# possibility of filtering deplating cell sludge?



## frank-20011 (Sep 16, 2017)

hello everyone,

in these days i process some Kg of plated contact stuff and now i ask me: is there a possibility to filter the sulfuric acid by vakkum with a glass filter frit...i think it's impossible because the sludge is much, much to fine?
what do you think?

if i do not filter my 97% H2SO4, how long does it take until the sludge has settled down WITH no dilution of the sulfuric acid?


best regards, frank!


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## nickvc (Sep 16, 2017)

I believe some use fiberglass as the filter but be very careful pouring as concentrated sulphuric is very dangerous, failing that it can take some time for the sludge to fully settle.


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## nickton (Aug 4, 2018)

where can one find more information on this? I am having trouble finding it.


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## FrugalRefiner (Aug 4, 2018)

Try a search for Charmin filter. The origin was using some bath tissue (Charmin is a brand) stuffed down into the neck of the funnel. The tighter it's packed in, the finer the filtering, but at the cost of speed. Of course, bath tissue won't work with sulfuric acid as the acid would quickly turn it to pulp, so someone came up with the clever idea of using fiberglass insulation in place of the bath tissue.

Dave


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## g_axelsson (Aug 4, 2018)

Check the links on this page, there should be some useful information there.
http://goldrefiningwiki.com/mediawiki/index.php/Sulfuric_acid_cell

Göran


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## Geo (Aug 6, 2018)

Try this video. It has a good representation of a charmin plug and how to use it.

https://youtu.be/SoAd0V_OERg


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## g_axelsson (Aug 6, 2018)

Some more links and info abut charmin plug. Another video for example.
http://goldrefiningwiki.com/mediawiki/index.php/Charmin_plug

Göran


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