Post by Admin on Sept 12, 2008 16:40:36 GMT 10
From: Jericho158 (Original Message) Sent: 25/08/2008 4:13 PM
Hi all I notice there has been a lot of talk about Miners Moss. How well do you think it works? Is it self cleaning or dose it retain the heavies which would mean you would need to clean out more often. Can anyone help with these questions? Thanks Jericho.
From: Banjo520 Sent: 25/08/2008 7:01 PM
Miners Moss, yes a lot seem to like miners moss. But as you say it is not self-cleaning. And will compel you to clean up much more frequent than what you would need do using other types of matting. The point been if you over shoot a cleanup you will lose gold. The best matting I have ever used was a grass type-matting boy was it good. Cheers James
From: White_Eagle653 Sent: 25/08/2008 7:39 PM
Miners Moss !
I am still testing it and found that it does work, but as James said it is not self cleaning, I set up my banjo slightly different today as what I did last week and found very little gold in the matting/moss
compared to last week, I believe the angle of the banjo and the water flow is very important, if it is to steep chances are you will loose gold, if it is not steep enough the riffles and matting will clog up and you will also loose gold, so you must have the level of your banjo at a perfect angle or you will do a lot of work for nothing. that obviously applies no matter what matting you use.
Cheers W/E
From: Banjo520 Sent: 25/08/2008 8:25 PM
The angle of the banjo and the water flow is very important mate how true are those words! I often see units set far too steep for fine flood gold it’s so important to run the sluice at a slower angle when working fine gold. James
From: KiwiJW2 Sent: 25/08/2008 8:59 PM
Hi there guys, I LOVE MINERS MOSS or nomad matting as it is also known as. I have it in my dredges, sluice boxes & banjo. As has been said, it is important to have the right slope on the box & the right velocity of water going down the box & over the riffles. It is also VERY important to have the riffles the right disatance apart so that the churning, dancing & vibrating action of the material & black sands inbetween the riffles is maintaned as they flow over the riffles. It is this action that flushes the lighter material on & out of the riffles & lets the heavy elements settle in behind the riffle & into the matting. If the action is correct then the gold should be shuffling the black sands out. The biggest mistake is to overload the riffles with too much material & this upsets that dancing ,vibrating action & doesnt let the heavy elements settle to the bottom. The riffles get clogged & the goodies just wash over the top of every thing & out the end of the box.
If this churning action is maintained it will also help keep the miners moss from getting too clogged up in most circumstances. The only time this may not be the case is when you encounter heaps of iron sands & you will then need to keep an eye on things & clean up more often. This is a big problem I have. Heaps of iron sand.
I had some pics I was going to put up but I cant delete old pics to make room for these ones GRRRRR. Same old problem. If I can sort this then I will put these pics up.
JW
From: Banjo520 Sent: 25/08/2008 9:14 PM
Iron sands dose it not drive you nuts, I know what your talking about JW. And Tin mate dose just the same sob James.
From: Banjo520 Sent: 25/08/2008 9:18 PM
I forgot to add corundum sands to the list same deal. James
From: Bbbungy2 Sent: 26/08/2008 9:43 AM
Jericho158,
Hi there - in response to your question and resulting/varying comments I wish to add my comments based on some recent equipment trials utilising Miners' Moss, backed with a small ribbed rubber mat obtained from Clarks Rubber.
Out of frustration a couple of years back I started casting and testing my own mats of various surface profiles to suit use in banjos,sluices etc.Generally they worked well but tended to be a bit pricey due to material costs for silicone rubbers and polyurethane used to make moulds and mats.Up to that point of time I was sceptical of Miners' Moss ( and just about every other mat obtainable from Bunnings etc.) having tried only the closed back mat variety - that indeed was very hard if not impossible to clear concentrates from.
I was provided with a small sample of the open backed version of Miners' Moss which I fitted and tried in the bottom tray under the riffle section of a banjo.I find that this works well so I discontinued making my own mats as there was nothing to be gained , by making my own. In performance and based on area/cost ,it was more expensive in terms of cost ,time and effort making them.
