acid rock drainage prediction manual march 1991

Then, to better assess long-term AGP, kinetic tests are usually performed to provide more information about the reaction rates of the acid-generating and acid-neutralizing minerals. The present work compares the classic Sobek static test with three mineralogical static tests to assess the importance of sample mineralogy in acid mine drainage (AMD) prediction. We also investigated how experimental procedures related to static tests can influence prediction results. We used three synthetic tailings samples made by mixing well-characterized pure minerals in calibrated proportions. Although basically different in their principles and procedures, the modified Sobek and mineralogical static tests gave similar results. These AGP predictions were then validated by the use of a kinetic test. The kinetic test protocol was also modified in this study and the results obtained correlated well with the static test results, in contrast to the standard kinetic test protocol. The present work highlights the limitations of static and kinetic test procedures, and provides recommendations for a better use of these tests for more reliable AMD prediction.Um das langzeitlich wirksame AGP zu bestimmen, werden haufig kinetische Test durchgefuhrt, um so die Reaktionsraten der saurebildenden und neutralisierenden Minerale zu ermitteln. In dieser Arbeit wird der klassische statische Versuch nach Sobek mit drei weiteren statischen Versuch verglichen, um die Bedeutung der mineralogischen Zusammensetzung der Proben bei der Vorhersage der Bildung von sauren Grubenabwassern zu untersuchen. Gleichzeitig wird betrachtet, wie sich die Versuchsbedingungen auf die Resultate auswirken. Hierzu werden drei kunstliche hergestellte Mischproben verwendet, welche aus gut charakterisierten reinen Mineralen bestehen. Obwohl sich samtliche Testvarianten hinsichtlich ihrer Grundlagen und Versuchsverlaufe unterscheiden, fuhren sie zu vergleichbaren Ergebnissen.

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Such contamination is termed acid rock drainage (ARD). The testing of waste materials can be carried out to provide data so that ARD can be predicted and controlled and to facilitate the implementation of cost effective waste management practices. Numerous laboratory and field test procedures to assess or predict generation of ARD are in use, or have been proposed. This Manual gives background information on ARD generation and its prediction and provides a guide to the components necessary for carrying out and implementing a prediction program. Detailed descriptions of recommended prediction procedures are provided. Alternative procedures are also presented. For each prediction method, the objectives, test principles, equipment and reagent requirements, test procedure, interpretation and reporting of results, advantages and disadvantages, are described. A selected bibliography and list of references is included. The development of new test procedures and revisions to existing procedures is ongoing. The Manual is designed to allow the inclusion of revisions and updates to registered subscribers. To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser. You can download the paper by clicking the button above. Reference material available from the Canadian Certified Reference Material Program - 613-995-4738; fax: 613-943-0573 (copy of the report also comes with purchase of reference materials). Five-volume manual available as CD-ROM. Five-volume manual available in hard copy. August 2002. The Prediction of Acid Rock Drainage. Vancouver, November 1996. Risk Assessment and Management. Vancouver, December 1998. Case Studies, Research Studies and Effects of Mining on Natural Water Bodies. Vancouver, December 1999. For enquiries, contact us.

Subscription will auto renew annually. Taxes to be calculated in checkout. CD, Les Editions de l’Ecole Polytechnique de Montreal, Canada Barazzuol L, Sexsmith K (2012) Application of an advanced mineralogical technique: sulphide mineral availability and humidity cell interpretations based on MLA analysis. In: Proceedings of the 9th international conference on acid rock drainage (ICARD), Ottawa, ON, Canada Benzaazoua M, Bussier B, Dagenais AM (2001) Comparison of kinetic tests for sulfide mine tailings. In: Proceedings of the tailings and mine waste 01.In: Proceedings of the 9th ICARD, Ottawa, ON, Canada Blowes DW, Ptacek CJ, Jambor JL, Weisener CG (2003) The Geochemistry of acid mine drainage. In: Holland HD, Turekian KK (eds) Ch 9.05, Treatise on geochemistry. ISBN: 0-08-043751-6 Bouzahzah H (2006) Prediction du potentiel du drainage minier acide des residus sulfures. MS thesis, University of Liege, Belgium Bouzahzah H, Califice A, Mermillod-blondin R, Benzaazoua M, Pirard E (2008) Modal analysis of mineralogical blends using optical image analysis versus X-ray diffraction and ICP. In: Proceedings of the 9th ICARD, Ottawa, ON, Canada Bouzahzah H, Benzaazoua M, Bussiere B (2013) Acid-generating potential calculation using mineralogical static test: modification of the Paktunc equation. In: Proceedings of the 23rd world mining congress, Montreal, QC, Canada Bussiere B (2007) Colloquium 2004: hydro-geotechnical properties of hard rock tailings from metal mines and emerging geo-environmental disposal approaches.In: Proceedings of the metallurgy soc AIME, paper A79-29 Fandrich R, Gu Y, Burrows D, Moeller K (2007) Modern SEM-based mineral liberation analysis.The prediction of acid rock drainage—lessons from the data base. In: Spiers G, Beckett P, Conroy H (eds) Mining and the environment, Sudbury 2003.

