Abstract
Coal fly ash can be used in in various configurations (e.g. as cap, bottom liner, or blending) at a mine site, but comparative studies investigating their capacity to control acid mine drainage are limited. Batch and column leaching experiments were conducted to investigate the effects of fly ash-mine tailings mix ratios and system configurations on leachate chemistry. Acidic mine tailings (pH 2.72) were obtained from waste piles at a former gold and pyrite mine. Mixing the fly ash with the tailings in a 1:1 (w/w) ratio decreased Zn, Ni, Fe, Mn, Pb, and Cu leaching by 90 ± 6%, increased the pH from extremely acidic (2.9) to alkaline (8.0), and decreased electrical conductivity from 4 to 2.5 mS cm−1 due to solute precipitation. Using the fly ash as a ‘chemical liner’ beneath the tailings, applying the fly ash as both a cap and bottom liner, or blending the fly ash with tailings produced significantly less acidity, salinity, and metal leaching than using the fly ash as a cap. The capacity of fly ash to control acid generation is attributed to its acid neutralizing capacity and high pH (11.1).
Zusammenfassung
Kohle-Flugasche kann auf verschiedene Weise, z. B. als Oberflächen- und/oder Basislage bzw. in verschiedenen Mischungsverhältnissen an Bergbaustandorten verwendet werden. Studien, welche den Einfluss der Einbauarten auf die Bildung saurer Grubenabwässern untersuchen, sind jedoch selten. Um die Auswirkungen unterschiedlicher Flugasche-Bergbauabfall-Gemische und Einbauarten auf die Laugungschemie zu untersuchen, werden Batch- und Säulenexperimente durchgeführt. Die untersuchten sauren Bergbauabfälle (pH-Wert 2.72) stammen aus Abraumhalden einer ehemaligen Gold- und Pyritmine. Ein Mischungsverhältnis von Flugasche mit Bergbaurückständen von 1:1 (Gew./Gew.) verringert die Zn-, Ni-, Fe-, Mn-, Pb- und Cu-Auswaschung um 90 ± 6%. Gleichzeitig wird der pH-Wert von extrem sauer (2.9) auf alkalisch (8.0) erhöht und die elektrische Leitfähigkeit von 4 auf 2,5 mS/cm, aufgrund der Ausfällung gelöster Stoffe, verringert. Der lagenweise Einbau von Flugasche („chemical liner“) unterhalb der Rückstände, das gleichzeitige Einbringen von Flugasche als Oberflächen- und Basislage oder die Mischung von Flugasche mit Bergbaurückständen führt zu einer wesentlich geringeren Säurebildung sowie geringeren Salz- und Metallauswaschungen als eine singuläre Verwendung der Flugasche als Oberflächenlage. Die Fähigkeit von Flugasche, die Säurebildung zu kontrollieren bzw. zu beeinflussen, wird auf ihre Säureneutralisationskapazität und ihren hohen pH-Wert (11.1) zurückgeführt.
Resumen
Las cenizas de carbón se pueden usar en varias configuraciones (por ejemplo, como cobertura, barrera inferior o mezcla) en un sitio de la mina aunque los estudios comparativos que investigan su capacidad para controlar el drenaje ácido de la mina son limitados. Se llevaron a cabo experimentos de lixiviación en lotes y columnas para investigar los efectos de las proporciones de mezcla de relaves de las cenizas de las cenizas volantes y las configuraciones del sistema en la química de los lixiviados. Los relaves de las minas ácidas (pH: 2,72) se obtuvieron de pilas de desechos en una antigua mina de oro y pirita. La mezcla de las cenizas volantes con los relaves en una proporción 1:1 (p/p) disminuyó la lixiviación de Zn, Ni, Fe, Mn, Pb y Cu en un 90 ± 6%, incrementó el pH de extremadamente ácido (2,9) a alcalino (8,0) y una conductividad eléctrica reducida de 4 a 2,5 mS/cm debido a la precipitación de solutos. Usando la ceniza volante como una “barrera química” debajo de los relaves, aplicando la ceniza tanto como cobertura como barrera inferior o mezclando las cenizas con los relaves produce significativamente menos acidez, salinidad y lixiviación metálica que el uso de la ceniza como cobertura exclusivamente. La capacidad de las cenizas para controlar la generación de ácido se atribuye a su capacidad neutralizadora de ácidos y su alto pH (11,1).