I have recently done some further trials with a rocker type concentrator in which I again used open back Miners' Moss with an underlay of the small ribbed rubber mat - the results were most satisfactory.Especially bearing in mind that a rocker sluice by it's design and method of operation would be far more prone to plugging of the retention mat compared to a banjo or sluice as it has very low fluid motion and velocities compared to the latter.I found that it was possible to work the rocker effectively putting through a very useful amount of wash dirt between clean ups and noted that there was no overloading of the Miners' Moss mat.Both fine and shotty gold became effectively trapped in the mat and were easily washed out for final panning clean up.Upon return home I have dried the mat and cleared out the few remaining bits of gravel panning them off for inspection - there was no gold left in the mat ( I can assure you that there was at the first field clean up).For cleaning the mat in the field I have fitted a 25mm. dowel along the long axis of a rectangular plastic camping hand wash basin- when I release the mat from the rocker tray I roll it carefully into a scroll ( open weave outwards) then place it in the plastic basin (filled with water to a level above the dowel) and slowly draw the mat backwards and forwards around the dowel several times which causes the concentate to be quickly and effectively discharged from the mat weave into the basin. Concentrate is then transferred to the dish for final panning and clean up/recovery.
I've done a fair bit of work checking this stuff out now and have to say so far it works well for me (previously a sceptic but now convinced it's good stuff). Price comparison with other materials is well within acceptable reason.That's my personal opinion on the subject and hope that it may be of asistance to yourself and others trying to decide on effective and affordable gold trapping mat materials.The rest is up to your own choices.
Regards.
Geoff/bbungy2
From: Banjo520 Sent: 26/08/2008 3:52 PM
Intresting topic this, it would appear that it all comes down to the amount of black sands which is in the area you are working as to how well the moss works. As stated there are 2 types of sands Iron based & corundum based, then you have stream tin all of which seems to effect the operation of the moss. For those of you who have never encountered the black non magnetic corundum sands boy are you in for a treat, more so when you try to separate the fine gold. {smile} James
From: KiwiJW2 Sent: 27/08/2008 8:17 PM
Hi all, One thing I have noticed with your guys banjo's is that the riffles are spaced quite far apart. I have always modled my sluice boxs riffles on the dredge sluice box riffle set up. Where they are quite close together & quite a few of them. This set up seems to keep that dancing, vibrating, churning action of the material between the riffles very lively. If the riffles are far apart you lose this action. The only area you will get this action (mildly) is straight after the material has bounced over the riffle on the down stream side of the riffle. Once the material has moved past the down stream side of the riffle & before it reaches the next riffle, the water pressure & velocity is only pushing the material with no more churning, dancing or vibrating action & therefore there is no shuffling of the material to concerntrate the heavies to the bottom & wash out the lighter stuff. This is where miners moss or nomad matting will quickly fill up with black sands as that concertrating action isnt there to keep the material lively.
JW
From: KiwiJW2 Sent: 27/08/2008 8:33 PM
Here is the very fine gold I got for an hours shoveling of some iron sand deposits that were left high & dry above the normal river flow after a pretty high flood we had a few weeks ago. This just shows the the ability of the banjo to retain this fine gold with the help of miners moss. I have no trouble at all in cleaning out the matting in the final wash up. The matting I am using has the solid backing. I have never tried the non backed matting.
Here is the matting
Happy golding
JW
From: KiwiJW2 Sent: 27/08/2008 8:43 PM
I forgot to mention that I ended up with about a cups of black sand & I just panned down to the iron sand stage at the river & then came home & used the Blue Bowl to seperate the fine gold from the black sands. I am a big fan of the Blue Bowl too as I would have normaly used mercury to recover this fine gold from the black sands, but not ant more.
JW
From: AlluvialRic Sent: 27/08/2008 8:50 PM
G'day JW. Is the Blue Bowl you use the real thing or one you have fashioned yourself?
Cheers Ric
From: White_Eagle653 Sent: 27/08/2008 8:51 PM
JW
how many riffles would you have in a banjo which is say 500mm
long ?? I have processed my fines which I did get yesterday and found only 5 little specks in the miners moss and nothing at all in the pan at the outlet of the bottom hopper, that indicates to me that the setup of my banjo was correct and that the water flow was correct but most of all my tray's were doing what they were designed to do.
Cheers W/E
From: Steve_B Sent: 27/08/2008 9:39 PM
I agree with JW, when I'm using miners moss I have my riffles closer together. In one study done in Canada it was found that you got optimum performance when the gap between 1" Hungarian riffles was 2" (that study used to be in a PDF file here, I don't know if it's still around). I now always set the gap to twice that of the riffle height and I find I only get compacting black sands when I inadvertently overload the sluice. Even then, the moss soon clears itself if you let the sluice run clean for a minute.
I do my cleaning of the black sands with a home-made blue bowl and it works quite well. I'm trying to get hold of a shop bought one though as I've used one and it works better than the one I made.