Die auf dieser Grundlage ermittelten AGP-Prognoseergebnisse wurden im Anschluss mit Hilfe eines kinetischen Versuchs validiert. Im Gegensatz zu standartgema?en Versuchsverlauf wurde der kinetische Test verandert, was jedoch die Vergleichbarkeit mit den statischen Versuchen erhoht. In der vorliegenden Arbeit werden die Grenzen von statischen und kinetischen Versuchsanwendungen aufgezeigt und Hinweise zur Verbesserung der Versuche abgeleitet. Dies fuhrt zu vertrauenswurdigeren Ergebnissen bei der Vorhersage der Bildung von sauren Grubenabwassern. Resumen Los ensayos estaticos que compararan la capacidad de generacion de acido y la capacidad de neutralizarlo para cierto residuo minero (colas o rocas residuales) estan caracterizados por una amplia zona de incertidumbre en la cual es imposible predecir adecuadamente la capacidad de generacion de acido (AGP). Luego, para un mejor relevamiento del AGP a largo plazo, los ensayos cineticos se realizan usualmente para dar mas informacion sobre las velocidades de las reacciones de generacion y neutralizacion de la acidez que presentan los minerales. Este trabajo compara el ensayo estatico clasico de Sobek con tres ensayos estaticos mineralogicos para relevar la importancia de la mineralogia de la muestra en la prediccion de AMD. Tambien investigamos como los procedimientos experimentales de los ensayos estaticos pueden influir en la prediccion de los resultados. Usamos 3 muestras de colas sinteticas preparadas mezclando en proporciones definidas minerales puros bien caracterizados. Aunque difieren en sus principios y procedimientos, los ensayos estaticos mineralogicos y los estudios modificados de Sobek dan resultados similares. Estas predicciones AGP fueron luego validadas utilizando un ensayo cinetico. El protocolo del ensayo cinetico tambien fue modificado y los resultados obtenidos correlacionaron bien con los resultados del ensayo estatico, en contraste con el protocolo estandar del ensayo cinetico.

The field water chemistry from springs and seeps on the mine site were compared with the static and long term aqueous leaching test results. During the ABA, NAG and long term paste pH tests, ore rich and ore bearing wastes showed a paste pH Zusammenfassung Mineralhaltiger Abraum und Nebengesteine waren Gegenstand von wassrigen Eluatversuchen, Saure-Basen-Berechnungen (ABA) und Net Generation Tests (NAG) sowie detaillierter mineralogischer Untersuchungen, um Vorhersagen zur Bildung von saurehaltigen Bergbau-Abwassern (AMD) in der gro?ten historischen Kupfer-Lagerstatte der Turkei zu treffen. Die Chemie der Oberflachenwasser von Quellen und der Sickerwasser aus dem Bergbau wurden mit den Ergebnissen der statischen und der Langzeit-Auswaschungstest verglichen. La quimica del agua de los manantiales y las filtraciones en el sitio de la mina se compararon con los resultados de la prueba de lixiviacion acuosa a largo plazo y estatica.Subscription will auto renew annually. Taxes to be calculated in checkout. In: Proceedings of 23rd World Mining Congress, Montreal, QC, Canada Bouzahzah H, Benzaazoua M, Bussiere B, Plante B (2014) Prediction of acid mine drainage: importance of mineralogy and test protocols for static and kinetic tests.In: Jambor JL, Blowes DW, Ritchie AIM (eds) Environmental aspects of mine wastes, vol 31.Report 67, Acid Drainage Technology Initiative, Springer, Berlin, Heidelberg Environ Monit Assess 187:374 Article ASA, Madison In: Plumlee GS, MJ Logsdon (eds) The environmental geochemistry of mineral deposits, Part A. Processes, techniques, and health issues. Reviews in economic geology, vol 6A.In: Amend JP, Edwards KJ, Lyons TW (eds) Sulfur biogeochemistry—past and present, vol 379.International Ltd, Ian Wark Research Institute Sobek AA, Schuller WA, Freeman JR, Smith RM (1978) Field and laboratory methods applicable to overburdens and mine soils.

