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kaveman
00:29:11 Tue
May 4 2010

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Re: Dredging w/Hydraulic Excavator

Just bringing this one back up to the top so it doesn't slip off into the archives where I can't get to it. If I can find a little time, I'll update it. Suffice to say that the dredging portion of the operation was a no-go. We were completely mudded out. The silt fence didn't work, but by the time we got the hole dug and got a look at the water in it, I wasn't surprised. Visibility was absolute zero. Zero,.............as in you couldn't see your orange glove no matter how hard you pressed it against your facemask. Dredging blind is one thing, but in pitch blackness it's a whole 'nother story. Once you got below a 6" depth there was no light a'tall.

Even after letting the hole sit for two weeks, it didn't improve. We did throw the dredge in and have a go, but the bottom was covered with a 6" layer of clay and the dredge didn't much care for that. Once you punched thru it with the nozzle, you could literally peel it back and roll it up. Even when you got thru to gravel, you couldn't maintain orientation and if you took your hand out of the hole for more than a few seconds, it would drift over with new fallen silt and you'd lose track of where it was. Other than that,......................it was also cold. A total nightmare. Reconfiguring the operation to exclude the diving portion, but we're still going to need some type of suction device, probably manuevered with the excavator more or less blindly.

I think I need dredger to post a detailed write-up of his nugget sucker. Looking at rippers for the exc and maybe sticking some sort of suction tube in behind it along with a blasting nozzle or two.
[1 edits; Last edit by kaveman at 01:08:07 Tue May 4 2010]

  
dredger
12:12:43 Tue
May 4 2010

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Re: Dredging w/Hydraulic Excavator

No worries kaveman, I have been trying to get back to this thread for ages, and I did know it was , about 5-6 pages back,

I have been doing alot of contemplating on fluidizing the smaller size cons, plenty of ideas, will post that here on this thread.asap,

Sorry guys, I have only just noticed last few posts, was that last x-mass or the one before, :confused:. some good ideas there,

Well, kaveman, we will have to work out what went wrong, but quickly looking at your post, I am a little worried the new guys might be getting confused, my dredging with a excavator was carried out in the current river gravels, and your operations were carried out on a high bench above your current river, which really should not have made that much difference, ??. so I don't see the prob is there.
Your silt fence sounds ? well it did not work, so could you please explain it construction and concept,
I have ? 4 more pics of my operation, showing clean work hole water, and dirty tailings water , I just putting arrows and directions on them before posting,asap.
Your description of work in the dark , been there done that, and liked it about as much as you did, haha, atleast we can laugh now, we survived haha.
One thought is ya comments on "probably manuevered with the excavator more or less blindly. ". I know what you mean about loosing track of where you are working, under water seems to increase loss of orientation, how ever when sitting in a excavator and feeling around with a bucket or sucker nozzle is much less of a problem of orientation, ( with practice ) you will get to know what the bed rock bottom of the hole looks like before ya start a dive, in clean water,

You wrote, " I think I need dredger to post a detailed write-up of his nugget sucker. Looking at rippers for the exc and maybe sticking some sort of suction tube in behind it along with a blasting nozzle or two ". what ever you need, no worries, a thought here is we need to know what you intend on running or powering which concept, sucker /blaster /s , and I was hoping you are able to do simple sketches on your computer, ??. hopefully you will be able to show how and where your hole and silt fences were set up,
Another thought is you may have to make application to remove a or a few truck loads of fine river gravels from the river, to use as a water filter medium,up on ya high bench, please note, I think those particular fine river gravels I use to filter water clean , you would not really find in a high bank deposit, that had already been dug by the old timers,

Out of time , but I am still sure you can dredge in clean clear water, if you can supply / recycle as much clean clear water as your sucking out, it can be done, and we will have to talk more, just rearrange the site, no worries,
On the up side , I know pitch black cold water is colder then clean clear sunlight water with 40' advisability, mate, please remember cold water is your friend, helps hide the pain in ya muscles, haha, and when ya dredging in clear water, the cold water helps ya work faster, haha,

back asap.dredger.

  
kaveman
03:50:20 Sat
May 8 2010

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Re: Dredging w/Hydraulic Excavator



Kinda makes you want to jump right in and spend the day under water,.....................doesn't it?

The dredge is an 8" subsurface that's been modified to feed from two 6" hoses w/nozzles. That's not the Loch Ness Monster; we had to float the hoses just so we could find the nozzles. Also helped immensely when it came time to clear the plug-ups in the hose. Unless you could lift the hose above the water surface, you couldn't see it. For the little bit of gravel we moved, we seemed to have a bunch of trouble with plugs. Suppose it was the 6" slugs of heavy clay going up the nozzles.

The discharge end of the dredge was bolted to the line running across the pond that the curtain was suspended from and the tailing went directly to the rear side of the pond. Whether the curtain had any effect I couldn't really say as there was zero visibility on both sides of it from start to finish. At any rate, it didn't seem to 'clean' the water any, although it may have been somewhat effective in preventing it from getting any worse(had that been possible). The curtain itself was a double layer of open weave poly tarp similar to shade fabric found here,......... http://www.gemplers.com/shade-cloth ,.................probably up around the 80-90% range. We had some of this stuff http://www.gemplers.com/product/139480/3-oz-Black-4-ft-x-300-ft-Non-woven-Spunbound-DeWitt-Weed-Fabric available to sandwich in between the poly tarps if needed, but we never got around to trying it. May have helped, but it would have been next to impossible to have added it once the tarps were stretched across the pond and removing and reinstalling the tarps would have been a four-day effort. We gave up on the diving.

Oh, BTW, we're not up on a bench,..............we're just on the bar maybe ten feet above the river but several hundred yards(meters)away from it.

I've been discussing our problems with everyone I come into contact with and one idea came from a friend who says he's had similar problems with dozed stock tanks down in Texas. Evidently the clay soil down there silts up the water in the cattle ponds in a similar way and it'll stand for weeks or months without clearing up. What they do is add lime to the water and it causes the silt to settle out in a day. Supposedly the water's slightly acidic which causes the silt particles to take on a weak positive charge that keeps them suspended(or so he believes). What they'll do is take two murky samples of water in clear glass jars and add a bit of gypsum or crushed lime to one of them and that one will be clear come next morning. Certainly might be worth experimenting with. If we can get the water cleared up initially, we might be able to come up with a system that'll keep it clear enough. It's the initial digging of the hole underwater that stirs up the silt in the first place. If we can knock it down just once, we may be able to keep it down.

