Pitch angle and flow rates effect on recovery

[Goldtarget]

I want to open the discussion by saying I'm certainly no expert when it comes to highbanking, but after doing some testing I've got a few questions about certain theories and i wondered if anyone else out there can provide some input. Obviously in the field there are many variables but i have noticed a strange occurrence in recovery rates whilst varying the pitch (or degree of angle slope) whilst using my little low banker. I've heard so many times the repeated mantra about an optimum angle being used that's not too steep, thus blowing out the gold, and not too shallow allowing build up to occur, packing riffles and eventually the box, and then blowing out the gold, out not refining it properly.

But here's what has had me thinking, in a regular box the entire length of the box remains a a single unbroken line along the horizontal. Varying the pitch along that static line the user can generally find that "sweet" spot, but without catching and checking the tailings and/or determining the actual type and size of the gold being processed can we be sure that the box is "optimum"? Flow rate not only has a direct correlation with recovery, but input cost, where the flow is drawn and regulated by a petrol driven pump. Adding pressure increases the input cost, not only in fuel, but wear and tear and therefore overall life of the pump. So back to my observation. If I increase the delivery angle of the material via slick plate it increase my flow rate without adding any load to the input (pump).

Secondly with the flow rate adjustable from the slick plate only i found i can decrease the angle of the box,(so the setup looks like a lazy L shape horizontally) and achieve better recovery because the unwanted material clears but the reduced pitch keeps the gold further up the delivery end of the box. However these angles must run parallel, in a two tier banker the flow changing direction from the top to bottom negates the velocity added to the flow.

My next testing is to run a lazy z pattern box to see what can be achieved. I currently run no riffles in my lowbanker, i have no need to interrupt the water race. Funnily enough another pa member did the same test using lead shot that i did, give one of those enough velocity and watch it bounce over the riffles and out the end with a steep pitch, and you can only imagine what a similar water worn picker would do. If you think about how gold behaves in stream you can quickly see how a long straight plane that is downward slopingusing gravity can encourage gold toward the bottom of the box. It's just my observations in revising recovery rates.

 

[dwt]

MY 2cents> When i first started building machines to recover gold i wanted to put out a recovery box that could 100% catch everything, much to my digust i almost found it impossible to do, catch all the heavies was no problem, but what about heavy fines and flat pieces (flakes & flour), since attempting this development for the best part of 4-5 years, i have still not been able to build such an item....
1) Sluice angle to steep loose small gold up to pickers 2) To flat over load sluice, block up riffles/mesh/moss/ect 3) Sluice set to 1 in every 12, sluice remains relativley clean seems to catch 90% of gold 4) Add clays to the 1 in every 12 theory, have test panned waste and found tiny flake gold 5)Level out 1/12 theroy run clays, now add rough course quartz and ironstone of various sizes, start blocking up riffles, mixed with clays start blocking grid mesh and build up riffles. 6) Increase water volume to keep box clear now add smooth rounded river pebble tese can and will get enough speed up up they will knock some picker size pieces out of the box 7)smoothe rounded river pebbles/clays rough quartz/ironstone rock/flat shaley rock (from reef) and now a whole new can of worms has been opend up. And if your like me where the loss of one tiny piece of gold leaves you lying on the dirt in the fetal position crying like an infant, you can possibly see why i have gone to such extremes... 8.(
What i have done to attempt, to combat this situation the best way i know how.... 8)
the below sluice box has punched sheet across the full length of the box, its removable in two sections, allowing anything under 8mm round to fall through, thus, not allowing flat reef rock, round river peeble and rough rock to impeed the working abilty of the below riffles and xpanded mesh.

This first section with its skid plate allows smooth travel down the punched sheet for any over size

Now you can see the riffles with the xpanded mesh section in between the first stage is missing allowing smalls to get some speed and lights to get some bouyancy to start their travel over the xpanded mesh

The below pic showing all parts seperated

key point to note the height of the punched sheet above the riffles must be relative the hole diameter size of the punched sheet + 5
by this i mean 8mm hole add 5mm =13mm/ 13mm is the height of sheet above riffles

And finally the seperating screen, this allows any oversize pieces of gold to be seperated from fine waste, making it easier to pick up with a detector after i have finished washing dirt.

This system has been working very well, there is marine carpet that goes below all of these seperators, this HOWEVER means large water capacity, AND constant sluice box maintenance, maintaining the sluice box during washing is paramount to ensure no gold gets knocked around during washing.
i do not use this system with trommels because of the screening done when trommeling.
THIS is not a 100% gaurantee im am not loosing gold but from 1000kg of dirt processed having put in some 30 pieces of lead(no 6 &4 lead shot) some flattend some still round, and 5 grams of steel swarf i managed to recover all of the above items.... hope this helps some people and good luck

 

[Goldagettin]

dwt.... wtf ...