摘要
粉煤灰在采场有多种用途(例如,做盖层、底衬或混合物),但有关粉煤灰控制酸性废水产出能力的比较研究并不多。通过批次和柱淋滤试验,研究了粉煤灰与尾矿混合比及其淋滤液的化学特性。酸性尾矿(pH: 2.72)取自从前金矿和黄铁矿的矸石堆。粉煤灰与尾矿按1:1(w/w)混合,它们可以减小90 ± 6%的锌、镍、铁、锰、铅和铜滤出,将pH从酸性2.9到碱性8.0,使电导率因沉淀反应而从4 降到 2.5 mS/cm。相对于粉煤灰作尾矿盖层,粉煤灰在尾矿底作 “化学衬垫”、粉煤灰同时铺设于尾矿盖层和底衬、粉煤灰与尾矿混合的方式都可以大幅降低尾矿酸性、盐度和金属滤出。粉煤灰控制产酸的能力源于它酸中和能力和较高的pH值。
Similar content being viewed by others
References
ASTM (American Society for Testing and Materials) (2005) ASTM C, 618. Standard specification for coal fly ash and raw calcined natural pozzolan for use in concrete. Am Soc Test Mater, West Conshohocken
Benatti CT, Tavares CRG (2012) Fenton’s process for the treatment of mixed waste chemicals. Organic pollutants ten years after the Stockholm convention-environmental and analytical update. InTech. http://cdn.intechopen.com/pdfs/29376.pdf. Accessed 12 Jan 2019
Dutta BK, Khanra S, Mallick D (2009) Leaching of elements from coal fly ash: assessment of its potential for use in filling abandoned coal mines. Fuel 88(7):1314–1323
Dzingayi E (2006) Bindura Nickel Corporation smelter operations. J South Afr Inst Min Metall 106(3):171–178
EC (European Community) (2003) EC Council Decision 2003/33/EC of 19 December 2002. Establishing Criteria and Procedures for the Acceptance of Waste at Landfills Pursuant to Article 16 and Annex II to Directive 1999/31/EC. European Community, Brussels
Finkelman RB, Giffin DE (1986) Hydrogen peroxide oxidation: an improved method for rapidly assessing acid-generating potential of sediments and sedimentary rocks. Reclam Reveg Res 5:521–543
Flint AL, Flint LE (2002) Particle density. In: Dane H, Topp GC (eds) Methods of soil analysis, part 4: physical methods. American Society of Agronomy, Soil Science Society of America, Madison, WI, pp 229–240
Frouz J, Zadinová R, Mihaljevič M, Rojík P, Řehoř M (2014) Effect of accelerated weathering and leaching on the chemistry and phytotoxicity of coal-mine overburden. Eur J Environ Sci 4(2):106–111
Galvín AP, Ayuso J, Agrela F, Barbudo A, Jiménez JR (2013) Analysis of leaching procedures for environmental risk assessment of recycled aggregate use in unpaved roads. Constr Build Mater 40:1207–1214
Garrabrants AC, Kosson DS, Stefanski L, DeLapp R, Seignette PFAB, van der Sloot HA, Kariher P, Baldwin M (2012) Interlaboratory validation of the leaching environmental assessment framework (LEAF) method 1313 and method 1316. US EPA/600/R-12/623, Washington DC
Gitari MW (2006) Evaluation of the leachable chemistry and contaminants attenuation in acid mine drainage by fly ash and its derivatives. PhD Thesis. Dept of Chemistry, University of Western Cape, South Africa
Gitari MW, Petrik LF, Etchebers O, Key DL, Iwuoha E, Okujeni C (2006) Treatment of acid mine drainage with fly ash: removal of major contaminants and trace elements. J Environ Sci Health A 41:1729–1747
Gwenzi W, Mupatsi N (2016) Evaluation of heavy metal leaching from coal fly ash-versus conventional concrete monoliths and debris. Waste Manag 49:114–123
Gwenzi W, Mashaike C, Chaukura N, Bunhu T (2017) Removal of trace metals from acid mine drainage using a sequential combination of coal fly ash—based adsorbents and phytoremediation by Bunchgrass (Vertiver [Vetivera Zizaniodes L.]). Mine Water Environ 36:520–531
Gwenzi W, Kosta GT, Chaukura N (2018) Potential leaching of heavy metals from pristine and accelerated weathered slag from recycling of automobile lead-acid batteries. Environ Process 5:611–629
Hui KS, Chao CYH, Kot SC (2005) Removal of mixed heavy metal ions in wastewater by zeolite 4A and residual products from recycled coal fly ash. J Hazard Mater 127(1–3):89–101. https://doi.org/10.1016/j.jhazmat.2005.06.027
Jones KB, Ruppert LF, Swanson SM (2012) Leaching of elements from bottom ash, economizer fly ash, and fly ash from two coal-fired power plants. Int J Coal Geol 94:337–348
Kadirvelu K, Goel J, Rajagopal C (2008) Sorption of lead, mercury and cadmium ions in multi-component system using carbon aerogels as adsorbent. JHazard Mater 153(1–2):502–507