We won't be out there again until late summer, so by then we'll be facing an entirely different situation. The hole will still be there, but the water will all be gone. I suspect the gravels will be safely tucked away under several inches of hardened clay. We'll get down in the hole with the digger and see how deep we can get working between the convolutions in the bedrock. I could feel the bucket skipping from crest to crest at the bottom of the pond, but without being able to see anything I wasn't having much luck getting down. Should make some headway once it's dry. 42" bucket is still going to be restricted from the narrower valleys, but if we can fabricate some sort of ripper tooth we should be able to at least loosen it up for excavating by hand. The ripper may also come in handy if we're still working this spot again in the spring when we'll be back to a full pond. That's where the ripper/sucker nozzle may be needed. I would expect to run maybe a 6" nozzle pumping directly to a 6" surface dredge floating in the pond,...................unless the water clarifying experiment is successful in which case we'll try diving again. Either dive with visibility and clean the bedrock with a dredge or rip the snot out of it from the cab of the digger in the blind. Those seem to be the only options.

Other stuff didn't work too well either, but we did have a few successes. Maybe get a chance to talk about some of those things over the weekend. Joe_S_Indy isn't going to be too surprised with what went wrong,...................his advice re: the washplant were spot on.
[2 edits; Last edit by kaveman at 05:11:26 Sat May 8 2010]

  
kaveman
00:43:13 Sun
May 9 2010

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Re: Dredging w/Hydraulic Excavator

From the archives,...............the shaker plant.

http://bb.bbboy.net/alaskagoldforum-viewthread?forum=50413641711&thread=6487

As predicted by many, we did have trouble with the plant. Once we got new belts installed and all the pulleys lined up, it ran fine. We had plenty of water for the sluice, even using the smaller than planned P350 pump. We do need new spraybars over the screens, but the gravel washed well enough even without a good spray. The screen was running a little shallow, but still shed the gravel easily at the small volumes we were able to run. The sluice may have been a little steep, so by jacking the tongue of the trailer we can improve both the screen and sluice slope(steeper screen and shallower sluice since the angle between the two in not adjustable). A single layer of 3/8" moss in the sluice left a few riffles floating above the carpet so we'll double up next run or place another layer of padding beneath the moss to close up the gaps. We were disappointed with the quantity of gold recovered, but still believe the recovery system itself is working well. We saved some unbelievably fine gold,.................there just didn't seem to be enough of it in the ore.

The big downer turned out to be the grizzly. Like Joe suggested, it flat did not work. As we feared, the slope was too shallow and the rocks jammed in the spaces at the crossmembers. Not surprised at that outcome, but it did rock up much faster than I had thought it would,..............as in 'instantly'. First bucket simply sat there and we had to shut down and shovel the load off the top. We only had a few days left to work so we had to come up with some fixes quick. I'll get some time in the next couple of days to explain what we did and show some pics/vids, but I just found the link to the washplant critique and wanted to get it posted up real quick for review. Need to get some sleep before I drop. More later.
[1 edits; Last edit by kaveman at 14:55:43 Sun May 9 2010]

  
dredger
03:04:05 Sun
May 9 2010

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Re: Dredging w/Hydraulic Excavator

Ok, Just noticed your posts, just finished this post, sleep tight,

I am Not trying to convince ya to dredge, only relate to how ya can dredge,and or a wash plant , and basically both. these will be hard and fast, not to hurt , but to help i hope,

FIRST 3 reliant factors,
1, anyone at your stage, excav / dredge. please note, the jump to super sucker bucket /blaster , cost money, mostly do it your self,but still cost money.
2,as you require, " sucker nozzle " cheap to build, then and buy a standard ripper Tyne, ( don't forget the cost of a quick hitch or quick change ), and using your current dredge very low cost, and rip /suck the work hole water clean with the nozzle on the excavator, before the diver jumps in just to do the crevices, ??. This method reduces the time, the diver dives, 6 " subby should have enough grunt to get a workable result, ( when i fitted a sucker nozzle I found the nozzle could supply alot more gravels into the box then the box could possibly handle, so I had a dredge hand stand and give me instructions as to how much materials was in the box, over loading was a big prob, and really you can only move a sucker nozzle around the work hole slowly ,
3, rearrange your hole / filter method at very low cost, also slightly modify the dredge, ( remove pontoons and and design / make a canvas "seal for the hose " and dredge in clean clear water as previously pictured , please note the water will not feel so cold when you can see as clear as day, got some dias nearly ready, please consider, we/you " what ever " blew it this time, so don't feel bad you can hit and clean a hole, 1 to 4 days per hole,, depending on how hard it is to chisels the gold out of the crevices, ect, my line of thought is 1 -2 weeks ya gotta cover the cost to date, if you can not do that , I would wonder if you are in ground with gold, or more to the point ,??. enough gold, ??.
4, is urgent , please monitor , if the water in the hole, causes turbidity in the river up to and well after the hole dries out, please take pics too, could be evidence required at a later date, reason for my concern is mainly for operations who continually pump clean water " up " to high operations, , as I experienced in Tasmania,where a operation excav / trommel had worked 2 weeks with such success that the operators took a weeks holiday to celebrate, 3 days into that holiday, they received an alert that the EPA, and WATER RESOURCES wanted to fine them, for silting the river, as I remember the soil was a different colour, but it was fine, and would carry silt for a mile, to fix that , it needed more dams and the dams where lined with or the walls were lined with light canvas,
5, is suggestion you have the line of thought that you won't spend more money up-dating, just get gold the way you thought you where gonna get it, pay for all up to date, and maybe get enough to pay for updates,for next time,

Anyway , gotta run,

Here is a pic of the dredge site, ( in river gravels, ) I suggest it will be easy for you to do same, dias following,

comments on arrows coming, asap;


Did you or can you pump the water to the hole, ??.

  
kaveman
14:46:18 Sun
May 9 2010

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Re: Dredging w/Hydraulic Excavator

We didn't pump any water to the hole. That's all ground water at this time of year. As the hole is being dug, water's seeping in and filling it. We also didn't pump any water out of the hole other than what's spraying into the washplant. Most of that water discharges directly back into the hole, although we had small ponds and puddles everywhere within 50' or so of the plant. That would all be soaked in by next morning. NO runoff and no chance of anything getting near the river. Not worried about that part of the operation.

