Real-Time Electrical Conductivity Monitoring and Correlation with Sulfate Release and Acid Mine Drainage Potential from a Gold/Silver Paste Tailing Storage

Safe disposal of tailings as high-density thickened tailings or paste tailings can reduce the environmental risks of conventional tailings deposits, reduce water use, minimize tailings storage facility footprints, reduce the potential for acid mine drainage (AMD), and minimize risks of failure, among other advantages. In the dewatering process, the addition of flocculants is key to improving the sedimentation of the tailings and the formation of a compact paste. Despite the environmental and operational advantages of using paste tailings, it is not clear how the chemical nature of coagulants and flocculants could influence the discharge of toxic elements (salts and metals) from tailings after storage. In this study, we show the results of the real-time evaluation of the release of polluting runoffs from a paste tailings deposit. To do this, we analyzed paste tailing samples for AMD potential through static and kinetic tests and monitored the electrical conductivity and real-time pH, evaluating the correlation with the sulfate in the thickener and downstream from the tailings deposit. Tailing samples have low sulfur content (<2%) and low acid-generating potential. Moreover, there is no evidence of a significant positive correlation (Pearson’s coefficient r < 0.8) between the sulfate concentrations with the pH or EC. Thus, the chemical nature of the paste tailings prior to discharge has no direct impact on the release of sulfate-rich runoffs from the tailings after its storage. This indicates that the tailings paste at the evaluated site is chemically stable in the short term.

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Microbiological monitoring of acid mine drainage treatment systems and aquatic surroundings using real-time PCR

Water Science & Technology ◽

10.2166/wst.2009.230 ◽

2009 ◽

Vol 59 (11) ◽

pp. 2083-2091 ◽

Cited By ~ 2

Author(s):

J. S. Han ◽

C. G. Kim

Keyword(s):

Water Quality ◽

Acid Mine Drainage ◽

Real Time ◽

Real Time Pcr ◽

Biological Diversity ◽

Mine Drainage ◽

Treatment System ◽

Microbiological Monitoring ◽

Mining Areas ◽

Acid Mine

In general, acid mine drainage (AMD) causes low pH and high metal concentrations in mining areas and surroundings. The aim of this research was to achieve microbiological monitoring for AMD and to assess whether mine water outflows have any ecological effects on the aqueous ecosystem receiving effluents from different types of treatment system. The water quality of aquatic sample was analyzed and the molecular biological diversity of the samples was assessed using 16S rRNA methods, which were implemented to determine which bacteria existed throughout various unit processes for different AMD treatment systems and their receiving water environments. Acidiphilium cryptum, a heterotrophic acidophile, was found at the AMD sites, and Rhodoferax ferrireducens, which can reduce iron using insoluble Fe(III) as an electron acceptor, was detected at many AMD treatment facilities and downstream of the treatment processes. Subsequently, quantitative real-time PCR was conducted on specific genes of selected bacteria. Surprisingly, obvious trends were observed in the relative abundance of the various bacteria that corresponded to the water quality analytical results. The copy number of Desulfosporosinus orientus, a sulfate reducing bacteria, was also observed to decrease in response to decreases in metals according to the downstream flow of the AMD treatment system.

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Assessment of two kinetic tests to predict the acid mine drainage in waste rock samples of a uranium mine

Rem Revista Escola de Minas ◽

10.1590/s0370-44672014000100016 ◽

2014 ◽

Vol 67 (1) ◽

pp. 107-113 ◽

Cited By ~ 1

Author(s):

Adriana Trópia de Abreu ◽

Efigênia Miranda de Faria ◽

Carla Thamilis Fonseca Chaves ◽

Adilson do Lago Leite ◽

Jorge Carvalho de Lena

Keyword(s):

Acid Mine Drainage ◽

Mine Drainage ◽

Waste Rock ◽

Abandoned Mines ◽

Uranium Mine ◽

Atmospheric Conditions ◽

System Quality ◽

Oxidation Reactions ◽

Acid Mine ◽

Kinetic Tests

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 drained water accelerates the solubility process of solid materials (rocks, soils and sediments) and favors metal and metalloid leaching making them available to the environment, which impairs the hydric system quality. This is a quite common situation at abandoned mines where the material is exposed, as at theOsamu Utsumi Mine in Caldas, MG. The main goal of this work was to assess and compare two kinetic tests in an attempt to predict the acid generation from the waste rock of the Osamu Utsumi Mine. The tests were carried out using a Soxhlet extractor and a leaching column. The leachate from the two tests was analyzed for the physical-chemical parameters (pH, Eh and electric conductivity) and metals and metalloids.

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Prediction of Acid Mine Drainage: Importance of Mineralogy and the Test Protocols for Static and Kinetic Tests

Mine Water and the Environment ◽

10.1007/s10230-013-0249-1 ◽

2013 ◽

Vol 33 (1) ◽

pp. 54-65 ◽

Cited By ~ 44

Author(s):

Hassan Bouzahzah ◽

Mostafa Benzaazoua ◽

Bruno Bussiere ◽

Benoit Plante

Keyword(s):

Acid Mine Drainage ◽

Mine Drainage ◽

Acid Mine ◽

Kinetic Tests

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Characteristics of Pores in Coals Samples Exposedto Acid Mine Drainage

10.21203/rs.3.rs-554654/v1 ◽

2021 ◽

Author(s):

Hao Tang ◽

Jin-zhi LUO ◽

Li-wei ZHENG ◽

Chi-yang LIU ◽

huahua LI ◽

...

Keyword(s):

Water Quality ◽

Electrical Conductivity ◽

Acid Mine Drainage ◽

Coal Seam ◽

Mine Drainage ◽

Significant Risk ◽

Quality Parameters ◽

Water Quality Parameters ◽

Shaanxi Province ◽

Acid Mine

Abstract Acid mine drainage commonly occupies some pore space after underground coal mining, and this severely depreciates coal pillars, thereby posing a significant risk to mine stability. Considering that such depreciation is reflected in the microstructures of these pillars, in the present study, we propose a static immersion method suitable for coal seam samples immersion in the laboratory. We immersed the No. 2-2 coal seam samples from the Ningtiao Tower Coal Mine in Yulin, Shaanxi Province, in different acid mine drainage solutions and monitored the pH, oxidation–reduction potential (ORP), electrical conductivity (EC), total dissolved solids (TDS) among other water quality parameters for 300 h. After the immersion tests, samples were examined using scanning electron microscopy (SEM). The pH, ORP, EC, and TDS of the prepared acid mine drainage solutions increased significantly as the immersion time increased. Changes in water quality parameters are attributed to the absorption of hydrogen ions by insoluble clay minerals in the coal, which reduced the acidity, increased the pH value, and enhanced the electrical conductivity of the acid mine drainage solutions. SEM analysis reveals differences in the pore characteristics of (pore throat size and orientation) of the coal samples, and these are caused by erosive effects of the acid mine drainage solutions. Pores with throat sizes greater than 10 µm increased by 95% as the pH of the acid mine drainage solutions decreased, while the dominant pore orientation (60–90°) decreased to the 0–30° or increased to the 150–180° range, thereby increasing their randomness.

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