Presented paper

IMWA2019 Students work

Stratification in Flooded Underground Mines – State of Knowledge and Further Research Ideas

Mugova, Elke (1); Wolkersdorfer, Christian (2,3)
1: Technische Hochschule Georg Agricola, Germany; 2: South African Research Chair for Acid Mine Drainage Treatment, Tshwane University of Technology (TUT), South Africa; 3: 3Lappeenranta University of Technology, Laboratory of Green Chemistry, Finland

Stratification between different water bodies is a phenomenon that applies mainly to lakes and oceans, but also appears in flooded underground mines. Density differences cause layering in which higher mineralized mine water stays in the lower levels of the flooded underground mine. Stratification might become a natural in-situ treatment method, although there is no deliberate application yet. Currently, it is not possible to predict stratification in flooded underground mines, as greater understanding of the process, particularly it´s occurrence, stability and break down scenarios is necessary.

During the presentation, results from literature studies will compared and a consolidation of all terms and relevant examples pertaining to the topic given. Traditional investigation methods such as depth logging, tracer tests, laboratory experiments and numerical modelling in conjunction with field data where compared and rated. The authors executed additional research measures, also including pump and tracer tests.

The existing literature about stratification in flooded underground mines describes many examples, though explanations about the process itself are generally not detailed. Through causal relationships between the geometry of a mine and stratification of mine water bodies, the authors will define possible scenarios for other mines. Different evaluation criteria were hereby developed. Additional lab findings and results from field experiments will be presented.

By predicting stratification in flooded underground mines it might be feasible to use the phenomena as an environmentally friendly in-situ treatment method for polluted mine water, thus reducing or avoiding the need for extensive end-of-the-pipe treatment. A concept on how the development of stratification can be enhanced by manmade intervention will be presented.