Lee G, Bigham JM, Faure G (2002) Removal of trace metals by coprecipitation with Fe, Al and Mn from natural waters contaminated with acid mine drainage in the Ducktown Mining District, Tennessee. Appl Geochem 17(5):569–581
Lin CY, Yang DH (2002) Removal of pollutants from wastewater by coal bottom ash. J Environ Sci Health A 37(8):1509–1522
Lo HM, Liao YL (2007) The metal-leaching and acid-neutralizing capacity of MSW incinerator ash co-disposed with MSW in landfill sites. J Hazard Mater 142(1):512–519
Ma Y, Si C, Lin C (2014) Capping hazardous red mud using acidic soil with an embedded layer of zeolite for plant growth. Environ Technol 35(18):2314–2321. https://doi.org/10.1080/09593330.2014.902113
Makomo Resources (2019) Thermal power products: Makomo coal thermal power Station Products Spreadsheet 2018. Makomo Resources (Pvt) Ltd. https://makomoresources.com/coal-products/. Accessed 12 Jan 2019
Mapanda F, Nyamadzawo G, Nyamangara J, Wuta M (2007) Effects of discharging acid-mine drainage into evaporation ponds lined with clay on chemical quality of the surrounding soil and water. Phys Chem Earth 32:1366–1375
Mohan D, Chander S (2006) Removal and recovery of metal ions from acid mine drainage using lignite—a low cost sorbent. J Hazard Mater 137(3):1545–1553
Mohan S, Gandhimathi R (2009) Removal of heavy metal ions from municipal solid waste leachate using coal fly ash as an adsorbent. J Hazard Mater 169:351–359
Morar DL, Aydilek AH, Seagren EA, Demirkan MM (2011) Leaching of metals from fly ash–amended permeable reactive barriers. J Environ Eng 138(8):815–825
OECD/OCDE (Organisation for Economic Cooperation and Development) (2004) Guidelines for the testing of chemicals. Leaching in soil columns, OECD/OCDE 312. OECD/OCDE, Paris
Oesterlen PM, Lepper J (2005) The Lower Karoo coal (k2–3) of the Mid-Zambezi basin, Zimbabwe: depositional analysis, coal genesis and palaeogeographic implications. Int J Coal Geol 61:97–118
Orakwue EO, Asokbunyarat V, Rene ER, Lens PN, Annachhatre A (2016) Adsorption of Iron (II) from acid mine drainage contaminated groundwater using coal fly ash, coal bottom ash, and bentonite clay. Water Air Soil Pollut 227(3):74. https://doi.org/10.1007/s11270-016-2772-8
Praharaj T, Powell MA, Hart BR, Tripathy S (2002) Leachability of elements from sub-bituminous coal fly ash from India. Environ Int 27(8):609–615
Prasad B, Kumar H (2015) Treatment of acid mine drainage using a fly ash zeolite column. Mine Water Environ 35(4):553–557. https://doi.org/10.1007/s10230-015-0373-1
Prasad B, Mortimer R (2011) Treatment of acid mine drainage using fly ash zeolite. Water Air Soil Pollut 218:667–679
Quina MJ, Bordado JCM, Quinta-Ferreira RM (2009) The influence of pH on the leaching behaviour of inorganic components from municipal solid waste APC residues. Waste Manag 29:2483–2493
Quispe D, Pérez-López R, Acero P, Ayora C, Nieto JM, Tucoulou R (2013) Formation of a hardpan in the co-disposal of fly ash and sulfide mine tailings and its influence on the generation of acid mine drainage. Chem Geol 355:45–55. https://doi.org/10.1016/j.chemgeo.2013.07.005
Ravengai S, Owen R, Love D (2004) Evaluation of seepage and acid generation potential from evaporation ponds, Iron Duke Pyrite Mine, Mazowe Valley, Zimbabwe. Phys Chem Earth 29:1129–1134
Ravengai S, Love D, Love I, Gratwicke B, Mandingaisa O, Owen RJS (2005) Impact of Iron Duke Pyrite Mine on water chemistry and aquatic life—Mazowe Valley, Zimbabwe. Water SA 32:1–4
Rayment GE, Higginson FR (1992) Australian laboratory handbook of soil and water chemical methods. Australian Soil and Land Survey Handbook. Inkata Press, Melbourne
Ruhl L, Vengosh A, Dwyer GS, Hsu-Kim H, Deonarine A (2010) Environmental impacts of the coal ash spill in Kingston, Tennessee: an 18-Month survey. Environ Sci Technol 44:9272–9278
Sahoo PK, Tripathy MK, Panigrahi SK, Equeenuddin MD (2012) Evaluation of the use of an alkali modified fly ash as a potential adsorbent for the removal of metals from acid mine drainage. Appl Water Sci 3:567–576
