Metal finishing Q&As since 1989

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Filtering of Carbon Residue from ferric chloride during chem milling

2004

Does anyone have any information regarding Filtering of Carbon Residue from ferric chloride [on eBay or Amazon] during chemical milling operations.

In spray etching of Spring steel we find an excessive amount of carbon sludge created.

Carbon is inert and cannot be redissolved.

Has anyone ever successfully filtered this material?

Ira R [last name deleted for privacy by Editor]
Equipment Manufacturer - Anaheim, California, USA

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1st of two simultaneous responses

That is a very easy problem to solve. A proper pump and a proper filter. It can be an in-tank system or a piped system. Lots of choices of vendors and equipment.Relatively high flow and a relatively "open" filter media.

James Watts
- Navarre, Florida
2004

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2nd of two simultaneous responses

We have had excellent results in the filtration of ferric chloride[on eBay or Amazon]as well as hydrochloric steel pickle solutions using membranes--an all polypropylene or all polyethylene membrane material in a PP housing that can be backflushed to restore flux rates without ever having to change the membrane! (At least not for a few years!) Depending on the volumes that you are processing, an economical solution is readily available.

Tom Baker
wastewater treatment specialist - Warminster, Pennsylvania
2004