Remediation options for wind-remobilised Pb-Zn old tailings: an example from an 80-year Pb-Zn-Ag mine in NW-Argentina

Author(s): 
Camilo de los Hoyos, Diego Marrero, Juan Sitjá y Balbastro, Julien Declerq, Robert Bowell
Date: 
Friday, September 14, 2018
First presented: 
11th International Conference on Acid Rock Drainage (ICARD) and International Mine Water Association Annual Conference
Type: 
Published paper
Category: 
Geochemistry

This article describes remediation options for wind-remobilised old tailings at an 81-year Pb-Zn-Ag mine in NW-Argentina. Long-term exposure of the dry surface of the older impoundments to wind led to spread of tailings over 2.5 km2. Scoping-level geochemical characterisation included grain-size analysis, ICP-MS whole-rock geochemistry, XRD mineralogy, ABA and SPLP tests, and sequential extraction. Results suggested that high Pb-Zn contents are restricted to remobilised waste material and no leaching to the underlying soil occurred. Thus, the thickness was the driving factor to define remediation options. For sectors with up to 0.3 m (22%), excavation and mobilisation was suggested. For thicknesses between 0.3 and 0.6 m (78%), re-vegetation without impermeabilization was considered the best option. For in-situ old tailings (0.1 km2), surface impermeabilization and re-vegetation was strongly suggested.

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Feature Author

Camilo Raúl de los Hoyos

Camilo de los Hoyos is a PhD in Geological Sciences and Senior Consultant Geologist at SRK´s Mendoza office with over 12 years of experience in water resource assessment, environmental geochemistry, lithium-potassium brine exploration in salars and igneous/metamorphic petrology. He has participated in several small- and medium-scale water resource projects in Argentina, Bolivia and Venezuela.

He has extensive experience in Acid Rock Drainage and Metal Leaching (ARDML) assessment as well as ARD treatment and mine waste remediation programs. Camilo´s experience in lithium-potassium brines includes comprehensive resource exploration programs, geological exploration/assessment of materials for brine processing and Technical Due Diligence. 

His Doctoral Thesis on geochemistry, isotope geochronology and geothermobarometry was applied to petrology and geotectonic.

Environmental Specialist
PhD
SRK Mendoza
SRK United Kingdom