Submit to Minerals Review for Minerals Propose a Special Issue

Journal Menu

Journal Browser

Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation

Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Minerals (ISSN 2075-163X). This special issue belongs to the section "Environmental Mineralogy and Biogeochemistry".

Deadline for manuscript submissions: closed (25 November 2022) | Viewed by 18257

Share This Special Issue

Special Issue Editors

Dr. Qiusong Chen

E-Mail Website
Guest Editor

School of Resources and Safety Engineering, Central South University, Changsha 410083, China
Interests: groundwater friendly backfilling; comprehensive utilization of solid waste from mining, dressing and smelting
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Xiaoshuang Li

E-Mail Website
Guest Editor

School of Urban Construction, Changzhou University, Changzhou 213164, China
Interests: mine enviroment; transferred underground mining from open-pit; mine slope engineering; ground pressure and strata control
Special Issues, Collections and Topics in MDPI journals

Dr. Simone Molinari

E-Mail Website
Guest Editor

Department of Geosciences, University of Padova, Padova, Italy
Interests: heavy metal pollution; cement-stabilization of contaminated soil; iron oxide nanoparticles; sustainable wastewater remediation

Dr. Chongchong Qi

E-Mail Website
Guest Editor

School of Resources and Safety Engineering, Central South University, Changsha, China
Interests: solid waste minimisation; cemented paste backfill; pollution reduction; recycling; first-principles calculations; molecular dynamics; artificial intelligence
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Hazardous waste, mainly generated by mining, smelting industrial, and agricultural activities, constitutes a serious threat to human health and environmental pollution due to its instability. To minimize the transportation of leachable substances from mineral solid waste to groundwater surrounding disposal sites, solidification/stabilization has found increasing applications for hazardous waste management, for instance, cemented paste backfills (CPB), soil remediation, sediment immobilization. These in situ or ex situ applications not only alleviate disposal problems but also have economic, ecological, and energy-saving advantages.

However, it is evident that solidified waste-binder assemblages would suffer environmental attacks sooner or later with the consistent contact of groundwater, especially under the influence of acid wastewater. For instance, the CPB will be partially or completely immersed in groundwater after the mine is closed, as well as the open pit backfill. Therefore, enhanced hazardous substance leaching may occur when alkaline components are exhausted, and physical–chemical protection subsequently disappears, especially in the acid environment. Further, the study of contaminants in recent decades is facing challenges in the appearance of new compounds (for instance, plastics and nanoparticles) and developing environment requirements.

The present Special Issue aims to collect innovative achievements in different perspectives of combating groundwater pollution in mines. The key areas include but are not limited to:

The coupling effect of factors affecting ions leaching from cemented paste backfill or other stabilized assemblages;
The parameters governing multipollutant transport in mine waste and aquifer;
Innovative leaching tests and numerical simulation;
Acid mining wastewater treatment to minimize its influence on pollutant leaching;
Basic research immobilization mechanisms of solidification/stabilization;
The key technology for backfilling the open pit in an environmentally friendly manner;
The safety evaluation of open pit backfills;
Related case presentations.

Dr. Qiusong Chen
Dr. Xiaoshuang Li
Dr. Simone Molinari
Prof. Dr. Chongchong Qi
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Mining solid waste minimization
Groundwater pollution
Solidification/stabilization
Cemented paste backfill
Acid wastewater
Open pit stability
Environment evaluation

Published Papers (9 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

18 pages, 3869 KiB

Open AccessArticle

Stabilization of As and Heavy Metal-Contaminated Soils by Two Mine Drainage-Treated Sludges

