# Home made Vacuum Pump



## ahmadbayoumi (Aug 18, 2017)

Dears,

We all know that one of the most time consuming steps in PMs recovery process is filtration.

To speed up the filtration step, a vacuum pump may be used with buchner funnel system.

The problem in this system is the vacuum pump as it costs a lot of money.

One alternative I found is to use a medical syringe as a vacuum source as in the below pics

So is it really going to work .. PLS help.


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## g_axelsson (Aug 18, 2017)

You need a certain flow to keep the filter paper stuck to the buchner funnel. I think it would be hard to do it with that setup.
This is a cheap alternative that is tested and actually works. Using it myself now and then.
https://www.youtube.com/watch?v=-ARwUAUeIsU

My setup can be seen in one of the pictures here, two years prior to that video.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=61&t=19840#p236827

Another cheap vacuum system is using an eductor with water. The only thing you need is water with enough flowrate and pressure. A normal tap works and is commonly found in laboratories in fume hoods.
One drawback is the risk of overflow, then any excess would be sucked out and washed away with the water.
Some people have built closed systems with an eductor and a water pump, circulating the water. In that case you can always recover from a catastrophic failure as any values are trapped in the circulating water.
http://goldrefiningwiki.com/mediawiki/index.php/Venturi

Göran


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