Minerals and Mine Drainage

Abstract

This chapter reviews the literature relating to environmental processes that affect mineral dissolution reactions and the generation of acid mine drainage (AMD), the fate and transport of metal contaminants within the environment, the toxic influences of metals and mine drainage on aquatic species, characterization of abandoned mines and their potential for contamination, and technologies for remediation of mining-impacted systems or removing metals from wastewater streams. SITE CHARACTERIZATION AND ASSESSMENTAslibekian and Moles (2003) performed an environmental risk assessment of metal-contaminated soils in the vicinity of an abandoned silver mine in Tipperary, Ireland. The authors report a procedure for conducting preliminary evaluation of environmental risk and found that the most affected areas were floodplains located 2-3 km downstream from the site that were influenced predominantly by surface runoff and seasonal groundwater seepage from the abandoned mine. A study by Tarras-Wahlberg and Lane (2003) investigated sediment-associated metal transport (Cd, Cu, Hg, Pb, and Zn) in the Puyango river basin, Ecuador. The site was assessed by combining both the suspended sediment rating method and Monte Carlo simulations for wet and dry years.The authors report that in wet years, the metal polluted sediment load accounted for a small proportion of the yield estimates whereas the in dry years the metal-polluted 1685 sediments had a more significant effect and posed a more severe environmental impact. Fleit and Lakatos (2003) studied the accumulation of metals (Cd, Hg, Pb, Cu, and As) in river sediments and uptake of the metals by fish in the Tisza and Azamos Rivers (in Romania) following mining related spills. The study results indicate that the bioavailability of the metals varied within the river systems; however, the metal content of the fish was found to be lower than regulatory standards. In an effort to identify the effects of a waste mine tailing detention pond on water quality in the Mediterranean Sea near northern Cyprus (Greece), Gokcekus and co-workers (2003) conducted a study that combined water sampling and wave modeling techniques. A combined sediment and water quality study was performed in January and May 1999 by Hudson-Edwards et al. (2003) on the Agrio-Guadiamar river systems (Aznalcollar, Spain), which had been the site of a mining spill in April 1998. The authors report that following initial clean-up operations, the sediment metal concentrations were still higher than pre-spill conditions and reactive sulfidic material continued to undergo oxidation reactions, as indicated by higher dissolved metal concentrations in May 1999 compared to January 1999. The authors also report the following sequence of sediment mobility: Zn>Cd>Cu>Pb>As.A number of studies were performed to characterize water quality and sedimentassociated metals in the Odiel River (Huelva, Spain). Sainz et al. (2003b) attempted to characterize the primary sources responsible for mine drainage within the basin -mine dumps, active m...

Physical Structures of Lipid Layers on Pyrite

“…As an alternative approach, some researched pollution-prevention strategies have included encapsulation of pyrite grains with silica coatings ( , ) and complexation of catalytic oxidation centers (mainly surficial Fe 3+ defects) with humic acid or other organic ligands ( , ). These strategies, however, have been unsuccessful under the low pH and highly oxic chemical environments of acid mine drainage ( , ). As a different approach suitable to the conditions of acid mine drainage, we proposed and demonstrated the use of two-tail lipid coatings to inhibit pyrite oxidation at low pH ( 11 , 13 , 18 ).…”

Effect of Phospholipid on Pyrite Oxidation and Microbial Communities under Simulated Acid Mine Drainage (AMD) Conditions

“…Acid mine drainage (AMD) is a severe environmental problem impacting streams and rivers in areas where there are active and/or abandoned coal mining sites. , A root cause of AMD is the exposure of mining waste (i.e., overburden, waste rock, and tailings), which typically contains 1–20% pyrite (FeS 2 ) and lower amounts of other metal sulfides (e.g., marcasite and pyrrhotite), to air, water, and microorganisms. , Both the abiotic and biotic oxidation of the metal sulfide, during and after mining activity, leads to the oxidation of the sulfur component to sulfuric acid (i.e., AMD). A composite reaction for the oxidation of pyrite by molecular oxygen under abiotic conditions can be written as Reaction , where dioxygen is the oxidizing agent, is relatively slow compared to the circumstance where ferric iron is the oxidizing agent.…”

“…1,2 A root cause of AMD is the exposure of mining waste (i.e., overburden, waste rock, and tailings), which typically contains 1−20% pyrite (FeS 2 ) and lower amounts of other metal sulfides (e.g., marcasite and pyrrhotite), to air, water, and microorganisms. 3,4 Both the abiotic and biotic oxidation of the metal sulfide, during and after mining activity, leads to the oxidation of the sulfur component to sulfuric acid (i.e., AMD). A composite reaction for the oxidation of pyrite by molecular oxygen under abiotic conditions can be written as…”