by Hyunji Tak, Seonhee Kim, Kyeongtae Kim, Sookyun Wang and Minhee Lee

Minerals 2023, 13(2), 148; https://doi.org/10.3390/min13020148 - 19 Jan 2023

Cited by 1 | Viewed by 1747

Abstract

This study explored and analyzed the potential of the practical use of acid mine drainage-treated sludge (AMDS) as a new soil stabilizer for arsenic (As) and heavy metals. Various analyses, toxicity evaluations, and extraction batch experiments were performed to investigate the characteristics of the AMDS as a soil stabilizer and to identify the main mechanisms to fix As and heavy metals on the AMDS in soil. Two types of AMDS, copper metal mine drainage-treated sludge (MMDS) and coal mine drainage-treated sludge (CMDS) and four contaminated soils with different pollution scenarios were used in the experiments. ‘Soil A’ and ‘Soil D’ were mainly contaminated with Cd, Pb and Zn. ‘Soil B’ and ‘Soil C’ were contaminated with As. Results from XRD, XRF, SEM-EDS, TG-DTA, and BET analyses suggested that AMDS is mainly composed of Fe- and Ca- bearing minerals such as CaCO₃, Ca(OH)₂ and amorphous Fe-oxide (hydroxide), which have a large surface area and high adsorption capacity for As and heavy metals. From batch extraction experiments, the Pb stabilization efficiency of both of the AMDSs in soil A, which has a high Pb and Zn content, was higher than 90%. The high heavy metal stabilization efficiency comes directly from the electrostatic attraction between metal cations and the negatively charged AMDS surface and/or from the co-precipitation of metal oxide (hydroxide) and CaCO₃, which occurs comprehensively on the AMDS surface. In the case of Zn, the stabilization efficiency in soil A was somewhat low due to the adsorption competition with Pb, but the Zn stabilization efficiency of the CMDS in soil A was higher than 80% (70% or higher for the MMDS). For soil D, the Zn stabilization efficiency of two AMDSs was higher than 85% because of the lower concentration of other heavy metals in soil D, compared to in soil A. The As stabilization efficiency of the AMDSs in soil contaminated with As (soil B and soil C) was higher than 85%, (mostly > 95%). The overall stabilization efficiency of two AMDSs for heavy metals and As were higher than 75% and 85% (mostly > 90%), respectively, regardless of soil type. We concluded that this high As stabilization efficiency was due to the formation of a new complex by ligand exchange between the Fe- (oxide) hydroxide and the arsenate and also to the cation bridge effect between the AMDS surface and the arsenate as well as the co-precipitation. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Figure 1

14 pages, 7227 KiB

Open AccessArticle

Development Law of Water-Conducting Fracture Zone in the Fully Mechanized Caving Face of Gob-Side Entry Driving: A Case Study

by Yi Tan, Han Xu, Weitao Yan, Wenbing Guo, Qi Sun, Dawei Yin, Yujiang Zhang, Xiaoqiang Zhang, Xiaofei Jing, Xiaoshuang Li, Sijiang Wei and Xiao Liu

Minerals 2022, 12(5), 557; https://doi.org/10.3390/min12050557 - 29 Apr 2022

Cited by 3 | Viewed by 1519

Abstract

This study is aimed at exploring the influence of narrow coal pillars in gob-side entry driving (GSED) on the development height of the water-conducting fracture zone (WCFZ) in the fully mechanized caving face. In reference to the geological mining conditions of working face 11915 of Gequan (GQ) Coal Mine, the development law of the WCFZ in the GSED fully mechanized caving face was studied by means of formula calculation, on-site measurement, theoretical analysis, and simulation. The research results disclose that the development height of the WCFZ in the GSED fully mechanized caving face is affected by narrow coal pillars of GSED. When the narrow coal pillars lose stability, the overburden failure changes from insufficient mining to sufficient mining, and the WCFZ in the overburden changes from an arch-shaped one to a saddle-shaped one. Additionally, the development height of the WCFZ surges. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Figure 1

19 pages, 6935 KiB

Open AccessArticle

Paste Backfilling Longwall Mining Technology for Thick Coal Seam Extraction under Buildings and above Confined Aquifers: A Case Study

by Peng Wen, Wenbing Guo, Yi Tan, Erhu Bai, Zhibao Ma, Dongtao Wu and Weiqiang Yang

