Conference Agenda

Mine Drainage Chemistry & Passive Treatment
Wednesday, 14/July/2021:
12:40pm - 2:45pm

Session Chair: Arabella Mary Louise Moorhouse-Parry
Location: Meeting Room 1

12:40pm - 1:05pm

🎓 Seasonal Geochemical Variation of Sediments in the Sabie River, Mpumalanga, South Africa

Rudzani Lusunzi1,2, Frans Waanders2, Robert Khashane Tshishonga Netshitungulwana1

1Council for Geoscience, South Africa; 2North West University, South Africa

There was no significant variation observed in terms of metal dispersion (Cr, Zn, Cu, Ni, Pb, As) during wet and dry seasons respectively. The mineralogy of sediments indicated that acid-producing minerals hematite and jarosite found in mine wastes are potential sources of pollution to the Sabie River. The CF, PLI and Igeo showed that sediments were unpolluted to extremely polluted by As. Acid-neutralizing mineral dolomite found in the sediments can act as buffers for potential acid. There was no evidence of metal dispersion from the Nestor tailings storage facility to the adjacent water resources, Klein-Sabie and Sabie River respectively.

1:05pm - 1:30pm

Evaluation Of A Short Period Increasing Water Influx In A Mine Drainage Facility Of A Former Hard Coal Mine

Birgitta Wiesner

RAG AG, Germany

RAG AG currently operates a mine drainage facility at the abandoned coal mine Amalie in the city of Essen, Germany. Throughout April 2020 a short-term increased water influx occurred at this mining site at one dam. To identify on-going processes in the mining plant water chemistry was analysed and investigated. One result was, that the break of a dam lead to a new water influx into the water system of the mine. This new water influx resulted in a permanently higher amount of water entering the mine and a significantly change in water composition by increased amounts of dissolved salts.

1:30pm - 1:55pm

Recovering Rare Earth Elements from Acid Mine Drainage with Mine Land Reclamation

Chin-Min Cheng, Tarunjit Butalia, John Lenhart, Jeffrey Bielicki

The Ohio State University, United States of America

In this study, we demonstrated a trap-extract-precipitate (TEP) process that effectively recovers rare earth elements (REEs) from coal mine drainage (CMD). This three-stage TEP process uses environmentally benign industrial by-products to retain CMD REEs from CMD. It then applies an extraction/precipitation procedure to produce a concentrate feedstock (>7.5 wt. % of total REEs) that can be economically processed to produce marketable rare earth oxides. We envision the TEP process can be integrated with abandoned mine land reclamation to create a commercially viable approach to mitigate CMD and restore lands that are adversely impacted by historical mining.

1:55pm - 2:20pm

Distributions of Rare Earth Elements in Coal Mine Drainages

Chin-Min Cheng, Tarunjit Butalia, John Lenhart, Jeffrey Bielicki

The Ohio State University, United States of America

In the U.S., rare earth elements (REEs) are reported to be closely associated with coal deposits, especially in the Appalachian Basins. Historical coal mining in the Northern Appalachian Coal field of the United States has produced significant amount of coal drainage (CMD). In this study, we investigated 29 abandoned CMDs in eastern Ohio, USA. The main objective of this study is to understand the geochemical behavior of REEs in CMD. Results obtained from this study provide the knowledge that will form the basis of a reactive transport model, which can be used to predict REE retention and recovery.

2:20pm - 2:45pm

Passive Solar Photocatalytic Treatment in Mining Process-affected Water

Jeffrey Thomas Martin1, Tim Leshuk1,2, Brad Wilson1,3, Zac Young1, Frank Gu1,2

1H2nanO Inc., 151 Charles St. W., Suite 299, Kitchener, ON, Canada; 2University of Toronto, Department of Chemical Engineering and Applied Chemistry, 200 College St., Toronto, ON, Canada; 3Stantec, 100-300 Hagey Boulevard, Waterloo, ON, Canada

H2nanO Inc. has developed SolarPass, a floating reactive barrier comprised of buoyant photocatalyst beads that provides a passive, light-activated treatment process for target contaminants, while simultaneously blocking volatile emissions. Recently, H2nanO validated the efficacy of SolarPass for in-situ treatment of mining tailings water through an outdoor pilot-scale system in Alberta, Canada. Under natural sunlight illumination, target contaminants were degraded, including volatile sulfurous compounds and organics, while simultaneously reducing emissions by >70%. These results demonstrate that the novel SolarPass process can address diverse challenges with mining-influenced waters and provides an effective solution for passive tailings and process water management and remediation.