Help with RP-4 table

[goldandbill]

I recently purchased an RP-4 shaker table. I prospect ocean beach gold from SW Oregon. Usually I screen it dry thru a 40 mesh screen using a small 110 V vibrating motor. I tried running this thru the RP-4 with poor results as the fine gold tends to mostly run under the black sand.I did try removing the magnetite, which did help some, but the process is too time consuming. Currently I am working on a 4X4X4 crib full of black sands. It is rich material. I am hoping some one with RP-4 experience can provide me with some tips on setting up my table. I would prefer to run the material right from the crib, with some screening. If not I will probably have to run it thru my home sluice, then thru the table.
When I run the table I have NOT used the water flow at the input site as I seem to need it more on the table to flush the sands away. Otherwise I have tinkered with the front to back slope with very limited success. The retailer suggested I screen it down further. Well I tried this also, but the material will hardly move thru a70 mesh, and takes forever thru a 90 mesh. I can't imagine trying to get it thru anything smaller, at least not with my current screens and methods.
Any helpful ideas are welcome.

 

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[jair]

I think you will need to screen several sizes,
Screen under water and make several different batches,
Run each size through the table ,
Yes time consuming .
That's wear I bought the gold cube .
But still have to pan it .

I made a rock crusher and needed a way to separate the gold from 200 mesh after crushing ,
I researched the RP-4 and had the company make a really good offer on the table for me but I'm am very happy with the cube . And it's very fast and efficient . Best thing I have found so far.

 

[mu50stang]

I had an Rp4 and a gold cube. I kept the cube and ditched the Rp4. Some tips are to make sure you have it bolted down to a solid concrete floor so there is no vibration. Feed the cons directly on to the separator screen. Make sure to use a feeder as you need a steady flow of material to keep your gold line steady.

 

[galenrog]

The RP-4 is a wonderful tool for both making concentrates and separating concentrates, if done correctly. The Gold Cube is probably the best small concentrator for the small scale placer miner. Both have advantages, as well as disadvantages, compared to other equipment and one another. I will not go into comparisons on this thread as that is not the primary question of the OP.

The problem being encountered, if I interpret properly, are separation of gold from screened beach sands using the RP-4. Without more information, the following is based on a few assumptions on my part. First I am assuming that the RP-4 is properly mounted on a solid concrete base. Most shaker tables, when improperly installed will develope both harmonic and erratic vibrations that impair operation of the table.

My second assumption is that you are only running 40 minus. This can give you a distinct disadvantage if you expect to separate the beach fines on only one or two passes over the table. Screening to several size ranges will aid recovery immensely.

The major problem seems to be heavy magnetic sands. The RP-4 is made with magnets installed to reduce loading problems caused by magnetic sands. If the quantity of these sands is overwhelming, separation of the magnetics prior to running over the table is essential. There are solutions, but many are not cheap. For the small scale, I have seen, but not used, a few smaller separators that could help out a lot. Action Mining (actionmining.com) and Tolle Enterprises (americangoldminer.com), both in Sandy, Oregon, make magnetic separators that may save you a lot of time and trouble. You can get demos with your own material at both shops.

If if you have your table set up properly for each run, and screen to several sizes, I believe your problem can be overcome with no additional equipment. There are several people between Bandon and Brookings that process beach sands. Some have the same model table as you. Find them. Find out who is successful. Learn from them.

 

[goldandbill]

Thanks to all for the feedback. A couple of points:
-the table is bolted to a poured concrete floor and I use buckets of sand to hang off the lower portion to further reduce vibration.
- I use bucket screens, but way too much time and energy for as much material as I have; -40 mesh will handle the material dry, -50 and smaller I do have to go to a wet set up, which is even more time consuming
-I use a modified A-52 sluice, but wouldn't that be like using a gold cube? I don't want to spend more $ as I haven't got the RP-4 to work yet.
Thanks again.

 

[galenrog]

Is the stand firmly anchored in concrete, as recommended by the manufacturer? If not, your table may have the harmonic and erratic vibrations I mentioned earlier. The addition of the sandbags tell me that, at a minimum, the stand is not installed properly. It should be immobile. The addition on sandbags will NOT stop unwanted vibrations and will likely lessen the wanted shaking action.

The stand MUST be level prior to installing the table. Both front to back and side to side. Once the table is installed there is one adjustment for angle of the table. It may take dozens of adjustments to get the angle right for your material. Once you have the table dialed in for a particular size range, use this as a
baseline and make all other adjustments from this.

it may take a month of Sunday's to get it dialed in initially, but once you do, everything will work smoothly.

