scholarly journals Mineralogical and Geochemical Characteristics of Lithium and Rare Earth Elements in High-Sulfur Coal from the Donggou Mine, Chongqing, Southwestern China

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 627
Author(s):  
Jianhua Zou ◽  
Longfei Cheng ◽  
Yuanchen Guo ◽  
Zhengcheng Wang ◽  
Heming Tian ◽  
...  

Coal and coal by-products are considered as the potential raw materials for critical elements (e.g., rare earth elements, Li, Ga, Ge, etc.), which have attracted much attention in recent years. The purpose of this study is to investigate the mineralogical and geochemical characteristics, and controlling geological factors of lithium and rare earth elements in the Lopingian (Wujiaping Formation) coal from the Donggou Mine, southeastern Chongqing Coalfield, China. Results indicate that lithium and rare earth elements are significantly enriched in the Donggou coals, which could be new potential alternative sources for critical elements. Concentrations of lithium and rare earth elements in the Donggou coals gradually increase from top to bottom. Lithium is mainly associated with kaolinite, while rhabdophane, florencite, goyazite, and xenotime are the main hosts of rare earth elements. The controlling geological factor is the groundwater leaching of underlying tuff, and to a lesser extent, the terrigenous clastic materials input from the top layer of the Kangdian Upland. This study provides mineralization information for lithium and rare earth elements exploration in coal measures.

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 301
Author(s):  
Fuqiang Zhang ◽  
Baoqing Li ◽  
Xinguo Zhuang ◽  
Xavier Querol ◽  
Natalia Moreno ◽  
...  

The highly elevated concentrations of the rare earth elements and yttrium (REY), U, Mo, Se, and Pb in late Permian coals in some coalfields in Guangxi Province, South China, have been widely investigated; however, the mode of occurrence and enrichment mechanism of these critical elements are still under debate. This study investigates the mineralogical and geochemical compositions of coals and non-coal rocks from the Xian’an Coalfield in Guangxi Province to discuss the geological factors influencing the distribution of critical elements. The mineral in the studied coals consists mainly of quartz, and to a lesser extent, muscovite and kaolinite, with a trace amount of anatase. The coals are significantly enriched in REY, Pb, Se, Mo, and U and display the REY–U–Se–Mo–Pb-enrichment horizon (Horizon I) and U–Mo-enrichment horizon (Horizon II) adjacent to the host rocks or partings. The REY, U, Se, and Pb show organic association while Mo is primarily hosted by Fe-sulfides within Horizon I. The U and Mo have a phosphate affinity within Horizon II. Both the input of pyroclastic and epiclastic materials and the leaching of acidic solutions jointly govern the distribution of the REY–U–Se–Mo–Pb-enrichment horizon (Horizon I) and the U–Mo-enrichment horizon (Horizon II). The concentrations of REY in Horizon I exceed the cutoff grade of REY, and, therefore, the coals in the Horizon I can be regarded as promising raw materials of REY.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4710
Author(s):  
Yunhu Hu ◽  
Mu You ◽  
Guijian Liu ◽  
Zhongbing Dong ◽  
Facun Jiao ◽  
...  

Strategically critical elements are becoming significant for the rising demand of emerging energy-efficient technologies and high-tech applications. These critical elements are mostly geologically dispersed, and mainly recovered from recycled materials. Coal with high concentrations of critical elements is supposed to stable alternative sources. The abundances of critical elements in coal varies widely among different deposits and regions. The high concentrations of critical elements are found in many Chinese and Russian coal ores. The global mining potential ratio (MPR) is applied and suggests scandium, hafnium, cesium, yttrium, germanium, gallium, thallium, strontium and rare-earth elements could be potential recovery from coal. A number of benefits are expected with the extraction of critical elements during coal utilization.


2017 ◽  
Vol 114 (2) ◽  
pp. 1103-1109 ◽  
Author(s):  
Jingxi Li ◽  
Chengjun Sun ◽  
Li Zheng ◽  
Xiaofei Yin ◽  
Junhui Chen ◽  
...  

2021 ◽  
Vol 63 (4) ◽  
pp. 477-483
Author(s):  
D. A. Elatontsev ◽  
A. P. Mukhachev ◽  
Yu. F. Korovin ◽  
N. D. Voloshin

2019 ◽  
Vol 12 (1) ◽  
pp. 208 ◽  
Author(s):  
Lassi Klemettinen ◽  
Riina Aromaa ◽  
Anna Dańczak ◽  
Hugh O’Brien ◽  
Pekka Taskinen ◽  
...  

The use of rare earth elements (REEs) is increasing, mainly due to the growing demand for electric vehicles and new applications in green technology. This results in annual growth of the in-use REE stocks and the amount of End-of-Life (EoL) products containing REEs. REEs are considered critical elements by the EU, mainly because the rest of the world is dependent on China’s supply. Recycling of REEs can help alleviate the criticality of REEs, however, no REEs are currently functionally recycled. In this study, the time-dependent behavior of REEs in copper matte-slag system in primary copper smelting conditions was investigated experimentally at a laboratory scale. Lanthanum and neodymium were chosen to represent all REEs, as they are generally found in the highest concentrations in EoL products, and because REEs all have similar chemical behavior. The experiments were conducted as a function of time in air and argon atmospheres. SEM-EDS, EPMA and LA-ICP-MS methods were used for sample characterization. The results of this work indicate that the REEs strongly favor the slag and the deportment to the slag begins almost instantly when the system reaches high temperatures. With increasing contact times, the REEs distribute even more strongly into the slag phase, where they may be recovered and recycled, if their concentrations are sufficiently high and a suitable hydrometallurgical process can be found.


2018 ◽  
Vol 56 ◽  
pp. 03024
Author(s):  
Sergei Ivannikov ◽  
Evgeniy Shamrai ◽  
Andrey Taskin ◽  
Aleksandr Yudakov

The results of an investigation of ash and slag wastes (ASW) of enterprises of the energy sector of Primorsky Krai are presented. The averaged contents of the main elements and mineral complexes in Primorsky Krai are given. It is shown that the mineral composition of the ASW data makes it possible to separate the primary raw materials into fractions with different compositions. A scheme is proposed for dividing the initial ash extractors into separate mineral fractions by the particle size and by their physical properties. The predominant concentration of gold, platinum, rare earth elements (REE) and a number of other valuable components in the heavy non-magnetic fraction isolated from the primary ASW was detected. Almost complete absence of gold, noble metals and REE in underburning of coal, magnetic and micro-dispersed fractions of ASW has been demonstrated. A device was offered for complex processing of ash and slag wastes of enterprises of the power industry of Primorsky Krai, which makes it possible to divide the initial ASW into mineral fractions, being raw materials for various industries.


Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 131 ◽  
Author(s):  
Lisa Brückner ◽  
Tobias Elwert ◽  
Thomas Schirmer

Rare earth-bearing gypsum tailings from the fertilizer industry are a potential source for an economically viable and sustainable production of rare earth elements. Large quantities are generated inter alia in Catalão, Brazil, as a by-product in a fertilizer production plant. Hitherto, the gypsum has been used as soil conditioner in agriculture or was dumped. The cooperative project, “Catalão Monazite: Economical exploitation of rare earth elements from monazite-bearing secondary raw materials,” intends to extract rare earth elements from these gypsum tailings. In this paper, a chemical process route to obtain a mixed rare earth carbonate from a monazite concentrate, was investigated. The results of the digestion, leaching, and precipitation experiments are presented and discussed herein. This includes reagent choice, process parameter optimization through experimental design, mineralogical characterization of the feed material and residues, purification of the leach solution, and precipitation of the rare earth as carbonates. The results showed that a rare earth extraction of about 90% without the mobilization of key impurities is possible during a sulfuric acid digestion with two heating stages and subsequent leaching with water. In the following purification step, the remaining impurities were precipitated with ammonium solution and the rare earth elements were successfully recovered as carbonates with a mixture of ammonium solution and ammonium bicarbonate.


2019 ◽  
Vol 108 ◽  
pp. 02011
Author(s):  
Karolina Kossakowska ◽  
Katarzyna Grzesik

Rare Earth Elements (REEs) are identified as critical raw materials for the European Union economy. REEs are not currently produced in the EU, while there are several sources not properly addressed. Within the ENVIREE project tailings from New Kankberg (Sweden) and Covas (Portugal) were identified as rich in REEs and chosen for recovery processing. The Life Cycle Assessment (LCA) methodology was used to evaluate the environmental impact of REEs recovery. The aim of this study is the detailed analysis of several scenarios with different electricity production schemes of REE recovery. The study discusses the share of energy use in the overall impact on the environment, taking into account diversification in the electricity production structure among EU countries. The energy use is a significant contributor to the overall environmental impact of studied cases. Its share in the total environmental burden is reaching up to 47%. The results show that applying the average electricity scheme production for Europe may lead to biased LCA results. For the accurate LCA results the local production schemes of energy for certain countries should be chosen.


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