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Clements C, Tunstall L, Bolanos Sosa HG, Hedayat A. Improvements in Hydrolytic Stability of Alkali-Activated Mine Tailings via Addition of Sodium Silicate Activator. Polymers (Basel) 2024; 16:957. [PMID: 38611215 PMCID: PMC11013743 DOI: 10.3390/polym16070957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/02/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
Over 14 billion tons of mine tailings are produced throughout the world each year, and this type of waste is generally stored onsite indefinitely. Alkali activation is a promising strategy for the reuse of mine tailings to produce construction materials, converting this waste stream into a value-added product. One major problem with alkali-activated mine tailings is their low durability in water (i.e., low hydrolytic stability). In this article, the influence of a mixed sodium hydroxide/sodium silicate alkali activator on the compressive strength, hydrolytic stability, and microstructure of alkali-activated materials (AAMs) were systematically investigated. XRD, FTIR, NMR, and NAD were used to investigate microstructural changes, and a water immersion test was used to show improvements in hydrolytic stability. For gold mine tailings activated with pure sodium hydroxide, the compressive strength was 15 MPa and a seven-day water immersion test caused a strength loss of 70%. With an addition of 1 M sodium silicate in the activator, the AAMs achieved a compressive strength of over 30 MPa and strength loss of only 45%. This paper proposes a mechanism explaining why the strength and hydrolytic stability of AAMs are dependent on the dosage of soluble silicate. A high dosage of sodium silicate inhibits the depolymerization of the source material, which results in a sample with less amorphous aluminosilicate gel and, therefore, lower hydrolytic stability.
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Affiliation(s)
- Cara Clements
- Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, USA; (L.T.); (A.H.)
| | - Lori Tunstall
- Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, USA; (L.T.); (A.H.)
| | - Hector Gelber Bolanos Sosa
- Metallurgical Engineering Department, National University of San Agustin de Arequipa, Santa Cataline No. 117, Arequipa 04000, Peru;
| | - Ahmadreza Hedayat
- Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, USA; (L.T.); (A.H.)
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Ilieva D, Angelova L, Radoykova T, Surleva A, Chernev G, Vizureanu P, Burduhos-Nergis DD, Sandu AV. Characterization of Bulgarian Copper Mine Tailing as a Precursor for Obtaining Geopolymers. MATERIALS (BASEL, SWITZERLAND) 2024; 17:542. [PMID: 38591411 PMCID: PMC10856451 DOI: 10.3390/ma17030542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 01/10/2024] [Accepted: 01/19/2024] [Indexed: 04/10/2024]
Abstract
Valorization of high-volume mine tailings could be achieved by the development of new geopolymers with a low CO2 footprint. Materials rich in aluminum and silicon with appropriate solubility in an alkaline medium can be used to obtain a geopolymer. This paper presents a study of copper mine tailings from Bulgaria as precursors for geopolymers. Particle size distribution, chemical and mineralogical composition, as well as alkaline reactivity, acidity and electroconductivity of aqueous slurry are studied. The heavy metal content and their mobility are studied by leaching tests. Sequential extraction was applied to determine the geochemical phase distribution of heavy metals. The studied samples were characterized by high alkalinity, which could favor the geopolymerization process. The water-soluble sulphates were less than 4%. The Si/Al ratio in mine tailing was found to be 3. The alkaline reactivity depended more so on the time of extraction than on the concentration of NaOH solution. The main part of the heavy metals was found in the residual fraction; hence, in high alkaline medium during the geopolymerization process, they will stay fixed. Thus, the obtained geopolymers could be expected to exert low environmental impact. The presented results revealed that studied copper mine tailing is a suitable precursor for geopolymerization.
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Affiliation(s)
- Darya Ilieva
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 8 “St. Kl. Ohridski” Blvd., 1756 Sofia, Bulgaria; (D.I.); (L.A.); (T.R.)
| | - Lyudmila Angelova
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 8 “St. Kl. Ohridski” Blvd., 1756 Sofia, Bulgaria; (D.I.); (L.A.); (T.R.)
| | - Temenuzhka Radoykova
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 8 “St. Kl. Ohridski” Blvd., 1756 Sofia, Bulgaria; (D.I.); (L.A.); (T.R.)
| | - Andriana Surleva
- Faculty of Chemical Technologies, University of Chemical Technology and Metallurgy, 8 “St. Kl. Ohridski” Blvd., 1756 Sofia, Bulgaria; (D.I.); (L.A.); (T.R.)
| | - Georgi Chernev
- Faculty of Metallurgy and Materials Science, University of Chemical Technology and Metallurgy, 8 “St. Kl. Ohridski” Blvd., 1756 Sofia, Bulgaria;
| | - Petrica Vizureanu
- Faculty of Materials Science and Engineering, “Gheorghe Asachi” Technical University of Iasi, 67 Prof. D. Mangeron Blvd., 700050 Iasi, Romania; (D.D.B.-N.); (A.V.S.)
