Gold Mining sluice box gravel pump.

Hello all. I'm hoping to pick some smart brains for a bit. Anybody have any experience pumping gravel? Long rambling explanation here. I operate a placer gold mine. Similar to what is shown on gold rush just scaled down to a 2 man operation. (Without the big TV $$$...) The best, really the only way to productivity mine my site is to have the wash plant set up on a high pad dumping fine tailings into old mined out pits. That involves hauling pay to the plant. And having to move half of that (coarse rock) around to finish backfilling. I am exploring setting up my wash plant on a excavator chassis and feeding it directly in the pit. Mounting a 50' conveyor for coarse rock. Swiveling the house should fan out the tailings enough to be out of the way. And let me keep it close to the hoe at the face. The catch is trying to get rid of fine tailings. Looking at options. I'd like to dump the sluice boxes into a containment box and pump them out of the pit. Be roughly 1,200 ish gallons of water a minute carrying 40-50 yards of 1/2" minus slurry per hour. Anybody have real world experience around gravel pumps? I'm trying to figure out how to make this problem work. The material coming off the sluices will vary by both the amount of gravel and the water volume itself will likely vary slightly as well. The gravel pump taking it away has to be able to handle the highest flow but yet not run dry enough to cavitate and quit pumping on the flip side. I'm figuring an electric motor and vfd but not sure in the real life how this will work. Any first hand experience?? Right now we spend half the time digging and hauling and the other half the time sluicing. If I can figure this out it would double our production and cut out the hauling completely. So it would be well worth it even if it's a constant fight. Thanks.

No experience with gravel pumps but interested to see if someone on here has input/experience. Would some type of sand screw be helpful? How high of head lift to get the fines/water out of the pit area? I do know that fine tailings build up pretty fast. We just dredge out our settling ponds with an excavator, set aside the wet sand and then use to backfill pits/reclamation later. We usually do progressive reclamation; so as the pit advances upstream we backfill and reclaim as we go. Our small double shaker deck plant is pretty easily moved... I also spend about half the day sluicing with the remainder digging pay, moving coarse tailings, keeping settling ponds clean, fueling/greasing/maintenance....

I've worked with plenty of trash pumps for dewatering coal mine pits. It doesn't take many solids before the slurry is too heavy to pump. The interior of the pump case and the impeller gets pretty sloppy real quick and then the amount of solids reduces the head height that can be pumped. If you are pumping level or down hill it might work. If we had that many solids to move we used conveyors.

BC Placer gold said: No experience with gravel pumps but interested to see if someone on here has input/experience. Would some type of sand screw be helpful? How high of head lift to get the fines/water out of the pit area? I do know that fine tailings build up pretty fast. We just dredge out our settling ponds with an excavator, set aside the wet sand and then use to backfill pits/reclamation later. We usually do progressive reclamation; so as the pit advances upstream we backfill and reclaim as we go. Our small double shaker deck plant is pretty easily moved... I also spend about half the day sluicing with the remainder digging pay, moving coarse tailings, keeping settling ponds clean, fueling/greasing/maintenance.... Click to expand... Good to find another placer miner here! I'm in the Yukon mining a relatively large, lowish grade fan deposit at the base of a canyon. Overburden ranges from hardly anything nearest the creek to 16' of clay the furthest out. South facing so only a couple feet of permafrost on top. Just below the organics is a coarse rock layer 6-12 feet that is my main pay. Below that is a dogs breakfast of sand and pea gravel with various thin seams of coarser rock/clay. I've gone down 40+ feet chasing clay layers but it's spotty. Bedrock is well over a hundred feet and unreachable. I'd love to run a floating wash plant like the Kiwi's do. I don't think you could beat the efficiency with a 2 man operation. Problem is I can't hold a pond with all the sand under me. My tailings ponds will drain to ground until they get silted off and filled with fine tailings. The idea of putting the wash plant on an excavator chassis would be to basically emulate a floating wash plant but on dry ground. Convey coarse rock off the end and Pump the tailings over the bank on top the coarse rock on the other end of a cut. Be basically backfilling continuously as we mine. Max vertical lift of maybe 20'to 30'. 400' max pipeline length. Deeper than that a guy could cheat a bit and push to the hoe with a cat and bench everything down enough to reach the bottom. It just bugs me the whole time hauling dirt around when all we are doing is washing it. Gotta be a better way!

I would look at pumping clean water into an eductor.

What's a eductor?

I have worked on lots of different 6 inch pumps and rest assured that the impellers do not last too long if there is too much fines or gravel. My suggestion is to watch closely what techniques the biggest use and try to do on small scale. Once you start using bigger hoses and stuff it quickly becomes a situation where you need more people to move stuff. I have watched quite a few of "Yukon Ali's" videos and hers is more yardage per hour than you are processing but same idea. Bigger gear will mean bigger repairs. Simon C

The Norton Sound placer bois like their Eddy Pumps for moving sand and gravel long distances.

We could ask Emily.

Coaldust said: The Norton Sound placer bois like their Eddy Pumps for moving sand and gravel long distances. Click to expand... I know the 3rd world countries mostly use slurry pumps with hand labor throwing the large rocks out of the way. I just don't know the real world wear on something like this. Say an impeller and liners every 50 hours or 500 hours??? The devil is always in the details.

We are mostly third world in Western Ak. That’s a good question. I’ll ask what the maintenance is like on them. Welcome to the HEF. We look forward to hearing about your mining adventures.

