Conference Agenda

Mine Water Treatment & Benefits Enhancement
Monday, 12/July/2021:
1:00pm - 3:30pm

Session Chair: Rhys John Savage
Location: Meeting Room 2

1:00pm - 1:25pm

Process For The Subsoil Treatment Of Acidified Groundwater Through Microbial Sulfate Reduction

Ralph Schöpke1, Manja Walko2, Konrad Thürmer3

1Brandenburgische Technische Universität Cottbus-Senftenberg, Germany; 2Lausitzer und Mitteldeutsche Bergbau-Verwaltungsgesellschaft mbH; 3Institut für Wasserwirtschaft, Siedlungswasserbau und Ökologie (IWSÖ GmbH)

Sulphate and the acidity formed mainly from ferrous iron ions are the main contaminants of groundwater affected by mining. The Chair of Wassertechnik & Siedlungswasserbau at BTU Cottbus-Senftenberg has developed a subsurface rehabilitation method using microbial sulfate reduction. The basis for dimensioning this technology is now available after a successful demonstration test in the Lusatian mining district. The used substrate guarantees complete implementation and does not trigger any further damaging effects. Nutritional supplements (N, P) are kept to a minimum. The concentration of hydrogen sulfide in equilibrium with the precipitated iron sulfides limits the treatment effect in the incorporation phase.

1:25pm - 1:50pm

Solvent Extraction To Recover Copper From Extreme Acid Mine Drainage

Amir Nobahar1,2, Alemu Melka1,2, Jorge Carlier1, Maria Clara Costa1,2

1Centre of Marine Sciences (CCMAR), University of the Algarve, Gambelas Campus, 8005-139 Faro, Portugal; 2Faculty of Sciences and Technology, University of the Algarve, Gambelas Campus, 8005 139 Faro, Portugal

This study evaluated the application of a solvent extraction process from an extreme Acid Mine Drainage (AMD) (with 5.3 ± 0.3 g/L Cu). The extractant Acorga M5640 showed high copper selectivity and 30% (v/v) of this extractant, extracted ~96% of this metal with a maximum loading capacity of ~16 g/L in the organic phase. Then, 2M sulfuric acid solution stripped ~99% of copper and through successive striping steps the concentration of copper was raised up to ~46 g/L, which is suitable for the electrowinning process. Recyclability of the organic phase was also confirmed in five successive extraction and stripping cycles.

1:50pm - 2:15pm

Enhancing Biological Nitrogen Removal from Mine Site Water in Cold Climate

Piia Juholin1, Kirsi-Marja Haanpää1, Elena Torresi2, Fernando Morgan-Sagastume2

1AFRY Finland Oy; 2AnoxKaldnes - Veolia Water Technologies AB

Biological nitrogen removal from cold mine water can be challenging due to low biological activity of the biomass, which may increase the size of the treatment unit and lead to increased costs. This paper introduces some design solutions that may improve the usability of biological nitrogen removal in cold climate. These solutions include taking advantage of warmer seasons and the thermal energy of underground mine water, heating and reuse of waste heat produced in concentration plants, treating a specific water stream with a considerable nitrogen load, and pretreating the influent.

2:15pm - 2:40pm

Innovative Adaptation of Mining Hydrogeology Practices during a Pandemic

Sofia Nazaruk, Grace Yungwirth, Jessica Nicholls, Gareth Digges La Touche

Golder Associates (UK) Limited

Traditional mining hydrogeology practices during site characterisation programmes have relied heavily on the availability of experienced practitioners to travel to mine sites. This was not possible during the COVID-19 pandemic and adaptations of previously established workflows were required. This paper aims to outline an approach for the remote oversight of field programmes by experienced practitioners and outlines the relative risks, rewards and key limitations to the approach developed.

2:40pm - 3:05pm

Employment Of A Double Continuum Model To Characterize Groundwater Flow In Underground Post-Mining Setups: Case Study Of The Ibbenbüren Westfield

Diego Bedoya-Gonzalez1,2, Timo Kessler2, Maria-Theresia Schafmeister2

1Department of Geography and Geology, University of Salzburg, Austria; 2Institute for Geography and Geology, University of Greifswald, Germany

Underground hard coal mining usually disrupt the mechanical equilibrium of the geological media, creating fractured zones in the bedrock. The present study employs a Double-Continuum model to assess the influence of the fractured and porous media on the percolation process at the Ibbenbüren Westfield. Model results displayed good agreement with measured mine water discharges. While fractured continuum reacts readily to heavy precipitations, water is released slowly from the matrix. This behavior generates a gradual decrease in the discharge over the dry season. Findings obtained from this approach can be integrated into reactive transport models to predict long-term evolution of mine drainages.