Conference Agenda

Mine Drainage Chemistry
Monday, 12/July/2021:
1:00pm - 3:30pm

Session Chair: Peter Clive Stanley
Location: Meeting Room 1

1:00pm - 1:25pm

Design, Operation, and Preliminary Findings from a Field Acid Rock Drainage (ARD) Study at the Bagdad Copper Mine in Arizona

Madhumitha Raghav1, Jessica Szaro1, Trika Graham2, Brent Callen2

1Freeport-McMoRan, Inc.; 2Freeport-McMoRan Bagdad, Inc.

A field test pad study is ongoing at the Bagdad mine in Arizona to understand acid rock drainage (ARD) and metal leaching (ML) potential of development rock and leached ore stockpiles under field conditions. Seepage oxidation-reduction potential (ORP) and dissolved oxygen (DO) data indicate test pads conditions are not oxygen limited and hence, are likely to promote sulfide oxidation. Seepage pH has remained in the circumneutral range for development rock pads. Seepage flow response suggests development of preferential flow paths within the pads. Study results will be used to support on-going mine planning and permitting processes at the Bagdad mine.

1:25pm - 1:50pm

Trace Element (As, F, U) Contamination and Hydrogeochemistry in the Vicinity of a Mexican Ore Mine

Andre Banning1,2, Desiree Schwertfeger1, Sócrates Alonso Torres3, Antonio Cardona Benavides4

1Hydrogeology Department, Faculty of Geosciences, Ruhr University Bochum, Germany; 2School of Biological, Earth and Environmental Sciences, University College Cork, Ireland; 3Postgraduate Program in Minerals Engineering, Faculty of Engineering, Universidad Autónoma de San Luis Potosí, Mexico; 4Earth Sciences Department, Faculty of Engineering, Universidad Autónoma de San Luis Potosí, Mexico

Dissolved fluoride (F), arsenic (As) and uranium (U) concentrations in ground and surface waters around the San Antonio el Grande Mine (Chihuahua/Mexico) exceed drinking water guidelines in 72.8%, 64.0% and 58.4% of all samples, thus threatening the most important drinking water source in the region.

To address the question of trace element origin and underlying mobilisation and transport processes, 125 water samples were analysed and evaluated.

Lithology is dominated by acidic igneous rocks and limestones with numerous mineralisation zones.

Solution processes were identified as the main driver for increased concentrations mainly depending on pH value and temperature.

1:50pm - 2:15pm

Effect of Mining to Water Quality in Chua and Revué Rivers, Mozambique

Clemencio Nhantumbo1, Estevao Pondja1, Dinis Juizo1, Antonio Cumbane1, Nelson Matsinhe1, Bruno Paqueleque1, Miguel Uamusse1, Gretchen Gettel2, Mário Franca2,3, Paolo Paron2

1Univerisidade Eduardo Mondlane, Mozambique; 2IHE-Delft Institute for Water Education; 3Delft University of Technology

Anthropogenic activities, particularly artisanal and industrial gold mining, have been affecting water resources in Manica Province, in Mozambique. Evaluation of water pollution in Révue and Chua rivers due to gold mining was done through field observations and laboratory analysis. This investigation revealed that water quality is being affected by activities developed in the river basin. Turbidity (200-5600 NTU) and concentration of sulfate (25-56 mg/L) are the most affected parameters. pH values measured were below 6.5 in two monitoring points. Although, agriculture is also present in the studied area, gold mining is likely to be the main source of water pollution.

2:15pm - 2:40pm

Efficacies of Pervious Concrete and Zero-valent iron as Reactive Media for Treating Acid Mine Drainage

Ayanda Nomaswazi Shabalala

University of Mpumalanga, South Africa

Batch reactor tests using pervious concrete (PervC) made at 0.27 water /cement ratio by mixing granite aggregate and Portland cement CEM I 52.5 R were performed to compare the use of PervC versus zero-valent iron (ZVI) for treatment of Acid Mine Drainage (AMD). The removal rates for Ca, Mg, Al, Fe, Mn, SO4 and Cu were greater for AMD samples that were treated with PervC reactive media relative to those treated with ZVI. The pH- driven metal precipitation and adsorption of precipitates onto the surface of PervC and gypsum by-product are the main mechanisms of removal of metals from AMD.

2:40pm - 3:05pm

🎓 Prediction Of Water Quality Parameters Using Unmanned Aerial Vehicle Multispectral Imagery In Acidic Water Bodies In The Iberian Pyrite Belt (Tharsis, SW Spain)

Melisa Alejandra Isgró1,2, María Dolores Basallote1, Luis Barbero2

1Department of Earth Sciences, Research Center on Natural Resources, Health and the Environment (RENSMA), University of Huelva, Campus El Carmen s/n, 21071 Huelva, Spain; 2Department of Earth Sciences, University of Cádiz, Campus Universitario de Puerto Real, 11510 Puerto Real, Cádiz, Spain

This study presents a novel approach of using high-resolution multispectral data acquired by an unmanned aerial system (UAS) combined with in situ chemical data to assess water quality parameters at 12 relatively small water bodies located in the Tharsis complex, an abandoned mining area highly affected by acid mine drainage (AMD) pollution. The spectral data jointly with water physicochemical data were used to estimate water quality parameters using regression analysis. Parameters including pH, ORP, EC, Al, Cu, Fe, Mn, S, Si, and Zn were estimated with high accuracy levels while Ba, Ca, and Mg showed low accuracy.