I'd still like to dredge it and we're not giving up on that just yet. The situation 'seems' to be this,......................there's good gold in this hole, but it's almost entirely below the 7 foot level. At 6 feet, we start hitting the crests of bedrock, so almost all the gold is lying in the 'valleys' where we have a real hard time digging it out. The bedrock itself does not dig,................it's hard as flint. Best we can do is dig all the overburden away(which is where we stand right now)and our gold is lying at the bottom of a pond(winter/spring)or the bottom of a dry pit(summer/fall).

This is vacation fun for us, so we fully expect to spend $5000 each and every time we go out, usually a month in the spring and a month in late summer/early autumn. Sure it would be nice to have the money(gold)coming in instead of going out, but there's enough to make steady improvements and investments if we take it slow. I can easily see a ripper/sucker/dredger outfit running $10,000 and I too would like to be 100% sure of what's in the hole before dropping that much more into it so we're probably going to find something workable for far less investment for now. I'm thinking dry digging in the fall(maybe with the addition of a single ripper shank attached to the bucket somehow)and dry screening into the back of the dump truck; then hauling the load to the plant that will be set up within reach of, but out of the way of, both the river and the digging operation.

All advice and suggestions are eagerly accepted and appreciated. We take criticism well. The only real problem that we face is that all this stuff is taking place 2000 miles from where we live, so our time on station is severely limited. We build stuff and we make changes, but things happen slowly. Occasionally we get to dig a little. Best we can do for now.

Dredging may be off the table until next year when the water's back. It would be possible to try again in the fall, but that would require constant pumping from the river and an additional $1000 worth of new hose purchase. I think it best to plan a dry operation for now and hit the dredging again in the spring. We've got about three months to come up with a new plan.

  
kaveman
15:41:33 Sun
May 9 2010

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Re: Dredging w/Hydraulic Excavator

OK, without going over a whole lot of old ground,..................the dredging of the bedrock didn't work and wasn't going to be made to work in the time we had left, so we wanted to get a look at what was in the bottom layer of gravels while we could. Only thing we had was the untested shaker plant and about a week of remaining time. Just fitting up the sluice carpets, the last of the water lines, and new belts took a couple of days. Once we had everything running and got the first bucket of clay/rock/gravel sent up to the plant, this is what we had,....................

Grizzly Video http://www.youtube.com/watch?v=v0gvv7rV5YI





Failure,............big time. The grizzly wasn't going to work. It wasn't steep enough and even with the 4 water nozzles blasting the top nothing was moving. Large rocks just sat there and 3-4" rocks clogged the openings. Our day was done so we retreated to camp and spent the evening thinking about it.

Long story short,....................we had to totally change it and decided to abandon the entire grizzly and replace it with heavy shaker screen solidly mounted but pitched up at about 40 degrees. We'd previously built up a stationary screen that worked reliably at about 35 degrees pitch but figured the extra few degrees would be a safer bet.



We took the next day off and ran into town for materials. Found a nice piece of heavy screen 5'x5' square made of 1/2 inch wire on three inch centers. Screening to 2-1/2" seemed about perfect for feeding over the shaker. Framing would all be done with 2"x2" square tube. 5'x5' at a 40 degree angle would be a fairly small target for a 42" excavator bucket, but it was the largest we had available and we figured to expand it somewhat by affixing wings onto the back and sides using salvaged plates from the original grizzly. Well,....................that was the plan on Monday anyway.

Tuesday started off with heavy rain and it wasn't until the afternoon before we got a break and managed to get down to the bar to look at the plant and see how much work it was going to be to cut the old grizzly off and get the new screen rigged up. We knew instantly that we were looking at a good week's worth of work and we only had a few days left before we needed to get packing up to leave, so we decided to put that project on hold and try something stupid for a change(yeah, right!).

Since the main object was to run SOME gravel NOW and we were going to dig that gravel from the pond(couldn't use the stationary trailer mounted screen pictured above for wet gravel), and the new screen wasn't going to be ready in time,..........we needed a quick project that could be completed in a day and MIGHT work.

Actually, I'd have maybe had to bet against it working, but I'd have lost that bet. This is what we came up with,......



Video here,..... http://www.youtube.com/watch?v=Rybf0dgB9ig

We knew that even if it worked it was going to be slow, and it is, but with a little practice and better layout of the mining operation I think I could feed the plant as fast as it's able to process material. As it was, we only managed to run about 15yds in 5 hours due to the plant being too close to the excavator, the pump and water lines being in the way, and generally being boxed in with trees, the pond, and all the rock piled up around. I think a steady feed rate of 10-15yd/hr could be achieved with better planning and that's all the sluice can handle.

Anyway, we had to modify the old grizzly slightly to accept the bucket-screened gravel, but here's how everything worked once we got going,........




Digging/Screening Vid http://www.youtube.com/watch?v=aEm04od0e0w

Feeding Plant Vid http://www.youtube.com/watch?v=NQsxz-rTbvo

Digging, screening, feeding got better with a little practice(these vids were shot early in the learning stages). Few notes:

A few oversize rocks still get into the bucket over the top of the bucket screen where it pivots, but that will be an easy fix. The shaker plant has been able to handle these few rocks OK.

One advantage is that the oversize rocks can be dumped anywhere you want them rather than right up alongside the shaker plant where the grizzly would shed them.

Even though it looks like you'd be losing undersize from the bucket when dumping the oversize, that doesn't seem to happen. Might be the wet material or maybe all the clay in it, but the oversize slides right off the screen and the undersize sticks right in the back of the bucket.

The feed is kinda touchy since the screen is free-swinging and the material is wet(occasionally it sticks and dumps out in a heap), but one of the changes necessary to get the feed up to 15yds/hr would be to include a feed tray above the shaker where an entire bucket could be dumped and washed without needing to take the time to jiggle it in bit by bit.

All in all, it worked exactly as we had hoped(and far better than we expected). It took one day to run back into town for the materials(didn't want to sacrifice the 5'x5' screen for the grizzly replacement and decided to go with heavier .250" wall 2x2 framing and it turned out that the day would have been lost to rain anyway)and another day to build it up and fit it to the bucket. Total cost of materials was $105(REALLY NICE SCREEN from the scrapyard,............CHEAP!).

We initially worried that it might not be sturdy enough, but after seeing it built and in place, it's going to be fine and it'll move a bunch of material before it'll show any sign of wear. We actually came up with the idea while standing in the rain thinking about cutting off the old grizzly. Design changed several times during the two-hour drive to the scrapyard and advanced from a fixed screen requiring all sorts of welded or bolted in support to the simple swinging screen we ended up with by the time we got there. It was welded up in camp(laid it out in the bucket with 2x4 scrap and a measuring tape)and fit like a glove when assembled. All we had to do was drill two 3/4" holes through the thin part of the bucket sides for the pivot pins.

