# Problem getting my gold dust out of my filter



## cableman (Feb 23, 2014)

I followed Lazer Steve's process for processing gold fingers with muratic acid and peroxide, washed the mash really well then dissolved in muratic and chlorox. I used very little chlorox (just enough to get the job done, so it would dissipate easily) and let it sit a couple of nights before adding triple the amount of water to dilute and then I separately dissolved my smb in a small jar before pouring into the solution to precipitate the gold. All worked well and I let it settle for a couple more nights before pouring off the liquid and caught all my gold powder in a 3 piece folded coffee filter. I have been patiently waiting for it to dry out but it has been cold here and I think that has something to do with it. I have a rectangular bowl about the right size to pour it out in and I can scrape it back up without losing any but it seems to want to stick to the filter and this is my pure gold I want to melt. I read some posts about burning filters with residue but I don't think that applies here. Does anyone have any pointers on how to get most all my gold dust off the filters so I can melt it in my crucible. Thanks in advance for any advice.


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## kurtak (Feb 23, 2014)

could you provide some pictures ?

Did you follow the proper washing instructions after dropping the gold & before filtering ? --- I ask because if you didn't get the acid washed out it wont dry & your filter is going to degrade & crumble apart - in which case you will need to incinerate to burn off the chems & then ether leach the gold back out of the ash - or melt/smelt with extra flux to flux off the ash

Why are you filtering anyway ?

I ask the last question because if you follow the prescribed methods talked about on this forum you should be able to drop your gold - wash your gold - & dry your gold - all in the same beaker

Kurt


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## nickvc (Feb 23, 2014)

Pit it into your crucible that's aware. Ot too hot and put into your furnace on a low flame and burn the filter off slowly then raise the temperature to melt your gold.


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## artart47 (Feb 23, 2014)

Hi !
You never have to filter gold you get from the process that you did! Disolve the foils in a beaker,when the chlorine is gone, drop it in the same beaker. after the powder drops siphon or carefuly pour off the solution, You only filter the pour-off to catch any gold that poured off by accident, the gold powder stays in that same beaker, like Kurtak said, till you are ready to put it in the melting dish!
Read about washing gold powder. Keep all the poured off solution, let it set. Sometimes alittle more fine powder will drop.

Your filter paper/gold ? I have had filter paper with gold in it. I put two clean beakers next to each other and put HCl/chlorox in one. put a strainer/w the filter/gold over the other and just start running the solution back and forth from beaker to beaker untill all the powder is out of the filter. Then wash the filter with H2O from a sprey bottle.
You have just made a new cleaner auric chloride solution and have lost no gold.
Hope this helped! Good luck! artart47.


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## g_axelsson (Feb 23, 2014)

artart47 said:


> Hi !
> You never have to filter gold you get from the process that you did! Disolve the foils in a beaker,when the chlorine is gone, drop it in the same beaker. after the powder drops siphon or carefuly pour off the solution, You only filter the pour-off to catch any gold that poured off by accident, the gold powder stays in that same beaker, like Kurtak said, till you are ready to put it in the melting dish!
> Read about washing gold powder. Keep all the poured off solution, let it set. Sometimes alittle more fine powder will drop.


Close but not perfect yet...


> Dissolve the foils in a beaker.
> Filter the solution until it is crystal clear, if cloudy from the beginning just pour it through the same filter again.
> When the chlorine is gone, drop it in the same beaker.
> After the powder drops siphon or carefully pour off the solution (decant), You only filter the pour-off to catch any gold that poured off by accident.
> ...


Some variations are possible, for example heating to expel chlorine before or after filtering.

Personally I pour all the liquids from the dropping the gold and the wash cycles into my stock pot without filtering (any ammonia wash is made acidic first to avoid creating explosive compounds). Any slow settling gold sediments there and any traces of PGM:s is also caught there.