Memoire de maitrise en Sciences appliquees (Genie Mineral), Ecole Polytechnique de Montreal, QC, Canada Jambor JL, Dutrizac JE, Raudsepp M, Groat LA (2003) Effect of peroxide on neutralization-potential values of siderite and other carbonate minerals.MEND Report 1.32.1, CANMET, Ottawa, ON, Canada Kwong YTJ, Ferguson KD (1997) Mineralogical changes during NP determinations and their implications.In: Proceedings of the 2nd annual west virginia surface mine drainage task force symp, West Virginia University, Morgantown, WV, USA Merkus HG (2009) Particle size measurements fundamentals, practice, quality.In: Plumlee GS, Logsdon MJ (eds) The environmental geochemistry of mineral deposits, part A: processes, techniques, and health issues. In: Azcue JM (ed) Environmental impacts of mining activities.Elsevier Science BV, Amsterdam In: Jambor DL, Blowes DW, Ritchie AIM (eds.), Environmental aspects of mine wastes, short course. Young RA (ed), Oxford Univ Press, Oxford, UK Skousen J, Renton J, Brown H, Evans P, Leavitt K, Brady B, Cohen L, Ziemkiewicz P (1997) Neutralization potential of overburden samples containing siderite.Lund University Press, Lund, Sweden Sietronics Pty Ltd, Belconnen In: Proceedings of the 8th ICARD, Skelleftea, Sweden Weber PA, Thomas JE, Skinner WM, Smart RSC (2004) Improved acid neutralization capacity assessment of iron carbonates by titration and theoretical calculation.Some financial support was also provided by the UQAT foundation (FUQAT) and the International Research Chairs Initiative (IDRC). The authors are also grateful to the “Unite de Recherche et de Service en Technologie Minerale” personnel for their technical assistance.Download citation Received: 22 January 2013 Accepted: 03 September 2013 Published: 19 November 2013 Issue Date: March 2014 DOI: Keywords Acid mine drainage prediction ABA static test Kinetic test Mineralogy Subscription will auto renew annually. Taxes to be calculated in checkout.

Limestone chips may be introduced into sites to create a neutralizing effect. Where limestone has been used, such as at Cwm Rheidol in mid Wales, the positive impact has been much less than anticipated because of the creation of an insoluble calcium sulfate layer on the limestone chips, binding the material and preventing further neutralization.A South African company that won the 2013 IChemE (ww.icheme.org) award for water management and supply (treating AMD) have developed a patented ion-exchange process that treats mine effluents (and AMD) economically.Typically, the effluent from constructed wetland receiving near-neutral water will be well-buffered at between 6.5-7.0 and can readily be discharged. Some of metal precipitates retained in sediments are unstable when exposed to oxygen (e.g., copper sulfide or elemental selenium), and it is very important that the wetland sediments remain largely or permanently submerged.In this process, Sulfate-reducing bacteria oxidize organic matter using sulfate, instead of oxygen. Their metabolic products include bicarbonate, which can neutralize water acidity, and hydrogen sulfide, which forms highly insoluble precipitates with many toxic metals.It is by no means complete, as worldwide, several thousands of such sites exist.The area has both natural and mining-exacerbated acid drainage flowing into the Wrightman Fork, then into the Alamosa River, which flows into the San Luis Valley Sept 16 to 18, 1991, Montreal, Quebec. Society for Mining, Metallurgy, and Exploration, Inc. Vol II, 1027-1034 Retrieved 13 July 2009. Retrieved 25 April 2011. Retrieved 12 December 2010. Retrieved 13 July 2009. Retrieved 2 July 2014. Retrieved 18 March 2013. Archived from the original (PDF) on 7 October 2011. Retrieved 6 December 2011. ISBN 0642725128 Accessed 21 May 2016. By using this site, you agree to the Terms of Use and Privacy Policy.