- Technical Sciences Academy of Romania, 26 Dacia Blvd., 030167 Bucharest, Romania
| | - Dumitru Doru Burduhos-Nergis
- Faculty of Materials Science and Engineering, “Gheorghe Asachi” Technical University of Iasi, 67 Prof. D. Mangeron Blvd., 700050 Iasi, Romania; (D.D.B.-N.); (A.V.S.)
| | - Andrei Victor Sandu
- Faculty of Materials Science and Engineering, “Gheorghe Asachi” Technical University of Iasi, 67 Prof. D. Mangeron Blvd., 700050 Iasi, Romania; (D.D.B.-N.); (A.V.S.)
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Effect of bismuth oxide nanoparticle on the electromagnetic interference shielding and thermal stability of industrial waste based-geopolymer composites. Sci Rep 2023; 13:1787. [PMID: 36720955 PMCID: PMC9889768 DOI: 10.1038/s41598-023-27623-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 01/04/2023] [Indexed: 02/02/2023] Open
Abstract
Gold mine tailings, fly ash, and bagasse ash has been repurposed to produce geopolymer (GP) with enhanced electromagnetic interference shielding efficiency (EMI-SE) and high thermal property. GP has low shielding efficiency compared to concrete. Due to this, an appropriate filler must be incorporated into its matrix to enhance its EMI-SE. For this study, bismuth oxide nanomaterial (BiNP) was utilized as the additive filler. The percent content of BiNP was varied to evaluate its influence on the EMI-SE of GP. Morphology shows that Bi2O3 was embedded in the matrix of GP, and no new aluminu-phyllosilicate minerals were formed. This indicates that some minerals acted only as internal fillers in the matrix. Compressive strength shows synthesized GP composites were more than 20 MPa, with neat GP reaching the maximum strength. Moreover, the EMI-SE of neat GP was 21.2 dB for 20-4500 MHz range. This indicates that GP alone has sufficient characteristics to attenuate EMI radiation. Addition of 5%, 10% and 15% weight of BiNP improves EMI-SE by 4-10%, with 5% BiNP shown to be the optimum ratio. Lastly, the addition of BiNP improves the thermal stability of GP. This study shows that GP incorporated with Bi2O3 can be recommended for small-scale construction and small residential building.
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Phengsaart T, Srichonphaisan P, Kertbundit C, Soonthornwiphat N, Sinthugoot S, Phumkokrux N, Juntarasakul O, Maneeintr K, Numprasanthai A, Park I, Tabelin CB, Hiroyoshi N, Ito M. Conventional and recent advances in gravity separation technologies for coal cleaning: A systematic and critical review. Heliyon 2023; 9:e13083. [PMID: 36793968 PMCID: PMC9922934 DOI: 10.1016/j.heliyon.2023.e13083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/22/2023] Open
Abstract
"Affordable and clean energy" is enshrined in the UN Sustainable Development Goals (SDGs; #7) because of its importance in supporting the sustainable development of society. As an energy source, coal is widely used because it is abundant and its utilization for electricity and heat generation do not require complex infrastructures and technologies, which makes it ideal for the energy needs of low-income and developing countries. Coal is also essential in steel making (as coke) and cement production and will continue to be on high demand for the foreseeable future. However, coal is naturally found with impurities or gangue minerals like pyrite and quartz that could create by-products (e.g., ash) and various pollutants (e.g., CO2, NOX, SOX). To reduce the environmental impacts of coal during combustion, coal cleaning-a kind of pre-combustion clean coal technology-is essential. Gravity separation, a technique that separates particles based on their differences in density, is widely used in coal cleaning due to the simplicity of its operation, low cost, and high efficiency. In this paper, recent studies (from 2011 to 2020) related to gravity separation for coal cleaning were systematically reviewed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 1864 articles were screened after removing duplicates, and after a thorough evaluation 189 articles were reviewed and summarized. Among of conventional separation techniques, dense medium separator (DMS), particularly dense medium cyclone (DMC), is the most popular technologies studied, which could be attributed to the growing challenges of cleaning/processing fine coal-bearing materials. In recent years, most of works focused on the development of dry-type gravity technologies for coal cleaning. Finally, gravity separation challenges and future applications to address problems in environmental pollution and mitigation, waste recycling and reprocessing, circular economy, and mineral processing are discussed.