Never had a project go from hairbrained idea to working example, all designed on the fly,...............in under 48 hours. I don't know that we'll use it much due to the limitations on capacity, but it's nice to have. It didn't show us much gold because the bucket still can't get down into the bedrock valleys, but at least we felt like we didn't waste our last few days. We got SOMETHING accomplished! We got to run a bit of gravel over the washplant(enough to cleanup, anyway). We got to put a few hours on the plant and see how it was going to work and see what further changes were going to be needed. We had a little fun.

Actually, the thrown-together cleanup sluice didn't work too badly. I'll post it here. http://bb.bbboy.net/alaskagoldforum-viewthread?forum=2&thread=796




[6 edits; Last edit by kaveman at 17:33:26 Sun May 9 2010]

  
dredger
06:51:31 Mon
May 10 2010

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Re: Dredging w/Hydraulic Excavator

Yellow arrow , far left side shows blue tarp over flow for work hole, please note, water level in dredge hole is down a few inches,

Other yellow arrow shows water level in work hole down a few inches,

White arrow shows water level down at the jet a few inches,

Pink arrow shows the hoses can be easerly seen in the clear water,

Black arrows on right show low water level in tailings dam,

Red arrow shows red Honda 13 hp, ( x 2 ).

Black arrow under red arrow shows working water level on pump frame in tailings dam, please note the distance between the tailings dam wall and across to the river,




  
dredger
08:04:40 Mon
May 10 2010

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Re: Dredging w/Hydraulic Excavator

WOW, alot of work kaveman.

So the first thing that comes to mind, you will get more confident and faster with more practice, no worries about that, fact of life, another fact is from my years of experience and passion about excavators, , I can tell you have got the right moves, few more tricks to learn, bit more throttle, and you will be as smooth as a babies back side,

Second is a thought about "a " method that is and appears very efficient, but wastes a lot of time being efficient , so, my line of thought is focused on your sluice, and suggest the sluice is the problem in so much that is " not " processing gravel all the time you are operating the excavator,, so please note in ya video's , ( great videos too.) that when the bucket is feeding the hopper, " sluice is processing the gravel, roughly 30 seconds,that the sluice is actually sluicing gold, then " waits " 60 secs for the bucket to get bigger rocks off the screen in the bucket ,and feed the screen and another 30 secs to acutely get the bucket filled, so the sluice is waiting 60 secs plus 7 secs for the bucket to return from the screen back to the hole, 97 secs in total,and the sluice is only working 30 secs of that time, 67 secs sluicing time wasted, more then 2/3 time wasted,

On the other hand if you were feeding the sluice with a constant feed you would process 2 times more gravels , in the same time, every hour you could be cut in half, to 30 minutes, and do twice as much in one day, generally speaking,

Solution, reinvent the hopper , to handle a full bucket of gravels that are just dumped in while gently laying the load across the screen, , a hopper that can handle a full bucket being gently and quickly dumped in it, with plenty of grunt to shake big rocks while being blasted with jets, ( please note the concept is to "leave the over size rocks on the screen being washed and shaking for the full 30 secs, until the next bucket load " brushes " ( side ways push ) to the , " left " off the screen onto a chute where they will slid on there own, then and at that time the bucket has stopped ready to dump the next lot of materials in the , across spread over the screen, giving those gravels a full 30 secs of shaking and washing, also enough storage area under the hopper screen for a bucket full of screened gravels, and orga / feed those screened gravels into your shaking screen / sluice in just under 30secs, ??.

Please note an interesting point here is without changing your original processing plant, but removing your grizzly , and redesigning it, to discharge out of a chute, over the sluice tailings, you will be able to load the hopper , and push or pull the vibrating screens tailing /rocks,to clear the rocks that have built up under the conveyor,
And clear ( or back fill the hole ), the over grizzly size washed rocks that have fallen on top of the sluice tailings, at the opposite end of the unit / conveyor belt, with tracking around to clear the oversize off the grizzly,

Please note in this Arch Cannon operation that the excavator removes / digs a bucket of pay dirt, and gets it to the plant in a smooth motions of the bucket, 15 secs, i suggest to dump and return under 15 secs, total 30 secs or under,



1,is the direction the bucket brushes the the washed shaken rocks to the left,
2, is the level the bucket enters the hopper,
3, is the chute that drops the rocks onto the fines sluice box,
4, is counter balanced weights spinning to vibrate the hopper, ( big time, ) as well as red springs that the whole hopper is sprung, high pressure jets not shown,
5, is storage area for under size ,
6, is adj hyd ORGA screw to feed your screen, constant controllable feed,
7, is 13 hp Honda drive hyd pump, ( hoses note shown, ).

I would suggest that the shaking screen not be attached to your trailer, instead it be sled mounted , and separate, ( might deliver too much vibration to the sluice,

A poss scenario, you have dug as much of the hole within its reach , so the excavator is moved forward a few yards, in the same direction as the trailer is pointing, any build up from the conveyor is " pushed away " and a chain is used to pull the trailer over where the conveyor had dropped rocks,a few yards forward,the excavator is then chained to the front high side of the hopper , and pulls the shaking hopper over your trailer again, to line up the orga , and your small hopper on your vibrating screen then the excavator reaches around to where the oversize and sluice tailing are piled and pulls them back into the hole for easy back filling the hole, then the excavator slews around and starts digging again, 30 secs per bucket, or 120 buckets per hour, only stopping to drag / pull the trailer and shaking screen a few yards,

just trying to help;

Back asap. dredger.

Ps, I suggest that concept would work well if the hole was dry, :devil:

  
kaveman
17:08:23 Mon
May 10 2010

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Re: Dredging w/Hydraulic Excavator

Wow dredger,......................you're putting more thought and effort into this than we are. Yeah, the de-rocker and feeder would be ideal. Frankly, I doubt this little pieced together shaker plant is worth all the effort, but some of the ideas are doable. I never considered it to be anything other than a test-plant and we have no hesitation when it comes to changing things around. I understand that the sluice is sitting there running nothing but muddy water most of the time, but that's how it worked out this trip. We had actually planned to run full buckets across it, but the size of the sluice mandated that we hold the rate to one bucket-load every 2-3 minutes. The plan was to meter the bucket-load in for the first 2 minutes at a rate the plant could handle and then dump the final bit; letting the water chew on that for 30 seconds while the excavator digs another bucket. That's what we would have done had the grizzly worked. Plans are nice to have. They give you something to talk about until everything goes wrong.

