Article
Green & Sustainable Science & Technology
Ying Shi, Ling Cheng, Ming Tao, SenSen Tong, Xiaojing Yao, Yefan Liu
Summary: The addition of modified quartz sand (MQS) can significantly reduce phosphate concentration in backfill, meeting discharge standards in a short time without adverse effects on long-term phosphate release. Furthermore, MQS addition promotes hydration processes, optimizes aggregate gradation, and enhances strength development of backfill.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Materials Science, Multidisciplinary
Qiu-song Chen, Shi-yuan Sun, Yi-kai Liu, Chong-chong Qi, Hui-bo Zhou, Qin-li Zhang
Summary: The study evaluated the feasibility of using cemented paste backfill for the remediation of phosphogypsum and examined fluorine immobilization mechanisms. Through physico-chemical analyses, it was discovered that calcium silicate hydrate gel is associated with fluorine retention. However, further modifications are needed for the simulation to be used as a predictive tool for phosphogypsum management options.
INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
(2021)
Article
Environmental Sciences
Zude Pan, Rongxiang Pan, Yang Cao, Qianlin Chen, Min Yang
Summary: Phosphogypsum cementitious paste backfill prepared with waste materials showed improved strength and water resistance, meeting the requirements for mine filling.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Environmental Sciences
Yikai Liu, Qiusong Chen, Maria Chiara Dalconi, Simone Molinari, Luca Valentini, Yunmin Wang, Shiyuan Sun, Peishen Wang, Gilberto Artioli
Summary: The use of cemented paste backfill (OCPB) for the solidification/stabilization of phosphogypsum provides a low-cost and alternative technique for recycling phosphogypsum stockpiles. This study investigates the retention mechanisms of fluoride and phosphate in immobilized OCPB using a framework combining chemical, mineralogical, and morphological analyses. The findings suggest that aluminate-rich calcium silicate hydrates play a crucial role in fluoride and phosphate retention, and the cementitious matrix acts as a buffering material to maintain high pH conditions necessary for retention.
ENVIRONMENTAL RESEARCH
(2022)
Article
Construction & Building Technology
Yikai Liu, Qiusong Chen, Maria Chiara Dalconi, Simone Molinari, Luca Valentini, Yunmin Wang, Shiyuan Sun, Peishen Wang, Gilberto Artioli
Summary: The in-situ solidification/stabilization of phosphogypsum (PG) is considered an effective technology for waste remediation, but there is uncertainty and controversy concerning fluorine and phosphorus transformation. This study explores the use of gamma-Al2O3 in PG remediation and finds that it promotes ettringite and amorphous precipitation, as well as providing mechanical stability for engineering applications and pollutant retention.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Shiyu Zhang, Yingliang Zhao, Hangxing Ding, Jingping Qiu, Zhenbang Guo
Summary: This study investigated the potential use of flue gas desulfurisation gypsum (FGDG) and phosphogypsum (PG) in cemented paste backfill (CPB), demonstrating their significant improvement on mechanical performance and acid erosion resistance of CPB. The findings also highlighted the promotion of ettringite formation, reduction in hydration heat, and enhanced stability by the addition of these mineral admixtures. The novel binders (SPC + FA + FGDG/PG + quicklime) exhibit promising application prospects in CPB technology.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Environmental Sciences
Guanzhao Jiang, Aixiang Wu, Yiming Wang, Yong Wang, Jianqiu Li
Summary: Cemented hemihydrate phosphogypsum (HPG) backfill is gaining popularity as a new branch of cemented paste backfill (CPB) in mine goaf treatments in China due to its low cost and efficient utilization. The gelling activity of HPG decreases with aging time due to its gradual conversion from hemihydrate to dihydrate form. Soluble P(2)O(5) forms insoluble brushite coatings, which significantly inhibit the HPG conversion. Increasing the Al2O3 content and reducing temperature further delay the HPG conversion.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Qiusong Chen, Qi Zhang, Yunmin Wang, Qinli Zhang, Yikai Liu
Summary: In this study, polymeric aluminum chloride (PAC) was added to the binder of phosphogypsum (PG) to promote cement hydration reaction and optimize the porosity and mechanical properties of specimens. PAC also played a role in the immobilization of fluoride. Therefore, PAC-augmented binders can ensure efficient fluoride retention in a technically feasible and financially profitable method.