Göran


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## cableman (Feb 24, 2014)

I was following Laser Steve's video on gold finger recovery and it showed him putting the foils in a filter before dissolving and then there is a lag in his video which doesn't show how he recovered his gold dust after precipitating except for him pouring the gold dust into the crucible from a folded paper. It was misleading to the fact that you could just pour your solution through a filter. There was no warning that it would stick like that.

I have heard two things to do which I am trying to decide between. One says wet the filter paper against the inside wall of a beaker and use a spray bottle to rinse all of the gold into the beaker and then let it evaporate like I was supposed to after decanting all the liquid I can off. The other way just says to cut the filter to size to fit my crucible and heat slowly to get rid of the ash and then go on and melt the gold as normal using maybe a little more borax than usual to clean it up. Anyone have thoughts on which is the best way?

And yes the gold has already been properly washed. It was ready to melt as soon as I got my dried powder.


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## Palladium (Feb 24, 2014)

How much gold are we talking about?


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## cableman (Feb 25, 2014)

There should be about three grams or better. There are no chemicals left from wash, only clean water but the gold seems to be absorbing into the filter since the dust is so fine of particles. The paper filter is holding up well so far. It is not wanting to rot away or anything like that. I am thinking about making a muratic/chlorox solution and pouring through the filter over and over to redissolve the gold and the re-precipitate properly by drying it correctly. Would that be a good option or would it be easier to just slowly burn off the filter ash slowly until gone and then melt the gold dust as normal?


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## kurtak (Feb 25, 2014)

Can you provide a picture

Kurt


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## Pantherlikher (Feb 25, 2014)

Cableman.
Just use a spray bottle to wash off what comes off and store the filter.
Later when you have another batch to run, mix HCL+ bleach and run the filter through it. I mix alittle bleach and HCL in a glass with the filter in it and let sit for a couple few minutes. Then pour off and use it for the new batch. Rinsing the filter good and use that water to dillute the mix to drop.

There really isn't enough gold trapped in the filter to worry about so do this and add the filters to the burn pile. When you get a bunch of filters, incinerate slowly and run through to gather anything still trapped.

B.S.
...Don't sweat the small things. Just add to the steps in the overall process...


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## kadriver (Mar 3, 2014)

If you still need help with this then here is a video I made that shows exactly how to recover the gold trapped in your filter paper:

[youtube]http://www.youtube.com/watch?v=GlozdhFuExk[/youtube]

kadriver


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## lazersteve (Mar 6, 2014)

I toss the paper into a straight walled beaker and redissolve the Au with fresh AR. 

Once the Au dissolves (no more brown solids in the beaker), I kill the excess nitric acid with sulfamic acid. 

This solution gets filtered until 100% free of particulate and solids. 

The transparent solution is then precipitated with dry SMB. I add enough SMB to turn the solution a deep chocolate brown and allow the powder to settle.

Test the solution with stannous chloride and confirm there is no purple stain. 

Pour of the clear solution. 

Rinse the gold powder until the rinse water is clear.

Place the straight walled beaker in a pyroceram dish over medium heat and drive off the excess liquid. Swirl the beaker periodically so the Au does not stick to the walls of the beaker while drying. 

The Au is dry when the powder moves freely around the beaker and no more steam can be seen exiting the powder. 

Pour the dry powder out of the straight walled beaker into your properly glazed melting dish and melt.

If you do not want to refine the Au a second time for higher purity as stated above, then place the filter paper and Au in a dish with the paper side up and heat gently with a MAPP gas torch until all of the paper burns off. I do not recommend using a borax blanket as Kevin shows in his video as it slows the vaporization of the carbon because it prevents oxygen from reaching the carbon. The oxygen is what converts the Carbon from the paper into a gas allowing it to dissipate. Light the paper then pull the torch away to allow the oxygen to burn away the carbon of the paper. Do this repeatedly until the paper and black carbon are all gone. Once the paper is gone, turn up the heat and melt the gold into a button. Allow the button to solidify, but the borax is still molten. While gripping the hot dish with a pair of long channel locks or pliers, use a silica or graphite rod to slide the hardened button into a deep steel pot of cold water.