What I saw on that program were eductors. We had them on ships for emergency pumps to dewater spaces, tanks and voids. Basically it is a pipe the is sucking on one end and discharge on the other. The water pump is hooked into the middle of the pipe into a jet mounted inside. The high pressure jet creates a suction. The problem I think is they don’t pump up hill much and you need a whole lot of water.

John C. said: What I saw on that program were eductors. We had them on ships for emergency pumps to dewater spaces, tanks and voids. Basically it is a pipe the is sucking on one end and discharge on the other. The water pump is hooked into the middle of the pipe into a jet mounted inside. The high pressure jet creates a suction. The problem I think is they don’t pump up hill much and you need a whole lot of water. Click to expand... So similar to a well jet pump. The pump forces water down the well in order to force more water up. The pressure through the valve down the well is like a venturi and creats more suction than the pump itself. Difference is the mud doesn't go through the pump

Futuro - Single Piston Pump To evacuate free stall manure containing limited amount of bedding. www.gea.com This is designed for manure with sand, do you think this would work?

Too bad you couldn't find an old concrete pump

John C. said: What I saw on that program were eductors. We had them on ships for emergency pumps to dewater spaces, tanks and voids. Basically it is a pipe the is sucking on one end and discharge on the other. The water pump is hooked into the middle of the pipe into a jet mounted inside. The high pressure jet creates a suction. The problem I think is they don’t pump up hill much and you need a whole lot of water. Click to expand... Similar concept to a gold suction dredge (Like a Keene...)

Iron Creek said: Good to find another placer miner here! I'm in the Yukon mining a relatively large, lowish grade fan deposit at the base of a canyon. Overburden ranges from hardly anything nearest the creek to 16' of clay the furthest out. South facing so only a couple feet of permafrost on top. Just below the organics is a coarse rock layer 6-12 feet that is my main pay. Below that is a dogs breakfast of sand and pea gravel with various thin seams of coarser rock/clay. I've gone down 40+ feet chasing clay layers but it's spotty. Bedrock is well over a hundred feet and unreachable. I'd love to run a floating wash plant like the Kiwi's do. I don't think you could beat the efficiency with a 2 man operation. Problem is I can't hold a pond with all the sand under me. My tailings ponds will drain to ground until they get silted off and filled with fine tailings. The idea of putting the wash plant on an excavator chassis would be to basically emulate a floating wash plant but on dry ground. Convey coarse rock off the end and Pump the tailings over the bank on top the coarse rock on the other end of a cut. Be basically backfilling continuously as we mine. Max vertical lift of maybe 20'to 30'. 400' max pipeline length. Deeper than that a guy could cheat a bit and push to the hoe with a cat and bench everything down enough to reach the bottom. It just bugs me the whole time hauling dirt around when all we are doing is washing it. Gotta be a better way! Click to expand... Hard to say for sure without seeing your ground/setup/equipment onsite...but sometimes simple could be best? What is the size fraction of the fines passing over your sluice runs? We are mining a large deposit with fine, well flattened flakes (average .5-2mm) and have been screening to minus 1/4" (lower screen); upper screen 1 1/4". This season we are switching the lower screen to 1/8" this will allow gold to pass to sluice runs but remove a lot of unnecessary small pebbles which interfere with the vortices created by the riffles. We anticipate significantly more through-put, along with better gold recovery. At the same time we will have less material flowing into the settling ponds. Our previous operation was a near source/coarse gold deposit and required coarser screens/nugget traps. A lot depends on the geology of your deposit... It may just be the nature of placer operations to have significant time into hauling pay, dredging ponds, moving coarse tailings etc. That said....having the plant on an excavator undercarriage could be a huge time saver, just move the plant to the pay and deal with the tailings in a more conventional manner. I know we have enough trouble on a 170' head lift of just clean water (4" for our small operation, Godwin dri-prime pump). I have been warned just the silt content of our large river in spring flood will be hard on the pump impeller and volute.... Our pump is working at max. the whole time and I know it is hard on the mechanical seal....Frictional loses/horsepower requirements when pumping a slurry must be enormous? There are a lot of efficiencies to be had in order to keep the cost/time of processing the pay down; it comes down to finding which ones are practical for your site....Good luck!

Iron Creek said: I know the 3rd world countries mostly use slurry pumps with hand labor throwing the large rocks out of the way. I just don't know the real world wear on something like this. Say an impeller and liners every 50 hours or 500 hours??? The devil is always in the details. Click to expand... For sure...I know that impeller and mechanical seals for our small Godwin Dri-prime pump are really expensive! I have seen a lot of really large pumps from the oil patch passing through Ritchie Bros. Nisku, perhaps there is some application in the oil patch that would work?

BC Placer gold said: I know that impeller and mechanical seals for our small Godwin Dri-prime pump are really expensive! Click to expand... ALL spare parts for Godwin pumps are expensive..!!

Check out Toyo sand pumps. Some are electric and some hydraulic.They make them for small marine dredging jobs. I remember doing a sheetpile cofferdam on the Yukon River in Whitehorse that needed to be kept dry .once it was dug down to elevation we dug a well in each corner and set 4" electric submersibles to keep the water down.Those submersibles pumped a substantial amount of sand,enough that the settling pond about 100 feet away ended up with truckloads of sand after a couple of weeks pumping.I know thats nothing compared to your volume,but we couldnt stop those little pumps from picking up the sand. A bigger dredge pump might work pretty well. Ive spent some time around the Yukon doing pile driving jobs,I had to get out of there before i caught the gold mining bug.Always admired the gold miners ingenuity in extracting $$ from dirt. Hope your mining goes well for you.