# Straining?



## ssharktu17 (Aug 27, 2022)

After dissolving sterling in nitric, what is the point of straining? I see people on YouTube using anything like a tshirt, coffee filter, etc is it just to make sure nothing insoluble pours in? Or is it to remove some chemicals from the dissolved portion so that you would need a fine filter?


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## Shark (Aug 27, 2022)

To remove impurities that can find its way back into your silver. After spending the time, effort and money, why leave anything behind that your trying to remove? Most who want to refine their metals are trying for the highest purity they can achieve.


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## ssharktu17 (Aug 27, 2022)

ssharktu17 said:


> After dissolving sterling in nitric, what is the point of straining? I see people on YouTube using anything like a tshirt, coffee filter, etc is it just to make sure nothing insoluble pours in? Or is it to remove some chemicals from the dissolved portion so that you would need a fine filter?


Is a coffee filter removing atoms? Seems like they would just go right through.


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## Shark (Aug 27, 2022)

We can’t see atoms. Filtering removes the things we see. It will not remove any chemicals. The course filters are good at removing the larger particles allowing for faster filtrations. Progressing to finer filters to remove the residues that make it through the course filters. Coffee filters are fairly large pored, good for general removal. They make filters for tea, usually they are slight smaller pores, and usually are commercial type filters, good for medium sized particles and general filtration. And slightly slower than coffee filters. I used tea filters for years that came from a restaurant. Coffee and tea filters aren’t as good as lab grade filters but if it is what you have, use them.
Just filter until there is no cloudiness left.

Edit for spelling.


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## ssharktu17 (Aug 27, 2022)

Shark said:


> We can’t see atoms. Filtering removes the things we see. It will not remove any chemicals. The course filters are good at removing the larger particles allowing for faster filtrations. Progressing to finer filters to remove the residues that make it through the course filters. Coffee filters are fairly large pored, good for general removal. They make filters for tea, usually they are slight smaller pores, and usually are commercial type filters, good for medium sized particles and general filtration. And slightly slower than coffee filters. I used tea filters for years that came from a restaurant. Coffee and tea filters aren’t as good as lab grade filters but if it is what you have, use them.
> Just filter until there is no cloudiness left.
> 
> Edit for spelling.


Thanks! So you might do more than one round of filtering?


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## Shark (Aug 27, 2022)

Yes. Even with lab filters and a Büchner funnel I often still need to filter twice. Just choose the filter based on the size particles you want to remove.


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## FrugalRefiner (Aug 27, 2022)

When you filter and the liquid is still cloudy, pour the filtered solution right back through the same filter. As the pores in the filter paper start to get blocked by the larger particles that have been filtered, it effectively decreases the pore size, so running the solution back through the same filter captures smaller and smaller particles. Sometimes it can take multiple passes through the same filter to end up with a completely clear solution.

Dave


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## cejohnsonsr1 (Aug 28, 2022)

Dissolving is to put the metals into solution. Other contaminants will remain in solid form. Filtering removes these solids from the solution so that only the precious metals are precipitated or cemented out of the solution. The process is always performed in 2 steps. Filtering is part of the 1st step: recovery. Recovery is the removal of everything that is NOT precious metals. Then comes refining, where the purity of the precious metals is increased as much as possible. With silver, I consider cementing part of recovery and the electrolytic cell refining.


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## ssharktu17 (Sep 29, 2022)

cejohnsonsr1 said:


> Dissolving is to put the metals into solution. Other contaminants will remain in solid form. Filtering removes these solids from the solution so that only the precious metals are precipitated or cemented out of the solution. The process is always performed in 2 steps. Filtering is part of the 1st step: recovery. Recovery is the removal of everything that is NOT precious metals. Then comes refining, where the purity of the precious metals is increased as much as possible. With silver, I consider cementing part of recovery and the electrolytic cell refining.


couldnt you just not pour the solids in? wouldnt they be at the bottom.


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## ssharktu17 (Sep 29, 2022)

FrugalRefiner said:


> When you filter and the liquid is still cloudy, pour the filtered solution right back through the same filter. As the pores in the filter paper start to get blocked by the larger particles that have been filtered, it effectively decreases the pore size, so running the solution back through the same filter captures smaller and smaller particles. Sometimes it can take multiple passes through the same filter to end up with a completely clear solution.
> 
> Dave


Why would it be cloudy? what is in there dissolved except an aqueous solution of metal ions? like if I dissolve sterling (silver and copper.) Why would there be cloudiness.


