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dredgerRe: Dredging w/Hydraulic Excavator
Ok that worked, :smile:

I have been trying to get "to " these pics to post them for weeks, my fault,

New guys please note, if you click on reply, you can scroll down and see all the work site pics on one page,

I refer back to the pic showing the rear of the trench, ( and drunk sleeping it off ) my line of thought when digging the trench, is first I dig a deep hole behind the sluice, for the tailings to build up in, ( and i dig out those tailings a few times a day, takes a few mins each time, ),
Then continue 10 – 15 feet of straight trench to direct the flow from the rear of the sluice, then I cut a trench back, Y section, 15' trench back to the foot valves, make a PAD for the engine frame, then back to the main trench, where I leave a “ dam” in the trench, please note this first sections of the trenchs have to be deep enough to ensure there is water covering the foot valves in the morning, the dam restricts the flow out of the front section or Y section trench, the focus is as soon as the pumps start pumping, the jet starts moving allot more water down the sluice, around the Y section and feeds the foot valves asap, the water level rises above the trench dam and flows down the remaining length of the trench, to the filtration wall section,
sorry back asap, dredger.
dredgerRe: Dredging w/Hydraulic Excavator
I have been having trouble with photobucket, my fault more then theirs,
Work site clearly marked ,

Worksite fg,

Work site after rehab,

testing, :confused:
dredgerRe: Dredging w/Hydraulic Excavator
Please note, I had already started back filling or levelling the rear of the rear of the tailings dam before I remember to take a picture, confused: sorry.
New guys please note, the large tree near the hole/trench, also in the river gravels as reference,
Please note the water height of the river,
On left of pic shows shallow tailings trench, with 3-4 foot wide base x 3-4 foot high filtration wall, on right side of trench.
Please note there is really no wall on the left side of the trench required, the rear of the trench I usually just curl the tail of the filtration dam,
Please note that the filtration dam and walls are basically very quick to dig, extend, modifying,
Sorry, back asap.
dredgerRe: Dredging w/Hydraulic Excavator

Please note, the filtering dam walls stop filtering as the silt builds up on the inside of the filtering dam wall, my experience was to dig the hole shown in pics, then a few days of dredging and crevices. I would see the tailings dam water level rise up to the catch tray, ?? (New guys please note the catch trays under the motors are to catch any or all oils that maybe accidently escape from the pump motors, and is part of the EPA Lic requirement,) At which time I use the excavator to skim the built up silt, building up the filter dam wall, this can be done very quickly, just by setting the bucket to skim the built up silt off the wall, and walking or driving the machine forward 30’ parallel to the dam wall,, and back again, a few minutes operating the excavator clears the silt for a few days more dredging, or just by using a wide broom, to sweep the built up silt, down off the wall into the trench, 10 mins,
So, at that time, my observation, was I quite surprised to see amazingly clean clear water about 4” deep flowing freely along about 30 feet of dam wall, into the main flow, “ in the beginning “ or when I first started dredging with a excavator, I dug long 100’ tailings dams, which works great, with hardly any filtered water passing through the wall into the flow, in fact, the dam wall was placed between the tailings dam the main river flow to stop the turbid tailings water entering the main river flow at all, which evolved into the “ small environmental Key hole mining foot print, focus of keeping the foot print or total surface area to a minimum, this also reduces the or any “bond” or moneys paid for or to ensure rehab.
New guys please note, I observed enough to suggest the best dam gravels to filter silt is not the light Sg gravels found high on the river banks, only the gravels found or travel in the main flood run carry the heavies, ( black sand and Gold ), do provide quick working and efficient filter medium,
Back asap.

testing.:smile:
dredgerRe: Dredging w/Hydraulic Excavator
Please note the height of the water in the work hole in both above pics, new guys please note the method being used, is focused on the sluice being placed or laid on an undisturbed gravels dam wall, the 12’ long x 6’ wide triple sluice basically has no frame, or floats, to get the sluice as low as possible, the focus is on raising the water “ under “ the jet to minimize lift in the expansion chamber, / jet, and level with the bottom of the box “at the head “, this improves dredge performance,
Please note top pic shows water level in the tailings dam is a few inches above the rear of the sluice, ( it takes a few hours of dredging to bring up the tailings dam water level, at which time I lift the engine pump frame up a few inches setting the level so the foot valves are only have a few inches lift,
Please note last pic, the dredge pumps are positioned in the tailings dam, also please note in the above larger picture, the rear of the sluice cannot be seen, but the 13hp red engine cover can be seen mounted in the frame, (petrol tank is removed) black exhaust cover can also be seen, please note motor sits in a s/s metal tray,
Please note the water level in the tailings hole will rise quickly, once the water level rises above the frame base, and the s/s metal tray more or less floats, this results in the pump inlet will only be a few inches above tailings dam water level, (less pump lift ) water level in the tailings dam is easy and quick to control,
Why control,??, = Minimum environmental foot print, and how long a tailings filtration dam has to be , and constructing a suitable efficient filtering dam to suit an 8 dredge water through put,
In my situation in my area, river erosion, rocks and all look roughly the same, as most other rivers, I would suggest a 8” dredge operation would require a 40’ tailings dam including foot valve area and 20-30’ filtration wall,
And I am guessing that a 10’dredge operation in the same river hole / materials might have to 60’ long respectively.
The length of the tailings and filter dam walls is relevant to the water through put of the dredge nozzle,
Back asap,
dredgerRe: Dredging w/Hydraulic Excavator
Please note the height of the water in the work hole in both above pics, new guys please note the method being used, is focused on the sluice being placed or laid on an undisturbed gravels dam wall, the 12’ long x 6’ wide triple sluice basically has no frame, or floats, to get the sluice as low as possible, the focus is on raising the water “ under “ the jet to minimize lift in the expansion chamber, / jet, and level with the bottom of the box “at the head “, this improves dredge performance,
Please note top pic shows water level in the tailings dam is a few inches above the rear of the sluice, ( it takes a few hours of dredging to bring up the tailings dam water level, at which time I lift the engine pump frame up a few inches setting the level so the foot valves are only have a few inches lift,
Dig time was about 2 and ½ hours, rehab about 2 hours,
back, asap.
dredgerRe: Dredging w/Hydraulic Excavator

