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Post by shivan on Sept 17, 2012 20:37:24 GMT 10
G'day all, i have allmost a small bucket full of black sand consentrates from our trips highbanking. These have all been run through a blue bowl and i would now like to see if there is any hidden micron gold trapped in the black sand. Just a bit of an experiment ;D Just trying to figure the best way to go about roasting them before throwing it in cold water. Could i just do small amounts over a gas burner? Would that be hot enough? Should i just build a fire and try to get something to roast it on? Sorry if it seems a basic sort of question i just have no idea of the sort of heat i need
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Post by stack992 on Sept 18, 2012 5:18:54 GMT 10
You only need to roast if you suspect sulphides,I'd go straight to a Aqua Regia digest,(look the recipe up) its powerful stuff and then you add sodium meta bisulphite (Beer bottle cleaner) available from home brew shops,this will precipitate the gold back out and it drops it in the form of a brown sludge,you filter this using coffee filters and then you fire the powder.There is also a borax method I have read about,all avialable on the net.
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Post by shivan on Sept 18, 2012 8:27:53 GMT 10
Thanks for the ideas stack. Iam actually not looking for sulphides but just would like to see if there is any free gold attached to the black sand. Thats why iam looking at roasting then thowing in cold water. Not expecting much but have heard of people ok from the process before.
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Post by someday on Sept 18, 2012 11:41:31 GMT 10
G'day Ian, the main reason for roasting is to unlock the gold particles by driving off the sulphur out of the gold sulphides, which can be done over the heat of a fire "outside BBQ", an old woke will do the trick, if you heat it and don't smell that typical sulphur smell, then yu ain't got sulphides! By plunging your now F@ing hot sands in cold water, will/can/maybe crack small amounts of gold that was previously trapped!!!
You really need to clean your heavy sands with Nitric acid, there's probably other acids available these days that will do the same job?
P.s. Merc hates sulphides, and uncleaned ore, when the above is done, re pan, after re panning, you can go through the cons again by adding that naughty word mercury! You can also dolly the heavy's before starting any of the above! Hope this helps
Cheers Chris.
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Post by shivan on Sept 18, 2012 11:59:48 GMT 10
Thanks Chris. I have read of people tumbling the sands in white vinagar to break things down a bit but then also read if roasting the vinigar/acid was not needed. So many things to take in..... I may end up splitting the sand into 3 batches. 1)just roasted 2)just acid/vinigar 3)tumble in acid/vinigar then roast.
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Post by someday on Sept 18, 2012 12:18:01 GMT 10
Your probably right with roasting alone! Remembering, this roasting was to unlock the wealth of gold trapped in the sulphides! Can't imagine the old-timers having rock tumblers ;D The vinegar trick I've heard is fast tracked a tad by adding tartaric acid "used for cooking" ratio's I have no idea!
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Post by stack992 on Sept 18, 2012 16:19:00 GMT 10
your wasting your time with vinegar,just an old tale.You need the hard stuff and Aqua Regia is it,used in small quantity's its extremely cost effective and will dissolve all metals in your black sand.Just wear rubber gloves and dont try drinking the stuff,you'll be right.Its effectivness is AWESOME !!!!
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Post by someday on Sept 18, 2012 17:41:57 GMT 10
G'day stack, there's a tad more behind this subject/post The use of vinegar and mild acids is being used to clean the cons for further treatment! nevu tried it meself, always used Nitric!!
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Post by stack992 on Sept 18, 2012 20:00:58 GMT 10
well I've used a super saturated salt solution with a bit of nitric as well as adding hydrochloric or sulphuric acid to adjust the Ph,I've tried chlorine,bromine and ammonia as well,I've roasted sulphur rich con's that were rich in arsenic.I've set up small leaching circuits with household bins and aquariam pumps and filter cloth,but I've never heard of cleaning up your con's with vinegar.Cleaning your gold with it,yes. AR all the way !!! it rocks,but each to their own.
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Post by shivan on Sept 18, 2012 20:09:50 GMT 10
This is some advise from another site.
I got interestesd from reading this.
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Post by stack992 on Sept 18, 2012 20:29:53 GMT 10
Leaching is a very interesting subject and I know Donny for one to have alot of experience in this area using CLS,but for my money,simplicity and effectiveness,Aqua Regia wins hands down.
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Post by stack992 on Sept 18, 2012 20:38:36 GMT 10
Try leaching this,i got a hill made of it.Its a poly metallic sulphide ore,and is made up of pyrohitite,chacolpyrite,arseniopyrite,lead,iron and somewhere inside it chemically locked up is GOLD!!!
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Post by danielkrupski on Jun 6, 2016 16:13:59 GMT 10
Hey shivan did you ever get round to seeing if it works?
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Post by shivan on Jun 6, 2016 16:48:37 GMT 10
Have not tried this out yet, have not had the time. We have just got a small fire pit out the back so i may be able to give it a go now. Then i can finally get rid of all my black sand
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Post by danielkrupski on Jun 13, 2016 19:09:23 GMT 10
I think I might give it a go. I got some concentrates that are sitting in the garage ready to be processed through the Angus concentrate cleaner and then the blue bowl. Thinking I might give what ever comes out of the blue bowl that isn't gold a bath in vinegar and then roast it. Don't have a tumbler so see what I get. Worst case scenario I wasted a couple dollars on a bottle of vinegar, or is the tumbling an important step ?
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