Abstract Acid rock drainage (ARD) is a major problem related to the management of mining wastes, especially concerning deposits containing sulphide minerals. Since drainage quality largely depends on the ratio and quality of acid-producing and neutralising minerals, mineralogical calculations could also be used for ARD prediction. In this study, several Finnish waste rock sites were investigated and the performance of different static ARD test methods was evaluated and compared. At the target mine sites, pyrrhotite was the main mineral contributing to acid production (AP). Silicate minerals were the main contributors to the neutralisation potential (NP) at 60% of the investigated mine sites. Since silicate minerals appear to have a significant role in ARD generation at Finnish mine waste sites, the behaviour of these minerals should be more thoroughly investigated, especially in relation to the acid produced by pyrrhotite oxidation. In general, the NP of silicate minerals appears to be underestimated by laboratory measurements. For example, in the NAG test, the slower-reacting NP-contributing minerals might require a longer time to react than is specified in the currently used method. The results suggest that ARD prediction based on SEM mineralogical calculations is at least as accurate as the commonly used static laboratory methods. Keywords: ABA test, NAG test, SEM, Waste rock, Risk assessment Introduction Acid rock drainage (ARD) with high concentrations of potentially harmful elements is considered as one of the main concerns related to the management of mining wastes (e.g. MEND 1991; Price 2003, Dold 2014; Mehta et al. 2018 ). This particularly applies to deposits containing sulphide minerals, which are prone to oxidisation under the influence of atmospheric conditions (e.g. Singer and Stumm 1970; Blowes and Ptacek 1994 ).

EPA-HQ-OW-2016-0012 Ustaomer T, Robertson AHF (1994) Late Paleozoic marginal basin and subduction-accretion: the Paleotethyan Kure Complex, Central Pontides, northern Turkey.Download citation Received: 28 May 2016 Accepted: 05 June 2017 Published: 15 June 2017 Issue Date: March 2018 DOI: Keywords ABA static tests Acid production Aqueous leaching Kure VMS copper deposits Paste pH Long term paste pH Subscription will auto renew annually. Taxes to be calculated in checkout. Areas where the earth has been disturbed (e.g. construction sites, subdivisions, and transportation corridors) may create acid rock drainage. In many localities, the liquid that drains from coal stocks, coal handling facilities, coal washeries, and coal waste tips can be highly acidic, and in such cases it is treated as acid rock drainage. This liquid often contains toxic metals, such as copper or iron. These, combined with reduced pH, have a detrimental impact on the streams aquatic environments.None of these other names have gained general acceptance.This break down is the main driver of acid mine drainage. When a mine is abandoned, the pumping ceases, and water floods the mine. This introduction of water is the initial step in most acid rock drainage situations.Colonies of bacteria and archaea greatly accelerate the decomposition of metal ions, although the reactions also occur in an abiotic environment. These microbes, called extremophiles for their ability to survive in harsh conditions, occur naturally in the rock, but limited water and oxygen supplies usually keep their numbers low. Special extremophiles known as Acidophiles especially favor the low pH levels of abandoned mines. The most commonly mined ore of copper, chalcopyrite, is itself a copper-iron-sulfide and occurs with a range of other sulfides. Thus, copper mines are often major culprits of acid mine drainage.

A general equation for this process is:The ferric cations produced can also oxidize additional pyrite and reduce into ferrous ions:The process also produces additional hydrogen ions, which can further decrease pH.The elevated levels of heavy metals can only be dissolved in waters that have a low pH, as is found in the acidic waters produced by pyrite oxidation.Aquatic macroinvertebrates living in streams or parts of streams affected by acid mine drainage show fewer individuals, less diversity, and lower biomass.In such cases the Environment Agency working with partners such as the Coal Authority have provided some innovative solutions, including constructed wetland solutions such as on the River Pelenna in the valley of the River Afan near Port Talbot and the constructed wetland next to the River Neath at Ynysarwed.Acidic water produced at active mines must be neutralized to achieve pH 6-9 before discharge from a mine site to a stream is permitted.In this application, a slurry of lime is dispersed into a tank containing acid mine drainage and recycled sludge to increase water pH to about 9. At this pH, most toxic metals become insoluble and precipitate, aided by the presence of recycled sludge. Optionally, air may be introduced in this tank to oxidize iron and manganese and assist in their precipitation. The resulting slurry is directed to a sludge-settling vessel, such as a clarifier. In that vessel, clean water will overflow for release, whereas settled metal precipitates (sludge) will be recycled to the acid mine drainage treatment tank, with a sludge-wasting side stream. A general equation for this process is:These systems are far less costly to build, but are also less efficient (i.e., longer reaction times are required, and they produce a discharge with higher trace metal concentrations, if present).Monosilicic acid remains in the bulk solution to play many roles in correcting the adverse effects of acidic conditions.

