Choosing filter papers

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Shark

Well-known member
Joined
Jun 8, 2014
Messages
2,922
Location
Alabama
I have a Coors Buchner funnel and a filtering flask that I would like to start using. I am needing help choosing the right filter papers. I am pretty sure a medium paper would be a good all around paper, but I would like to have a selection from time to time when working on other things such as slime's from copper cells and so on. What brand and porosity would be good as a back up / secondary filter?
 
I have a small unit I built from a garden sprayer. I actually like it better than the brake bleeder system I have since the sprayer acts as a vacuum reservoir.
 
Vacuum is essential, but an aspirator running off a surplus pump works wonders. Just recirculate the water and check the ph on occasion.

Whatman 42 for gold
Glass fiber filter for your sludges, as the sulfuric can be hard on paper filters.

Send me your address in a pm and I'll send you a piece of poly screen. Figure out what diameter filter papers and I may have some surplus available.


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Thanks Guys, it all helps. I should have said up front I guess, but it uses 11cm papers. I am wanting to get away from some of the "make do" filters and try to improve my accuracy and consistency. While I have been pleased with my results so far, there is always room to improve.
 
Shark said:
Thanks Guys, it all helps. I should have said up front I guess, but it uses 11cm papers. I am wanting to get away from some of the "make do" filters and try to improve my accuracy and consistency. While I have been pleased with my results so far, there is always room to improve.
That's just a baby! I'll get you a care package in the mail.




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On roughly the same topic, can anyone explain to a non chemist what the difference between qualitative and quantitative filter papers are, and which ones I want to buy for general solution cleaning ? Thanks!
 
So I've sent you some whatman 41, whatman 1, a glass fiber filter from sterlitech grade c-42 and some plastic screen to speed up the process. I cut my plastic screens to be about 1/2" smaller than the diameter of the holes on the buchner, but your filter paper has to seal to the porcelain at the edges, so you may need a little more.

Please report back on how you like them.

Unfortunately, they are all bigger than your buchner, so you'll have to pretend you are in kindergarten, get out the safety scissors and go to town. Take snack and naptime afterward.
 
Whatman number 1 are a great all rounder. I am not sure what your budget stretches to Shark but I've noticed you're really getting into this so I'll throw an idea out there.

If you get a $100 vacuum pump single stage, and a vacuum regulator then you're set to filter almost anything. You'll know when your settings are too high because you'll blow the filter so practice a lot.

I change the oil in my pumps every day if they have had acidic gases through them and they are still working after nearly 2 years. Oil is cheap.

A final addition would be a flask with sodium Hydroxide in it to pull your air through before hitting your pump. I guess you could also put an inline filter in place however as above I've not needed to do it and the pumps have been running for many hours at a time.

Take what you need from this Shark and discard the rest but I hope some is of use to you.

Jon
 
Thanks Snoman, I will give them all a test.
Thanks Jon, the budget right now is in the air, but things are changing, and more so with my next button. But the $100 is not out of range. The question is I do I buy more material or equipment? Decisions, decisions, :lol:
 
Almost forgot,

Kernels I would like to know that as well. Also, what, if any difference it makes on the porosity of the filter or does it concern more of what the filter is made from?
 
To be honest I don't know the exact answer to the question lads.

All I know is that the paper works, maybe someone could expand upon the differences. I understand the difference between qualitative and quantative with regards to testing but no with regards to papers.

Sorry fellers.

Jon

Edit: Actually whilst having a smoke I thought about it a little more. Would a quantative paper have an exact weight so you could determine the weight of the product on it when dry?
 
Shark said:
Thanks Snoman, I will give them all a test.
Thanks Jon, the budget right now is in the air, but things are changing, and more so with my next button. But the $100 is not out of range. The question is I do I buy more material or equipment? Decisions, decisions, :lol:

The single biggest time bottleneck is filtering. As you get more batches it becomes a bigger problem so I'd go for the equipment if you're looking to save time and make your process more effective.
 
I wish I was comfortable posting pictures from work, but I'm not willing to do so at this time. But he's got three $17 aspirators ganged together running off a pool pump in a recirculating bath of about 30 gallons. It will easily run four 12" filters at a time.

Given that you are in Alabama so you don't have to worry about freezes, get yourself a blue barrel, about 40 gallon. Then, the cheapest sump pump you can find and some PVC tubing to a cheap aspirator. Total cost for a garage saler is under 50 bucks. No oil to change, just check the pH once in a while. As long as you aren't pulling a lot of fumes, you'll never have to adjust the pH.

Always release your vacuum at the flask prior to shutting off the pump and you'll keep water out of your vac lines.

https://www.amazon.com/Bel-Art-Aspirator-Polyethylene-Disconnect-F32947-0000/dp/B002VBW41E/ref=sr_1_8?ie=UTF8&qid=1520377569&sr=8-8&keywords=vacuum+aspirator

With the screen, you'll never blow filter papers, and it speeds up the filtration quite a bit.
 
When i saw difference in filtering between any kind of filter papers and charmin plug with regular wet towels - i stopped using filter papers. So much better filtering that made my yields go up.

More about it here:
https://goldrefiningforum.com/phpBB3/viewtopic.php?f=60&t=15258#p282596

vfgrgr.jpg
 
I well understand the filter and waiting. I am waiting on a slow filter now. But it sure does look good :D

Just a shame it isn't no more than what it is.
 
Tzoax do you use a vacuum?

If you regularly get 2l and 3l and 4l solutions that need filtering then it surely would take forever without one?

Ahh thanks Sno
 
anachronism said:
Tzoax do you use a vacuum?

If you regularly get 2l and 3l and 4l solutions that need filtering then it surely would take forever without one?

Amen!

The first time i saw a solution blow through the filter at a gallon a minute my jaw dropped.

Or so fast that you can have a nice little pile of precipitate in the center and just keep the outside edges of the filter paper wet. It's beautiful!
 
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