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Affiliation(s)
- Theerayut Phengsaart
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand,Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan,Corresponding author. Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand.
| | - Palot Srichonphaisan
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Chinawich Kertbundit
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Natatsawas Soonthornwiphat
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Somthida Sinthugoot
- Department of Groundwater Resources, Ministry of Natural Resources and Environment, Bangkok 10900, Thailand
| | - Nutthakarn Phumkokrux
- Department of Geography, Faculty of Education, Ramkhamhaeng University, Bangkok 10240, Thailand,Department of Earth Sciences, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Onchanok Juntarasakul
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kreangkrai Maneeintr
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Apisit Numprasanthai
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Ilhwan Park
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Carlito Baltazar Tabelin
- Department of Materials and Resources Engineering Technology, College of Engineering and Technology, Mindanao State University-Iligan Institute of Technology, Iligan City 9200, Philippines
| | - Naoki Hiroyoshi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Mayumi Ito
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan
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Tabelin CB, Uyama A, Tomiyama S, Villacorte-Tabelin M, Phengsaart T, Silwamba M, Jeon S, Park I, Arima T, Igarashi T. Geochemical audit of a historical tailings storage facility in Japan: Acid mine drainage formation, zinc migration and mitigation strategies. JOURNAL OF HAZARDOUS MATERIALS 2022; 438:129453. [PMID: 35797786 DOI: 10.1016/j.jhazmat.2022.129453] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/14/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Historical tailings storage facilities (TSFs) are either abandoned or sparsely rehabilitated promoting acid mine drainage (AMD) formation and heavy metal release. To sustainably manage these sites, a geochemical audit coupled with numerical simulation to predict AMD flow paths and heavy metal migration are valuable. In this study, a 40-year-old TSF in Hokkaido, Japan was investigated. Tailings in this historical TSF contain pyrite (FeS2) while its copper (Cu) and zinc (Zn) contents were 1400-6440 mg/kg and 2800-22,300 mg/kg, respectively. Copper and Zn were also easily released in leaching tests because they are partitioned with the exchangeable phase (29% of Zn; 15% of Cu) and oxidizable fraction (25% of Zn; 33% of Cu). Kinetic modeling results attributed AMD formation to the interactions of pyrite and soluble phases in the tailings with oxygenated groundwater, which is supported by the sequential extraction and leaching results. Calibrations of groundwater/AMD flow and solute transport in the 2D reactive transport model were successfully done using hydraulic heads measured on-site and leaching results, respectively. The model forecasted the quality of AMD to deteriorate with time and AMD formation to continue for 1000 years. It also predicted ~24% AMD flux reduction, including lower Zn release with time when recharge reduction interventions are implemented on-site.
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Affiliation(s)
- Carlito Baltazar Tabelin
- School of Minerals and Energy Resources Engineering, The University of New South Wales, Sydney, NSW, Australia.
| | - Asuka Uyama
- Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, Japan
| | - Shingo Tomiyama
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Mylah Villacorte-Tabelin
- Developmental Biology Laboratory, PRISM, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines; Department of Biological Sciences, College of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Theerayut Phengsaart
- Department of Mining and Petroleum Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand
| | - Marthias Silwamba
- Department of Metallurgical Engineering, School of Mines, University of Zambia, Lusaka, Zambia
| | - Sanghee Jeon
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Ilhwan Park
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Takahiko Arima
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Toshifumi Igarashi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
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Paste Backfill Corrosion Mechanisms in Chloride and Sulfate Environments. MINERALS 2022. [DOI: 10.3390/min12050551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To study paste backfill corrosion mechanisms in chloride and sulfate environments, we studied the effect of chloride and sulfate on the strength of paste backfill after 7, 14, 28, and 40 days. The chloride solutions and sulfate solutions in concentrations are 0 g/L, 0.5 g/L, 1.5 g/L, 4.5 g/L, or 15 g/L. The obtained specimens were analyzed by performing uniaxial compressive strength tests, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results show that chloride and sulfate significantly increased the uniaxial compressive strength of the specimen at a very fast speed in the early stage of the test, and the original structure of the specimen was destroyed and its uniaxial compressive strength decreased with the gradual corrosion. The reason for this characteristic is because the chloride reacts with the paste backfill to form calcium chloroamine hydrate (Ca4Al2O6Cl2·10H2O), and the sulfate reacts with the paste backfill to form dihydrate gypsum (CaSO4·2H2O), mirabilite, and ettringite. In the early stage, these substances can fill the pores to improve the compressive strength, and then expand to damage the structure of the backfill and reduce its compressive strength. In addition, sulfate can enhance the decomposition of C-S-H, which results in a faster destruction of specimens than in chloride environments.
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Development of Backfill Concrete Including Coal Gangue and Metakaolin and Prediction of Compressive Strength by Extreme Learning Machine. MINERALS 2022. [DOI: 10.3390/min12030330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The main aim of this investigation is to develop backfill concrete including coal gangue and metakaolin to reduce solid waste. For this purpose, a total of 30 concrete mixtures were designed by the inclusion of 0%, 25%, 50%, 75% and 100% coal gangue as coarse aggregates and 0%, 10% and 20% metakaolin as binder at 0.55 and 0.45 water to cement ratios. The compressive strength was tested after 3, 7 and 28 days for a total of 90 samples. Meanwhile, the influences of coal gangue and metakaolin on the elastic modulus, ultrasonic pulse velocity, rebound number and open porosity were explored. Then, the relationship between physical and mechanical properties was revealed by design code expressions and empirical models. Furthermore, an extreme learning machine was developed to predict compressive strength by concrete mixtures. The results show that the inclusion of coal gangue results in a poor performance in physical and mechanical properties of concrete. However, the drawbacks of concrete containing coal gangue can be compensated by metakaolin. The predicted results of design code expressions and empirical models are closed to the experiment results, with a 10% error. In addition, the findings reveal that the extreme learning machine offers significant potential to predict the compressive strength of concrete with high precision.
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Editorial for Special Issue “Novel and Emerging Strategies for Sustainable Mine Tailings and Acid Mine Drainage Management”. MINERALS 2021. [DOI: 10.3390/min11080902] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Climate change is one of the most pressing problems facing humanity this century [...]
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The Effect of Polymer Waste Addition on the Compressive Strength and Water Absorption of Geopolymer Ceramics. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11083540] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The quantity of polymer waste in our communities is increasing significantly. It is therefore necessary to consider reuse or recycling waste to avoid an increase in the risk to public health. This project is aimed at using pulverized low-density polyethylene (LDPE) waste as a source to reinforce and improve compressive strength, and to reduce the water absorption of geopolymer ceramics (GC). Clay:LDPE composition consisting of 5%, 10%, and 15% LDPE was geopolymerized with an NaOH/Na2SiO3 solution and cured at 30 °C and 50 °C. Characterization of the geopolymer samples was carried out using XRF and XRD. The microstructure was analyzed by SEM and chemical bonding by FTIR. The SEM micrographs showed LDPE particle pull-out on the geopolymer ceramics’ fracture surface. The result showed that the compressive strength increases with the addition of pulverized polymer waste compared to the controlled without LDPE addition. Water absorption decreased with an increase in LDPE addition in the geopolymer ceramics composite.
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Opiso EM, Tabelin CB, Maestre CV, Aseniero JPJ, Park I, Villacorte-Tabelin M. Synthesis and characterization of coal fly ash and palm oil fuel ash modified artisanal and small-scale gold mine (ASGM) tailings based geopolymer using sugar mill lime sludge as Ca-based activator. Heliyon 2021; 7:e06654. [PMID: 33869866 PMCID: PMC8042442 DOI: 10.1016/j.heliyon.2021.e06654] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/29/2020] [Accepted: 03/29/2021] [Indexed: 11/30/2022] Open
Abstract
The continuous accumulation of artisanal and small-scale gold mining (ASGM) tailings in the Philippines without adequate storage and disposal facility could lead to human health and environmental disasters in the long run. In this study, ASGM tailings was simultaneously stabilized and repurposed as construction material via geopolymerization using coal fly ash, palm oil fuel ash and a powder-based alkali activator. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) identified iron sulfides in the tailings containing arsenic (As), cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn), which could be released via weathering. The average unconfined compressive strengths (UCS) of tailings-based geopolymers at 14 days curing were 7.58 MPa and 7.7 MPa with fly ash and palm oil fuel ash, respectively. The tailings-based geopolymers with palm oil fuel ash had higher UCS most likely due to CASH reaction product formation that improved strength formation. The toxicity characteristic leaching procedure (TCLP) results showed very low leachabilities of As, Pb and Fe in the geopolymer materials suggesting ASGM tailings was effectively encapsulated within the geopolymer matrix. Overall, the geopolymerization of ASGM tailings is a viable and promising solution to simultaneously stabilize mining and industrial wastes and repurpose them into construction materials.