Drainage quality largely depends on the mineralogical and chemical composition of the mine wastes, and particularly on the ratio of acid-producing and neutralising minerals (e.g. Blowes and Jambor 1990; Blowes and Ptacek 1994 ), combined with reactions catalysed by microbes (e.g. Singer and Stumm 1970 ). Since ARD plays a major role in the generation of environmental issues, the accurate prediction of ARD is of utmost importance (e.g. Parbhakar-Fox and Lottermoser 2015; Dold 2017 ). Nevertheless, prediction of the ability of mine waste materials to produce ARD is sometimes challenging, as ARD generation depends on various mineralogical, chemical, hydrological and microbiological factors (e.g. Blowes and Jambor 1990; Nordstrom 2000; Dold 2010; Blowes et al. 2014 ). The characterisation methods for assessing the acid production potential (APP) and ARD risk can be divided into static and kinetic tests (Lapakko 2002 ). Static tests are short-term (duration usually measured in hours or days) laboratory analyses. Kinetic tests are long-term tests (from several months to years), revealing information on the time scale of drainage events (Lapakko 2002 ). The potential risk can then be estimated based on the ratio of the NP and AP (neutralisation potential ratio, NPR) or the subtraction NP-AP (net neutralisation potential, NNP), as is customary in Finland, for instance. Many variations of the ABA test exist, including the standard ABA originally developed for coal mining (Sobek et al. 1978 ), the modified ABA (Lawrence et al. 1989; Lawrence and Wang 1997 ) and “acid addition on the basis of the carbonate content” (EN 15875), which is a recommended standard method within Europe.

The AP is usually calculated based on the total sulphur content of the sample and expressed as a pyrite equivalent, since it is assumed that pyrite is the most common sulphide mineral and that 4 mol of protons is produced during the oxidation process (Colmer and Hinkle 1947; Singer and Stumm 1970; Nordstrom 2000; Dold 2014 ). The NP is typically estimated by titrating the sample with acid (Price et al. 1997; White et al. 1999 ), but it can also be calculated, for example, based on the carbonate carbon content of the rock material (Lawrence and Wang 1997 ). The ABA method has some disadvantages. Some carbonate minerals containing iron, particularly siderite (FeCO 3 ), do not necessarily contribute to neutralisation (Lawrence and Wang 1997; Haney et al. 2006 ). The method does not take into account the reactive non-carbonate minerals that may contribute to acid neutralisation, e.g. easily dissolving silicate minerals. Moreover, it does not consider the groups of Fe(III) hydroxides and Fe(II) hydroxide sulphates together with metal chlorides and sulphates as a proton source, although they might be a significant source of acidity (Dold 2017 ). Furthermore, in the ABA test, the AP is calculated by multiplying the wt% of S by the factor 31.25 based on the hypothesis that 2 mol of protons (released from pyrite oxidation) are neutralised by 1 mol of calcite (e.g. Gard Guide; Verburg et al. 2009 ). However, at a circumneutral pH, the most common carbonate species is bicarbonate (Appelo and Postma 2010 ), and the calculation factor should then be 62.5, as two times more calcite is needed to neutralize the same quantity of protons (Dold 2017 ). Another commonly used static test for ARD prediction is the net acid generation (NAG) test, which is based on the reaction of a sample with hydrogen peroxide (H 2 O 2 ), which accelerates the oxidation of sulphide minerals in the sample. The test is also easier to conduct in a field laboratory than other static tests.