I don't think we're up to the task of engineering and building all that apparatus, but a simple stationary feedpan might work well enough. Just an inclined hopper that can take the full load of the bucket where the blasting nozzles can work on it. The material( this material at this spot)washes very easily and is pretty clean by the time it hits the screens. The screens size it, but don't have to clean it. Thinking about having at least one of the blasting nozzles controllable from the ground so a man can even out the feed a little. Being able to free up the excavator and keep it moving would be a huge improvement, especially now that the digging is so slow.

I don't claim to be much of an operator yet, but it's hard to be smooth the way we had this operation set up. The excavator was so close to the plant that I had to bring the stick all the way in to the stops and then boom all the way up to the stops to keep from hitting it when raising the bucket. Undo that to lower the bucket. Dumping the oversize off the bucket screen required that the boom be lowered and the stick all the way out to clear our waterlines. I was reaching out into the pond as far as I could for each load. Stop to stop,........stop to stop,........stop to stop,....................not a very efficient way to dig. It got pretty ugly a few times and I can assure you that I have vids that show that I really am not very good. But I'm smart enough not to post the really ugly stuff. Suffice to say that the plant got inadvertently 'modified' a few times during the day.

What you can't see in the vids is the stacked rock to the left and the trees to the rear along with all the tools and crap we have scattered around the worksite. It was like trying to work in a cluttered closet all day. Well,...............at least nobody got hurt. We had a good day.

I have a few simple ideas for regulating the flow of material through the plant. Mostly just making a couple of spots that will hold stuff back until the flowing water can work it out. The only visual cue I get from the cockpit that tells when there's too much feed or too little is the conveyor. I can see when it's running full or empty, but that's about thirty seconds downstream from what I'm doing with the bucket so it's not much help. Better would be a camera looking up from the discharge end of the shaker screen. If I can keep a steady load on the screen, I can probably run the plant at capacity and maybe multiply our throughput by 7-8x. Unless we get deeper in the hole, we'll still be going broke at that rate tho. We haven't seen anything other than flood gold in the stuff we've processed so far. The test pit that this hole is built around showed much heavier gold than we're seeing and as for quantity,....................1/10yd from the testhole had more in it than the 15yd we just ran. My math says we should improve by 150x eventually.
[1 edits; Last edit by kaveman at 17:13:42 Mon May 10 2010]

  
dredger
05:45:45 Sat
May 15 2010

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Re: Dredging w/Hydraulic Excavator

Sorry kaveman, bussy as, back asap. sorry . phill.

  
billcosta_rica
20:05:52 Sat
May 15 2010

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Re: Dredging w/Hydraulic Excavator

kaveman
check this video out http://www.hollowaybar.com/videos/hb15.html
and there are a few more... food for thought.

bill-cr

  
kaveman
15:04:54 Sun
May 16 2010

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Re: Dredging w/Hydraulic Excavator

Thanks for the link bill. I spent most of last night checking out the vids. That feedpan is very much like what I'm thinking. He used the bed from an old dump truck and it seems to do the trick.

  
dredger
23:05:22 Sun
May 16 2010

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Re: Dredging w/Hydraulic Excavator

Thanks Bill, that is certainly my kind of digging, " fast Forward ". :smile:.

Hey Kaveman,

Great video, Aye, I liked the dozer spreading the tailings, but , dozers cost money, so a thought for your consideration, could be to make your processing unit " mobile " , I would suggest you check out how cheap you can buy complete hyd excavator track and base units , you just remove ya trailer wheels /axles, and attach / weld the complete track / and track frame on to ya trailer, only small ones, maybe 3 -5 ton track bases, fit small hyd pump to your screen engine, and pipe it to the tracks,

Your conveyor belt, would be very handy then, " scenario " by just touching a control stick mounted near your hopper, with your bucket, the mobile unit tracks would move the unit and conveyor belt to spread the tailing around where you like, and also be close or the right distance for loading,


You say " That feed pan is very much like what I'm thinking. He used the bed from an old dump truck and it seems to do the trick ". I agree, and suggest you set up water jets so that are directed " up " to the gravels, you have just dumped, that way the gravels are blasted and roll or move down the angle, which does not stop or fluctuate the flow of water into the screen, if you try to blast or push gravel down the hopper, you stop the water flow,intermittently, until it builds up and flows over the gravels you just dumped, and causes major floods on and over the screen, and or down and out of the hopper,

Back asap;

  
dredger
23:21:12 Sun
May 23 2010

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Re: Dredging w/Hydraulic Excavator

Sorry kaveman,

Sorry again, I am really out of control. bussy ,please accept my apology, I will be back asap. dredger.

  
kaveman
00:29:28 Mon
May 24 2010

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Re: Dredging w/Hydraulic Excavator

Ahh, no rush at all. Looks like nothing's going to happen until September at the earliest. So far, all I've done is corral a couple of ripper shanks off a Cat dozer. Missed a great deal on a 24" bucket that could have been modified for my machine relatively easily,..............but I hesitated since it was 2000 miles away. I coulda shoulda bought it. Might still get another chance at it as it didn't sell but it also hasn't been relisted yet.

Yes, spray from below in the feedpan for sure. Let the water spray do the work and regulate the flow of material to the screen/sluice, just like in this operation,................. http://bb.bbboy.net/alaskagoldforum-viewthread?forum=2&thread=44

Also similar to the cleanup sluice we set up,.... http://bb.bbboy.net/alaskagoldforum-viewthread?forum=2&thread=796

  
dredger
00:41:41 Thu
May 27 2010

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Re: Dredging w/Hydraulic Excavator

Sorry , been busy as , and still am, but got a few mins,

I have some interesting points or clues,about the link and the , that are killing me to share with new guys,

First , I hope finnishdigger takes no offence at or from my blar, blar, cause i do not mean any offense and my heart bleeds for him waiting, to hear from the Government, and I wonder if the Government is banning dredging just in Natioal Parks, or banning dredging in "all water courses ", in the country, ????.