testing
dredgerRe: Dredging w/Hydraulic Excavator
Ok, am having trouble with photobucket, so I will have to leave the filtering tips until I get photobucket working,
One point of interest that sticks in my mind is about digging a hole in dry ground then filling it with water and dredging it,
Generally speaking to new guys, I suggest this line of thought be maintained, the dredge hole or more important the height of the water in the dredge hole is a important factor, as opposed to digging the tailings filter dam,
In fact, when the hole remains open over night, next morning the dredge hole will be full, and the tailings dam will be empty, drained over night,
So I would suggest to keep the work hole more like a swimming pool, as opposed to the tailings dam aka drainage pit,
My experience is to tap into the main flow, my observation was while digging the intended hole, it fills with water, the focus was on dropping the gold, by washing the gravels using the forces the excavator does produce, which forces most clay silt mud into suspension, and because the water level is as high as I can get it, that water is actually being forced through and out the surrounding gravels walls, carrying the silt with it, resulting the walls block up with silt, at which time you have to start restricting the flow into the hole,


Cooks on site

dredgerRe: Dredging w/Hydraulic Excavator
I said,
Hey jake,
I agree very much, but for the new guys information, we also have to consider which %90 we are talking about,
For example, placer situation, and the top layer is glacial silt, ect, with no gold bearing gravels, laying on layers of gold bearing gravels,
"Why not do 90 % of the work with the excavator
Then flood the hole and use the dredge to just clean the bedrock good ",
Agreed,
Now the bit I forgot,
I should have been more specific and said " use the sucker nozzle attached to the excavator to clean and recover most gold on bedrock or on hard packed layers,, then the diver goes in and quickly checks the bottom, and does any crevices”,
Another new 30 sec old thought is to fit a clip on suction hose for the diver?? 5”, to the suction nozzle, ??. so the excavator fits the sucker nozzle, and starts sucking the bottom, after Ό of the hole /bottom has been sucked clean, the water in the hole will be clear, the diver takes his ?? 30’ of?? 4” very flexible suction hose, and attaches his hose to the excavator suction nozzle , and both the diver and the excavator operator can work / suck safely because the water is clear, and the excavator operator can see everything, and focuses on moving the machine slowly around the other end or Ύ of the hole, more on the new ideas on a super excavator suction nozzle coming,
Back asap
dredgerRe: Dredging w/Hydraulic Excavator
Sorry guys , been on the road 5 days, and busy as right now,
Hey jake,
I agree very much, but for the new guys information, we also have to consider which %90 we are talking about,
For example, placer situation, and the top layer is glacial silt, ect, with no gold bearing gravels, laying on layers of gold bearing gravels,
"Why not do 90 % of the work with the excavator
Then flood the hole and use the dredge to just clean the bedrock good ",
Agreed,
Another example is in my situation where river gold bearing gravels start at the top, so I dig a hole which is full of water and I wash everything, as part of the method of dropping in the gold as I dig the hole,
So new guys please note we are talking about removing gold bearing gravels and none gold bearing materials, and either having water in the hole or not, ??. so,

My line of thought right now is about getting fresh clean water in the work hole, filtering dirty water and even recycling filtered dirty water into the work hole,
More dredging with excavator stuff, please note the first sketches, tapping into the flow, and recycling filtered clear water back into the work hole,
http://bb.bbboy.net/alaskagoldforum-viewthread?forum=2&thread=506&postnum=0
New guys Please note in the aerial pictures (two sites, USA and Australia) the flowing stream there are small rapids, this indicates the water flow is falling at a good angle, that and the fact if you dig a hole out of stream in the gravels it will fill with some or allot of water, my point being you can tap into clean filtered water moving through the gravel bed, ok it is dirty when it is dug, but quickly clears,
Trench.

I cut this trench as quick as I could just to get clean water from the flow on the other side of the river, I also observed that soon more water was filtering with the high side wall of the trench then was coming from the river flow, which was enough to have clear dredging water, please note digging the hole and trenching results in dirty water for a short term, then the mud settles, 3-6” deep, so if you are a new guy and never actually dredged before, you will quickly learn to keep the water clear, you suck up the mud layer before disturbing it, it is that easy ,

Filtering dredge tailings water is in my experience is a little tricky, for the new guy with no experience, some good tips coming asap,

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