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Peter Freedman

2 Inch Pump Needed For Re-Circ Setup: Trash Or Semi Trash?

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Hi All, 

 

I know there are other posts on the subject of pumps however, I cannot not find the info I need. 

 

I am looking to purchase a 2 inch pump for my mining project, planning on using 2x 300 Gallon horse troughs in series. The first trough used to settle and the second one to supply the pump. 

 

1) Will a semi trash pump work? or do I need a full trash pump?

 

2) Is there a brand people recommend?

 

Many thanks in advance. 

 

-Peter

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As long as you have a foot valve or screen on the intake too filter out any large trash a semi-trash pump will work fine, a full trash pump can take solids through the pump, e.g. heavy mud, small rocks, grass clumps, etc.,  a semi-trash pump can take small particles but nothing big.

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It is pretty hard to beat Honda engines on smaller pumps.

Now the problem is 2" pumps have a free-flow rate of 150-200gpm.

Free-flow defined as straight out the outlet; no hose, no nozzle, just water spaying out the outlet.

With some restrictions on the outlet, this flow rate might be about 80-100gpm.

2 X 300 gallon stock tanks don't provide much for settling time.

You actually only have 1 tank for settling as the pump strainer is underwater in the second tank.

Next, you need to consider water losses in a system with less than 600 gallon capacity.

This means make-up water will be required and probably on a daily basis.

rabbit46 brought up a real valid problem: clean-out.

Clean-out of tails is not washing gold. Ergo you want to make clean-out quick and easy.

Dumping isn't practical for a couple reasons. You need to haul the tails away and potential damage to the tanks.

What will work is pumping it out. Semi-trash pumps have no problem with slurried mud.

This requires more water for clean-out and then more for refilling the stock tanks.

One oft overlooked resource is a big hole in the ground lined with heavy plastic. Yep, an artificial pond. Make it long and somewhat narrower to provide plenty of length to increase settling time.

In hotter climate zones, covering the tanks with a tarp help will reduce losses to evaporation.

Just some thoughts. Hope some of it helps with your decision making process.

Water limitations sure make things even more difficult.

eric

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Eric, I have been thinking about the liner in a pond.  But how to clean out the muck from the liner.  Or, dump into a catch tub 1st then into the pond.  Still will have some muck to clean out later.  I'm using two larger tubs now as Peter stated.  and catching into a smaller clean out tub directly below the end of the sluice, that I clean out when it is full.  Still we get a layer of muck to clean out in the last tub.     

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That was the reasoning behind making the pond long and narrow enough to muck out from the sides with a plastic grain shovel. Plus you don't need to muck it out spotless.

If you intend to move it to another location, muck it out like normal and then let it dry for a couple days. Instead of mud, you'll deal with clods.

eric

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I have been thinking about this issue a lot. My claim, although it contains a stream, has waned so badly during this drought, that the flow is down to percolation. If I want to wash gravel, at least for the forseeable future, I will either need to either sink a well of some type, or create a recirc system. I conducted a pretty exhaustive online search for recirc systems and found out that a lot of peole have made them with varying results. I have decided that there are a number of varying factors when choosing how to design a system:

 

1. Amount and type of pay that you are going to wash in a given period of time. How many yards per hour or per day? What material particle size will classified down to before washing? Soil properties: clay, pebble, etc. (affects settling time and frequency of clean-outs).

2. Number of people participating in processing the pay.

3. How to get enough water to the processing site, and how to keep it there (the water loss inherent in your system design that is mentioned by others above).

4. What size pump to use.

5. What type of filters to use between settling ponds and my pump, if any.

6. How many settling ponds or containers and what types?

 

Bear in mind please that I am a real NOOB when it comes to placer mining. These thoughts, above, are all things I have learned by reading. I have not actually designed or tried out a recirc system...yet. That part comes this Spring and Summer. I have used large plastic garbage cans filled with water at home on my 2.5" Highbanker as initial trial. That didn't work. 

 

SUMMARY:

 

I just need to find out what else doesn't work, and I will be on my way. Heh.

 

Onward through the fog.

:)

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I've got a fair amount of experience with recirculating. We first classify the material to -1/2" then we use a sluice screen at the end of the highbanker sluice that prevents anything larger than 60 mesh from entering the supply tank which is 70 gal. The supply water is pulled from the tank and ran through a vortex tank which forces the heavy small material (-60 mesh) down into another holding tank of 28 gal. The vortex draws cleaner water up from the middle of the vortex while the grit is spinning around the sides of the vortex. I use a Honda WX15 1.5" pump to run the system. It is not a trash pump and does not like grit running through it. The trade off is a stronger pump that is much smaller than a trash pump. You just need to filter the water (and learn how to replace the bearing seal...) The real issue is the fine clays that will eventually build up and render the supply water useless. We started out with a simple system and are now on the 4th generation system and have improved the water life on every generation. Now that I have the vortex tank working I can now proceed to the final filtration using 20-50 micron filters that are valved into and out of the system. When the water gets unusable (hopefully around 100+ buckets of -1/2" material) I can then valve the micron filters into the system and clean up the water. then valve out the micron filters and continue working. The clays need a long time to settle, usually overnight but as soon as they are disturbed they dissipate quickly back into a suspended state. Recirculating is all about extending the water life. When we are in areas with no water all we have is what we bring which is 125 gal + 3-4 5 gal jugs. I attached my most recent video if you are interested. There are many past versions of my systems on my youtube channel RotGrub Mining Clan. Let me know if you have any questions.

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