This is the best I can do off the top of my head. I have not done any beach mining since a
stroke a few years ago, and may have left a few things out.

 

[Reed Lukens]

When I run the table I have NOT used the water flow at the input site as I seem to need it more on the table to flush the sands away.

You need to be able to run the feed water because it puts the heavies in the top corner and that's how it's designed, this is the beginning of the process and it is a slow process. It sounds like it's running to fast if you have water problems and it might not be level. Depending on how it was mounted, put a level on the base and add shims to the floor to level it. If there is a slope on your floor then this is the problem. All of the clean gold should ride down the top edge and into the collector. If it seems like you need more water then it's probably tilted forward to much Start it at a point where the heavies are hardly moving and then adjust it from there if needed. You're going to have to run it a few times at different settings to get everything anyway and honestly you should screen to at least 50 mesh, 80 to 100 would be better additions. You need at least a ball or rod mill to begin with to crush everything down to a consistent running size.

Your A52 has nothing on the gold cube. You should be able to take the cons from a cube and come out with clean gold after the RP4 but crushing and screening is and always has been the key.

 

[bakergeol]

I recently purchased an RP-4 shaker table. I prospect ocean beach gold from SW Oregon. Usually I screen it dry thru a 40 mesh screen using a small 110 V vibrating motor. I tried running this thru the RP-4 with poor results as the fine gold tends to mostly run under the black sand.I did try removing the magnetite, which did help some, but the process is too time consuming. Currently I am working on a 4X4X4 crib full of black sands. It is rich material. I am hoping some one with RP-4 experience can provide me with some tips on setting up my table. I would prefer to run the material right from the crib, with some screening. If not I will probably have to run it thru my home sluice, then thru the table.
When I run the table I have NOT used the water flow at the input site as I seem to need it more on the table to flush the sands away. Otherwise I have tinkered with the front to back slope with very limited success. The retailer suggested I screen it down further. Well I tried this also, but the material will hardly move thru a70 mesh, and takes forever thru a 90 mesh. I can't imagine trying to get it thru anything smaller, at least not with my current screens and methods.
Any helpful ideas are welcome.

I used to own an equivalent RP4 table. The big problem is running only minor amounts of gold and you do not get a clean con.
It is after all a displacement table. The gold displaces the black sand and when you have little gold you mainly end up with mostly black sand.
It was far more effective for ultra fine gold than the cube. In addition a lot of the fine gold ends up in the middlings.
This is why I sold my RP4 table and now only use wave tables which are far more effective for ultra fine gold.

Here is a discussion by GollyMcscience about the RP4 and fine gold.

" lot depends on the nature of the gold. A shaker table works well for continuous feed of relatively high volumes. Since most riffle designs rely on heavies filling the riffles and displacing the lighter stuff it is important that you have enough gold in the material to displace the rest of the heavies or your final con will not be as clean. Generally the way to deal with that is to run the first time and reserve the high grade. The middling is set aside and added to the next run to be upgraded. Each con is collected until the con volume can justify a run on the table and then you rerun the con all by itself with the hope/expectation that there is enough gold to get the displacement system perking. The mids from this run are added back to the mids barrel to be added to the next bulk run and around and around you go. You might still have to run your final high grade on a miller to get the last black sand out.
I find a well run shaker table can handle down to 180 mesh from a minus 30 split. If running meaningful amounts of minus 150 though its better to do a minus 30 to 80 or 100 and then a minus split run by intself just because the water and table motion are harder to fine tune if that wide a range of gold is on the table constantly.
The wave table produces a line of gold that needs to be sucked off the table but it has the advantage that it does not require gold to displace the other minerals. What gold there is will work its way to the top line and stay there. There will still be a middling line so quite often I will suck just the cleanest part of the line leaving the less concentrated section to just perk away as I add more material letting the gold line build up once again. If dealing with a lot of gold in the minus 150 range the wave table makes a good clean con if you are patient enough to wait for it to form a good line.
The regular shaker table has a real hard time running samples of only a couple of 5 gallon pails because the system has to get established and it is constant clearing stuff off the table to let new stuff on. The wave table can run smaller samples because the material is held in suspension on the table with only the lightest stuff actually moving down and off while the retained bed just keeps sorting whatever material it is holding in the wave bed at the upper end of the table. Thus a relatively small sample can be run because the sample might barely fill the retained bed but if you wait the gold will work its way out to the line at the very top edge."

