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Carbon Dioxide for pH Control in thickening/dewatering (1 reply)

8 months ago
E 8 months ago


We have tested CO2 shortly couple years ago in our tailings thickening pilot where we added the gas in to feed tank (open tank reactor). We only had two open 1/2" steel pipes in bottom of the tank without any ejectors or diffusers. pH dropped easily from 10 to 7.5 but there might be some improvements to do with gas consumption. Because lack of time this test was very short, just too see does CO2 has any effect.

Today we are planning to do a test using CO2 for pH control in our concentrator thickening/dewatering process for replacing sulphuric acid.

Has someone practices this?  What kind of methods do you use for adding gas? 

Into pipe with ejector or without?

Into tank or pump sump, does it need some sparger etc. for creating bubbles?

What do you think about adding gas into thickener feedwell, just gas-pipe trough the feed-well liquid surface into some depth?

8 months ago
David 8 months ago

Hello E, and welcome. I have never done this myself.  I would, however, be careful in adding gas into the thickener feed-well.  If you material contained reagents, it could froth-up your and prevent good settling and clear water. 

Yes sparging  would be great but you might be OK and see results just in aerating into the pumpbox the furtherest away from the thickener.  The pump impeller will do additional mixing. 

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