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Affiliation(s)
- Einstine M Opiso
- Geo-environmental Engineering Group, Civil Engineering Department, Central Mindanao University, Bukidnon, Philippines
| | - Carlito B Tabelin
- School of Minerals and Energy Resources Engineering, The University of New South Wales, Sydney, NSW, Australia
| | - Christian V Maestre
- Materials Science Research Group, Physics Department, Central Mindanao University, Bukidnon, Philippines
| | - John Paul J Aseniero
- Materials Science Research Group, Physics Department, Central Mindanao University, Bukidnon, Philippines
| | - Ilhwan Park
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Mylah Villacorte-Tabelin
- Department of Biological Sciences, College of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
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Cross-Organizational Learning Approach in the Sustainable Use of Fly Ash for Geopolymer in the Philippine Construction Industry. SUSTAINABILITY 2021. [DOI: 10.3390/su13052454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The construction industry faces a challenging situation in attaining sustainable development goals. The carbon footprint of the production and use of construction materials such as the use of ordinary Portland cement in concrete products is still on the rise despite of many alternatives and technologies. In this paper, the local cross-organizational learning approach (COLA) and a systematic review of academic and professional literatures were applied in analyzing the use of fly ash as a geopolymer in the Philippine construction industry. Three primary stakeholders were considered: academe, professional organizations, and industry. Documents from each stakeholder were collected, with keywords including sustainability, fly ash, and geopolymer. These documents included published materials, newsletters, department orders, codes, and policies. Text analytics throughout the documents were applied using the Latent Dirichlet Allocation model, which uses a hierarchal Bayesian-modelling process that groups set of items into topics to determine the maturity level of the organizational learning. An adoption framework is proposed aligning COLA with the awareness, interest, desire, and action (AIDA) funnel model. Results show that the organizational maturity until optimization of academe is sufficient towards interest and desire, while industry is highly encouraged to increase organizational maturity from managed to optimization towards desire and action. Factors such as organizational intelligence (OI) and organizational stupidity (OS) are to be considered in balancing critical thinking across organizations. Further studies are recommended by considering the use of COLA with ASEAN organizations in the development of sustainable construction materials.
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Optimization of the Mix Formulation of Geopolymer Using Nickel-Laterite Mine Waste and Coal Fly Ash. MINERALS 2020. [DOI: 10.3390/min10121144] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Geopolymer cement has been popularly studied nowadays compared to ordinary Portland cement because it demonstrated superior environmental advantages due to its lower carbon emissions and waste material utilization. This paper focuses on the formulation of geopolymer cement from nickel–laterite mine waste (NMW) and coal fly ash (CFA) as geopolymer precursors, and sodium hydroxide (SH), and sodium silicate (SS) as alkali activators. Different mix formulations of raw materials are prepared to produce a geopolymer based on an I-optimal design and obtained different compressive strengths. A mixed formulation of 50% NMW and 50% CFA, SH-to-SS ratio of 0.5, and an activator-to-precursor ratio of 0.429 yielded the highest 28 d unconfined compressive strength (UCS) of 22.10 ± 5.40 MPa. Furthermore, using an optimized formulation of 50.12% NMW, SH-to-SS ratio of 0.516, and an activator-to-precursor ratio of 0.428, a UCS value of 36.30 ± 3.60 MPa was obtained. The result implies that the synthesized geopolymer material can be potentially used for concrete structures and pavers, pedestrian pavers, light traffic pavers, and plain concrete.