Minerals 2022, 12(4), 470; https://doi.org/10.3390/min12040470 - 12 Apr 2022

Cited by 8 | Viewed by 1928

Abstract

Backfill mining is an effective measure to control surface subsidence and restrain floor water inrush. It is an essential part of green mining technology. To solve the problem of confined water in mines under buildings, this study was carried out by combining theoretical analysis, laboratory simulation, and numerical simulation, taking the Liangbei coal mine as the research area. The coal seam floor failure characteristics of traditional longwall caving and paste filling mining methods were compared and analyzed. Based on the relevant mining theory, the key parameters, such as mining thickness and filling rate under the critical state of water inrush, were obtained. Then, the feasibility of backfill mining was expounded, and the surface subsidence of paste backfill mining was predicted and measured on site. The results demonstrated that the longwall caving mining method not only had the risk of water inrush, but also the possibility of step cracks at the surface, with the potential to result in serious damage to buildings. However, the backfill mining method reduced the floor damage depth of the coal seam from 12 m to 7 m, which reduced the water inrush coefficient by 12%, the maximum vertical concentrated stress by 42.1%, and the displacement subsidence value by 78.8%. These parameters correlated negatively with backfill strength. Meanwhile, the maximum subsidence, maximum inclined deformation, and horizontal displacement deformation were estimated as 730 mm, 2.5 mm/m, and 1.1 mm/m, respectively, consistent with the measured values (608 mm, 2.1 mm/m, and 0.9 mm/m, respectively). More relevantly, there were no obvious cracks found in the surface buildings, ensuring the safety of mining above confined water on the working face, and realizing the effective protection of surface buildings. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Figure 1

14 pages, 3618 KiB

Open AccessArticle

Association Study on the Pore Structure and Mechanical Characteristics of Coarse-Grained Soil under Freeze–Thaw Cycles

by Yao Liu, Hongwei Deng, Jingbo Xu, Guanglin Tian and Junren Deng

Minerals 2022, 12(3), 314; https://doi.org/10.3390/min12030314 - 28 Feb 2022

Cited by 9 | Viewed by 2097

Abstract

In this study, the relationship between the pore structure and macroscopic mechanical characteristics of coarse-grained soils from mine dumps is explored under various freeze–thaw cycles. A series of experiments were conducted on the mine dump materials using a standard cube sample of 7 cm × 7 cm × 7 cm, a moisture content of 7.5%, and a density of 2.34 g/cm³. The pore structure test and uniaxial compressive strength test were carried out on the coarse-grained soil samples under different freeze–thaw cycles by using a nuclear magnetic resonance (NMR) instrument and a universal servo material testing machine. The study explores the change law of the strength and pore structure of coarse-grained soil, and establishes the correlation model between the pore structure and mechanical characteristics. The results showed that: (1) With the increase in the number of freeze–thaw cycles, the porosity of the coarse-grained soil gradually increased, and the bonding ability between the internal soil particles weakened, resulting in a decrease in strength. (2) With the increase in freeze–thaw cycles, the proportion of pore volume of the main peak and secondary peak 2 of T-2 spectrum curve increases gradually, and the internal pore structure of coarse-grained soil gradually develops towards medium and large pores. (3) There is an exponential function between the variation of pore volume proportion of each peak of coarse-grained soil and the relative strength value, and there is a good fitting coefficient between the two, indicating that the change of pore structure can well reflect the evolution law of strength. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Figure 1

12 pages, 5874 KiB

Open AccessArticle

Pore Structure Evolution and Seepage Characteristics in Unclassified Tailing Thickening Process

by Huazhe Jiao, Wenxiang Zhang, Yixuan Yang, Liuhua Yang, Kaijian Hu and Jianxin Yu

