Biological sulfate reduction has been slowly replacing chemical unit processes to treat acid mine drainage (AMD). Bioremediations for AMD treatment are favored due to their low capital and maintenance cost. This paper describes the available AMD treatment, current SRB commercialization such as THIOPAQ® and BioSulphide® technologies, and also the factors and limitations faced. THIOPAQ® and BioSu...

s of the International Mine Water Conference 19 – 23 October 2009 Proceedings ISBN Number: 978-0-9802623-5-3 Pretoria, South Africa Produced by: Document Transformation Technologies cc Conference organised by: Cilla Taylor Conferences RECOVERY OF SULPHUR FROM WASTE GYPSUM N.R. MBHELE, W. VAN DER MERWE, J.P. MAREE and D. THERON Exxaro Resources, P.O Box 9229, Pretoria, 0001, South Africa; E-mail...

A fly ash was used to increase pH and decrease arsenic leaching from an acidic mine waste. Both the amended system as well as the control system was leached with ultra pure water. pH in the control increased from 1.7 to 2.7 at the end of the experiment while the pH in the amended system decreased from 12.6 to 11.5. compared to the control the initial concentrations of arsenic decreased with alm...

Acid mine drainage is the result of the oxidation process of sulfide bearing rocks. This process occurs when the sulfide material is exposed to atmospheric conditions. Under these conditions, successive oxidation reactions yield sulfuric acid generating acidic waters. This problem becomes more serious when the surrounding rocks are not able to neutralize the acid. The low pH condition of the dr...

Acid mine drainage (AMD) and mine tailing environments are well-characterized ecosystems known to be dominated by organisms involved in iron- and sulfur-cycling. Here we examined the microbiology of industrial soft coal slags that originate from alum leaching, an ecosystem distantly related to AMD environments. Our study involved geochemical analyses, bacterial community profiling, and shotgun ...

The Gold King Mine spill in August 2015 released 11 million liters of metal-rich mine waste to the Animas River watershed, an area that has been previously exposed to historical mining activity spanning more than a century. Although adsorption onto fluvial sediments was responsible for rapid immobilization of a significant fraction of the spill-associated metals, patterns of longer-term mobilit...

One of the most difficult problems in mining operation is how to determine optimum cut-off grades of ores at different periods over the lifespan of the mine that will maximize the net present value (NPV) of the mine. Maximizing the NPV of a mining operation, subject to different constraints is a nonlinear programming problem. Cut-off grade optimization is used to arrive at an operating strategy...

Acidophilic microorganisms thrive in extremely low pH natural and man-made environments such as acidic lakes, some hydrothermal systems, acid sulfate soils, sulfidic regoliths and ores, as well as metal and coal mine-impacted environments. The most widely studied acidophiles, prokaryotes that oxidize reduced iron and/or sulfur, are able to catalyze the oxidative dissolution of metal sulfide min...

ABSTRACT Modeling of fluid flow and solute transport through fractured rock is an important component of engineering analysis in many disciplines including groundwater contamination, nuclear waste disposal, petroleum and gas production, mine excavation and geothermal production. Several studies have been conducted on single rock fracture using parallel plate model. An attempt has been made to s...

The paper concerns numerical modelling of complicated GeoTechnical problems as mine stability, performance of underground radioactive waste repositories or microstructure modelling of geocomposites. The modelling uses finite elements and parallel computing based on overlapping domain decomposition. Important implementation issues for this approach are discussed: inexact solution of subproblems,...