Second , thanks for sharing your operation on the forum, I love the whole method, machines and all, simplicity in action, best of luck with the Government,

I hope you don't mind me pointing out some points of interest in your operation video for the rest of the guys, and the new guys too, especially the new guys, by new guys I refer to myself who after over 30 years mining with a passion only A FEW DAYS AGO, LEARNED, well i am suggesting / and hopping, I have learned something new, something the very new guys should /could consider, when ya out looking for some gold, and what gravels they may have in which ever part of the world ya in,

Ok, it is all about watching finnishdiggers vid link, first pic in my mind is how easy and well f/d's bucket digs , looking at that bucket and pay gravels, and "why it is so easy " for the water jets to break up and wash gravels out of the bucket ", ?????, N/G please note the rocks slidding off the screen has no clay balls or clumps of clay,

I am guessing that much gold in the pan, would possibly mean f/d is in the pay run, I note this because in my experience in Auss , NZ, Tassy ,there would be some or lots of clay, ??.

Please also note , that the bucket has no teeth, it is a blade, but still digs well, in my experience I /we use teeth on the bucket, because of the clay ,and also I suggest that F /D's gravels are "softer " then river gravels I have experienced, which are harder " packed ". in gold runs,??.

Next is what clues did I see when F/ D cleaned out his sluice,

After that , what clues did I see in F/D's Pan,

And What clues / observations did I see in a sample under my scope from Finland that are relative ,

More on that asap.sorry,but at least I have shared some thoughts and suggestions, a start is a start,

Kaveman,you say.
Ahh, no rush at all. Looks like nothing's going to happen until September at the earliest. So far, all I've done is corral a couple of ripper shanks off a Cat dozer. Missed a great deal on a 24" bucket that could have been modified for my machine relatively easily,..............but I hesitated since it was 2000 miles away. I coulda shoulda bought it. Might still get another chance at it as it didn't sell but it also hasn't been relisted yet.

Been there done that,, :smile:, later,dredger,:smile:

Ps, still trying to find time to finish those bucket dias too, sorry,

  
dredger
05:20:50 Thu
May 27 2010

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Re: Dredging w/Hydraulic Excavator

Ok, back again,

Ok F/D' s sluice , the video sweeps up the sluice, riffles first, no problem, then sweeps up the expanded mesh with one of the miners moss type plastic matting under the mesh,, which show almost no river gravels or black sands , recovered or retained behind the expanded mesh, ??. for the new guys, my experience is there is always atleast some black sands somewhere, please note when F/D knocks out the mesh frame and turns it on it's side, please note, the finer sands stuck at the head of the screen are a lighter colour, perhaps more browner then black,

Next is when F / D pans out, there is almost no real heavy black sands visible, just lighter colour, and lighter Sg tan sands,moving in the pan and around the gold. AMAZING TO ME.

As to my sample from around that area, I did receive it a few years ago, and was amazed that I could not see any black sands in the sample, unfortunately, I lost contact with the owner of the sample just before i could get permission to pic and post the on the forum, I have and did wonder why there was no b/s, but only when F/D showed the video did i think or learn that F/D is dredging in heaven , haha, NO BLACKSANDS, and suggest there may be other parts of the world that also do not have black sands as well, for the new guy , my kind of dredging with no black sands would be heaven, I dream of dredging with no black sands cause there would be no heavy Specific Gravity to pick up and throw, heaven,

Finnishdigger, nice operation, and I am very happy to see ya family there too, good luck in the future, :devil:. and I hope you don't mind another suggestion which hopefully might help you to continue your operation, apply for a new license over the area, and explain you will reduce the work site " foot print " by modifying your method, to be only clearing a much smaller area, processing that area, and progressively back filling and re habitation to original contours, Take pics, before / during / and after , showing no visible change caused by your works, also insist you will recover all heavy metal " pollutants " , such as lead left by shooters, and fisherman, and also remove any and all Mercury left by previous old time miners, ( if there is good gold , it is likely the old timers where there, and used Hg to recover the gold in the area, ). please let me know if I can be of any help. and please consider some sort of suction concept to clean the bottom or water filled holes,

Hey Kaveman, please consider if you use a similar method and have clay and heavy black sands , it might require a lot more high pressure water jets to break up clay balls, which would jamb a screen similar to F/D,
:confused:.
back asap. dredger.:smile:everyone.

  
dredger
02:52:46 Sun
Jul 11 2010

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Re: Dredging w/Hydraulic Excavator

Wow, bussy as,

Hey kaveman,

ok.sorry this has taken so long, the sucker, the blaster,with screen back flusher, camera and lights,excavator buckets " concept ".

Not the real thing, actually a toy, and quickly cut and assembled, a few pics first,

Oh please note, I intend on having an extremely high velocity vac and extremly high pressure and low pressure blaster,

Ok toy excavator bucket, ( no real teeth ).



please note, 4 thin " ribs " shaped to the " back" or rear of the bucket, ( only card board and painted in blue ), as with most concepts, this proto model has 4 rear ribs, the real bucket may have 6 or more, ??. see what happens when building it, ribs could be profile cut and 2" or more inches thick,the ribs are part of the blaster concept,

Inside the bucket,



Please note 3 ribs,fit inside bucket,I later cut them back a bit, and added a cover plate,



testing,

  
dredger
04:01:12 Sun
Jul 11 2010

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Re: Dredging w/Hydraulic Excavator

A few points of interest are,

The size of the screened materials would or could vary according the different areas, and I am yet undecided on my area, and the % of small to large rocks,so the model is no real indication of the/my screen size,

One thought might be to process 3" and under, meaning the slots could be 3" wide and 6" or more high, ??,

Or 1" wide and 3-6" high, at this point I am undicided,

Another thought is the bucket would loose volume with a screen/plate mounted inside the back bucket, plus the fact I am considering or want a 2 cu mtre. / yds bucket of materials moved with each pass, so the line of thought is I will construct a 2 mtre /yd bucket,

For the new guys, please note a 20 ton excavator usually uses a single or just under one cu mtre /yrd bucket, works and digs well, but / and or a 30 ton excavator usually uses 2 CU MTRE /YD bucket, close to 2 yds wide,which is fair enough, and will dig well because it is 30 ton machine, so my line of thought is to build a bucket with 2 cu mtre cap, with a one metre wide mouth, and fit it to a 30 ton machine, resulting in very easy digging, ( for a 30 tonner, ) and my required 2 cu mtre per pass, 6 seconds,

Now back to the ribs on the back or rear of the bucket,and blaster manifold,



testing.




  
dredger
04:19:05 Sun
Jul 11 2010

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Re: Dredging w/Hydraulic Excavator

Next a 1" cover plate, ( pink paper ) , and please note i have drawn a pipe fitting on the plate, high pressure water is pumped in,



And exits or is forced out through the slots, High pressure and around 1 and 1/2 cu mtres of water in under 2 and 1/2 seconds,