Just how many bloody toys do you have????????

Some of us have the "gold fever"... but you my friend are...... well...... YOUR OBSESSED

I love it, I have already sunk a heap of cash into this fever and am now working on a trommel and a high banker and.....
All this and I have only found a few specs in a local creek. I recon once I start getting good color I'm going to have to move to a place with a bigger workshop and buy a tri axle trailer to cart my gear around in.....lol

Keep up the good work, you are an inspiration in my book.

cheers

 

[Teemore]

DWT that's some serious recovery toys you 're playing with there, the local steel merchant must love you walking through the door.
I'm thrilled when I can process a few bucket loads, guess you're doing front end loader loads to keep those babies happy.
Hope the recovery rates equal you input, looks like you deserve it with that much effort,
Cheer Tom

 

[Goldtarget]

Awesome Dwt, just helps put some pics to the discussion of your processes, I'll sit and analyse this when i have some time, i love how everyone has an approach to recovery and in testing different theories, which i exactly why i started this thread, this all began from a YouTube clip i watched on a comparison of riffle systems with diff flow rates adding expanded and different Mains, the guy was pretty comprehensive and some of what he discovered and showed was very interesting, the tiny changes and their effect on recovery opened my eyes. As with everything gold related if we always do what we've always done we may never improve.

 

[dwt]

I was reluctant to post this pic then i thought what the hell!!!, this is my first ever high banker/sluice box. built some 5 years ago i used some old gal sheet i found in the bush, a screen off a protective heat cover from a fire place and fish tank filters....... it caught gold......from the damage you can see i was THAT excited after finding my first piece of wash dirt gold, i backed strait over the top of it in a rush to get home and show it off to the mrs... 8.(

i plan on using some of these machines (obviously not the above pic) on PA member day outs or weekenders, i'd like to think that i could even make it as far up as N.S.W for one of those PA get togethers.

I would like to emphasize that in no way am i trying to impeed on the efforts of people out there who are doing this on a budget or with little resources, i have the upmost respect for those choose to do DIY's (its where i started).I only share my information in an attempt to help others out so they dont have to go to the lenghts and expense i went to,just to recover some gold.
Good luck to you all and dont hesitate to ask any questions or offer any advice, if its one thing in life i have learned, you can never stop learning......

 

[20x]

MY 2cents> When i first started building machines to recover gold i wanted to put out a recovery box that could 100% catch everything, much to my digust i almost found it impossible to do, catch all the heavies was no problem, but what about heavy fines and flat pieces (flakes & flour), since attempting this development for the best part of 4-5 years, i have still not been able to build such an item....
1) Sluice angle to steep loose small gold up to pickers 2) To flat over load sluice, block up riffles/mesh/moss/ect 3) Sluice set to 1 in every 12, sluice remains relativley clean seems to catch 90% of gold 4) Add clays to the 1 in every 12 theory, have test panned waste and found tiny flake gold 5)Level out 1/12 theroy run clays, now add rough course quartz and ironstone of various sizes, start blocking up riffles, mixed with clays start blocking grid mesh and build up riffles. 6) Increase water volume to keep box clear now add smooth rounded river pebble tese can and will get enough speed up up they will knock some picker size pieces out of the box 7)smoothe rounded river pebbles/clays rough quartz/ironstone rock/flat shaley rock (from reef) and now a whole new can of worms has been opend up. And if your like me where the loss of one tiny piece of gold leaves you lying on the dirt in the fetal position crying like an infant, you can possibly see why i have gone to such extremes... 8.(
What i have done to attempt, to combat this situation the best way i know how.... 8)
the below sluice box has punched sheet across the full length of the box, its removable in two sections, allowing anything under 8mm round to fall through, thus, not allowing flat reef rock, round river peeble and rough rock to impeed the working abilty of the below riffles and xpanded mesh.
https://www.prospectingaustralia.co...28/1397430673_15_april_2014_003-optimized.jpg
This first section with its skid plate allows smooth travel down the punched sheet for any over size
https://www.prospectingaustralia.co...28/1397430673_15_april_2014_004-optimized.jpg

Now you can see the riffles with the xpanded mesh section in between the first stage is missing allowing smalls to get some speed and lights to get some bouyancy to start their travel over the xpanded mesh
https://www.prospectingaustralia.co...28/1397430673_15_april_2014_005-optimized.jpg
The below pic showing all parts seperated
https://www.prospectingaustralia.co...28/1397431274_15_april_2014_006-optimized.jpg

key point to note the height of the punched sheet above the riffles must be relative the hole diameter size of the punched sheet + 5
by this i mean 8mm hole add 5mm =13mm/ 13mm is the height of sheet above riffles

https://www.prospectingaustralia.co...28/1397431274_15_april_2014_007-optimized.jpg