Cheers,
Steve
From: KiwiJW2 Sent: 27/08/2008 10:48 PM
Hi guys,
Ric, the blue bowl is the real thing. I got it in from the States off ebay. At first I wasnt that impressed with it. I thought it too slow & I guess in my impatients speed it up too much & didnt recover much fine gold. In time I learnt to slow the water feed down for the fine gold & use a lttle gold sucker bottle to suck up the fine gold left behind on the outer edge of the bowl as the sands gravitate towards the center. This is done by turning off the water feed, sucking up the gold, blowing the sands with the sucker bottle back to the outside edgfe of the bowl & then turn the water back on. This is repeated until there is no more gold & the sands have droped down the center of the bowl & into the waste bucket. Not that the sands are thrown away but kept for further treatment. It pays to only process about half a cup of sands at a time & to keep an eagle eye on the sands & gold to make sure no fine gold is going down the waste hole. If it is then the water is backed off a bit.
W/E, as to the riffle distance what Steve said is pretty good. My riffles are 20mm high & on a 45 degree angle & spaced about 60mm apart. They wouldnt want to be any more than 3 times their height apart. They could even be a bit closer as Steve said about twice their height. I rememmber a while back seeing a study report done on this but I havnt been able to find it again & I have tried. If what you are doing is working for you then stick with it. I havnt got a catch tray in my set up & have just stuck to what I have done with my river sluice riffles over the years & what works with the dredge. It is like majic to see the sands dancing backwards & forwards, shuffling & churning between the riffles, & you just know that that is all good & that the gold is shuffling back in behind the riffles & settling into the matting with that action. Ther real secret is not to be too impatient & put through too much material at a time but let the water do its job with out over loading the riffles. Otherwise the goodies will dance on out down the end of the box.
In this pic the riffle ladder is 410 mm long & the riffles were 80mm apart. I have since added another riffle & shortened the distance to 60mm
The miners moss is in two pieces. Top of the box & bottom of the box. The reason being that on clean up the gold should be in the top carpet.
If there is gold in the bottom carpet then things arent running correctly & adjustments need to be made. There is also expanded mesh under the riffles & on top of the carpet. I was actualy considering using a much larger expanded mesh as a riffle system on its own. I will try that one day.
Go for gold
JW
From: Steve_B Sent: 27/08/2008 11:13 PM
Hi JW,
This is the one I think:
www.geology.gov.yk.ca/publications/tech/analysis_sluice.pdf
Cheers,
Steve
From: AlluvialRic Sent: 28/08/2008 9:16 AM
That file and many others are still here in the Maps & Pdf folder.
Go to Maps & pdf files then click "Books" then click "Book 1" and there is enough info there to keep you reading for weeks.
Cheers Ric.
From: AlluvialRic Sent: 28/08/2008 9:25 AM
J W,
I was watching the U tube video of the Blue Bowl the other day and I was impressed with its operation.
I was looking at one "in the flesh" at Miners Den last week but the price is very steep.
From: KiwiJW2 Sent: 28/08/2008 6:56 PM
Hi there Ric, Out of interest, how much was the blue bowl at Miners Den?? I paid US$60 for the bowl plus freight. I cant rememmber now how much all up it was. That was a few years ago now.
It is a bit slow to use but it does a good job. Kind of job to do on a crap day when you cant do much outside & you have a bit of time.
Happy golding
JW
From: Sigron2 Sent: 28/08/2008 7:33 PM
Have a look at
www.pioneermining.com
Ron
From: Banjo520 Sent: 28/08/2008 9:21 PM
Guys you better read the full story to Analysis of a Sluice, some very good reading in the reports. James
www.geology.gov.yk.ca/publications/tech/gold_loss.pdf
www.geology.gov.yk.ca/publications/tech/fine_gold_recovery_sluiceboxes.pdf
www.geology.gov.yk.ca/publications/tech/placerrecovery.pdf
This report you got to pay 4. Sob
search.informit.com.au/documentSummary;dn=846215796438657;res=IELENG
From: AlluvialRic Sent: 28/08/2008 9:50 PM
G'day JW
I think the Blue Bowl was about $170.00
Put it this way, I gasped and lost my breath and said a bad word when I saw the price.lol
I reckon our mate Geoff (bbungy) could put one together with his plastics fabrication skills.
Whatdoya reckon Geoff??
Cheers Ric
From: Steve_B Sent: 28/08/2008 10:23 PM
G'day Ric,
Here's a photo of the one I put together. The hard part was finding a washing up bowl with a flat bottom. The one I found was a bit bigger than I would have liked but works ok if you don't put the concentrates too near the outside. I've also fitted a proper valve to regulate the water flow since this photo was taken.
Cheers,
Steve
From: Steve_B Sent: 28/08/2008 10:46 PM
G'day James,
There's some good reading in those documents. The creek that I pan has gold in all shapes and sizes, from flat to round and from fine to chunky. There's also a lot of black sand (mainly magnetite): a few hours work with my sluice can give you almost a full pan of the stuff. What that means is that there's no one method that will catch everything. The one that does a decent job is the black rubber matting that Andy uses in his sluice but even that I usually run with a set of Hungarians following it (both with moss under them). The other thing I do is make sure I've got plenty of water depth over the riffles. This stops the riffles making white water (the big cause of losing fine flaky gold) and also keeps the slurry very dilute, reducing the risk of compacting the riffles and allowing the gold to get down more easily. One thing I have tried is putting an extra section, without any riffles at all, upstream of the first riffles to allow the feed material to mix better before it hits the riffles. Again, this helps stop overloading the riffles with surges of material. The only problem with this is it makes the sluice quite long (each of my sections is 600mm). It's not so bad if you're setting up in one spot for a while but makes it difficult if you have to move around a bit.
Cheers,
Steve
From: KiwiJW2 Sent: 29/08/2008 3:56 PM
Hi guys, Ric...Im not surprised that price took your breath away etc etc. You would get one for a lot cheaper if you got one off ebay
Has anybody tried one of those spiral gold wheels? There was a new one up on our local auction site a few weeks ago. It was between another bloke & me but I gave up on it. They can be put in reverse & used for amalgamating (mercury) & then put forward to get rid of the sands & leave the amalgam behind. I kind of liked that idea too.
Steve great job on your bowl matewell done. On my store bought one the top lip of the hole where the waste goes down has a small 45 degree lip kicking slightly back into the bowl. This is to help drop any gold that gets washed up to the top of that cone before it goes down the gurgler. Sort of like a tiny riffle.
I dont believe it ......but it looks like we are in for a fine weekend & I am off to my little creek tomorrow for the first time since the weekend before Queens Birthday weekend. Be interesting to see it after all the rain & floods we have had.
Take care guys & have a golden weekend
JW
From: Bbbungy2 Sent: 30/08/2008 8:54 PM
Hi JW.
A couple of years back I purchased a Desert Fox 7 start spiral goldwheel from Camel Mining Products in the good old US of A - the exchange rate wasn't too flash at that time and landed it ran close to $500.00 Aus. (kept that one bloody quiet around home).
Used it a few times and wasn't all that impressed - well made and looked good but was pretty slow in all honesty.Eventually sold it on consignment and actually got my $500.00 bucks back! Shows that there's actually more than one born every minute,doesn't it. As I recall ,to mercury amalgamate with it (it didnt have a reverse switch ,although you could simply reverse the 12v terminals to achieve that) you adjusted the wheel to near vertical and shut off the water flow to stop the sands rising to the centre.
I do have the bowl still of a 2 start wheel my mate Bob and I built and used back in the '80's - that was a good one actually with a 20" diameter wheel. It was a bit heavy and bulky but with some modernisation it should spring in to life again soon .I also have the plug mould of the spiral somewhere in the shed as well.Did hope to have it ready for Eldorado this year but it's well back on the list of procrastinations just at present - it would only be a novely event anyway as I reckon that with a set of nesting sieves ranging 10 to 60 mesh and using the plastic pan as trained by James of banjo fame it would be quicker method of gold recovery than the wheel anyway.It is cliamed that they can be direct fed without pre - classification but I reckon that's a bit far fetched - you'd beat the hell out of it with a Garret Super Sluice dish .
Regards.
Geoff'/bbungy2.
From: Bbbungy2 Sent: 30/08/2008 9:19 PM
Hi Ric.
Recall seeing one of those blue bowls a long time ago - they were also flogging a mini sluice made by the same crowd too.Both of them were fed by a 12v bilge pump.Seemed pretty slow as I remember it.
Steve seems to have come up with a good facsimile of the said item so could have some input re building one.I would tend to think that the water inlet might be the critical issue requiring a particular tangent angle to induce the correct flow patten - trial and error could determine that but prior knowledge would save a lot of mucking around. Possibly a good quality water metering (needle) valve might also be required to set the correct amount of water flow and velocity too as that wouldn't be satisfactorily achieved with a ball or gate valve .
I believe my mate Bob Crawford will make it to Eldorado again this year - he's the plastics man.If it can be made and made economically he will know how.If some one brings a unit along for us to have a look at then feasibility and worth can quickly be determined.
I'll just stick to the stuff I can pick up out of the pan myself - I'm getting too lazy for all these fancy gizmos and my shed is too full of good ideas gathering cobwebs.
Regards.
Geoff/bbungy2.
Hi all I notice there has been a lot of talk about Miners Moss. How well do you think it works? Is it self cleaning or dose it retain the heavies which would mean you would need to clean out more often. Can anyone help with these questions? Thanks Jericho.
From: Banjo520 Sent: 25/08/2008 7:01 PM
Miners Moss, yes a lot seem to like miners moss. But as you say it is not self-cleaning. And will compel you to clean up much more frequent than what you would need do using other types of matting. The point been if you over shoot a cleanup you will lose gold. The best matting I have ever used was a grass type-matting boy was it good. Cheers James
From: White_Eagle653 Sent: 25/08/2008 7:39 PM
Miners Moss !
I am still testing it and found that it does work, but as James said it is not self cleaning, I set up my banjo slightly different today as what I did last week and found very little gold in the matting/moss
compared to last week, I believe the angle of the banjo and the water flow is very important, if it is to steep chances are you will loose gold, if it is not steep enough the riffles and matting will clog up and you will also loose gold, so you must have the level of your banjo at a perfect angle or you will do a lot of work for nothing. that obviously applies no matter what matting you use.
Cheers W/E
From: Banjo520 Sent: 25/08/2008 8:25 PM
The angle of the banjo and the water flow is very important mate how true are those words! I often see units set far too steep for fine flood gold it’s so important to run the sluice at a slower angle when working fine gold. James
From: KiwiJW2 Sent: 25/08/2008 8:59 PM
Hi there guys, I LOVE MINERS MOSS or nomad matting as it is also known as. I have it in my dredges, sluice boxes & banjo. As has been said, it is important to have the right slope on the box & the right velocity of water going down the box & over the riffles. It is also VERY important to have the riffles the right disatance apart so that the churning, dancing & vibrating action of the material & black sands inbetween the riffles is maintaned as they flow over the riffles. It is this action that flushes the lighter material on & out of the riffles & lets the heavy elements settle in behind the riffle & into the matting. If the action is correct then the gold should be shuffling the black sands out. The biggest mistake is to overload the riffles with too much material & this upsets that dancing ,vibrating action & doesnt let the heavy elements settle to the bottom. The riffles get clogged & the goodies just wash over the top of every thing & out the end of the box.
If this churning action is maintained it will also help keep the miners moss from getting too clogged up in most circumstances. The only time this may not be the case is when you encounter heaps of iron sands & you will then need to keep an eye on things & clean up more often. This is a big problem I have. Heaps of iron sand.
I had some pics I was going to put up but I cant delete old pics to make room for these ones GRRRRR. Same old problem. If I can sort this then I will put these pics up.
JW
From: Banjo520 Sent: 25/08/2008 9:14 PM
Iron sands dose it not drive you nuts, I know what your talking about JW. And Tin mate dose just the same sob James.
From: Banjo520 Sent: 25/08/2008 9:18 PM
I forgot to add corundum sands to the list same deal. James
From: Bbbungy2 Sent: 26/08/2008 9:43 AM
Jericho158,
Hi there - in response to your question and resulting/varying comments I wish to add my comments based on some recent equipment trials utilising Miners' Moss, backed with a small ribbed rubber mat obtained from Clarks Rubber.
Out of frustration a couple of years back I started casting and testing my own mats of various surface profiles to suit use in banjos,sluices etc.Generally they worked well but tended to be a bit pricey due to material costs for silicone rubbers and polyurethane used to make moulds and mats.Up to that point of time I was sceptical of Miners' Moss ( and just about every other mat obtainable from Bunnings etc.) having tried only the closed back mat variety - that indeed was very hard if not impossible to clear concentrates from.
I was provided with a small sample of the open backed version of Miners' Moss which I fitted and tried in the bottom tray under the riffle section of a banjo.I find that this works well so I discontinued making my own mats as there was nothing to be gained , by making my own. In performance and based on area/cost ,it was more expensive in terms of cost ,time and effort making them.
I have recently done some further trials with a rocker type concentrator in which I again used open back Miners' Moss with an underlay of the small ribbed rubber mat - the results were most satisfactory.Especially bearing in mind that a rocker sluice by it's design and method of operation would be far more prone to plugging of the retention mat compared to a banjo or sluice as it has very low fluid motion and velocities compared to the latter.I found that it was possible to work the rocker effectively putting through a very useful amount of wash dirt between clean ups and noted that there was no overloading of the Miners' Moss mat.Both fine and shotty gold became effectively trapped in the mat and were easily washed out for final panning clean up.Upon return home I have dried the mat and cleared out the few remaining bits of gravel panning them off for inspection - there was no gold left in the mat ( I can assure you that there was at the first field clean up).For cleaning the mat in the field I have fitted a 25mm. dowel along the long axis of a rectangular plastic camping hand wash basin- when I release the mat from the rocker tray I roll it carefully into a scroll ( open weave outwards) then place it in the plastic basin (filled with water to a level above the dowel) and slowly draw the mat backwards and forwards around the dowel several times which causes the concentate to be quickly and effectively discharged from the mat weave into the basin. Concentrate is then transferred to the dish for final panning and clean up/recovery.
I've done a fair bit of work checking this stuff out now and have to say so far it works well for me (previously a sceptic but now convinced it's good stuff). Price comparison with other materials is well within acceptable reason.That's my personal opinion on the subject and hope that it may be of asistance to yourself and others trying to decide on effective and affordable gold trapping mat materials.The rest is up to your own choices.
Regards.
Geoff/bbungy2
From: Banjo520 Sent: 26/08/2008 3:52 PM
Intresting topic this, it would appear that it all comes down to the amount of black sands which is in the area you are working as to how well the moss works. As stated there are 2 types of sands Iron based & corundum based, then you have stream tin all of which seems to effect the operation of the moss. For those of you who have never encountered the black non magnetic corundum sands boy are you in for a treat, more so when you try to separate the fine gold. {smile} James
From: KiwiJW2 Sent: 27/08/2008 8:17 PM
Hi all, One thing I have noticed with your guys banjo's is that the riffles are spaced quite far apart. I have always modled my sluice boxs riffles on the dredge sluice box riffle set up. Where they are quite close together & quite a few of them. This set up seems to keep that dancing, vibrating, churning action of the material between the riffles very lively. If the riffles are far apart you lose this action. The only area you will get this action (mildly) is straight after the material has bounced over the riffle on the down stream side of the riffle. Once the material has moved past the down stream side of the riffle & before it reaches the next riffle, the water pressure & velocity is only pushing the material with no more churning, dancing or vibrating action & therefore there is no shuffling of the material to concerntrate the heavies to the bottom & wash out the lighter stuff. This is where miners moss or nomad matting will quickly fill up with black sands as that concertrating action isnt there to keep the material lively.
JW
From: KiwiJW2 Sent: 27/08/2008 8:33 PM
Here is the very fine gold I got for an hours shoveling of some iron sand deposits that were left high & dry above the normal river flow after a pretty high flood we had a few weeks ago. This just shows the the ability of the banjo to retain this fine gold with the help of miners moss. I have no trouble at all in cleaning out the matting in the final wash up. The matting I am using has the solid backing. I have never tried the non backed matting.
Here is the matting
Happy golding
JW
From: KiwiJW2 Sent: 27/08/2008 8:43 PM
I forgot to mention that I ended up with about a cups of black sand & I just panned down to the iron sand stage at the river & then came home & used the Blue Bowl to seperate the fine gold from the black sands. I am a big fan of the Blue Bowl too as I would have normaly used mercury to recover this fine gold from the black sands, but not ant more.
JW
From: AlluvialRic Sent: 27/08/2008 8:50 PM
G'day JW. Is the Blue Bowl you use the real thing or one you have fashioned yourself?
Cheers Ric
From: White_Eagle653 Sent: 27/08/2008 8:51 PM
JW
how many riffles would you have in a banjo which is say 500mm
long ?? I have processed my fines which I did get yesterday and found only 5 little specks in the miners moss and nothing at all in the pan at the outlet of the bottom hopper, that indicates to me that the setup of my banjo was correct and that the water flow was correct but most of all my tray's were doing what they were designed to do.
Cheers W/E
From: Steve_B Sent: 27/08/2008 9:39 PM
I agree with JW, when I'm using miners moss I have my riffles closer together. In one study done in Canada it was found that you got optimum performance when the gap between 1" Hungarian riffles was 2" (that study used to be in a PDF file here, I don't know if it's still around). I now always set the gap to twice that of the riffle height and I find I only get compacting black sands when I inadvertently overload the sluice. Even then, the moss soon clears itself if you let the sluice run clean for a minute.
I do my cleaning of the black sands with a home-made blue bowl and it works quite well. I'm trying to get hold of a shop bought one though as I've used one and it works better than the one I made.
Cheers,
Steve
From: KiwiJW2 Sent: 27/08/2008 10:48 PM
Hi guys,
Ric, the blue bowl is the real thing. I got it in from the States off ebay. At first I wasnt that impressed with it. I thought it too slow & I guess in my impatients speed it up too much & didnt recover much fine gold. In time I learnt to slow the water feed down for the fine gold & use a lttle gold sucker bottle to suck up the fine gold left behind on the outer edge of the bowl as the sands gravitate towards the center. This is done by turning off the water feed, sucking up the gold, blowing the sands with the sucker bottle back to the outside edgfe of the bowl & then turn the water back on. This is repeated until there is no more gold & the sands have droped down the center of the bowl & into the waste bucket. Not that the sands are thrown away but kept for further treatment. It pays to only process about half a cup of sands at a time & to keep an eagle eye on the sands & gold to make sure no fine gold is going down the waste hole. If it is then the water is backed off a bit.
W/E, as to the riffle distance what Steve said is pretty good. My riffles are 20mm high & on a 45 degree angle & spaced about 60mm apart. They wouldnt want to be any more than 3 times their height apart. They could even be a bit closer as Steve said about twice their height. I rememmber a while back seeing a study report done on this but I havnt been able to find it again & I have tried. If what you are doing is working for you then stick with it. I havnt got a catch tray in my set up & have just stuck to what I have done with my river sluice riffles over the years & what works with the dredge. It is like majic to see the sands dancing backwards & forwards, shuffling & churning between the riffles, & you just know that that is all good & that the gold is shuffling back in behind the riffles & settling into the matting with that action. Ther real secret is not to be too impatient & put through too much material at a time but let the water do its job with out over loading the riffles. Otherwise the goodies will dance on out down the end of the box.
In this pic the riffle ladder is 410 mm long & the riffles were 80mm apart. I have since added another riffle & shortened the distance to 60mm
The miners moss is in two pieces. Top of the box & bottom of the box. The reason being that on clean up the gold should be in the top carpet.
If there is gold in the bottom carpet then things arent running correctly & adjustments need to be made. There is also expanded mesh under the riffles & on top of the carpet. I was actualy considering using a much larger expanded mesh as a riffle system on its own. I will try that one day.
Go for gold
JW
From: Steve_B Sent: 27/08/2008 11:13 PM
Hi JW,
This is the one I think:
www.geology.gov.yk.ca/publications/tech/analysis_sluice.pdf
Cheers,
Steve
From: AlluvialRic Sent: 28/08/2008 9:16 AM
That file and many others are still here in the Maps & Pdf folder.
Go to Maps & pdf files then click "Books" then click "Book 1" and there is enough info there to keep you reading for weeks.
Cheers Ric.
From: AlluvialRic Sent: 28/08/2008 9:25 AM
J W,
I was watching the U tube video of the Blue Bowl the other day and I was impressed with its operation.
I was looking at one "in the flesh" at Miners Den last week but the price is very steep.
From: KiwiJW2 Sent: 28/08/2008 6:56 PM
Hi there Ric, Out of interest, how much was the blue bowl at Miners Den?? I paid US$60 for the bowl plus freight. I cant rememmber now how much all up it was. That was a few years ago now.
It is a bit slow to use but it does a good job. Kind of job to do on a crap day when you cant do much outside & you have a bit of time.
Happy golding
JW
From: Sigron2 Sent: 28/08/2008 7:33 PM
Have a look at
www.pioneermining.com
Ron
From: Banjo520 Sent: 28/08/2008 9:21 PM
Guys you better read the full story to Analysis of a Sluice, some very good reading in the reports. James
www.geology.gov.yk.ca/publications/tech/gold_loss.pdf
www.geology.gov.yk.ca/publications/tech/fine_gold_recovery_sluiceboxes.pdf
www.geology.gov.yk.ca/publications/tech/placerrecovery.pdf
This report you got to pay 4. Sob
search.informit.com.au/documentSummary;dn=846215796438657;res=IELENG
From: AlluvialRic Sent: 28/08/2008 9:50 PM
G'day JW
I think the Blue Bowl was about $170.00
Put it this way, I gasped and lost my breath and said a bad word when I saw the price.lol
I reckon our mate Geoff (bbungy) could put one together with his plastics fabrication skills.
Whatdoya reckon Geoff??
Cheers Ric
From: Steve_B Sent: 28/08/2008 10:23 PM
G'day Ric,
Here's a photo of the one I put together. The hard part was finding a washing up bowl with a flat bottom. The one I found was a bit bigger than I would have liked but works ok if you don't put the concentrates too near the outside. I've also fitted a proper valve to regulate the water flow since this photo was taken.
