Workshop
Valonia-Bruselas, Casos de Éxito, de la investigación a
la innovación y emprendimiento
Agua, energía y valorización de residuos
14 de abril
2014
Universidad
Católica del Norte
Drenaje Electro-ósmotico De la
investigación científica a soluciones
tecnológicas para la minería
Claudio Acuña.
Director Departamento Ingeniería Química UCN
Líder en Minería Ceitsaza
Organizan
Desert Water Technology Research Center
Developing and transferring
technology for a sustainable
use of water resources
in arid zones
www.ceitsaza.cl/
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Applications of
Electro-osmotic de-watering
In dump leaching
Patent in progress
Funded
BHP-Cluster program
World class chain of suppliers
of technology and Innovation
2012-2013
Prepared by:
Claudio Acuña
Leonardo Romero
Julio Valenzuela
December 10th, 2013
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Topics
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Electro-osmotic de-watering since when?.
How useful are papers
Fine particles an clays
Applications in mining
Scaling up: To be or not to be
Experience in industrial heap leaching
How much does it cost?
Environment / Economy
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Electro Osmotic De-watering (EOD)
• Phenomenology since 1912
• McGill Papers application on food and tailings
• Application in tailings and remediation IN SITU
• Solution transport independent of permeability
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Electro Osmotic De-watering, process
EOD and clay base minerals
Inovative process in a heterogenous media.
Clays and rocks
Clays are fine particles (below 38 microns)
High capilary presure (water retention)
Remediation + solution recovery (water, acid,
metals)
Limiting factor solid electrical resistance
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EOD in fine sludge applications
sludge 92% fines, 78% humedad
K. Reddy, A. Urbanek, A.Khodadoust,2006,
Electroosmotic dewatering of dredged sediments,
J. of Env. Mng. 78 pp. 200–208 )
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Electro-osmotic de-watering, levels
EOD application on soils
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Electro-osmotic de-watering (EOD)
Electric field application.
Effect of DEO after 3 weeks
(Fouri, Johns, Jones. Dewatering of mine tailing using EOD. Can Geotech. 2007. J. 44: 160-172)
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Origin of the problem in heap
leaching dumps
• Dump leaching accumulation: acid solution
• 10 to 19% humidity: acid and metals (0.8 -15 gpl)
• Millions of accumulated of solids: potential percolation
Solution occurrence of acid solutions by the road
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EOD testing and scale up
Validation
Bench scale
(50 mm and 200 mm)
5 kg
Configuration design
Lab scale
( 20 liters)
50 kg
Filed testing
Pilot scale
( 1 m3)
1500 kg
EOD impact on water drainage
0.16 a 0.52
Reducción de humedad, proyectados 72ho
con base SOLO a las 18 horas
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Pilot scale results
Comparison with base line (natural drainage)
Configuration
(confidential)
Humudity difference
with base line
Time reduction to
achieve same
humidity
Kw-hr/m3
Energy consumption
1-4
1.3
0.32
14.9
2-5
1.4
0.24
32.5
3-4
2.0
0.19
13.5
4-6
2.0
0.25
6.8
Conclusion and future work
• Electro-osmotic de-watering can be applied in copper
heap leaching reducing drainage time and humidity.
• Additional solution can be recovered reducing eventual
percolation in final dump with energy consumption from
6 to 15 kW-hr/m3
• The technique can be adapted to different ore types
selecting an electrode configuration.
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