Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
3.9
2.5
Journals
Minerals
Special Issues
Trace Elements in Coal-Based Resources: Occurrence, Enrichment and Recovery
share announcement

Trace Elements in Coal-Based Resources: Occurrence, Enrichment and Recovery

A special issue of Minerals (ISSN 2075-163X). This special issue belongs to the section "Mineral Processing and Extractive Metallurgy".

Deadline for manuscript submissions: closed (31 August 2023) | Viewed by 8343

Special Issue Editors

Dr. Jinhe Pan

E-Mail Website
Guest Editor
School of Chemical Engineering and Technology (SCET), China University of Mining and Technology (CUMT), Xuzhou, China
Interests: mineral processing; trace element occurrence; hydrometallurgy; critical raw materials; utilization of coal combustion waste
Special Issues, Collections and Topics in MDPI journals
Dr. Wencai Zhang

E-Mail Website
Guest Editor
Department of Mining and Minerals Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
Interests: mineral processing; extractive metallurgy; critical elements recovery
Special Issues, Collections and Topics in MDPI journals
Dr. Wei Cheng

E-Mail Website
Guest Editor
National & Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas, Guizhou Key Laboratory of Comprehensive Utilization of Non-metallic Mineral Resources, College of Materials and Metallurgy, Guizhou University, Guizhou 550025, China
Interests: trace element geochemistry; mineral processing; utilization of solid waste

Special Issue Information

Dear Colleagues

Trace elements, an associated matter of coal utilization, have been of interest for nearly a century. Their unique properties decide their applications as geochemistry indictors for coal origin, history and coalification. The large-scale and extensive use of coal over the past 50 years has given rise to environmental concerns regarding the discharge of trace elements, especially toxic ones. Over the last 30 years, trace elements, particularly critical ones, have gained considerable attention from researchers, companies and governments due to the extending gap between market demands and their traditional supplies.

Trace elements in coal at specifical locations are enriched in considerable amounts, with the potential to be considered for industrial recovery. However, their recovery is hindered by the presence of heavy stones or challenges from occurrence modes, separation and enrichment, extraction technologies and environmental concerns. Thus, scientific researchers have been encouraged by the utilization of trace elements in coal-based resources to explore their migration and occurrence, reveal their mechanisms of enrichment and extraction and the development of novel techniques for their recovery. The evaluation of a trace element’s value in coal is also welcome, due to the limitation of a low content and noticeable costs.

The Special Issue aims to offer a platform for discussions regarding recent progress in the extraction of trace elements in coal-based resources. Research papers or reviews concerning materials (coal, shale, refuse, ash, mine drainage, etc.) and interests (characterization, process, remediation, recovery, the evaluation of environment/economic factors, etc.) are encouraged. Three field have been organized for convenience and understanding.

Section 1: The occurrence modes of trace elements in coal-based resources: studies regarding the occurrence modes of both valuable and toxic trace elements in coal-based resources, the transformation of trace elements during the combustion, conversion and weathering of coal-based resources and their environmental effects and changes in the occurrence modes of trace elements during enrichment and recovery.

Section 2: The enrichment of trace elements in coal-based resources: studies regarding the enrichment of trace elements in coal-based resources using physical and/or physicochemical methods, such as gravity, adsorption and froth flotation separations.

Section 3: The recovery of trace elements from coal-based resources: studies regarding the recovery of trace elements from coal-based resources using chemical methods and the production of high-purity trace element products from coal-based resources.

Dr. Jinhe Pan
Dr. Wencai Zhang
Dr. Wei Cheng
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

  • coal-based resources
  • geochemical characteristic
  • modes of occurrence
  • critical metals recovery
  • enrichment/beneficiation
  • hydrometallurgy
  • environment concern