George

 

[goldandbill]

I used to own an equivalent RP4 table. The big problem is running only minor amounts of gold and you do not get a clean con.
It is after all a displacement table. The gold displaces the black sand and when you have little gold you mainly end up with mostly black sand.
It was far more effective for ultra fine gold than the cube. In addition a lot of the fine gold ends up in the middlings.
This is why I sold my RP4 table and now only use wave tables which are far more effective for ultra fine gold.

Here is a discussion by GollyMcscience about the RP4 and fine gold.

" lot depends on the nature of the gold. A shaker table works well for continuous feed of relatively high volumes. Since most riffle designs rely on heavies filling the riffles and displacing the lighter stuff it is important that you have enough gold in the material to displace the rest of the heavies or your final con will not be as clean. Generally the way to deal with that is to run the first time and reserve the high grade. The middling is set aside and added to the next run to be upgraded. Each con is collected until the con volume can justify a run on the table and then you rerun the con all by itself with the hope/expectation that there is enough gold to get the displacement system perking. The mids from this run are added back to the mids barrel to be added to the next bulk run and around and around you go. You might still have to run your final high grade on a miller to get the last black sand out.
I find a well run shaker table can handle down to 180 mesh from a minus 30 split. If running meaningful amounts of minus 150 though its better to do a minus 30 to 80 or 100 and then a minus split run by intself just because the water and table motion are harder to fine tune if that wide a range of gold is on the table constantly.
The wave table produces a line of gold that needs to be sucked off the table but it has the advantage that it does not require gold to displace the other minerals. What gold there is will work its way to the top line and stay there. There will still be a middling line so quite often I will suck just the cleanest part of the line leaving the less concentrated section to just perk away as I add more material letting the gold line build up once again. If dealing with a lot of gold in the minus 150 range the wave table makes a good clean con if you are patient enough to wait for it to form a good line.
The regular shaker table has a real hard time running samples of only a couple of 5 gallon pails because the system has to get established and it is constant clearing stuff off the table to let new stuff on. The wave table can run smaller samples because the material is held in suspension on the table with only the lightest stuff actually moving down and off while the retained bed just keeps sorting whatever material it is holding in the wave bed at the upper end of the table. Thus a relatively small sample can be run because the sample might barely fill the retained bed but if you wait the gold will work its way out to the line at the very top edge."

George

George, you and others, make some really good points. I did level the table after I bolted it to the concrete floor.The sand is in buckets and is suspended from the lower portion of the table, not in bags. I plan to double check the table, maybe start over on the leveling, just to be sure.
As you noted, the fines are small and not frequent or rich enough to run a solid line. As a result I can see much small fines running under the black sand.The larger ones do run high into the #1 port. So then much is in the # 2 port. This is really frustrating as I then have to re-run # 2 etc. to get it down to anything close to real concentrates. I also took some concentrated material from a previous operation and ran it thru, it did a better job of holding the gold in line for the # 1 port.Due, I guess, to the amount of gold, as you and others have noted it would.
I wish I had a wave table to compare the one table to the other.
At this time I think I'll run my raw material thru my sluice set-up and then thru the RP-4. It is too much volume to run all thru the table first.My sluice is an A-52,the header or slick plate has shallow matting, the lower portion is lined with green felt, then Gold Hog matting, this then dumps into a shorter sluice, which has the lining and regular V matting, but is set with less slope.I clean it out frequently. I don't know how this would compare to a Gold Cube.The guys I know who run material at the beach had a Gold Cube, they sold it and went to Gold Hog matting in combined sluices.They say they get better retention.
I do know that much of this material is what would be known as micron gold, as it will easily drop thru a - 90 screen.It looks like orange sand when concentrated.But, there is lot of, of course it takes a lot to make up any volume. Every now and then I will find some flakes that won't go thru a 20 mesh screen.
Thanks again for all who have responded. It all helps me to better understand what is going on.
George, do you know anyone with a second hand wave table??

 

[bakergeol]

Hi
Wave tables are very expensive. I believe Action Mining's M5 table (smallest table) is about 4K. Used
M-5 tables are rare on the market.
You want to look at my thread- My 25lb wave table.
http://www.treasurenet.com/forums/gold-prospecting/439070-my-25lb-wave-table.html
Plans for building this small wave table and parts list are in the thread. Just click on the thumbnail icon.
Parts cost was about $400- This was a bit high as I used AL instead of ABS plastic.
Actually building a small wave table is easier than attempting to build a small displacement
shaker table.

George

 

[hgeiger]

I live in California just south of brookings I also have a RP4 and I find it works best for beach sand if ran almost flat. Hit me up on here I will help you out as much as possible