Article
Engineering, Chemical
Yikai Liu, Peishen Wang, Maria Chiara Dalconi, Simone Molinari, Luca Valentini, Yunmin Wang, Shiyuan Sun, Qiusong Chen, Gilberto Artioli
Summary: The use of cement for solid waste solidification/stabilization is widely used but has come under scrutiny due to its greenhouse gas emissions. However, cement-immobilized solid waste may serve as a CO2 sink and reabsorb atmospheric CO2, which has not been explored before. This study investigates the potential CO2 absorption effect of phosphogypsum (PG) based cemented paste backfill (PCPB), finding that with a high PG utilization rate, PCPB application in China may produce 16.7 Mt/year of CO2, but a reduction of 5.76 Mt/year could be achieved considering future reabsorption. Impurities in PG and maintaining alkalinity limit industrial applications. Phosphate impurities hinder CO2 uptake, while fluorides accelerate hydration reactions and carbonation. Geochemical modeling suggests that maintaining a basic pH condition can enhance CO2 capture capacity. PCPB is considered an effective way to immobilize PG with scalable potential, providing guidance for the management of dumped PG and phosphorus fertilizer industry emissions.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Review
Construction & Building Technology
Shenghua Yin, Zepeng Yan, Xun Chen, Rongfu Yan, Dapeng Chen, Junwei Chen, Gongcheng Li
Summary: Cemented paste backfill (CPB) technology has the potential to greatly improve tailings management in the mining industry, but ensuring proper roof-contact is crucial for personnel safety. The use of expansion agents (EA) in civil engineering can enhance roof-contact for CPB. This paper reviews the development history of CPB technology, identifies the challenges in achieving proper roof-contact, and focuses on the mechanism of expansion-extrusion-bonding. The comparison and analysis of different concrete EA and expansion matrix properties are conducted, and future research directions for expansion backfill technology are discussed.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Chendi Min, Zhixiang Liu, Ying Shi, Xinyue Lu
Summary: This study aimed to enhance the strength performance of phosphogypsum (PG) backfill by optimizing the type of binder used. Silicate-based cements and (sulpho)aluminate-based cements were selected as binders. The results showed that using (sulpho)aluminate-based cements led to rapid hardening and significant strength enhancement of the backfill samples.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Geochemistry & Geophysics
Andrew Pan, Mohammadamin Jafari, Lijie Guo, Murray Grabinsky
Summary: This study presents a new apparatus for evaluating the hybrid failure of CPB and utilizes experimental and finite element analysis to show that the coupled stress is a combination of tensile and shear strength, with the strength properties of CPB dependent on curing time and binder content. The FEA results confirm the effectiveness of the proposed model in predicting the hybrid failure of CPB.
Article
Chemistry, Physical
Yikai Liu, Qiusong Chen, Yunmin Wang, Qinli Zhang, Hongpeng Li, Chaoyu Jiang, Chongchong Qi
Summary: The study used water-washing pre-treatment to purify phosphogypsum, resulting in optimized cemented paste backfill with significantly improved mechanical properties. Unstable cracks appeared but with better residual structures, providing a scientific reference for efficient phosphogypsum recycling.
Article
Engineering, Geological
Jiahao Qin, Jian Zheng, Li Li
Summary: Cemented paste backfill (CPB) exhibits different shrinkage behavior compared to uncemented paste backfill (uCPB), with CPB generally having higher unsaturation onset water content and void ratio, shrinkage limit and final void ratio than uCPB. The shrinkage behaviors of CPB and uCPB are significantly influenced by the initial water content.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Andrew Pan, Murray Grabinsky
Summary: Tensile strength is a crucial parameter in cemented paste backfill (CPB) and directly measuring it can optimize mining operations. This study presents a novel technique to determine tensile strength and finds that the traditional UCS-to-tensile strength ratio underestimates the strength.
