1
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Wang YJ, Li JG, Tao MJ, Zhang X, Zhang JB, Qin S, Liu SH, Peng LJ, Zhang XP, Zeng YN. Investigation of the acicular aragonite growth behavior in AOD stainless steel slag during slurry-phase carbonation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166750. [PMID: 37659537 DOI: 10.1016/j.scitotenv.2023.166750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/11/2023] [Accepted: 08/30/2023] [Indexed: 09/04/2023]
Abstract
This study presents a novel method for producing acicular aragonite using argon oxygen decarburization (AOD) slag while controlling the reaction temperature, reaction time, stirring speed, and the magnesium-to‑calcium stoichiometric ratio. This approach provides steel plants with an opportunity to decrease their CO2 emissions and promote efficient resource utilization and CO2 storage through the production of high-quality value-added products. The experimental results showed that reaction temperature was the most significant factor affecting the carbonation efficiency of AOD slag, followed by reaction time, stirring speed, CO2 partial pressure, and the liquid-to-solid ratio (L/S). The study also found that elevated temperature and prolonged reaction duration favored the preferential precipitation of aragonite. Additionally, raising the temperature and the magnesium-to‑calcium stoichiometric ratio was shown to enhance the formation of aragonite, affecting its crystal growth orientation and dimensions. The optimal combination of reaction parameters for the preparation of acicular aragonite was found to be the reaction time of 8 h, the magnesium-to‑calcium stoichiometric ratio of 0.8, the reaction temperature of 120 °C, and the stirring speed of 200 r·min-1. Under these conditions, the resulting acicular aragonite exhibited excellent overall uniformity, a large aspect ratio, and a smooth crystal surface, with a content of 91.49 %, a single crystal length ranging from 9.86 to 32.6 μm, and a diameter ranging from 0.63 to 2.15 μm. This study provides valuable insights into the efficient production of acicular aragonite from steel slag while reducing CO2 emissions and promoting the sustainable use of resources.
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Affiliation(s)
- Ya-Jun Wang
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China
| | - Jun-Guo Li
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China.
| | - Meng-Jie Tao
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China.
| | - Xi Zhang
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China
| | - Jian-Bao Zhang
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China
| | - Song Qin
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China
| | - Shao-Hua Liu
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China
| | - Li-Jie Peng
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China
| | - Xiao-Pei Zhang
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China
| | - Ya-Nan Zeng
- College of Metallurgy and Energy, North China University of Science and Technology, 21 Bohai Street, Tangshan 063210, China.
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2
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He B, Zhu X, Cang Z, Liu Y, Lei Y, Chen Z, Wang Y, Zheng Y, Cang D, Zhang L. Interpretation and Prediction of the CO 2 Sequestration of Steel Slag by Machine Learning. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:17940-17949. [PMID: 37624988 DOI: 10.1021/acs.est.2c06133] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2023]
Abstract
The utilization of steel slag for CO2 sequestration is an effective way to reduce carbon emissions. The reactivity of steel slag in CO2 sequestration depends mainly on material and process parameters. However, there are many puzzles in regard to practical applications due to the different evaluations of process parameters and the lack of investigation of material parameters. In this study, 318 samples were collected to investigate the interactive influence of 12 factors on the carbonation reactivity of steel slag by machine learning with SHapley Additive exPlanations (SHAP). Multilayer perceptron (MLP), random forest, and support vector regression models were built to predict the slurry-phase CO2 sequestration of steel slag. The MLP model performed well in terms of prediction ability and generalization with comprehensive interpretability. The SHAP results showed that the impact of the process parameters was greater than that of the material parameters. Interestingly, the iron ore phase of steel slag was revealed to have a positive effect on steel slag carbonation by SHAP analysis. Combined with previous literature, the carbonation mechanism of steel slag was proposed. Quantitative analysis based on SHAP indicated that steel slag had good carbonation reactivity when the mass fractions of "CaO + MgO", "SiO2 + Al2O3", "Fe2O3", and "MnO" varied from 50-55%, 10-15%, 30-35%, and <5%, respectively.
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Affiliation(s)
- Bingyang He
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xingyu Zhu
- Department of Electronic and Information Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Hong Kong SAR 999077, China
| | - Zhizhi Cang
- Beijing Building Materials Academy of Sciences Research, Beijing 100041, PR China
| | - Yang Liu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yuxin Lei
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhaohou Chen
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yanlin Wang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yongchao Zheng
- Beijing Building Materials Academy of Sciences Research, Beijing 100041, PR China
| | - Daqiang Cang
- School of Metallurgy and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Lingling Zhang
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
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3
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Rashid MI, Yaqoob Z, Mujtaba M, Fayaz H, Saleel CA. Developments in mineral carbonation for Carbon sequestration. Heliyon 2023; 9:e21796. [PMID: 38027886 PMCID: PMC10660523 DOI: 10.1016/j.heliyon.2023.e21796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/17/2023] [Accepted: 10/28/2023] [Indexed: 12/01/2023] Open
Abstract
Mineral technology has attracted significant attention in recent decades. Mineral carbonation technology is being used for permanent sequestration of CO2 (greenhouse gas). Temperature programmed desorption studies showed interaction of CO2 with Mg indicating possibility of using natural feedstocks for mineral carbonation. Soaking is effective to increase yields of heat-activated materials. This review covers the latest developments in mineral carbonation technology. In this review, development in carbonation of natural minerals, effect of soaking on raw and heat-activated dunite, increasing reactivity of minerals, thermal activation, carbonations of waste materials, increasing efficiency of carbonation process and pilot plants on mineral carbonation are discussed. Developments in carbonation processes (single-stage carbonation, two-stage carbonation, acid dissolution, ph swing process) and pre-process and concurrent grinding are elaborated. This review also highlights future research required in mineral carbonation technology.