As a disadvantage, the test does not give a value for the neutralisation potential, and additional NP measurement is therefore required to calculate the NAPP. Some contradictory predictions have also been noted when NAG test results have been compared with ABA results (Morin and Hutt 1999 ). The widely used static ABA and NAG tests have known limitations related to the mineralogy of the sample material (White III et al. 1999; Paktunc 1999b; Jambor 2003; Parbhakar-Fox and Lottermoser 2015; Dold 2017; Parbhakar-Fox et al. 2018 ). For example, the APP may be overestimated if there are other sulphide- or sulfur-containing minerals than rapidly acid-producing pyrite or pyrrhotite. Conversely, the APP may be underestimated if the waste contains large amounts of easily dissolvable and acid-generating iron sulphate minerals or siderite. The NP may be underestimated if the weathering of silicate minerals is not considered in APP estimations (Lawrence and Scheske 1997; Paktunc 1999b ). On the other hand, the NP determined in the laboratory using strong acids will sometimes overestimate silicate mineral reactivity and hence the NP (Lawrence and Scheske 1997; Jambor and Blowes 1998 ). In addition, static tests do not indicate the source minerals of the NP and AP (Lawrence and Scheske 1997; Paktunc 1999b ). Therefore, some mineralogical-based approaches have been proposed, e.g. by Lawrence and Scheske ( 1997 ), Parbhakar-Fox and Lottermoser ( 2015 ) and Jamieson et al. ( 2015 ). As pointed out by Dold ( 2017 ), scanning electron microscopy (SEM)-based automated mineral quantification methods have considerably developed in the last decades, increasing the available mineralogical data that could be utilised in ARD prediction. In this study, we compared the ABA test as presented in the standard EN 15875, the single-addition NAG test as presented in the AMIRA guidebook (Smart et al.

2002 ), SEM mineralogy-based ARD predictions based on Lawrence and Scheske ( 1997 ) and Dold ( 2017 ) and actual drainage quality at the target mine sites. For the ABA test, the NP was determined by standard titration and was also calculated based on the carbonate content, as presented by Lawrence and Wang ( 1997 ). The AP was calculated with the commonly used factor of 31.25 and the factor of 61.5 proposed by Dold ( 2017 ), and the results were compared. Data and samples from several Finnish mine waste sites were utilised, representing a wide range of deposit types. The objective of this study was to assess the functionality of standard static and mineralogical ARD prediction methods in the Nordic environment and whether static laboratory ARD tests could be substituted in some cases by an ARD prediction based only on SEM mineralogy. Furthermore, the ARD-related properties of various Finnish waste rock sites, including the main minerals responsible for neutralisation and the acid generation potential, are presented. From the Hitura target site, two sets of waste rock and water samples were taken from the same place: the first in 2014 and the second in 2016. The Kylylahti mine site was first visited for waste rock and water samples in 2014 and thereafter revisited for an additional water and rock sample from the same location in 2017. For this second Kylylahti rock sample, which was clearly more weathered than during the first sampling, only static laboratory tests were conducted, not SEM mineralogy. Table 1 The geology of the ore deposits and a description of waste rocks sampled at the target mine sites Mine site Commodity Deposit type Waste rocks and sulphides related to the deposit Target waste rock pile active Reference Pampalo Au Archaean (2.

7 Ga) metamorphic hydrothermal orogenic, gold mainly occurring in quartz veining in the native form, with disseminated sulphide ore minerals Feldspar porphyry, metavolcanics, metasedimentary rocks and metakomatite, soapstone. In two cases (Horsmanaho new pile and Hammaslahti), no visible flowing stream could be found, and the samples were taken from a pond at the waste rock pile. The measurement was conducted at the site using a portable multi-parameter YSI sonde, which was calibrated to pH 4 and 7 prior to every field trip. The alkalinity was determined with a Hach titrator with 0.16 or 1.60 N H 2 SO 4 to an end point of pH 4.5. The titration pH was measured with the Mettler Toledo SevenGo pH meter, which was calibrated daily to pH 4 and 7. The mine waste samples were analysed in an accredited laboratory (Labtium Oy). Laboratory duplicates for four waste rock samples and certified reference materials were employed for quality control of the analyses. The rock samples were first dried at 70%, Mineralogical analyses Mineralogical analyses were conducted at the GTK Research Laboratory by FE-SEM-EDS: JEOL JSM 7100F Schottky, combined with an Oxford Instruments EDS spectrometer X-Max 80 mm 2 (SDD). The crushed and ground sample materials for geochemical analysis were also used to prepare mineralogical polished samples cast in epoxy and covered with graphite to enhance electric conductivity. To investigate the modal mineralogy, around 10,000 individual mineral particles were analysed from each sample utilising Feature software. The results are semi-quantitative and were normalised to 100%. Mineral identification was based on comparing the numerical element composition obtained from EDS spectra with the mineralogical database of GTK. This class mainly includes mixed analyses generated from various mineral phases.