Minerals 2022, 12(2), 164; https://doi.org/10.3390/min12020164 - 28 Jan 2022

Cited by 6 | Viewed by 2014

Abstract

The tailing paste thickening technology was investigated to achieve goaf reduction treatment and tailing resource utilization of metal mines and reach the effect of controlling two hazards with one waste. However, superfine tailing particles could easily form suspended water-locking flocs in the thickening process, which seriously affected the increase in the underflow concentration in the thickener. Undisturbed compression-stage bed samples were extracted using an in situ sampling method through a continuous dynamic thickening experiment. Then, the morphologies and geometrical structures of micropores were analyzed through high-precision computed tomography scanning. Subsequently, the influences of the shear evolution of pore structure and seepage channel on the dewaterability of underflow slurry were explored by combining Avizo software and 3D reconstruction technology. The thickening and dewatering mechanism of underflow slurry was also revealed. Results showed that under the shear action, the flocs were deformed and compacted, forming a high-concentration underflow. On this basis, the original micropores were extruded, deformed and segmented. Moreover, many loose micropores were formed, the connectivity became poor and the total porosity declined. The diameter of the water-conducting channel in the sample was enlarged because of the shear force and the seepage effect improved. The maximum flow velocity inside the pores was 1.537 μm/s, which was 5.49% higher than that under the non-shear state. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Figure 1

13 pages, 3419 KiB

Open AccessArticle

Study on the Effect of Bond Strength on the Failure Mode of Coarse-Grained Sandstone in Weakly Cemented Stratum

by Xianda Yang, Lihui Sun, Jiale Song, Bensheng Yang, Chengren Lan and Qingfeng He

Minerals 2022, 12(1), 55; https://doi.org/10.3390/min12010055 - 31 Dec 2021

Cited by 5 | Viewed by 1226

Abstract

Bond strength is one of the most important parameters and can affect the macroscopic mechanical properties and the damage state of rock to some degree. Coarse-grained sandstone was studied using the controlled variable method. The influence of parallel bond strength on the peak strength and failure mode of coarse-grained sandstone was simulated, and the evolution law of peak strength and the failure mode of bond strength were comprehensively analyzed. The results show that the peak strength of the rock was positively correlated with the bond strength; the difference in quantity between the tensile and shear cracks was negatively correlated with tensile bond strength and positively correlated with shear bond strength. With a tensile-shear bond strength ratio of less than 0.5, the peak strength of the rock was usually stable at the certain extreme value under a constant tensile bond strength. The tensile cracks were negatively correlated with the tensile-shear bond strength ratio, and the shear cracks were positively correlated with the tensile-shear bond strength ratio. The main failure mode of the coarse-grained sandstone in the weakly cemented stratum of the Hongqinghe coal mine is shear failure. The research results can be used to guide the ground control of other mine stopes or roadways with weak cementation lithology. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Figure 1

11 pages, 2546 KiB

Open AccessArticle

Two-Dimensional Soil Geometric Tortuosity Model Based on Porosity and Particle Arrangement

by Jin Gan, Zhiquan Yang, Zhiwei Zhang, Chaoyue Li, Yi Yang, Yingyan Zhu, Yanhui Guo, Renchao Wang, Bihua Zhang, Yingchao Fang, Dongliang Yu, Jie Zhang, Hao Liu and Jiankun Su

Minerals 2022, 12(1), 43; https://doi.org/10.3390/min12010043 - 28 Dec 2021

Cited by 1 | Viewed by 1717

Abstract

Porosity and particle arrangement are important parameters affecting soil tortuosity, so it is of great significance to determine the intrinsic relationship between them when studying soil permeability characteristics. Theoretical derivation and geometric analysis methods are used to derive a two-dimensional geometric tortuosity model. [...] Read more.

m

and

θ

) and porosity. An analysis of the model and its parameters shows that: (1) The arrangement of particles is one of the reasons for the different functional relationship between tortuosity and porosity, which proved that the tortuosity is not only related to the porosity but also affected by the particle arrangement. (2) The greater the anisotropy parameter

m

is, the greater the tortuosity is, indicating

m

varies when fluid passes through the soil from different sides resulting in different values of permeability. (3) The tortuosity increases with the increase in the blocking parameters

θ

. (4) With increasing porosity, the influence of the parameters

m

and

θ

on the tortuosity gradually decreases, suggesting that the influence of particle arrangement on tortuosity gradually decreases. The results presented here increase the understanding of the physical mechanisms controlling tortuosity and, hence, the process of fluid seepage through soil. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Figure 1