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Affiliation(s)
- Muhammad Imran Rashid
- Chemical, Polymer and Composite Materials Engineering Department, University of Engineering and Technology, Lahore (New Campus), 39021, Pakistan
- Discipline of Chemical Engineering, University of Newcastle, Callaghan NSW 2308, Australia
| | - Zahida Yaqoob
- Department of Material Science and Engineering, Institute of Space Technology, Islamabad, 44000, Pakistan
| | - M.A. Mujtaba
- Department of Mechanical Engineering, University of Engineering and Technology (New Campus), Lahore 54890, Pakistan
| | - H. Fayaz
- Modeling Evolutionary Algorithms Simulation and Artificial Intelligence, Faculty of Electrical & Electronics Engineering, Ton Duc Thang University, Ho Chi Minh City, Viet Nam
| | - C Ahamed Saleel
- Department of Mechanical Engineering, College of Engineering, King Khalid University, Asir-Abha 61421, Saudi Arabia
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4
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Mechanochemical activation for improving the direct mineral carbonation efficiency and capacity of a timber biomass ash. J CO2 UTIL 2023. [DOI: 10.1016/j.jcou.2022.102367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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5
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Valuable reutilization of Basic Oxygen Furnace (BOF) slag for the CO2 sorption from oxy-fuel combustion in a fluidized bed reactor. J CO2 UTIL 2022. [DOI: 10.1016/j.jcou.2022.102280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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6
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RushendraRevathy TD, Ramachandran A, Palanivelu K. Utilization of steelmaking slag for carbon capture and storage with flue gas. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:51065-51082. [PMID: 34786621 DOI: 10.1007/s11356-021-17493-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
Carbon capture and storage is a necessary action for the reduction of CO2 emissions, and thereby mitigation of climate change and its impacts. Especially, in India, with its growing fuel needs and very little attention paid towards carbon capture and storage, mineral carbonation technology is a suitable option as it is cost-effective and could be retrofitted to existing plants that emit CO2. Given the development of carbon capture and storage technology, this study attempts direct mineral carbonation of steelmaking slag with flue gas. Response surface methodology was employed to design gas-solid and slurry phase aqueous carbonation experiments. A maximum reduction of about 36.1% was achieved through aqueous carbonation at 61.1 °C, 46.24 bar, and a liquid-to-solid ratio of 14.5, corresponding to a sequestration capacity of 127.4 g of CO2/kg of slag. The temperature was found to be the most vital parameter in both the aqueous and gas-solid carbonation processes. Regression models used to study the carbonation process were found to be statistically significant. The carbonated slag consisted of mineral phases, namely, calcite and dolomite. The results demonstrated the sequestration potential of Indian steelmaking slag with flue gas. Carbonation of steelmaking slag with flue gas poses to be a promising option for the development of carbon capture and storage technology in the country.
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Affiliation(s)
| | - Andimuthu Ramachandran
- Centre for Climate Change and Disaster Management, Anna University, Chennai, 600 025, India
| | - Kandasamy Palanivelu
- Centre for Climate Change and Disaster Management, Anna University, Chennai, 600 025, India
- Centre for Environmental Studies, Anna University, Chennai, 600 025, India
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7
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8
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Yuan Y, Lu W, Cheng W, Qi G, Hu X, Su H, Wang M, Zhang M, Liang Y. Method for rapid mineralization of CO2 with carbide slag in the constant-pressure and continuous-feed way and its reaction heat. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2022.117148] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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9
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Slurry-Phase Carbonation Reaction Characteristics of AOD Stainless Steel Slag. Processes (Basel) 2021. [DOI: 10.3390/pr9122266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Argon oxygen decarburization stainless steel slag (AOD slag) has high mineral carbonation activity. AOD slag carbonation has both the resource utilization of metallurgical waste slag and the carbon reduction effect of CO2 storage. This paper aimed to study carbonation reaction characteristics of AOD slag. Under the slurry-phase accelerated carbonation route, the effect of stirring speed (r) and reaction temperature (T) on AOD slag’s carbonation was studied by controlling the reaction conditions. Mineral composition analysis and microscopic morphology analysis were used to explore the mineral phase evolution of AOD slag during the carbonation process. Based on the unreacted core model, the kinetic model of the carbonation reaction of AOD slag was analyzed. The results showed that the carbonation ratio of AOD slag reached its maximum value of 66.7% under the reaction conditions of a liquid to solid ratio (L/S) of 8:1, a CO2 partial pressure of 0.2 MPa, a stirring speed of 450 r·min−1, and a reaction temperature of 80 °C. The carbonation reaction of AOD slag was controlled by internal diffusion, and the calculated apparent activation energy was 22.28 kJ/mol.