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## FrugalRefiner (Sep 29, 2022)

ssharktu17 said:


> Why would it be cloudy? what is in there dissolved except an aqueous solution of metal ions? like if I dissolve sterling (silver and copper.) Why would there be cloudiness.


Because sometimes not everything dissolves.

If the solution is completely clear, there is no need to filter.

If anything remains undissolved, we filter it out. Sometimes, the undissolved material can be very fine. If it's smaller than the pore size of the filter paper, it can pass through, and the filtered solution can still be cloudy. But the pores in the filter paper start to get plugged up by the larger undissolved particles, effectively reducing the pore size, so pouring the filtered solution back through the same filter will result in a clearer solution.

Dave


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## ssharktu17 (Sep 29, 2022)

FrugalRefiner said:


> Because sometimes not everything dissolves.
> 
> If the solution is completely clear, there is no need to filter.
> 
> ...


What can it be if it is Undissolved but suspended in solution? If it is organic would it just burn off in the melting process?


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## Yggdrasil (Sep 30, 2022)

ssharktu17 said:


> What can it be if it is Undissolved but suspended in solution? If it is organic would it just burn off in the melting process?


It can be anything, for instance Silver Chloride or anything else not soluble in Nitric, sometimes even soluble things may end up as partly dissolved.
So depending on the reason for dissolving the Sterling in the first place, we always strive to get as clear and cleans solution as possible.


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## cejohnsonsr1 (Sep 30, 2022)

ssharktu17 said:


> couldnt you just not pour the solids in? wouldnt they be at the bottom.


No. It’s impossible to not disturb the solids while pouring off the solution some contaminants remain suspended in the solution. Filtering is necessary.


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## Shark (Sep 30, 2022)

If you could leave it in the bottom and pour off the clear solution you would waste a lot of solution. Unless you intend to filter only the concentrated contaminants afterwards. I have let solutions settle, decant the majority off, (I still filter it first) then run the heavy stuff through the filter last. This way the majority filters fairly quick, reduces the pore size in the filter and catch’s the sediment better in the last part of the solution. Those left over residues can be any type material, including metals that reacted differently to your acids. Some maybe (for example) sulfates, and others maybe chlorides. Melting some of these produces a nice mess that is harder to deal with than taking the time to do a quality filtering job. Filtering is the most important step to producing high quality gold or silver. Some people are not to concerned about quality and are just after the quantity due to the place they sell their metals. I am small time and I don’t mind spending the time to make it the best I can produce.


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## ssharktu17 (Sep 30, 2022)

Shark said:


> If you could leave it in the bottom and pour off the clear solution you would waste a lot of solution. Unless you intend to filter only the concentrated contaminants afterwards. I have let solutions settle, decant the majority off, (I still filter it first) then run the heavy stuff through the filter last. This way the majority filters fairly quick, reduces the pore size in the filter and catch’s the sediment better in the last part of the solution. Those left over residues can be any type material, including metals that reacted differently to your acids. Some maybe (for example) sulfates, and others maybe chlorides. Melting some of these produces a nice mess that is harder to deal with than taking the time to do a quality filtering job. Filtering is the most important step to producing high quality gold or silver. Some people are not to concerned about quality and are just after the quantity due to the place they sell their metals. I am small time and I don’t mind spending the time to make it the best I can produce.


Ya I am kinda wondering if it’s worth the extra step in bulk if I were planning to run the silver cell next.


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## Shark (Sep 30, 2022)

Running it through a silver cell with out proper filtering kind of defeats the purpose of the cell. You can get to from 97% to maybe 99% without the cell. A silver cell push’s that to 99% plus if done right. 

“There is no elevator to success, you have to take the stairs.” Follow known processes, step by step. Those steps are there for a reason. 

Another quote I like. “The fastest way to succeed is to follow success”. 

I get very stubborn about filtering, I am that firm in believing it is THE key to improving the quality of my gold or silver. It is the reason I spent extra money to have proper filtering equipment also. I went so far as to make my first Büchner funnel and used it until broke.


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## ssharktu17 (Sep 30, 2022)

Shark said:


> Running it through a silver cell with out proper filtering kind of defeats the purpose of the cell. You can get to from 97% to maybe 99% without the cell. A silver cell push’s that to 99% plus if done right.
> 
> “There is no elevator to success, you have to take the stairs.” Follow known processes, step by step. Those steps are there for a reason.
> 
> ...


I was thinking even 97% would be good enough to run through a cell and get to 9999. But I agree short cuts aren't good unless they boost margins substantially.


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