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air lifting mechanisms for oxidation in underground mines. Bruce Leavitt PE PG, Consulting Hydrogeologist Washington, Pennsylvania. Prepared in conjunction with West Virginia University under a grant from the Office of Surface Mining Applied Science Research Program. In Situ Aeration
Bruce Leavitt PE PG, Consulting Hydrogeologist
Prepared in conjunction with West Virginia University
under a grant from
the Office of Surface Mining
Applied Science Research Program
4 pipe diameters (12”, 10”, 8”, and 6”)
Multiple air flow rates
Oxygen Transfer Testing
High volume low DO source
Same pipe diameters and diffusers
Sintered glass diffuser
2 inch dia. #10 well screen
Adjust dock height to less than ¼ inch from overflow
Measure depth to diffuser.
Warm up blower.
Measure and adjust air flow. (before and after test)
Open 4 inch ball valve in dam.
Close bypass valve & time tank filling.
Pump produced water back into lake.
Closing the Ball Valve
Squares are set about 4 feet
Diamonds are set about 3 feet
All air flows used in this testing can be achieved with a ¾ hp high-pressure regenerative blower. (smaller units are possible)
At $0.10 / kW hr the daily cost of operation would be $1.34 or $490.00 per year.
A ¾ hp high-pressure regenerative blower can be purchased for $700.00
The use of low pressure air to create flow in a zero static head setting has been demonstrated.
The volume of water moved with such a small volume of air surpassed expectations.
Five cubic feet of air per minute is able to generate 200 gallons per minute of water flow.
Oxygen transfer to the produced water only achieved 25 percent to 30 percent saturation under the best conditions.
In most tests, there is not a significant difference between the DO produced by the well screen and the stone diffuser at the same depth.
There is a tendency for the shallower depth setting to produce a higher DO than the deeper setting.
Based on the calculated oxygen delivery to the mine, between 23.8 and 35.1 grams of iron per minute can be oxidized. This rate of iron oxidation is equal to 75.6 to 111.4 pounds iron per day.
Based on these tests the 8 inch riser with stone diffusers is the most economical configuration.
Construction of a large diameter borehole may be expensive, but the cost of equipment and it’s operation is low.
Borehole maintenance will be required.
27th Annual Meeting of the American Society of Mining and Reclamation12 Annual PA Abandoned Mine Reclamation Conference 4th Annual Appalachian Regional Reforestation Initiative Mine Land Reclamation Conference