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10
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Chen Z, Cang Z, Yang F, Zhang J, Zhang L. Carbonation of steelmaking slag presents an opportunity for carbon neutral: A review. J CO2 UTIL 2021. [DOI: 10.1016/j.jcou.2021.101738] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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11
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Luo Y, He D. Research status and future challenge for CO 2 sequestration by mineral carbonation strategy using iron and steel slag. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:49383-49409. [PMID: 34331652 DOI: 10.1007/s11356-021-15254-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Mineral carbonation can simultaneously realize the effective treatment of CO2 and iron and steel slag; thus, it is of great significance for the low carbon and sustainable development of iron and steel industry. In this article, the researches of mineral carbonation process using iron and steel slag as feedstock are reviewed, and the carbonation reaction mechanism and the parameters affecting the reaction rate and carbonation degree are analyzed. Furthermore, the effect of different enforcement approaches, such as ultrasonic enhancement, mixed calcination, microbial enhancement, and cyclic coprocessing on mineral carbonation reaction, is introduced. The additional effects of mineral carbonation, such as solving the problem of poor volume stability of steel slag, weakening the leaching of heavy metal ions, and reducing the pH of the leachate, are also illustrated. Moreover, issues related to mineral carbonation technology that should be emphasized upon soon, such as the production of valuable products, use of industrial wastewater, aqueous phase recycling use, multiparameter coupling analysis, and research on the properties of carbonation residues, are also discussed, which contribute some perspectives to the future development of mineral carbonation of iron and steel slag.
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Affiliation(s)
- Yinbo Luo
- Department of Ferrous Metallurgy, School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Dongfeng He
- Department of Ferrous Metallurgy, School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
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12
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Ragipani R, Bhattacharya S, Suresh AK. A review on steel slag valorisation via mineral carbonation. REACT CHEM ENG 2021. [DOI: 10.1039/d1re00035g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Alkaline slags, a waste product of steel industry, provide an opportunity for carbon sequestration and creation of value at the same time. This requires an understanding of the mechanisms of leaching and carbonation.
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Affiliation(s)
- Raghavendra Ragipani
- IITB-Monash Research Academy
- Indian Institute of Technology Bombay
- Mumbai
- India
- Department of Chemical Engineering
| | | | - Akkihebbal K. Suresh
- Department of Chemical Engineering
- Indian Institute of Technology Bombay
- Mumbai
- India
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13
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Zhao Q, Chu X, Mei X, Meng Q, Li J, Liu C, Saxén H, Zevenhoven R. Co-treatment of Waste From Steelmaking Processes: Steel Slag-Based Carbon Capture and Storage by Mineralization. Front Chem 2020; 8:571504. [PMID: 33195057 PMCID: PMC7596899 DOI: 10.3389/fchem.2020.571504] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 08/17/2020] [Indexed: 11/25/2022] Open
Abstract
The iron and steel industry is an energy-intensive sector, and large amounts of waste/ by-products are generated during the steelmaking process, such as CO2, metallurgical slag, and wastewater. Enhancing the development and deployment of treating waste from the steelmaking process will be environment friendly and resource-saving. Capturing CO2 by steel slag (SS) via mineralization is regarded to be an excellent choice due to the high basicity of the slag. In this paper, recent research on the steel slag-based carbon capture and storage (SS-CCS) by mineralization was summarized. Three routes of SS-CCS are compared including, direct gas-solid carbonation, direct aqueous carbonation, and indirect carbonation, respectively. Furthermore, the challenges and prospects for further development of the SS-CCS were discussed.
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Affiliation(s)
- Qing Zhao
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang, China.,School of Metallurgy, Northeastern University, Shenyang, China
| | - Xinyi Chu
- School of Metallurgy, Northeastern University, Shenyang, China
| | - Xiaohui Mei
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang, China.,School of Metallurgy, Northeastern University, Shenyang, China
| | - Qingzhang Meng
- School of Metallurgy, Northeastern University, Shenyang, China
| | - Jingyu Li
- School of Metallurgy, Northeastern University, Shenyang, China
| | - Chengjun Liu
- Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang, China.,School of Metallurgy, Northeastern University, Shenyang, China
| | - Henrik Saxén
- Process and Systems Engineering Laboratory, Åbo Akademi University, Åbo/Turku, Finland
| | - Ron Zevenhoven
- Process and Systems Engineering Laboratory, Åbo Akademi University, Åbo/Turku, Finland
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14
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Zhang H, Zuo Q, Wei C, Lin X, Dong J, Liao C, Xu A. Closed-circulating CO 2 sequestration process evaluation utilizing wastes in steelmaking plant. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:139747. [PMID: 32531592 DOI: 10.1016/j.scitotenv.2020.139747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/25/2020] [Accepted: 05/25/2020] [Indexed: 06/11/2023]
Abstract
The wastes network system exploration in metallurgical process imposes of great significance for advancing green circular economy in steel plant. This paper originally proposes a closed-circulating CO2 sequestering process for wastes appreciation and harmless disposal, and the effect of two circulation strategy, i.e. Slag circulation strategy and cold-rolling waste water(CRW) circulation strategy, on the CO2 uptake efficiency, carbonation degree and desalination rate were systemically discussed. Then, their kinetics are analyzed by model and molecular simulation in detail, respectively. In addition, the energy consumption and the cost are simulated for comprehensively evaluating its superiority. The experimental and molecular simulation results all show that the peak values for both strategies could be achieved when circulation times is in the range of three to five. CRW circulation strategy has a better CO2 uptake efficiency than slag circulation strategy, the CO2 uptake efficiency is about 487kgCO2/tslag and corresponding desalination rate is 48.9%, when CRW is circulated for five times at 60 °C and 20 L/g for 90 min. Adopting CRW circulation strategy, the CO2 sequestration efficiency is averagely doubled comparing to previous results. 129%-183% energy consumption and 35.6% cost would be reduced, which represents that the proposed routine is economical to step forward to industrial application.