17 pages, 2972 KiB

Open AccessArticle

Penetration Grouting Mechanism of Time-Dependent Power-Law Fluid for Reinforcing Loose Gravel Soil

by Tingting Guo, Zhiwei Zhang, Zhiquan Yang, Yingyan Zhu, Yi Yang, Yanhui Guo, Renchao Wang, Bihua Zhang, Yingchao Fang, Dongliang Yu, Yapeng Mi, Jiankun Su, Hao Liu, Jie Zhang, Yongfa Guo and Honglei Wang

Minerals 2021, 11(12), 1391; https://doi.org/10.3390/min11121391 - 08 Dec 2021

Cited by 8 | Viewed by 2699

Abstract

The time-dependent behavior of power-law fluid has a significant influence on the grouting effects of reinforcing loose gravel soil. In this paper, based on basic rheological equations and the time-dependent behavior of rheological parameters (consistency coefficient and rheological index), rheological equations and penetration equations of time-dependent power-law fluid are proposed. Its penetration grouting diffusion mechanism for reinforcing loose gravel soil was then theoretically induced. A set of indoor experimental devices for simulating penetration grouting was designed to simulate the penetration grouting of power-law fluid with different time-dependent behaviors for reinforcing loose gravel soil. Then, relying on the COMSOL Multiphysics platform and Darcy’s law, three-dimensional numerical calculation programs for this mechanism were obtained using secondary-development programming technology. Thus, the numerical simulations of the penetration grouting process of power-law fluid with different time-dependent behaviors for reinforcing loose gravel soil were carried out. This theoretical mechanism was validated by comparing results from theoretical analyses, indoor experiments, and numerical simulations. Research results show that the three-dimensional numerical calculation programs can successfully simulate the penetration diffusion patterns of a time-dependent power-law fluid in loose gravel soil. The theoretical calculation values and numerical simulation values of the diffusion radius obtained from this mechanism are closer to indoor experimental values than those obtained from the penetration grouting diffusion theory of power-law fluid without considering time-dependent behavior. This mechanism can better reflect the penetration grouting diffusion laws of a power-law fluid in loose gravel soil than the theory, which can provide theoretical support and guidance for practical grouting construction. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Figure 1

20 pages, 4359 KiB

Open AccessArticle

Experimental Investigation of Porous and Mechanical Characteristics of Single-Crack Rock-like Material under Freeze-Thaw Weathering

by Songtao Yu, Yuxian Ke, Hongwei Deng, Guanglin Tian and Junren Deng

Minerals 2021, 11(12), 1318; https://doi.org/10.3390/min11121318 - 26 Nov 2021

Cited by 9 | Viewed by 1552

Abstract

Freeze-thaw weathering changes the pore structure, permeability, and groundwater transportation of rock material. Meanwhile, the change in rock material structure deduced by frost heaving deteriorates mechanical properties of rock material, leading to instability and insecurity of mine slopes in cold regions. In this paper, rock-like specimens containing prefabricated cracks at different angles and having undergone various freeze-thaw cycles are used as the object. Their pore structure, compressive mechanical properties, strain energies, failure characteristics, and the connection between pore structure and mechanical properties are analyzed. Results show that the porosity, spectrum area of mesopores, and spectrum area of macropores increase with the increase in freeze-thaw cycles, while crack angle shows no obvious influence on pore structure. Peak stress and elastic modulus drop with the increase in freeze-thaw cycles, while peak strain shows an increasing trend. Peak stress and elastic modulus decrease in the beginning, and then increase with the increase in crack angle, while peak strain shows a reverse trend. Elastic strain energy and pre-peak strain energy drop with the increase in freeze-thaw cycles. Elastic strain energy decreases first, and then increases with the increase in crack angle. The correlation between the spectrum area of macropores and elastic modulus is the strongest among different pores. Elastic modulus and peak stress decrease with the increase in macropore spectrum area, and peak strain increases with the increase in macropore spectrum area. Full article

(This article belongs to the Special Issue Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation)

► Show Figures

Journal Menu

Journal Browser

Groundwater Protection Challenges in Mine: Retention of Hazardous Substances with Solidification/Stabilization Implementation

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (9 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI