scholarly journals Infrared Thermography: A Method to Visualise and Analyse Sulphide Oxidation

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 933
Author(s):  
Marjan Knobloch ◽  
Bernd G. Lottermoser
Keyword(s):  
Acid Rock Drainage ◽  
Size Fraction ◽  
Sulphide Mineral ◽  
Oxidation Reactions ◽  
Acid Rock ◽  
Sulphide Oxidation ◽  
Geochemical Properties ◽  
Thermographic Camera ◽  
Ph Conditions ◽  
Optically Detected

Environmental testing of sulphidic ores and wastes aims to assess the release of metals and metalloids at acid pH conditions and the samples’ likelihood to produce acid rock drainage (ARD). However, the majority of established ARD tests measure geochemical properties of samples and cannot visualise the exothermic oxidation reactions and their intensity leading to metalliferous drainage in all pH environments. This paper proposes a new protocol to detect and visualise the sulphide oxidation in ores and wastes. Six nearly monomineralic sulphides were crushed, sieved to two size fraction (0.09–4 mm), milled to powder and treated with H2O2. The thermal energy released upon sulphide oxidation was optically detected and temperatures measured using a portable infrared thermographic camera. Based on temperature–time progression curves, the oxidation reactivity of sulphides was derived from high to low: chalcopyrite > arsenopyrite > pyrite > sphalerite > stibnite > galena, which depends on grain size, amount of sulphides and other non-sulphide mineral phases present in the sample material. The study demonstrates that the application of H2O2 to sulphide sample powders and subsequent visualisation of the treated materials using a thermographic camera represents a rapid technique in revealing the presence of oxidising sulphides under all pH conditions.

scholarly journals Acid Rock Drainage or Not—Oxidative vs. Reductive Biofilms—A Microbial Question

2018 ◽  
Author(s):  
Margarete Maria Kalin ◽  
Soeren Bellenberg ◽  
William Nielson Wheeler
Keyword(s):  
Acid Rock Drainage ◽  
Mine Waste ◽  
New Technology ◽  
Field Tests ◽  
Inhibitory Effect ◽  
Organic Coating ◽  
Coal Waste ◽  
Mineral Surface ◽  
Acid Rock ◽  
Sulphide Oxidation

Abstract: Measures to counteract AMD generation need to start at the mineral surface, inhibiting mineral-oxidizing, acidophilic microbes. Laboratory and long-term field tests with pyrite-containing mining wastes, where Carbonaceous Phosphate Mining Waste (CPMW) was added, resulted in low acidity, and near neutral drainage. The effect was reproducible, nd confirmed by several independent research groups. This was shown to involve an organic coating, likely a biofilm. The biofilm formation was confirmed when CPMW was added to lignite coal waste with an initial pH of 1. Forty five days after the addition, the coal waste was dominated by heterotrophic microorganisms in biofilms. A review of the scientific literature supports that CPMW has physical and chemical characteristics which are capable of inducing a strong inhibitory effect on sulphide oxidation by forming an organic coating over the mineral surface. CPMW characteristics appear to provide the cornerstone of a new technology for the reduction of sulphide oxidation in mine wastes. An hypothesis for testing this technology is presented which could result in an economical and sustainable approach to mine waste and water management.

PREDICTING ACID ROCK DRAINAGE FROM A NICKEL MINE WASTE PILE AND METAL LEVELS IN SURROUNDING SOILS

2017 ◽  
Vol 16 (9) ◽  
pp. 2089-2096
Author(s):  
Artwell Kanda ◽  
George Nyamadzawo ◽  
Jephita Gotosa ◽  
Nathan Nyamutora ◽  
Willis Gwenzi
Keyword(s):  
Acid Rock Drainage ◽  
Mine Waste ◽  
Acid Rock ◽  
Metal Levels

scholarly journals Nanometre-Scale Visualization of Chemical Parameter Changes by T1-Weighted ODMR Imaging Using a Fluorescent Nanodiamond

Chemosensors ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 68
Author(s):  
Takahiro Fujisaku ◽  
Ryuji Igarashi ◽  
Masahiro Shirakawa
Keyword(s):  
Magnetic Resonance ◽  
Laser Pulse ◽  
Real Time ◽  
Physical Parameters ◽  
Biological Processes ◽  
Chemical Parameter ◽  
Ph Conditions ◽  
Optically Detected ◽  
Life Phenomena ◽  
Selection Of

The dynamics of physical parameters in cells is strongly related to life phenomena; thus, a method to monitor and visualize them on a single-organelle scale would be useful to reveal unknown biological processes. We demonstrate real-time nanometre-scale T1-weighted imaging using a fluorescent nanodiamond. We explored optically detected magnetic resonance (ODMR) contrast at various values of interval laser pulse (τ), showing that sufficient contrast is obtained by appropriate selection of τ. By this method, we visualized nanometre-scale pH changes using a functionalized nanodiamond whose T1 has a dependence on pH conditions.

Small-scale field evaluation of geochemical blending of waste rock to mitigate acid rock drainage potential

2021 ◽  
pp. geochem2021-066
Author(s):  
S.J. Day
Keyword(s):  
Acid Rock Drainage ◽  
Field Evaluation ◽  
Waste Rock ◽  
Small Scale ◽  
Proof Of Concept ◽  
Acidic Water ◽  
Acid Rock ◽  
Acid Generation ◽  
Acidic Waters ◽  
Critical Consideration

Blending of potentially acid generating (PAG) waste rock with non-PAG waste rock to create a rock mixture which performs as non-PAG is a possible approach to permanent prevention of acid rock drainage (ARD) for PAG waste rock. In 2012, a field weathering study using 300 kg samples was implemented at Teck Coal's Quintette Project located in northeastern British Columbia, Canada to test the prevention of acid generation in the PAG waste rock by dissolved carbonate leached from overlying non-PAG waste rock and direct neutralization of acidic water from PAG waste rock by contact with non-PAG waste rock.After eight years of monitoring the experiments, the layered non-PAG on PAG barrels provided proof-of-concept that as the thickness of the PAG layer increases relative to the thickness of the non-PAG layers, acidic waters are more likely to be produced. The PAG on non-PAG layering has resulted in non-acidic water and no indications of metal leaching despite accelerated oxidation in the PAG layer shown by sulphate loadings. The study has demonstrated that the scale of heterogeneity of PAG and non-PAG materials is a critical consideration for providing certainty that rock blends designed to be non-PAG will perform as non-PAG in perpetuity. This is contrary to the standard paradigm in which an excess of acid-consuming minerals is often considered sufficient alone to ensure ARD is not produced.

scholarly journals The Formation of Silicate-Stabilized Passivating Layers on Pyrite for Reduced Acid Rock Drainage

2017 ◽  
Vol 51 (19) ◽  
pp. 11317-11325 ◽  
Author(s):  
Rong Fan ◽  
Michael D. Short ◽  
Sheng-Jia Zeng ◽  
Gujie Qian ◽  
Jun Li ◽  
...  
Keyword(s):  
Acid Rock Drainage ◽  
Acid Rock

Geochemical Characterization for Prediction of Acid Rock Drainage Potential in Hydrothermal Deposit

2014 ◽  
pp. 773-779
Author(s):  
Rudy Sayoga Gautama ◽  
Ginting Jalu Kusuma ◽  
Dyah Firgiani ◽  
Salmawati Mustakar ◽  
Prasetyaningtyas Ekarini
Keyword(s):  
Acid Rock Drainage ◽  
Hydrothermal Deposit ◽  
Acid Rock ◽  
Geochemical Characterization

Environmental risk assessment of acid rock drainage under uncertainty: The probability bounds and PHREEQC approach

2016 ◽  
Vol 301 ◽  
pp. 187-196 ◽  
Author(s):  
Getnet D. Betrie ◽  
Rehan Sadiq ◽  
Craig Nichol ◽  
Kevin A. Morin ◽  
Solomon Tesfamariam
Keyword(s):  
Risk Assessment ◽  
Environmental Risk ◽  
Environmental Risk Assessment ◽  
Acid Rock Drainage ◽  
Acid Rock ◽  
Probability Bounds

scholarly journals Acid-rock drainage at Skytop, Centre County, Pennsylvania, 2004

2005 ◽  
Author(s):  
Jane M. Hammarstrom ◽  
Keith Brady ◽  
Charles A. Cravotta
Keyword(s):  
Acid Rock Drainage ◽  
Acid Rock
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