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Affiliation(s)
- Huining Zhang
- Faculty of Materials, Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China.
| | - Quanqin Zuo
- Faculty of Materials, Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Chao Wei
- Faculty of Materials, Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Xin Lin
- Faculty of Materials, Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Jianping Dong
- Faculty of Materials, Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Chunfa Liao
- Faculty of Materials, Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Anjun Xu
- School of Metallurgy and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
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15
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Zhang X, Chang J. Effect of Different Hydration Time on Carbonation Degree and Strength of Steel Slag Specimens Containing Zeolite. MATERIALS 2020; 13:ma13173898. [PMID: 32899283 PMCID: PMC7503824 DOI: 10.3390/ma13173898] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 11/24/2022]
Abstract
Steel slag partially substituted by zeolite (SZ) was beneficial for improving the compressive strength and carbonation degree of SZ specimens after a combined curing (hydration and then carbonation) process due to pozzolanic reaction between them. By previous work results, the zeolitic substitution ratios of 5 wt.% and 15 wt.% in steel slag specimens (SZ5 and SZ15) gained the optimum compressive strength and carbonation degree, respectively, after 1 day hydration and then 2 h carbonation. This study investigated the effect of previous hydration time (1, 3, 7, 14, and 196 days) on carbonation degree and strength of SZ specimens after subsequent carbonation curing. Two zeolitic substitution ratios (5 wt.% and 15 wt.%) were selected and pure steel slag specimens were also prepared as controls. Compressive strength results revealed that the optimum hydration curing time was 1 day and the optimum zeolitic substitution ratio was 5 wt.%. The pozzolanic reaction happened in SZ specimens was divided into early and late pozzolanic reaction. In the late hydration, a new mineral, monocarboaluminate (AFmc) was produced in SZ15 specimens, modifying the carbonation degree and strength further. And the mechanism of pozzolanic reaction in early and late hydration in SZ specimens was explained by several microscopic test methods.
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Affiliation(s)
| | - Jun Chang
- Correspondence: ; Tel.: +86-151-6408-2089
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16
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Ho HJ, Iizuka A, Shibata E, Tomita H, Takano K, Endo T. CO 2 Utilization via Direct Aqueous Carbonation of Synthesized Concrete Fines under Atmospheric Pressure. ACS OMEGA 2020; 5:15877-15890. [PMID: 32656408 PMCID: PMC7345389 DOI: 10.1021/acsomega.0c00985] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/09/2020] [Indexed: 05/16/2023]
Abstract
Mineral carbonation using alkaline wastes is an attractive approach to CO2 utilization. Owing to the difference between waste CO2 and feedstock CO2, developing CO2 utilization technologies without CO2 purification and pressurization is a promising concept. This study investigated a potential method for CO2 utilization via direct aqueous carbonation of synthesized concrete fines under atmospheric pressure and low CO2 concentration. The carbonation reaction with different solid-liquid ratios and different concentrations of introduced CO2 was examined in detail. Under basic conditions, a CO2 uptake of 0.19 g-CO2/g-concrete fines demonstrated that direct aqueous carbonation of concrete fines under atmospheric pressure and low CO2 concentration is effective. The CaCO3 concentration, degree of carbonation, and reaction mechanism were clarified. Furthermore, characterization of the carbonated products was used to evaluate ways of utilizing the carbonated products.
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Affiliation(s)
- Hsing-Jung Ho
- Department
of Environmental Studies for Advanced Society, Graduate School of
Environmental Studies, Tohoku University, Aoba-468-1 Aramaki, Aoba-ku, Sendai, Miyagi 980-0845, Japan
| | - Atsushi Iizuka
- Center
for Mineral Processing and Metallurgy, Institute of Multidisciplinary
Research for Advanced Materials, Tohoku
University, 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Etsuro Shibata
- Center
for Mineral Processing and Metallurgy, Institute of Multidisciplinary
Research for Advanced Materials, Tohoku
University, 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Hisashi Tomita
- Business
Development Department, Resources, Energy & Environment Business
Area, IHI Corporation, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 135-8710, Japan
| | - Kenji Takano
- Business
Development Department, Resources, Energy & Environment Business
Area, IHI Corporation, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 135-8710, Japan
| | - Takumi Endo
- Business
Development Department, Resources, Energy & Environment Business
Area, IHI Corporation, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 135-8710, Japan
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17
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Chen B, Han L, Yoon S, Lee W, Zhang Y, Yuan L, Choi Y. Applying steel slag leachate as a reagent substantially enhances pH reduction efficiency for humidification treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:18911-18923. [PMID: 32207005 DOI: 10.1007/s11356-020-08429-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 03/12/2020] [Indexed: 06/10/2023]
Abstract
A cost-effective, easy-to-implement, and sustainable approach is needed to mitigate the production of alkaline leachate from steel slags that are reused or disposed in the environment. To address this issue, a humidification treatment process, which is operated by wetting a stack of steel slag using aqueous reagents and letting atmospheric CO2 to be passively diffused into the slag pores to induce slag carbonation reaction, was previously developed. In this study, we demonstrate that the leachate of raw steel slag can be recycled and used as a humidification reagent to substantially enhance the treatment efficiency as well as to enable operating the process with neither synthetic chemical consumption nor wastewater discharge. In a 24-h study, a 0.61-unit reduction in slag pH is achieved using a raw slag leachate as a reagent, which is substantially greater than a 0.28-unit reduction using deionized water. The net amount of CaCO3 produced during an extended humidification duration of 4 weeks is increased by 2.7-fold when the leachate is used instead of deionized water. A series of systematically designed experiments demonstrates that the pH (11.0) and ionic strength (0.0048) are the two major characteristics of the raw slag leachate that contribute to the enhanced efficiency of humidification treatment. With further demonstration at larger scales in follow-up studies, the novel humidification process that utilizes the leachate generated on-site as a reagent is expected to be a feasible alternative for alkali waste treatment prior to its reuse or disposal.