Santini T, Hinz C, Rate AW, Carter CM, Gilkes RJ (2011) In-situ neutralization of uncarbonated bauxite residue mud by cross layer leaching with carbonated bauxite residue mud. J Hazard Mater 194:119–127. https://doi.org/10.1016/j.jhazmat.2011.07.090
Shackelford CD (1991) Laboratory diffusion testing for waste disposal: a review. J Contam Hydrol 7:177–217
Silva LFO, Querol X, da Boit KM, de Vallejuelo SF-O, Madariaga JM (2011) Brazilian coal mining residues and sulphide oxidation by Fenton’s reaction: an accelerated weathering procedure to evaluate possible environmental impact. J Hazard Mater 186:516–525
Spliethoff H (2010) Steam power stations for electricity and heat generation. In: Power generation from solid fuels. Power systems. Springer, Berlin, Heidelberg, pp 73–219. https://doi.org/10.1007/978-3-642-02856-4_4
SPSS Inc. (2007) SPSS for Windows, Version 16.0. Released 2007. SPSS Inc, Chicago
Ugurlu A (2004) Leaching characteristics of fly ash. Environ Geol 46:890–895
U.S. EPA (United States of America Environmental Protection Agency) (1995) A guide to the biosolids risk assessment for the EPA Part 503 Rule EPA/B32-B-93-005.U.S. EPA. Office of Wastewater Management, Washington DC
U.S. EPA (United States of America Environmental Protection Agency) (2014) Method 1313 liquid-solid partitioning as function of extract pH using a parallel batch extraction procedure SW-846 Update V. U.S. EPA, Washington DC
Vercoutere KU, Fortunati H, Muntau BG, Maizer EA (1995) The certified reference material CRM 142R light sandy soil, CRM 143R sewage sludge amended soil and CRM, 145R sewage sludge for quality control in monitoring environmental and soil pollution. Fresenius J Anal Chem 352(1–2):197–202
Wang S, Wu H (2006) Environmental-benign utilisation of fly ash as low-cost adsorbents. J Hazard Mater 136(3):482–501
Williams TM, Smith B (2000) Hydrochemical characterization of acute acid mine drainage at Iron Duke Mine, Mazowe, Zimbabwe. Environ Geol 39:272–278
Yan Z, Jianquo J, Moazhe C (2008) MINTEQ modelling for evaluating the leaching behaviour of heavy metals in MSWI fly ash. J Environ Sci 20:1398–1402
Ye N, Chen Y, Yang J, Liang S, Hu Y, Xiao B, Huang Q, Shi Y, Hu J, Wu X (2016) Co-disposal of MSWI fly ash and Bayer red mud using an one-part geopolymeric system. J Hazard Mater 318:70–78. https://doi.org/10.1016/j.jhazmat.2016.06.042
Yeheyis MB, Shang JQ, Yanful EK (2009) Long-term evaluation of coal fly ash and mine tailings co-placement: a site specific study. J Environ Manag 91:237–244. https://doi.org/10.1016/j.jenvman.2009.08.010
You G-S, Ahn J-W, Han G-C, Cho H-C (2006) Neutralizing capacity of bottom ash from municipal solid waste incineration of different particle size. Korean J Chem Eng 23(2):237–240
Zhang M (2011) Adsorption study of Pb(II), Cu(II) and Zn(II) from simulated acid mine drainage using dairy manure compost. Chem Eng J 172:361–368
Zhang H, He PJ, Shao LM, Li X (2008) Leaching behaviour of heavy metals form municipal solid waste incineration bottom ash and its geochemical modelling. J Mater Cycles Waste 10:7–13
ZPC (Zimbabwe Power Company) (2019) Harare power station. Zimbabwe Power Co. www.zpc.co.zw/powerstations/3/harare-power-station. Accessed 12 Jan 2019
Acknowledgements
We are grateful to the technical staff from the Department of Soil Science and Agricultural Engineering for laboratory support. We also thank the three anonymous reviewers and the editor whose comments greatly improved the quality and presentation of the manuscript. This research was solely funded by the authors and received no additional external funding.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Mungazi, A.A., Gwenzi, W. Cross-Layer Leaching of Coal Fly Ash and Mine Tailings to Control Acid Generation from Mine Wastes. Mine Water Environ 38, 602–616 (2019). https://doi.org/10.1007/s10230-019-00618-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10230-019-00618-0