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Tabelin CB, Silwamba M, Paglinawan FC, Mondejar AJS, Duc HG, Resabal VJ, Opiso EM, Igarashi T, Tomiyama S, Ito M, Hiroyoshi N, Villacorte-Tabelin M. Solid-phase partitioning and release-retention mechanisms of copper, lead, zinc and arsenic in soils impacted by artisanal and small-scale gold mining (ASGM) activities. CHEMOSPHERE 2020; 260:127574. [PMID: 32688316 PMCID: PMC7351430 DOI: 10.1016/j.chemosphere.2020.127574] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/23/2020] [Accepted: 06/29/2020] [Indexed: 05/28/2023]
Abstract
Artisanal and small-scale gold mining (ASGM) operations are major contributors to the Philippines' annual gold (Au) output (at least 60%). Unfortunately, these ASGM activities lacked adequate tailings management strategies, so contamination of the environment is prevalent. In this study, soil contamination with copper (Cu), lead (Pb), zinc (Zn) and arsenic (As) due to ASGM activities in Nabunturan, Davao de Oro, Philippines was investigated. The results showed that ASGM-impacted soils had Cu, Pb, Zn and As up to 3.6, 83, 73 and 68 times higher than background levels, respectively and were classified as 'extremely' polluted (CD = 30-228; PLI = 5.5-34.8). Minerals typically found in porphyry copper-gold ores like pyrite, chalcopyrite, malachite, galena, sphalerite and goethite were identified by XRD and SEM-EDS analyses. Furthermore, sequential extraction results indicate substantial Cu (up to 90%), Pb (up to 50%), Zn (up to 65%) and As (up to 48%) partitioned with strongly adsorbed, weak acid soluble, reducible and oxidisable fractions, which are considered as 'geochemically mobile' phases in the environment. Although very high Pb and Zn were found in ASGM-impacted soils, they were relatively immobile under oxidising conditions around pH 8.5 because of their retention via adsorption to hydrous ferric oxides (HFOs), montmorillonite and kaolinite. In contrast, Cu and As release from the historic ASGM site samples exceeded the environmental limits for Class A and Class C effluents, which could be attributed to the removal of calcite and dolomite by weathering. The enhanced desorption of As at around pH 8.5 also likely contributed to its release from these soils.
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Affiliation(s)
- Carlito Baltazar Tabelin
- School of Minerals and Energy Resources Engineering, The University of New South Wales, Sydney, NSW, Australia.
| | - Marthias Silwamba
- Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, Japan
| | - Florifern C Paglinawan
- Developmental Biology Laboratory, PRISM, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Alissa Jane S Mondejar
- Developmental Biology Laboratory, PRISM, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Ho Gia Duc
- Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, Japan
| | - Vannie Joy Resabal
- Department of Materials and Resources Engineering and Technology, College of Engineering and Technology, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines
| | - Einstine M Opiso
- Geo-environmental Engineering Research Group, Civil Engineering Department, Central Mindanao University, Bukidnon, Philippines
| | - Toshifumi Igarashi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Shingo Tomiyama
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Mayumi Ito
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Naoki Hiroyoshi
- Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
| | - Mylah Villacorte-Tabelin
- Developmental Biology Laboratory, PRISM, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines; Department of Biological Sciences, College of Science and Mathematics, Mindanao State University-Iligan Institute of Technology, Iligan City, Philippines.
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Improved pyrolysis behavior of ammonium polyphosphate-melamine-expandable (APP-MEL-EG) intumescent fire retardant coating system using ceria and dolomite as additives for I-beam steel application. Heliyon 2019; 6:e03119. [PMID: 31909279 PMCID: PMC6940668 DOI: 10.1016/j.heliyon.2019.e03119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/05/2019] [Accepted: 12/20/2019] [Indexed: 11/28/2022] Open
Abstract
This study describes the effects of ceria (CeO2) and dolomite [CaMg(CO3)2] additives on the pyrolysis behavior and fire resistive property of conventional intumescent flame retardant (IFR) coating system for I-beam steel substrate called ammonium polyphosphate-melamine-expandable graphite (APP-MEL-EG) system. The fire resistance of various formulations was evaluated using the standard vertical Bunsen burner fire test. Thermogravimetric analysis (TGA) was used to understand the degradation of coating formulations. Observations by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) demonstrated that significant amounts of additives favored the formation of homogeneous compacted char structures, which were predominantly composed of carbon (C), phosphorus (P) and oxygen (O). These three main components of the char were also found to be in various binding combinations with other lighter elements like nitrogen (N) and hydrogen (H) as illustrated by the attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy results. X-ray photoelectron spectroscopy (XPS) further suggest that polyethylene([(CH2–C2H2–CH2)n−]) free radicals were abundant on the char surface for the two best formulations and the binding energy of this radical promoted the formation of aromatic carbon chains that enhanced the char's thermal stability. This means that the selection of appropriate additives and combinations of flame-retardant ingredients could significantly change the morphology of the char layer and improve its thermal stability during fire exposure.
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15
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Latha D, Prabu P, Gnanamoorthy G, Munusamy S, Sampurnam S, Arulvasu C, Narayanan V. Size-dependent catalytic property of gold nanoparticle mediated by Justicia adhatoda leaf extract. SN APPLIED SCIENCES 2018. [DOI: 10.1007/s42452-018-0148-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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