Steve


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## kadriver (Mar 7, 2014)

lazersteve said:


> This solution gets filtered until 100% free of particulate and solids.
> 
> Steve



Steve, I was working with a small amount of gold the other day, I speak of it in this thread:

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=2064&start=20

There was a slight bit of cloudiness in the Gold Chloride solution.

I filtered it over and over through the same filter paper but the slight bit of cloudiness refused to filter out completely.

Has this ever happened to you and if yes, then how did you end up getting it to clear up?

Thank you.

kadriver


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## kurtak (Mar 7, 2014)

kadriver

Does the cloudiness appear after you dilute your solution - if so that's because dilute solutions will precip some base metals as well as Ag/CL as colloids - tin being the most common base metal to do this

I have had solutions go cloudy (after diluting) that would flat out not settle let alone filter

using a coagulant &/or flocculant (only takes a drop or two) is one way to deal with it (needs to be stirred so stir/hot plate is good to have) you can then filter & send solids to stock pot they will have gold colloids

If its Ag/CL you can try this (need stir/hot plate) heat solution on hot plate (warm/hot) turn on stir - heat & stirring action will sometimes help the Ag/CL to coagulate --- adding a few drops of Ag/CL may help with this as it gives the colloids something to latch onto

Freezing the solution will also work sometimes & when you thaw it back out the solids will settle

or you can cement your gold out (although this is taking you backwards in the process) get your solution warm/hot before putting your copper in which will help your gold come down faster with larger grain size which helps to bring the colloids down with it --- you can then redo the water wash followed by the ammonia wash if its Ag/CL --- if its base metals (like tin) then water wash - dry - incinerate - HCL wash

Avoiding the problem to start with (previous steps in the process) is of course the best route - but it does happen even to those of us with experience - those are things I have tried & that have worked for me

Kurt


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## kadriver (Mar 7, 2014)

Kurt,

Thanks, I thought about adding some AgCl to increase the amount of solids to "load up" the filter paper.

I know ammonia will dissolve silver chloride. After 2 ammonia boils, rinsing with distilled water after each to flush out any dissolved AgCl, the solution was absolutely clear and bright with no traces of cloudiness after dissolving the gold powder in AR.

I rinsed the solution out of the filter paper with cold distilled water and the cloudiness did not show up again.

In the very beginning of the process the solution was slightly cloudy. It stayed cloudy after the second refining and it would not filter out.

I have had this happen many times in the past. I hate boiling ammonia, but it always seems to get rid of the cloudiness.

Thank you for the tips.

kadriver


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## lazersteve (Mar 8, 2014)

In bad cases, I clear any final traces of cloudiness with a Charmin plug filter under a vacuum. This method works to clear troublesome solutions. 

A word of advise on Charmin plug filtration: Always perform a coarse and fine filtration prior to using the Charmin plug, otherwise you might end up clogging the Charmin plug which will result in extremely slow filtration times. Typically I will perform a coarse gravity filtration to remove any bulk trash (solder mask, plastic, etc.) using a few layers of coffee filters. I follow this up with a medium speed single layer of paper in the buchner filter under vacuum. If the solution still looks cloudy after two passes through the same filter paper under vacuum, I go with the Charmin plug packed to allow 2 -3 drops per second through under vacuum. A properly packed Charmin plug should flow quickly, but not allow any fine particles through. 

In a worst case scenario (sludge and slimes), allow the solution to settle overnight, decant the transparent up layer, and proceed as above with the remaining solution that contains the sediment.

Steve


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## Geo (Mar 9, 2014)

I try to never trap gold in a filter, unless its a liquid. Gold powder is heavy, being 19 times heavier than water, it will sink quickly in clean water. If it's powder from a stripping cell, i decant as close as i can and dilute the rest with water. The black powder settles quickly in dilute sulfuric acid. I siphon this off and evaporate for re-use. Gold foils will get trapped in any filter. Like Steve, I place the filter in AR and rinse and squeeze it out. Then it's dried and put with my filters for later processing.


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