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Affiliation(s)
- Bo Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, China
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, Republic of Korea
| | - Longxi Han
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, China
| | - Sangwon Yoon
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, Republic of Korea
| | - Wooram Lee
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, Republic of Korea
| | - Yi Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, China
| | - Lingling Yuan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, China
- National Center of Oceanographic Standards and Metrology, Tianjin, China
| | - Yongju Choi
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, Republic of Korea.
- Institute of Construction and Environmental Engineering, Seoul National University, Seoul, Republic of Korea.
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18
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Omale SO, Choong TSY, Abdullah LC, Siajam SI, Yip MW. Utilization of Malaysia EAF slags for effective application in direct aqueous sequestration of carbon dioxide under ambient temperature. Heliyon 2019; 5:e02602. [PMID: 31667417 PMCID: PMC6812231 DOI: 10.1016/j.heliyon.2019.e02602] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/20/2019] [Accepted: 10/02/2019] [Indexed: 11/12/2022] Open
Abstract
Iron and steel industries are among the contributors of CO2 emission in large volume into the atmosphere, causing detrimental effects to the environment and the ecosystem at large scale. These industries also generate solid wastes in the form of electric arc furnace (EAF) slag during operations which result in about 10–15% slag wastes per ton of steel produced. In this study, the EAF slags from an iron and steel-making factory in Klang, Malaysia was utilized for CO2 sequestration through direct aqueous mineral carbonation. According to the surface area analysis, the fresh EAF slag has a mesoporous structure, its elemental composition shows the presence of 20.91 wt.% of CaO that was used for the sequestration of CO2 through carbonation. The sequestration capacity was found to be 58.36 g CO2/kg of slag at ambient temperature in 3 h, with the liquid/solid (L/S) ratio of 5:1 and using <63μm particle size. Moreover, the shrinking core model (SCM) was used to analyze the solid-fluid reaction in a heterogeneous phase and the CO2 sequestration shows to be controlled by the product layer phase. The EAF slag is demonstrated to have the potential of CO2 sequestration at ambient temperature.
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Affiliation(s)
- Sunday O Omale
- Sustainable Process Engineering Research Center (SPERC), Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia
| | - Thomas S Y Choong
- Sustainable Process Engineering Research Center (SPERC), Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia.,INTROP, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia
| | - Luqman C Abdullah
- Sustainable Process Engineering Research Center (SPERC), Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia.,INTROP, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia
| | - Shamsul I Siajam
- Sustainable Process Engineering Research Center (SPERC), Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia
| | - Mun W Yip
- Dept. of Mechanical Engineering, Tunku Abdul Rahman University College, Malaysia
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19
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Librandi P, Nielsen P, Costa G, Snellings R, Quaghebeur M, Baciocchi R. Mechanical and environmental properties of carbonated steel slag compacts as a function of mineralogy and CO2 uptake. J CO2 UTIL 2019. [DOI: 10.1016/j.jcou.2019.05.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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20
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Pullin H, Bray AW, Burke IT, Muir DD, Sapsford DJ, Mayes WM, Renforth P. Atmospheric Carbon Capture Performance of Legacy Iron and Steel Waste. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:9502-9511. [PMID: 31317734 PMCID: PMC6706800 DOI: 10.1021/acs.est.9b01265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 06/10/2023]
Abstract
Legacy iron (Fe) and steel wastes have been identified as a significant source of silicate minerals, which can undergo carbonation reactions and thus sequester carbon dioxide (CO2). In reactor experiments, i.e., at elevated temperatures, pressures, or CO2 concentrations, these wastes have high silicate to carbonate conversion rates. However, what is less understood is whether a more "passive" approach to carbonation can work, i.e., whether a traditional slag emplacement method (heaped and then buried) promotes or hinders CO2 sequestration. In this paper, the results of characterization of material retrieved from a first of its kind drilling program on a historical blast furnace slag heap at Consett, U.K., are reported. The mineralogy of the slag material was near uniform, consisting mainly of melilite group minerals with only minor amounts of carbonate minerals detected. Further analysis established that total carbon levels were on average only 0.4% while average calcium (Ca) levels exceeded 30%. It was calculated that only ∼3% of the CO2 sequestration potential of the >30 Mt slag heap has been utilized. It is suggested that limited water and gas interaction and the mineralogy and particle size of the slag are the main factors that have hindered carbonation reactions in the slag heap.
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Affiliation(s)
- Huw Pullin
- School
of Earth and Ocean Sciences, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - Andrew W. Bray
- School
of Earth and Environment, University of
Leeds, Leeds LS2 9JT, United Kingdom
| | - Ian T. Burke
- School
of Earth and Environment, University of
Leeds, Leeds LS2 9JT, United Kingdom
| | - Duncan D. Muir
- School
of Earth and Ocean Sciences, Cardiff University, Cardiff CF10 3AT, United Kingdom
| | - Devin J. Sapsford
- School
of Engineering, Cardiff University, Cardiff CF24 3AA, United Kingdom
| | - William M. Mayes
- Department
of Geography, Geology and Environment, University
of Hull, Hull HU6 7RX, United Kingdom
| | - Phil Renforth
- School
of Engineering and Physical Sciences, Heriot-Watt
University, Edinburgh EH14 4AS, United Kingdom
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21
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Chen B, Yoon S, Zhang Y, Han L, Choi Y. Reduction of steel slag leachate pH via humidification using water and aqueous reagents. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 671:598-607. [PMID: 30933816 DOI: 10.1016/j.scitotenv.2019.03.362] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/16/2019] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
A slag humidification process that aims to reduce the leachate pH of steel slag via carbonation was accomplished by simply wetting the slag and exposing it to the atmosphere for passive diffusion of atmospheric CO2. The optimization parameters of the process were studied. Results showed that by wetting the slag using various aqueous solutions (deionized water, NaCl solution and NaOH solution), such that its moisture content nearly reaches its water holding capacity, a significant reduction in leachate pH could be achieved. Pretreatment of the slag using 1 M NaOH and subsequent humidification using deionized water showed the best efficiency of 1.1 pH unit reduction among the tested conditions. Slag pretreatment could substantially enhance the carbonation degree on the slag surface, leading to conservation of the treatment effectiveness up to three times the leachate replenishment using deionized water. The benefit of the alkaline treatment to promote slag carbonation could also be achieved using a low to moderate (0.005-0.1 M) NaOH solutions for humidification without the pretreatment step. A 72.5% increase in the treatment efficiency could be achieved via a humidification treatment using 0.005 M NaOH solution compared to that using deionized water. This study shows the promise of humidification treatment as a low-cost, easily implemented, and environmentally friendly slag pH neutralization process that can be applied in the field for slag treatment prior to its use or disposal in the environment.
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Affiliation(s)
- Bo Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, China; Department of Civil and Environmental Engineering, Seoul National University, Seoul, Republic of Korea
| | - Sangwon Yoon
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, Republic of Korea
| | - Yi Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, China
| | - Longxi Han
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, China
| | - Yongju Choi
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, Republic of Korea; Institute of Construction and Environmental Engineering, Seoul National University, Seoul, Republic of Korea.
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22
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Ho HJ, Iizuka A, Shibata E. Carbon Capture and Utilization Technology without Carbon Dioxide Purification and Pressurization: A Review on Its Necessity and Available Technologies. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b01213] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Hsing-Jung Ho
- Department of Environmental Studies for Advanced Society, Graduate School of Environmental Studies, Tohoku University, Aoba-468-1 Aramaki, Aoba-ku, Sendai, Miyagi 980-0845, Japan
| | - Atsushi Iizuka
- Center for Mineral Processing and Metallurgy, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Etsuro Shibata
- Center for Mineral Processing and Metallurgy, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
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23
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Reddy KR, Gopakumar A, Rai RK, Kumar G, Chetri JK, Grubb DG. Effect of basic oxygen furnace slag particle size on sequestration of carbon dioxide from landfill gas. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2019; 37:469-477. [PMID: 30726168 DOI: 10.1177/0734242x18823948] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The mineral carbon sequestration capacity of basic oxygen furnace (BOF) slag offers great potential to absorb carbon dioxide (CO2) from landfill emissions. The BOF slag is highly alkaline and rich in calcium (Ca) containing minerals that can react with the CO2 to form stable carbonates. This property of BOF slag makes it appealing for use in CO2 sequestration from landfill gas. In a previous study, CO2 and CH4 removal from the landfill gas was investigated by performing batch and column experiments with BOF slag under different moisture and synthetic landfill gas exposure conditions. The study showed two stage CO2 removal mechanism: (1) initial rapid CO2 removal, which was attributed to the carbonation of free lime (CaO) and portlandite [(Ca(OH)2)], and (2) long-term relatively slower CO2 removal, which was attributed to be the gradual leaching of Ca2+ from minerals (calcium-silicates) present in the BOF slag. Realising that the particle size could be an important factor affecting total CO2 sequestration capacity, this study investigates the effect of gradation on the CO2 sequestration capacity of the BOF slag under simulated landfill gas conditions. Batch and column experiments were performed with BOF slag using three gradations: (1) coarse (D50 = 3.05 mm), (2) original (D50 = 0.47 mm), and (3) fine (D50 = 0.094 mm). The respective CO2 sequestration potentials attained were 255 mg g-1, 155 mg g-1, and 66 mg g-1. The highest CO2 sequestration capacity of fine BOF slag was attributed to the availability of calcium containing minerals on the slag particle surface owing to the highest surface area and shortest leaching path for the Ca2+ from the inner core of the slag particles.
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Affiliation(s)
- Krishna R Reddy
- 1 University of Illinois at Chicago, Department of Civil & Materials Engineering, Chicago, IL, USA
| | - Archana Gopakumar
- 1 University of Illinois at Chicago, Department of Civil & Materials Engineering, Chicago, IL, USA
| | - Raksha K Rai
- 1 University of Illinois at Chicago, Department of Civil & Materials Engineering, Chicago, IL, USA
| | - Girish Kumar
- 1 University of Illinois at Chicago, Department of Civil & Materials Engineering, Chicago, IL, USA
| | - Jyoti K Chetri
- 1 University of Illinois at Chicago, Department of Civil & Materials Engineering, Chicago, IL, USA
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24
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Abstract
Carbon capture, utilisation and storage (CCUS) via mineral carbonation is an effective method for long-term storage of carbon dioxide and combating climate change. Implemented at a large-scale, it provides a viable solution to harvesting and storing the modern crisis of GHGs emissions. To date, technological and economic barriers have inhibited broad-scale utilisation of mineral carbonation at industrial scales. This paper outlines the mineral carbonation process; discusses drivers and barriers of mineral carbonation deployment in Australian mining; and, finally, proposes a unique approach to commercially viable CCUS within the Australian mining industry by integrating mine waste management with mine site rehabilitation, and leveraging relationships with local coal-fired power station. This paper discusses using alkaline mine and coal-fired power station waste (fly ash, red mud, and ultramafic mine tailings, i.e., nickel, diamond, PGE (platinum group elements), and legacy asbestos mine tailings) as the feedstock for CCUS to produce environmentally benign materials, which can be used in mine reclamation. Geographical proximity of mining operations, mining waste storage facilities and coal-fired power stations in Australia are identified; and possible synergies between them are discussed. This paper demonstrates that large-scale alkaline waste production and mine site reclamation can become integrated to mechanise CCUS. Furthermore, financial liabilities associated with such waste management and site reclamation could overcome many of the current economic setbacks of retrofitting CCUS in the mining industry. An improved approach to commercially viable climate change mitigation strategies available to the mining industry is reviewed in this paper.
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25
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Abstract
Carbon capture and sequestration (CCS) is taking the lead as a means for mitigating climate change. It is considered a crucial bridging technology, enabling carbon dioxide (CO2) emissions from fossil fuels to be reduced while the energy transition to renewable sources is taking place. CCS includes a portfolio of technologies that can possibly capture vast amounts of CO2 per year. Mineral carbonation is evolving as a possible candidate to sequester CO2 from medium-sized emissions point sources. It is the only recognized form of permanent CO2 storage with no concerns regarding CO2 leakage. It is based on the principles of natural rock weathering, where the CO2 dissolved in rainwater reacts with alkaline rocks to form carbonate minerals. The active alkaline elements (Ca/Mg) are the fundamental reactants for mineral carbonation reaction. Although the reaction is thermodynamically favored, it takes place over a large time scale. The challenge of mineral carbonation is to offset this limitation by accelerating the carbonation reaction with minimal energy and feedstock consumption. Calcium and magnesium silicates are generally selected for carbonation due to their abundance in nature. Industrial waste residues emerge as an alternative source of carbonation minerals that have higher reactivity than natural minerals; they are also inexpensive and readily available in proximity to CO2 emitters. In addition, the environmental stability of the industrial waste is often enhanced as they undergo carbonation. Recently, direct mineral carbonation has been investigated significantly due to its applicability to CO2 capture and storage. This review outlines the main research work carried out over the last few years on direct mineral carbonation process utilizing steel-making waste, with emphasis on recent research achievements and potentials for future research.
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26
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Microwave-Supported Leaching of Electric Arc Furnace (EAF) Slag by Ammonium Salts. MINERALS 2017. [DOI: 10.3390/min7070119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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27
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Ghacham AB, Pasquier LC, Cecchi E, Blais JF, Mercier G. CO2 sequestration by mineral carbonation of steel slags under ambient temperature: parameters influence, and optimization. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:17635-46. [PMID: 27236443 DOI: 10.1007/s11356-016-6926-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 05/18/2016] [Indexed: 05/28/2023]
Abstract
This work focuses on the influence of different parameters on the efficiency of steel slag carbonation in slurry phase under ambient temperature. In the first part, a response surface methodology was used to identify the effect and the interactions of the gas pressure, liquid/solid (L/S) ratio, gas/liquid ratio (G/L), and reaction time on the CO2 removed/sample and to optimize the parameters. In the second part, the parameters' effect on the dissolution of CO2 and its conversion into carbonates were studied more in detail. The results show that the pressure and the G/L ratio have a positive effect on both the dissolution and the conversion of CO2. These results have been correlated with the higher CO2 mass introduced in the reactor. On the other hand, an important effect of the L/S ratio on the overall CO2 removal and more specifically on the carbonate precipitation has been identified. The best results were obtained L/S ratios of 4:1 and 10:1 with respectively 0.046 and 0.052 gCO2 carbonated/g sample. These yields were achieved after 10 min reaction, at ambient temperature, and 10.68 bar of total gas pressure following direct gas treatment.
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Affiliation(s)
| | | | | | | | - Guy Mercier
- INRS-ETE, 490 rue de la Couronne, Québec, QC, G1K 9A9, Canada
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28
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Polettini A, Pomi R, Stramazzo A. CO2 sequestration through aqueous accelerated carbonation of BOF slag: A factorial study of parameters effects. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 167:185-195. [PMID: 26686071 DOI: 10.1016/j.jenvman.2015.11.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 06/05/2023]
Abstract
A factorial study was conducted on basic oxygen furnace slag from a steelmaking industry with the aim of systematically identifying the individual and joint effects of the operating parameters (total pressure, CO2 concentration in the gas phase and temperature) on the CO2 sequestration yield of a direct aqueous carbonation process. Each operating parameter was varied over a range of three levels according to a 3(3) factorial design, resulting in 27 carbonation experiments. The carbonation performance and the changes in particle size and mineralogical characteristics of the slag were investigated in detail. The analysis of the experimental results indicated large effects of the operating factors on CO2 uptake, which was observed to span the range 6.7-53.6 g CO2/100 g slag. The best carbonation performance achieved was particularly significant compared to previous studies, even more considering the relative mild operating conditions adopted (P = 5 bar, C = 40% vol. CO2, T = 50 °C, t = 4 h). The analysis of the solid and liquid phases at the end of the carbonation treatment evidenced significant changes in the physical, chemical and mineralogical composition of the material. In particular, evidence was gained of other elements (Mg, Fe, Mn, Zn) in addition to Ca being intensively involved in the carbonation reactions, with a variety of carbonate phases being produced in addition to calcium carbonate forms.
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Affiliation(s)
- Alessandra Polettini
- Department of Civil and Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18 - 00184, Rome, Italy.
| | - Raffaella Pomi
- Department of Civil and Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18 - 00184, Rome, Italy.
| | - Alessio Stramazzo
- Department of Civil and Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18 - 00184, Rome, Italy.
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29
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Costa G, Polettini A, Pomi R, Stramazzo A. Leaching modelling of slurry-phase carbonated steel slag. JOURNAL OF HAZARDOUS MATERIALS 2016; 302:415-425. [PMID: 26489916 DOI: 10.1016/j.jhazmat.2015.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 10/01/2015] [Accepted: 10/04/2015] [Indexed: 06/05/2023]
Abstract
In the present work the influence of accelerated mineral carbonation on the leaching behaviour of basic oxygen furnace steel slag was investigated. The environmental behaviour of the material as evaluated through the release of major elements and toxic metals under varying pH conditions was the main focus of the study. Geochemical modelling of the eluates was used to derive a theoretical description of the underlying leaching phenomena for the carbonated material as compared to the original slag. Among the investigated elements, Ca and Si were most appreciably affected by carbonation. A very clear effect of carbonation on leaching was observed for silicate phases, and lower-Ca/Si-ratio minerals were found to control leaching in carbonated slag eluates as compared to the corresponding untreated slag sample as a result of Ca depletion from the residual slag particles. Clear evidence was also gained of solubility control for Ca, Mg and Mn by a number of carbonate minerals, indicating a significant involvement of the original slag constituents in the carbonation process. The release of toxic metals (Zn, V, Cr, Mo) was found to be variously affected by carbonation, owing to different mechanisms including pH changes, dissolution/precipitation of carbonates as well as sorption onto reactive mineral surfaces. The leaching test results were used to derive further considerations on the expected metal release levels on the basis of specific assumptions on the relevant pH domains for the untreated and carbonated slag.
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Affiliation(s)
- G Costa
- Department of Civil Engineering and Computer Science Engineering, University of Rome "Tor Vergata", Via del Politecnico 1, 00133 Rome, Italy
| | - A Polettini
- Department of Civil and Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18, 00184 Rome, Italy.
| | - R Pomi
- Department of Civil and Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18, 00184 Rome, Italy
| | - A Stramazzo
- Department of Civil and Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18, 00184 Rome, Italy
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30
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Direct Aqueous Mineral Carbonation of Waste Slate Using Ammonium Salt Solutions. METALS 2015. [DOI: 10.3390/met5042413] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Baciocchi R, Costa G, Polettini A, Pomi R. Effects of thin-film accelerated carbonation on steel slag leaching. JOURNAL OF HAZARDOUS MATERIALS 2015; 286:369-378. [PMID: 25596552 DOI: 10.1016/j.jhazmat.2014.12.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/26/2014] [Accepted: 12/30/2014] [Indexed: 06/04/2023]
Abstract
This paper discusses the effects of accelerated carbonation on the leaching behaviour of two types of stainless steel slags (electric arc furnace and argon oxygen decarburisation slag). The release of major elements and toxic metals both at the natural pH and at varying pH conditions was addressed. Geochemical modelling of the eluates was used to theoretically describe leaching and derive information about mineralogical changes induced by carbonation. Among the investigated elements, Ca and Si were most appreciably affected by carbonation. A very clear effect of carbonation on leaching was observed for silicate phases; geochemical modelling indicated that the Ca/Si ratio of Ca-controlling minerals shifted from ∼ 1 for the untreated slag to 0.5-0.67 for the carbonated samples, thus showing that the carbonation process left some residual Ca-depleted silicate phases while the extracted Ca precipitated in the form of carbonate minerals. For toxic metals the changes in leaching induced by carbonation appeared to be mainly related to the resulting pH changes, which were as high as ∼ 2 orders of magnitude upon carbonation. Depending on the specific shape of the respective solubility curves, the extent of leaching of toxic metals from the slag was differently affected by carbonation.
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Affiliation(s)
- R Baciocchi
- Laboratory of Environmental Engineering, University of Rome "Tor Vergata", Via del Politecnico 1 - 00133 Rome, Italy
| | - G Costa
- Laboratory of Environmental Engineering, University of Rome "Tor Vergata", Via del Politecnico 1 - 00133 Rome, Italy
| | - A Polettini
- Department of Civil and Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18 - 00184 Rome, Italy.
| | - R Pomi
- Department of Civil and Environmental Engineering, University of Rome "La Sapienza", Via Eudossiana 18 - 00184 Rome, Italy
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