Published Papers (4 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

24 pages, 5768 KiB  
Article
Distribution of Se in Floating Coals with Densimetric Fractions in China
by Guchun Zhang, Qiyan Feng, Heng Zhao, Na Zhang, Meng Wu, Xiaoqing Wang, Mingzhong Wen, Yexin Deng and Zhao Yang
Minerals 2023, 13(3), 396; https://doi.org/10.3390/min13030396 - 13 Mar 2023
Cited by 1 | Viewed by 1150
Abstract
Scholars at home and abroad have studied the concentrations of Se in coal and the relationship between Se and sulfur assignment. However, little attention has been paid to the study of Se in floating coal, especially the distribution pattern of Se in floating [...] Read more.
Scholars at home and abroad have studied the concentrations of Se in coal and the relationship between Se and sulfur assignment. However, little attention has been paid to the study of Se in floating coal, especially the distribution pattern of Se in floating coal of densimetric fractions and the influencing factors. A total of 138 coal samples were collected from 14 provinces and cities in China to test the Se and sulfur concentrations in coal, and we carried out the comparison of Se with forms of sulfur with 81 of them. A total of 10 coal samples were selected for float-and-sink analyses to investigate the distribution pattern of Se in floating coal. The results showed that the average Se concentration of Chinese coal was 2.26 μg/g, which is identical with the results of previous research studies, which found an average Se concentration of 2~3 μg/g. Selenium was not uniformly distributed in floating coals of densimetric fractions but it had some regularity. The main controlling factor was the sulfur content in the coal. The Se concentrations of the high-sulfur coal showed a “linear growth” distribution with an increasing density, the Se concentrations of the floating coal in each densimetric fraction increased slowly and the Se concentrations of the floating coal of a densimetric fraction > 2.00 g/cm3 increased sharply. The other controlling factor was the ash yield of the coal. The Se concentrations of the low–medium-sulfur floating coal showed a “parabolic-like” distribution, i.e., low Se concentrations at both ends and high Se concentrations at the middle densimetric fraction. With the increase in the ash content of the coal from 18.23% to 51.92%, the densimetric fraction with the highest Se concentration gradually progressed from 1.40 g/cm3 to 1.50 g/cm3, 1.60 g/cm3 and 1.80 g/cm3 in order. The correlation between the selenium of the raw coal from different regions and the total sulfur, pyrite sulfur and organic sulfur was not significant. However, there existed a significant correlation between Se, total sulfur, pyrite sulfur and organic sulfur in floating coals from the same mining area and depositional environment, among which pyrite sulfur was the most correlated with Se, followed by total sulfur and organic sulfur. Full article
(This article belongs to the Special Issue Trace Elements in Coal-Based Resources: Occurrence, Enrichment and Recovery)
►▼ Show Figures

Figure 1

13 pages, 2665 KiB  
Article
Study on Solvent Extraction of Rare Earth Elements from Leaching Solution of Coal Fly Ash by P204
by Jinhe Pan, Xindi Zhao, Changchun Zhou, Fan Yang and Wanshun Ji
Minerals 2022, 12(12), 1547; https://doi.org/10.3390/min12121547 - 30 Nov 2022
Cited by 7 | Viewed by 2312
Abstract
Due to the increasing demand for rare earth elements (REE) resources in the market and the shortage of their direct sources, the research on REE in coal fly ash (CFA) has attracted the increasing attention of scholars because of its high content of [...] Read more.
Due to the increasing demand for rare earth elements (REE) resources in the market and the shortage of their direct sources, the research on REE in coal fly ash (CFA) has attracted the increasing attention of scholars because of its high content of rare earth. To extract and separate REE from the leaching solution of CFA, the method of solvent extraction after acid leaching is usually adopted. In this paper, the leaching solution of coal fly ash from Panbei, south China, with an average REE content of 478 μg/g, was taken as the research object. The extracted di-2-Ethylhexyl phosphonic acid (P204) was used to explore the solvent extraction effect and mechanism. When performed with the conditions: pH value of 2.1, oil-water ratio (O/A) of 1, extraction time of 25 min, solvent concentration of 6% and temperature of 30 ℃, the extraction rates of La, Ce, Pr, Nd, and Y were 89.16%, 94.11%, 95.56%, 96.33%, and 99.80%, respectively. It was indicated that the P204 extraction system separated REE well from the aqueous phase. The structure of the extraction complex was deduced by taking yttrium as an object of analysis, and the extraction mechanism equation was determined by using the slope method. In this extraction system, the molecular formula of the complex is YCl2(HA2) and the enthalpy change (△H) is +86.68 kJ/mol, which provides theoretical guidance for the extraction of REE in industrial production. Full article
(This article belongs to the Special Issue Trace Elements in Coal-Based Resources: Occurrence, Enrichment and Recovery)
►▼ Show Figures