So that when the bucket is being forced into the gravels at or on the bed bedrock,


The jet of water is direct forward under the bucket teeth, hopefully blowing gold out of crevices and gold laying or dropped on the bedrock to blow forward, and then hopefully will become affected by the suction inside the bucket,
[1 edits; Last edit by dredger at 04:21:13 Sun Jul 11 2010]

  
dredger
01:51:49 Mon
Jul 12 2010

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Re: Dredging w/Hydraulic Excavator

So, bottom pic shows the bottom of the bucket in a flat on bedrock scenario, high pressure water blasting from left to right,and sqeezed under the bucket to the work face ok, big problem here is, keeping the bucket flat or at slightly more angle so as not to drag the rear / bottom of the bucket on the bed rock, and just keep the teeth slimming over the bed rock,and feeling the bedrock, the high pressure and correct angle should keep the blaster slots from blocking with rock, the slots could be 2 - 3 "s deep, by the width of which ever bucket,figure that out as required,

For the new guys, the truth is the bucket is likely to be under dirty water, 6-8 feet deep,and or the dipper arm can also be under 16-20 feet of dirty water, and if ya have the boom half under dirty water at around 27-35 feet deep, you or well I, have never been really sure if the bucket is flatish and the teeth a just skimming the bed rock, 6 times a minute, 12 hours a day, none stop while the going is good,generally speaking.

So what I had in mind next time i dredge, was to fit a simple mechanism,to the excavator that would give me clear vision and exact position/ angle of the bucket and dipper at all times, be handy for learning, so the scenario is I/we am sitting in the cab, hands on the controls, watching everything through the front glass or open window of the cab, also using our perifial vision, ( hate a spell checker that does not know everything, ) on the left is the open door, or open glass on the door, and on the right is limited vision of the right hand side of the cab and machine, limited by the boom, big fat boom, my idea is to mount it right there,on the boom, the indicator, would consist of a 10" x 2" strip of metal a few mil thick, representing the dipper, and a 4" x 4" flat steel, representing and shaped like the bucket, screwed and pivoted against the side of the boom, ( right in ya face, ), two or perhaps more light weight " push / pull cables, attached the the pusher arm, and one at the dipper / boom pivot point, actually i would suggest the idea is so kiss, and it will work,not forgetting that it will not show depth,unless you want to make it a little more complicated,

So back to the bucket,


So back to the bucket,

  
kaveman
06:03:20 Mon
Jul 12 2010

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Re: Dredging w/Hydraulic Excavator

I'm still following, but wow,...........by my calculations 1.5 cu meter water per 2-1/2 seconds equates to 10,000GPM. That's the output of 6-7 P1500 pumps and roughly 400HP. Obviously it only runs in spurts, but that's a pretty impressive spurt!

  
dredger
07:49:03 Mon
Jul 12 2010

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Re: Dredging w/Hydraulic Excavator

No worries, aim high, haha, as long as I end up with a impressive spurt, that will be ,I think at first spray or splash muddy water all over me and cab, ( in say 4 ft deep pond, ) untill i back off on the throttle,and or perhaps decrease the size from 2 cu mtre down to one, maybe that is all that will be requiried maybe a 1/2 cu mtre of water, to blast the bedrock, and sweep any /all gold infront of the bucket, and hopefully break up, or loosen up the face,

Also perhaps some already processed or heavy black sand materials can be added to the blaster to make it a grit or wet sand blaster affect,

Yes, 2 and 1/2 second spurts, timed in sequence in a 6 second pass,it was also my intention to place small electric trip switches on the bucket/dipper angle indicator, mounted on the boom, to stop false or wrong bucket angle spurts, working on that.

My line of thought is not a P1500 water pump concept per-say, it is a cylinder and piston,( suck and spurt ) in fact a number of rams and piston / cylinders, the blaster will have the bigger cylinder, and the others will be used in the filtration, and moving / dewatering / filterable solids / gold / water through recovery system/s/s/s, ect,working on that, too.

Another post coming asap.,

  
dredger
08:27:57 Mon
Jul 12 2010

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Re: Dredging w/Hydraulic Excavator

Please note these are only first proto type concepts, and certain aspects of the the model will have to be modified, such as high pressure water flow, through or around the ribs, or removing parts of the ribs,to ensure correct high pressure flow, and correct suction feed behind the screen,

Also it will be my intention to fit a small zoom camera /s and lights inside the blaster manifold,to be used when the pressure / volume of water is greatly reduced to displace dirty water and get a good look into crevices,( in a dirty water work hole,

Interesting here, is the proposed source of high pressure bursts and low pressure filtered clean clear water supply,

the high pressure blaster will use some over 200 hp ( of a 350 hp unit ) driving a 100 gpm hyd pump, with enlarged porting and hoses, to a large ram, similar to a / one 30 ton excavator " boom ram " which will drive a piston type cylinder water, ( syringe ).2 cu mtre capacity with an outlet size of around 6" heavy duty high pressure hose, some 32 ft in length, to the blaster manifold,

The low pressure clean water supply will be sourced from the processing plants, " de-watering / filtration system ", and also a 2 or 3 cu mtre capacity, which should allow a few minutes to search around a small area or surface of the bedrock, for missed gold, and crevices,

Scenario could be, remove overburden over small area / surface of bedrock, within the reach of the machine,

Place the bucket flat and horizontal, on the bedrock, and open the bucket ( un - crowd the bucket, )to half way of vertical,( or less ) and engage clean water supply, and watch the small close circuit TV screen mounted in the cab, hope will show clean water " dispersing the dirty water with clean water, which should give good vision of bedrock about the width of the bucket and or by a few feet behind the bucket,which effectively sandwiches the clean water, while slowly moving or sliding the bucket teeth around the cleared work area,
:devil:
:smile:.

Lighting is next, with a lot of choices of natural lighting colors, which can help make the gold on the or in the bedrock brighter, and more visible.

Another pic shows white out sections in which the suction manifold is fitted and welded,



back soon,

  
dredger
01:27:39 Thu
Jul 15 2010

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Re: Dredging w/Hydraulic Excavator

OK, bussy as here, but ,:confused:, this concept is still coming together and evolving as we go,

After, alot of thought about a bucket suction manifold, I tried to sketch a suction on the back of the model bucket piced above, present some probs, so lets first consider the " factors ". which may explain or help me to get the suction manifold to work,

Thanks kaveman,nice to have some figures to work with, :smile:

MATE, i am so preoccupied with family probs, I cannot get my head around working out " how long would a 8" hose have to be if it had say 1 cu meter of water / slurry inside it ",??. be a great help please,

1.5 cu meter water per 2-1/2 seconds equates to 10,000GPM. That's the output of 6-7 P1500 pumps and roughly 400HP.

