Study on the infiltration mechanism of injecting chelating agent into deep low permeable coal seam

Rare earth elements (REE) are necessary for advanced technological and energy applications. To support the emerging need, it is necessary to identify new domestic sources of REE and technologies to separate and recover saleable REE product in a safe and economical manner. Underclay rock associated with Central Appalachian coal seams and prevalent in coal utilization waste products is an alternative source of REE to hard rock ores that are mainly composed of highly refractory REE-bearing minerals. This study utilizes a suite of analytical techniques and benchtop leaching tests to characterize the properties and leachability of the coal seam underclays sampled. Laboratory bench-top and flow-through reactor leaching experiments were conducted on underclay rock powders to produce a pregnant leach solution (PLS) that has relatively low concentrations of gangue elements Al, Si, Fe, and Th and is amenable to further processing steps to recover and produce purified REE product. The leaching method described here uses a chelating agent, the citrate anion, to solubilize elements that are adsorbed, or weakly bonded to the surface of clay minerals or other mineral solid phases in the rock. The citrate PLS produced from leaching specific underclay powders contains relatively higher concentrations of REE and lower concentrations of gangue elements compared to PLS produced from sequential digestion using ammonium sulfate and mineral acids. Citrate solution leaching of underclay produces a PLS with lower concentrations of gangue elements and higher concentrations of REE than achieved with hydrochloric acid or sulfuric acid. The results provide a preliminary assessment of the types of REE-bearing minerals and potential leachability of coal seam underclays from the Central Appalachian basin.

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Experimental research on increasing effect of water injection in coal seam with chelating agent

Energy Sources Part A Recovery Utilization and Environmental Effects ◽

10.1080/15567036.2019.1682723 ◽

2019 ◽

pp. 1-11

Author(s):

Lianman Xu ◽

Kaixuan Lu ◽

Yishan Pan ◽

Xiangfeng Lv

Keyword(s):

Coal Seam ◽

Experimental Research ◽

Water Injection ◽

Chelating Agent ◽

Effect Of Water

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Study on the Influence of Bedrock Thickness on Deformation and Failure of Overlying Soil Layer in Thin Bedrock Coal Seam Mining

Физико-технические проблемы разработки полезных ископаемых ◽

10.15372/ftprpi20200403 ◽

2020 ◽

Keyword(s):

Coal Seam ◽

Soil Layer ◽

Deformation And Failure ◽

Thin Bedrock ◽

Seam Mining

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Forecast of Methane Emission on the Working Face at Coal Seam Mining

Occupational Safety in Industry ◽

10.24000/0409-2961-2017-6-31-35 ◽

2017 ◽

Vol 6 ◽

pp. 31-35

Author(s):

V.S. Zaburdayev ◽

Keyword(s):

Coal Seam ◽

Methane Emission ◽

Working Face ◽

Seam Mining

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Phosphorus minerals in tonstein; coal seam 405 at Sośnica-Makoszowy coal mine, Upper Silesia, southern Poland

Acta Geologica Polonica ◽

10.2478/agp-2013-0012 ◽

2013 ◽

Vol 63 (2) ◽

pp. 271-281 ◽

Cited By ~ 5

Author(s):

Magdalena Kokowska-Pawłowska ◽

Jacek Nowak

Keyword(s):

Trace Elements ◽

Coal Seam ◽

Mineral Composition ◽

Coal Mine ◽

Chemical Compositions ◽

Coal Basin ◽

Upper Silesia ◽

Southern Poland ◽

Basin Area

Abstract Kokowska-Pawłowska, M. and Nowak, J. 2013. Phosphorus minerals in tonstein; coal seam 405 at Sośnica- Makoszowy coal mine, Upper Silesia, southern Poland. Acta Geologica Polonica, 63 (2), 271-281. Warszawa. The paper presents results of research on tonstein, which constitutes an interburden in coal seam 405 at the Sośnica- Makoszowy coal mine, Makoszowy field (mining level 600 m), Upper Silesia, southern Poland. The mineral and chemical compositions of the tonstein differ from the typical compositions described earlier for tonsteins from Upper Silesia Coal Basin area. Additionally, minerals present in the tonsteins include kaolinite, quartz, kaolinitised biotite and feldspars. The presence of the phosphatic minerals apatite and goyazite has been recognized. The presence of gorceixite and crandallite is also possible. The contents of CaO (5.66 wt%) and P2O5 (6.2 wt%) are remarkably high. Analysis of selected trace elements demonstrated high contents of Sr (4937 ppm) and Ba (4300 ppm), related to the phosphatic minerals. On the basis of mineral composition the tonstein has been identified as a crystalline tonstein, transitional to a multiplied one.

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