Figure 1

17 pages, 3581 KiB  
Article
The Effect of Physical Separation and Calcination on Enrichment and Recovery of Critical Elements from Coal Gangue
by Lei Zhang, Hangchao Chen, Jinhe Pan, Zhiping Wen, Shulan Shi, Xin Long and Changchun Zhou
Minerals 2022, 12(11), 1371; https://doi.org/10.3390/min12111371 - 28 Oct 2022
Cited by 5 | Viewed by 1735
Abstract
Critical metallic elements in coal gangue have great utilization potential, especially due to the current shortage of these metals. This paper focused on examining the feasibility of physical separation (screening and float-sink tests) and calcination treatment for the enrichment of critical elements (Li, [...] Read more.
Critical metallic elements in coal gangue have great utilization potential, especially due to the current shortage of these metals. This paper focused on examining the feasibility of physical separation (screening and float-sink tests) and calcination treatment for the enrichment of critical elements (Li, Ga, and rare earth elements plus yttrium (REY)) from coal gangue. The impacts of these enrichment methods on the acid leaching recovery of these elements were then studied. Screening tests indicated that Li and Ga were enriched in >0.125 mm size fraction and the content of REY was highest in <75 μm size fraction. Float-sink tests showed that high-density fractions were enriched in Li and Ga, and low-density fractions were enriched in REY. Physical separation cannot significantly improve the leaching rate of Li, Ga, and REY. Notably, Li, Ga, and REY were enriched significantly, and their acid leaching recoveries were increased by 54~68% after calcination under 400 °C. Sequential chemical extraction tests showed that the majority of insoluble Li, Ga, and REY was converted into soluble forms at the above temperature, which is attributed to the formation of amorphous metakaolinite and the decomposition of organic matter. Based on the results, a conceptually combined flowsheet was proposed for the extraction of Li and Ga from coal gangue. Full article
(This article belongs to the Special Issue Trace Elements in Coal-Based Resources: Occurrence, Enrichment and Recovery)
►▼ Show Figures

Figure 1

14 pages, 15450 KiB  
Article
Distribution and Speciation of Rare Earth Elements in Coal Fly Ash from the Qianxi Power Plant, Guizhou Province, Southwest China
by Lun Wu, Liqiang Ma, Gen Huang, Jihui Li and Hongxiang Xu
Minerals 2022, 12(9), 1089; https://doi.org/10.3390/min12091089 - 28 Aug 2022
Cited by 8 | Viewed by 2179
Abstract
Coal fly ash (CFA), hazardous to the environment and human health, has been considered to be a potential alternative source for rare earth elements (REEs) in recent years. However, information on how REEs distribute and occur in coal fly ash is still incomplete. [...] Read more.
Coal fly ash (CFA), hazardous to the environment and human health, has been considered to be a potential alternative source for rare earth elements (REEs) in recent years. However, information on how REEs distribute and occur in coal fly ash is still incomplete. In this work, particle size analysis, inductively coupled plasma–mass spectrometry, scanning electron microscopy, and electron probe microanalysis were applied to study the occurrence and distribution of REEs in a fly ash sample from the Qianxi coal-fired power plant in Guizhou province. The results show that the REEs content in the CFA was 630.51 ppm. Wet grinding-enhanced leaching experiments revealed that a part of the rare earth particles was encapsulated within the glass body. These rare earth particles could be liberated and released to a certain extent by wet grinding, which would increase the acid-leaching recovery of REEs from 23.49% to 41.68%. This study classifies the speciation of REEs in coal fly ash as (1) amorphous glassy particles with REE minerals or compounds encapsulated inside; (2) amorphous glassy particles with REEs distributed throughout; and (3) discrete REE minerals or compounds. The results of this study are a basis for developing an economically viable and environmentally sustainable technology for recovering REEs from CFA. Full article
(This article belongs to the Special Issue Trace Elements in Coal-Based Resources: Occurrence, Enrichment and Recovery)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-4
Back to TopTop