And finally the seperating screen, this allows any oversize pieces of gold to be seperated from fine waste, making it easier to pick up with a detector after i have finished washing dirt.
https://www.prospectingaustralia.co...28/1397431274_15_april_2014_008-optimized.jpg

This system has been working very well, there is marine carpet that goes below all of these seperators, this HOWEVER means large water capacity, AND constant sluice box maintenance, maintaining the sluice box during washing is paramount to ensure no gold gets knocked around during washing.
i do not use this system with trommels because of the screening done when trommeling.
THIS is not a 100% gaurantee im am not loosing gold but from 1000kg of dirt processed having put in some 30 pieces of lead(no 6 &4 lead shot) some flattend some still round, and 5 grams of steel swarf i managed to recover all of the above items.... hope this helps some people and good luck

reading this just cracked me up big time, the fetal position(can relate BIG TIME) :lol: :lol: ....no wonder im having a nightmare trying to work out how to GET IT ALL from my system. I think I have to agree that there just is no 1 size fits all for all gold and ground types. ive been dealing with everything you just said in 1 spot as far as ground type goes and as a newby its done my head in big time. brilliant sluice build mate...a reflection of real passion,determination and enginuity

 

[20x]

I want to open the discussion by saying I'm certainly no expert when it comes to highbanking, but after doing some testing I've got a few questions about certain theories and i wondered if anyone else out there can provide some input. Obviously in the field there are many variables but i have noticed a strange occurrence in recovery rates whilst varying the pitch (or degree of angle slope) whilst using my little low banker. I've heard so many times the repeated mantra about an optimum angle being used that's not too steep, thus blowing out the gold, and not too shallow allowing build up to occur, packing riffles and eventually the box, and then blowing out the gold, out not refining it properly.

But here's what has had me thinking, in a regular box the entire length of the box remains a a single unbroken line along the horizontal. Varying the pitch along that static line the user can generally find that "sweet" spot, but without catching and checking the tailings and/or determining the actual type and size of the gold being processed can we be sure that the box is "optimum"? Flow rate not only has a direct correlation with recovery, but input cost, where the flow is drawn and regulated by a petrol driven pump. Adding pressure increases the input cost, not only in fuel, but wear and tear and therefore overall life of the pump. So back to my observation. If I increase the delivery angle of the material via slick plate it increase my flow rate without adding any load to the input (pump).

Secondly with the flow rate adjustable from the slick plate only i found i can decrease the angle of the box,(so the setup looks like a lazy L shape horizontally) and achieve better recovery because the unwanted material clears but the reduced pitch keeps the gold further up the delivery end of the box. However these angles must run parallel, in a two tier banker the flow changing direction from the top to bottom negates the velocity added to the flow.

My next testing is to run a lazy z pattern box to see what can be achieved. I currently run no riffles in my lowbanker, i have no need to interrupt the water race. Funnily enough another pa member did the same test using lead shot that i did, give one of those enough velocity and watch it bounce over the riffles and out the end with a steep pitch, and you can only imagine what a similar water worn picker would do. If you think about how gold behaves in stream you can quickly see how a long straight plane that is downward slopingusing gravity can encourage gold toward the bottom of the box. It's just my observations in revising recovery rates.

my 1.5 cents worth, 2 sluices set on different pitches, regardless of flow rates and pitch angles set on either the gold drops in 1 or the other BUT...slowing the feed rate changes everything regardless of everything else, I feed a maximum of 20 shovels slowly and rather than just stand there and watch the clogging ofthe expanded clear I allways have my drum at the end to catch the fine tailings and I continuously liquify it with the shovel and skim the top out so I end up with cons in that to. shortening my runs and cleanouts seems to help to but then I just end up with con-overload and I might aswell just leave it in the ground and speed pan till my back seizes :lol: :lol:

great topic mate

 

[Goldtarget]

Excellent point, and food for thought, thanks for putting this in. Currently brainstorming and in production of a couple of prototypes of a completely different nature to much of what is out there after spending some time with an industrial engineer and explaining and discussing a few concepts with him about gold processing and capture, blew my mind what these guys can can up with, armed with my requirements and problems and set to task in an area he had never designed for he came up with some unique designs. These of course remain unproven until I'm done tinkering but I'm very excited. Money well spent to gain a fresh perspective.