Article
Construction & Building Technology
Chendi Min, Xibing Li, Suya He, Shitong Zhou, Yanan Zhou, Shan Yang, Ying Shi
CONSTRUCTION AND BUILDING MATERIALS
(2019)
Article
Multidisciplinary Sciences
Yanan Zhou, Xibing Li, Ying Shi, Quanqi Zhu, Jing Du
Summary: This research focuses on the feasibility of pretreating phosphogypsum (PG) with the water washing method to improve its reuse as aggregate in cemented backfill. The results show that the pretreated PG enhances the fluidity and strength development of the backfill, meeting environmental standards for integrated wastewater discharge. This study has important implications for sustainable mining practices.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Chendi Min, Ying Shi, Yanan Zhou, Zhixiang Liu
Summary: The effects of protocols for slurry preparation on the release of pollutants into bleeding water from cemented phosphogypsum backfill were investigated in this study. The concentrations of phosphate, fluoride, and sulfate and the pH values of the bleeding water were measured. The study found that the slurry preparation protocols affected the quantities of pollutants through the concentrations of pollutants in the bleeding water and the bleeding rate. The binder/PG ratio was identified as the key factor influencing the concentrations of all pollutants in the bleeding water, while the binder type and mixing procedure had varying degrees of influence on fluoride, phosphate, and sulfate concentrations. The most effective slurry preparation protocol reduced the bleeding rate and minimized the phosphate concentration in bleeding water.
Article
Chemistry, Multidisciplinary
Tubing Yin, Rushi Yang, Jing Du, Ying Shi
Article
Green & Sustainable Science & Technology
Lars odegaard Bentsen, Narada Dilp Warakagoda, Roy Stenbro, Paal Engelstad
Summary: This study investigates uncertainty modeling in wind power forecasting using different parametric and non-parametric methods. Johnson's SU distribution is found to outperform Gaussian distributions in predicting wind power. This research contributes to the literature by introducing Johnson's SU distribution as a candidate for probabilistic wind forecasting.
JOURNAL OF CLEANER PRODUCTION
(2024)
Article
Green & Sustainable Science & Technology
Xing Liu, Qiuchen Wang, Yunhao Wen, Long Li, Xinfang Zhang, Yi Wang
Summary: This study analyzes the characteristics of process parameters in three lean gas ethane recovery processes and establishes a prediction and multiobjective optimization model for ethane recovery and system energy consumption. A new method for comparing ethane recovery processes for lean gas is proposed, and the addition of extra coolers improves the ethane recovery. The support vector regression model based on grey wolf optimization demonstrates the highest prediction accuracy, and the multiobjective multiverse optimization algorithm shows the best optimization performance and diversity in the solutions.
JOURNAL OF CLEANER PRODUCTION
(2024)
Article
Green & Sustainable Science & Technology
Cairong Song, Haidong Yang, Xian-Bing Meng, Pan Yang, Jianyang Cai, Hao Bao, Kangkang Xu
Summary: The paper proposes a novel deep learning-based prediction framework, aTCN-LSTM, for accurate cooling load predictions. The framework utilizes a gate-controlled multi-head temporal convolutional network and a sparse probabilistic self-attention mechanism with a bidirectional long short-term memory network to capture both temporal and long-term dependencies in the cooling load sequences. Experimental results demonstrate the effectiveness and superiority of the proposed method, which can serve as an effective guide for HVAC chiller scheduling and demand management initiatives.
JOURNAL OF CLEANER PRODUCTION
(2024)
Article
Green & Sustainable Science & Technology
Zhe Chen, Xiaojing Li, Xianli Xia, Jizhou Zhang
Summary: This study uses survey data from the Loess Plateau in China to evaluate the impact of social interaction on the adoption of soil and water conservation (SWC) technology by farmers. The study finds that social interaction increases the likelihood of farmers adopting SWC, and internet use moderates this effect. The positive impact of social interaction on SWC adoption is more pronounced for farmers in larger villages and those who join cooperative societies.
JOURNAL OF CLEANER PRODUCTION
(2024)
Article
Green & Sustainable Science & Technology
Chenghua Zhang, Yunfei Yan, Kaiming Shen, Zongguo Xue, Jingxiang You, Yonghong Wu, Ziqiang He
Summary: This paper reports a novel method that significantly improves combustion performance, including heat transfer enhancement under steady-state conditions and adaptive stable flame regulation under velocity sudden increase.
JOURNAL OF CLEANER PRODUCTION
(2024)