Guys please note, I am guessing most of this, as we go,

Factors, concerning the suction manifold,ect,

I want to suck wet / dry vacuum 1.5 cu meter of water or a undersized gravels, wet slurry, in 2.5 seconds, long tube of slurry, with ?? perhaps 10 foot of lift,

The suction manifold will have to " gulp up " 1.5 cu meter or perhaps a more realistic, 1 cu meter of water /slurry, per 2.5 secs, with around 350 -450 HP, and a mother of a sucker pump, hold on, my intention will be to run this concept flat out, and then throttle back for good fuel eco and make the plants last, so please don't think this thing will be running flat out, no.it will be strong,

For the new guys here, costs are a big factor in running a operation, fuel for these machines per second, thats 2 x 350 hp excavators, and 350 to perhaps 450 hp processing plant, please note ,the excavator /s x 2 or x 3 will be very economical due to the fact that most of the time they will only be using just above half throttle.

Sg of those gravels would have a factor if not for the extreme velocity, My line of thought is a simple scenario of getting a foam tub slighly smaller then my heavy duty wet dry vacuum cleaner say a few feet long,and feed it in the nozzle, thump it is gone, ,

Sorry gotta run back asap. dredger.

  
kaveman
02:44:32 Thu
Jul 15 2010

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Re: Dredging w/Hydraulic Excavator

It would take 31 meters or nearly 101 feet of 8" hose to contain one cubic meter of water/slurry.

  
baub
13:24:08 Thu
Jul 15 2010

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Re: Dredging w/Hydraulic Excavator

If you can get a sufficient water depth, a simpler method might be an airlift style dredge. Uses 2 pipes and a large air compressor. One small pipe for the air going down and a larger one for the upchuck from the bottom. Needs 30 feet plus water depth to work properly and the deeper it is, the better it operates. Works well with loose stuff.
If complexity is not an issue, and you want to penetrate the bedrock, using this in conjunction with your 30tonner would require 2 people minimum and let your machine head stay down, reducing cycling time.
Action Mining has a compilation of articles from it's old magazine, Popular Mining. Volume 3, page 127 has an article that descibes this quite well. There may be additional articles as well. I would suggest reading this first and see if any of it applies to your situation.
The complete set is about $150 US plus shipping etc
Action Mining Services in Sandy Oregon, USA

b

  
dredger
20:16:49 Thu
Jul 15 2010

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Re: Dredging w/Hydraulic Excavator

Hey Baub,
Thanks , and I hear what your saying, but I am focusing on the situation in my area, which is “shallow to bedrock “ river gravels, ( 4 - ? 20 feet deep ) line of thought with that is “ erosion “ is my friend, cause erosion will transport and concentrate most gold into a “ run “,on or above the bedrock, ( and collect in crevices, ect ), as it moves or erodes from the source or sources, and shallow bedrock means I only have to move the least amount of gravels to get to bedrock, actually I am intending that the whole operation excavators / processing plant all on tracks, will dig and work the work hole , and back fill the hole progressively at about 1.5 meters per hour, perhaps faster, ( work hole would or could be say 35 feet wide, x same front to back, )
So, basically a airlift dredge is unsuitable for shallow work, HOWEVER, thanks for the inspiration, AIRLIFT, AMAZING, I have been search for two answers, to two ??. irritations,
1, being what to do or what can I do with with the exhausted air blast created from the wet /dry suction dredge bucket nozzle concept,
2, being how to “ wash out “ ( or fine mud and clay, silt, fine light Sg gravels , and yes, fine small flaky flighty gold, and clean all other gravels in preparation for classifications, like when ya wash the dirty water off when panning,
3, possible line of thought is to add “ some airlift to the gravels washing process, I like it , thanks for the idea,
Thanks kaveman, 101 foot, wow, meaning around 33 foot hose would be around or just over 1/3 of a cubic meter of water, and 330 kg, also allowing for Specific gravity for the lighter gravels to black sands,??? Kg,rough guess, ouch, traveling at extreme velocity, :smile:.
Another factor is the suction will only be sucking inside the bucket for the or around 2 and 1/2 secs, in a roughly 6 second cycle, that will give me a few seconds to empty the sucked materials, and not suck water without gravels,
Also, arr, forgot, no, How many cub meters of screened undersized gravels are there in 3 cu meters of river gravels in " my area ", to make my point, a scenario could be,
1, i have a 2 cub meter bucket, and am capable of sucking 1 cub meter per 6 second or 3 cub meter cycle, in my area, river gravels are at a ratio of 1 cub meter fines of below screened size, Mixed with 2 cub meter of over size, ( just guessing ).
2, Same excavators and same sucker bucket processing unit on a beach, where mostly all is under size sand, and definitely not much oversize, resulting in this concept not working, due to suction cycle, which is related to processing,
3, However I would suggest that some river and placer / areas have different % of under / over size river gravels.
4, These above variables could be tuned by having a interchangeable sucker bucket screens which focus on screen size and total surface area of the screen,
So , the above is related to the bucket suction manifold , which I was previously talking, and I have been trying to find time to think about, please also note, that the bucket suction manifold, and suction hose connector fitting , will be incorporated with the high pressure bucket blaster concept hose connector / fitting, to back flush the screen inside the bucket,
To enable the operator to flick a switch , that will give the operator 3 settings on the suction hose, ( 8” ) “ VALVE / GATE “, first setting , AIR / SLURRY FLOW into processing unit, second setting , allows fresh air to enter the hose at the fitting, ( this is to stop further fine materials ( or small rocks ) passing through the screen while the over screen size gravels are being dumped into the processing unit hopper, ) third setting is to block the suction hose , which also engages / diverts / the or a high pressure water blast into the back though the suction screen in the bucket, and backflushing the screen, “ over the hopper “.
Out of time, but there is also a quick release and quick engage mechanism for the suction hose, and high pressure from the processing unit hoses,incorporated at the bucket,small package, thinking about it, do some drawings,
Sorry gotta run, docs again, back asap. dredger.


[1 edits; Last edit by dredger at 10:27:11 Fri Jul 16 2010]

  
baub
21:58:18 Thu
Jul 15 2010

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Re: Dredging w/Hydraulic Excavator

You're welcome. Good luck Dredger and pls keep us informed.

b

  

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