Cheers,
Steve
From: Steve_B Sent: 28/08/2008 10:46 PM
G'day James,
There's some good reading in those documents. The creek that I pan has gold in all shapes and sizes, from flat to round and from fine to chunky. There's also a lot of black sand (mainly magnetite): a few hours work with my sluice can give you almost a full pan of the stuff. What that means is that there's no one method that will catch everything. The one that does a decent job is the black rubber matting that Andy uses in his sluice but even that I usually run with a set of Hungarians following it (both with moss under them). The other thing I do is make sure I've got plenty of water depth over the riffles. This stops the riffles making white water (the big cause of losing fine flaky gold) and also keeps the slurry very dilute, reducing the risk of compacting the riffles and allowing the gold to get down more easily. One thing I have tried is putting an extra section, without any riffles at all, upstream of the first riffles to allow the feed material to mix better before it hits the riffles. Again, this helps stop overloading the riffles with surges of material. The only problem with this is it makes the sluice quite long (each of my sections is 600mm). It's not so bad if you're setting up in one spot for a while but makes it difficult if you have to move around a bit.
Cheers,
Steve
From: KiwiJW2 Sent: 29/08/2008 3:56 PM
Hi guys, Ric...Im not surprised that price took your breath away etc etc. You would get one for a lot cheaper if you got one off ebay
Has anybody tried one of those spiral gold wheels? There was a new one up on our local auction site a few weeks ago. It was between another bloke & me but I gave up on it. They can be put in reverse & used for amalgamating (mercury) & then put forward to get rid of the sands & leave the amalgam behind. I kind of liked that idea too.
Steve great job on your bowl matewell done. On my store bought one the top lip of the hole where the waste goes down has a small 45 degree lip kicking slightly back into the bowl. This is to help drop any gold that gets washed up to the top of that cone before it goes down the gurgler. Sort of like a tiny riffle.
I dont believe it ......but it looks like we are in for a fine weekend & I am off to my little creek tomorrow for the first time since the weekend before Queens Birthday weekend. Be interesting to see it after all the rain & floods we have had.
Take care guys & have a golden weekend
JW
From: Bbbungy2 Sent: 30/08/2008 8:54 PM
Hi JW.
A couple of years back I purchased a Desert Fox 7 start spiral goldwheel from Camel Mining Products in the good old US of A - the exchange rate wasn't too flash at that time and landed it ran close to $500.00 Aus. (kept that one bloody quiet around home).
Used it a few times and wasn't all that impressed - well made and looked good but was pretty slow in all honesty.Eventually sold it on consignment and actually got my $500.00 bucks back! Shows that there's actually more than one born every minute,doesn't it. As I recall ,to mercury amalgamate with it (it didnt have a reverse switch ,although you could simply reverse the 12v terminals to achieve that) you adjusted the wheel to near vertical and shut off the water flow to stop the sands rising to the centre.
I do have the bowl still of a 2 start wheel my mate Bob and I built and used back in the '80's - that was a good one actually with a 20" diameter wheel. It was a bit heavy and bulky but with some modernisation it should spring in to life again soon .I also have the plug mould of the spiral somewhere in the shed as well.Did hope to have it ready for Eldorado this year but it's well back on the list of procrastinations just at present - it would only be a novely event anyway as I reckon that with a set of nesting sieves ranging 10 to 60 mesh and using the plastic pan as trained by James of banjo fame it would be quicker method of gold recovery than the wheel anyway.It is cliamed that they can be direct fed without pre - classification but I reckon that's a bit far fetched - you'd beat the hell out of it with a Garret Super Sluice dish .
Regards.
Geoff'/bbungy2.
From: Bbbungy2 Sent: 30/08/2008 9:19 PM
Hi Ric.
Recall seeing one of those blue bowls a long time ago - they were also flogging a mini sluice made by the same crowd too.Both of them were fed by a 12v bilge pump.Seemed pretty slow as I remember it.
Steve seems to have come up with a good facsimile of the said item so could have some input re building one.I would tend to think that the water inlet might be the critical issue requiring a particular tangent angle to induce the correct flow patten - trial and error could determine that but prior knowledge would save a lot of mucking around. Possibly a good quality water metering (needle) valve might also be required to set the correct amount of water flow and velocity too as that wouldn't be satisfactorily achieved with a ball or gate valve .
I believe my mate Bob Crawford will make it to Eldorado again this year - he's the plastics man.If it can be made and made economically he will know how.If some one brings a unit along for us to have a look at then feasibility and worth can quickly be determined.
I'll just stick to the stuff I can pick up out of the pan myself - I'm getting too lazy for all these fancy gizmos and my shed is too full of good ideas gathering cobwebs.
Regards.
Geoff/bbungy2.