advertising and marketing of "NEW" gadgets that come into the market. Claims are made and rarely demonstrated.

The claim is "MORE GOLD is the only focus".

In the subtitle:

"Jarvine Riffle is the next best thing for your dredge or high banker. Results rule, MORE GOLD is the only focus. From Old to NEW is the journey of advancing technology. The train is leaving the station, All Aboard!"

The video shows sizes and orientations of the Jarvine Riffles. Is there something missing?

We still have time before the season opens up in Alaska. Someone, please grab some of this and do a video!

- Geowizard

[PickaxeCA]

Yes, I would be interested in seeing more testing, where all tailings are caught and panned. As you say, it would need to be a single camera take.

There aren't enough economic incentives for objective third party testing of any matting, overlay or gold capture system. It's also pretty tough to make it truly scientific.

[Geowizard]

Science or marketing;

The question of product testing comes down to the objective. Is the testing done for science or marketing?

If a product offers a new, higher function that serves a special purpose or application, then testing serves the virtue of helping mankind. We need more of that!

The lesser testing as we commonly see without controls or standards for the marketing of a new gimmick only supports the trickery of selling snake oil to an unwary public.

- Geowizard

[chickenminer]

There aren't enough economic incentives for objective third party testing of any matting, overlay or gold capture system. It's also pretty tough to make it truly scientific.

Actually there is, on the commercial side. The Poling/Hamilton and the Clarkson studies are about as scientific as we have had. With the radiotracer use for tracking the traveling of gold particles down various systems in actual real time conditions comes about as close as we'll get.