Dream mat to classify or not to classify

[Anolphart]

I bought an 8 Gold Rat sluice that uses the dream mat several months ago and have used it a couple of times in a local river. Whilst there has been gold mining and dredging activity in the area in years gone by, its not a high yielding river, however the Rat has caught some gold there and I am pleased with its performance.

My normal procedure is to classify the material prior to feeding it through the sluice, but the other day I experimented by feeding 3 buckets of unclassified material straight through the sluice and the returns appeared to be no less productive than when I had classified them. The unclassified material contained some golf ball sized rocks which were washed down the dream mat and spat out without too much trouble. Occasionally an odd shaped rock would jam, but for the most part it seemed to work quite well. I guess on hindsight I should have tested the tailings to see whether I had lost any gold but I was wondering what you guys do. Do you classify your material when using the dream mat?

PS; I might add that I had not altered the angle nor the volume of water flowing through the sluice.

 

[Caconym]

I haven't used the dream mat myself, but I seem to recall from their website that the 6" mini mat is sold as requiring classification, which makes me think the larger mat is somewhat designed to not require it so much. Curious to see what others say as I'm interested in buying one.

 

[MikeB05]

G'day Anolphart (love your name!)

I also have an 8 inch dream mat river sluice.

Must admit I have classified down to half inch. My results are good with capture of very fine gold.

I also keep a pan at the end of the sluice and check tailings to see if any gold gets through to that pan...zip...so pretty happy.

I recall when these mats first came out there was a suggestion of no need to classify.

Great question...maybe Golddigg can give a definitive answer on 'classify or not'.

In summary..I am a very happy dream mat user and the sluices made by Gold Rat Highbankers are excellent quality.

cheers
Mike

 

[AussieChris]

I have the 12" the 8" and a little 6".

For me personally, it comes down to how much water I have running over the mat. Summer here was brutally dry and most places either dried up or came down to a trickle. So if the water was a bit low and slow, I definitely would screen it down, this mat certainly loves and can handle quite a bit of water.

Sometimes, however, you need to just push volume over quality. If the river is kind to me and there is plenty of water for the 12" I won't classify, but at the same time I'm not chucking boulders down it either.

The urethane seems to be tough as nails, but I really don't want to push its durability with oversized/jagged rocks tumbling down it, I'm sure Dustin has thrown everything he could at it in the testing process already.

I certainly do screen the 6", but that is my little backpacker unit and I doubt there would be any sluice that size that you would not screen. Geez they are good for fine gold though, last time I went out with that one I came home with well over a gram, I love seeing those cells churning with colour.

We had rain here the last 5 days so I was all super keen to head out early this morning, of course, something came up.......lol hobbled again for the weekend!

 

[Anolphart]

I have the 12" the 8" and a little 6".

For me personally, it comes down to how much water I have running over the mat.

That makes sense. I was fortunate that I had enough water on that occasion, but of course a lower volume probably would not have enough power to move the bigger rocks and then it's back to screening.

 

[Shep]

While the gold rat products I have are a 12 highbanker and a little clean up sluice I would only classify if there wasnt enough flow to clear the bigger rocks. I have Shoveled a metric crapload of material through my highbanker and always have a pan at the bottom and have only ever found one little flake and chances are it was in the pan before putting under the sluice.

 

[G0lddigg@]

Great to hear good feedback fellas, and sounds advice above.

If i can offer my two bobs worth. the wide cell green dream mat is a self classifying cell by design, there are several small features in that profile which prevent most oversize from settling in to the mat, in saying that there are limitations in the type of rock which will self clear. Large shale or slate whihc has a large surface area will have too much surface area to tumble clear same as any sluice so when working bedrock with a crowbar i do use a half inch sieve in a bucket to remove these. 99% of the time i shovel straight it without classification this is because I've control tested and batch tested these profiles extensively and it is very hard to see migration past the first 50% of the mat, even with rocks building up displacement is rare and instead of gold being blown out the rock within the vortex tends to create mini vortexes instead and the gold still pins down and winds its way toward the holding cell (the little circles).

where i do recommend using a sieve is to liberate gold, if you dump and chunk of clay with cobble into the sluice yes it will be ground up to an extent but the gold will often be stuck in a large rock under clay so i use a sieve to bust my clay into a pan then dump the whole pan in.

As has bee said above if you find yourself in a really low flow situation you have to think about how much water pressure it takes to move a larger rock, just like hosing a peddle on the driveway it takes quite a bit of force, no different here you can still use your dream mat in low flow but classifying will allow you to move more material faster through that low flow.

the new cell the mini that was designed with a particle grade from the start, and from my testing in the final design 8mesh was rock solid so that's what i recommended, but i have to say that's partly aesthetics i dont like seeing rocks hanging around the same principles apply in the mini as the large cell in that the mini vortexes will still pin gold down and the sheer volume of prospectors i see every day on facebook around the world using the mini and not classifying and the gold they get is astonishing, better than i ever imagined when we released this product.

One of the tests we do is use 1 ounce of ground tungsten which has the same SG as gold and we have a mine customer who charges their gold particles with radiation then they blast tonnage through the plant and we see if we can displace the gold, the ratation charged particles are always still in the top few cells thats how we measure migration.

its all good fun, i cant wait to get out and wash some rocks soon been stuck in the office for too long

 

[Jomfi]

Hi I using this mat I buy from second hand I testing this mat u need classify for small gold pus it's problem when you have Dark sand filling up non stop it's good stuffs but big rocks alway stucks in hole. I like it but if not enough water it's not working properly sometim.

 

[G0lddigg@]

HI Jomfi

yes any recovery system will load up if you dont have enought water and dream mat is no different. the aim is 3/4 inch of water over your mat at all times and for me is generally end up sitting at between 8.5 and 9.5 degrees. I hope that helps you dial your sluice in.

 

[Jomfi]

Ok tank you but small gold is flying away when I put too much. Water How I fix I using for clean up alot of Dark sands

 

[G0lddigg@]

small gold will not migrate very well in a dream with sufficient flow, my only guess is that you are running your mat way to low of an angle and are overfilling and overfeeding the cells. if you cant see the material exchanging in the cells i.e. dancing around you either don't have enough flow or angle or both.
If the cells are full of heavy sands and not moving most likely your sluice is too wide. this system isn't a gimmick its a proven system using advanced fluid dynamics its very rare to lose fine gold. I have over 30 mines on my books all running dream mat exclusively all catching extremely fine gold.
maybe you could show us some photos of videos of your set-up so I can help.

 

[Anolphart]

Learning is all about experimenting and getting to know what works (and doesn't work) in different conditions ... and then you push the boundaries to learn some more.

Thank you for all the information.

 

[Jomfi]

No it's ok must cleaning every 2 hour. I see America has mat and they say is good is best one I want to buy it. Who is making dream mats is America or not

 

[G0lddigg@]

Dream mat is made right here in Australia, its also made in Montan USA, Canada, UK