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Coal Geology & Exploration

Abstract

The exploitation and utilization of critical metals in coal measures is of great significance to alleviate the shortage of strategic mineral resources in China. In addition to the critical metal germanium (Ge), the low-rank coal from Wulantuga Coal Mine of Shengli Coalfield in Inner Mongolia, China is enriched with the toxic elements Be, F, As, Hg, Sb and W. Considering the extraction and utilization of key metals and environmental protection, the coal in the study area must be washed. As shown in the previous study, flotation is relatively good for the removal of As, Sb and W inWulantuga coal, but relatively poor for the removal of F and Hg. Hence, the distribution characteristics of the critical metal Ge and the toxic elements, such as Be, F, As and Hg, in different density fractions of coal were studied with the experiment and test methods, including floating-sinking experiment (the gravity separation), XRD, XRF, SEM-EDS and EMPA. The results show the following: (1) The minerals in Wulantuga coal mainly include gypsum, quartz, pyrite and kaolinite, the mineral content increases with the increasing of coal density fraction, and the Co, As, Sb and Hg occurs in pyrite according to the results of electron probe analysis. (2) After gravity separation, Ge is enriched in the low-density cleaned coal, indicating that Ge mainly exists in organic state, and Be, F, and As may be associated with the organic matter or occur in the fine grained minerals embedded in organic matter. Hg and most lithophile elements have higher concentrations in coals at higher density fractions, which indicates they occur in minerals. (3) Gravity separation is good for the removal of Hg, and flotation has a better effect for the removal of Be, F, As and some sulfurophilic or siderophile elements than gravity separation. Therefore, the gravity separation and flotation combined process is recommended for the removal of toxic elements in Wulantuga low-rank coal.

Keywords

trace element,distribution characteristic,high-germanium coal,gravity separation,Wulantuga

DOI

10.12363/issn.1001-1986.22.03.0204

Reference

[1] 代世峰,刘池洋,赵蕾,等. 煤系中战略性金属矿产资源:意义和挑战[J]. 煤炭学报,2022,47(5):1743−1749

DAI Shifeng,LIU Chiyang,ZHAO Lei,et al. Strategic metal resources in coal−bearing strata:Significance and challenges[J]. Journal of China Coal Society,2022,47(5):1743−1749

[2] 蒋少涌,温汉捷,许成,等. 关键金属元素的多圈层循环与富集机理:主要科学问题及未来研究方向[J]. 中国科学基金,2019,33(2):112−118

JIANG Shaoyong,WEN Hanjie,XU Cheng,et al. Earth sphere cycling and enrichment mechanism of critical metals:Major scientific issues for future research[J]. Bulletin of National Natural Science Foundation of China,2019,33(2):112−118

[3] 毛景文,杨宗喜,谢桂青,等. 关键矿产:国际动向与思考[J]. 矿床地质,2019,38(4):689−698

MAO Jingwen,YANG Zongxi,XIE Guiqing,et al. Critical minerals:International trends and thinking[J]. Mineral Deposits,2019,38(4):689−698

[4] 宁树正,邓小利,李聪聪,等. 中国煤中金属元素矿产资源研究现状与展望[J]. 煤炭学报,2017,42(9):2214−2225

NING Shuzheng,DENG Xiaoli,LI Congcong,et al. Research status and prospect of metal element mineral resources in China[J]. Journal of China Coal Society,2017,42(9):2214−2225

[5] 宁树正,黄少青,朱士飞,等. 中国煤中金属元素成矿区带[J]. 科学通报,2019,64(24):2501−2513

NING Shuzheng,HUANG Shaoqing,ZHU Shifei,et al. Mineralization zoning of coal−metal deposits in China[J]. Chinese Science Bulletin,2019,64(24):2501−2513

[6] 翟明国,吴福元,胡瑞忠,等. 战略性关键金属矿产资源:现状与问题[J]. 中国科学基金,2019,33(2):106−111

ZHAI Mingguo,WU Fuyuan,HU Ruizhong,et al. Critical metal mineral resources:Current research status and scientific issues[J]. Bulletin of National Natural Science Foundation of China,2019,33(2):106−111

[7] QIN Shenjun,SUN Yuzhuang,LI Yanheng,et al. Coal deposits as promising alternative sources for gallium[J]. Earth–Science Reviews,2015,150:95−101.

[8] 代世峰,赵蕾,魏强,等. 中国煤系中关键金属资源:富集类型与分布[J]. 科学通报,2020,65(33):3715−3729

DAI Shifeng,ZHAO Lei,WEI Qiang,et al. Resources of critical metals in coal–bearing sequences in China:Enrichment types and distribution[J]. Chinese Science Bulletin,2020,65(33):3715−3729

[9] 代俊峰,李增华,许德如,等. 煤型关键金属矿产研究进展[J]. 大地构造与成矿学,2021,45(5):963−982

DAI Junfeng,LI Zenghua,XU Deru,et al. Coal–hosted critical metal deposits:A review[J]. Geotectonica et Metallogenia,2021,45(5):963−982

[10] DAI Shifeng,REN Deyi,CHOU Chenlin,et al. Geochemistry of trace elements in Chinese coals:A review of abundances,genetic types,impacts on human health,and industrial utilization[J]. International Journal of Coal Geology,2012,94:3−21.

[11] DUAN Piaopiao,HAN Sijie,WANG Wenfeng,et al. Distribution and migration of trace elements during flotation in Ge−rich low−rank coal from Wulantuga Coal Mine,Inner Mongolia,China[J]. ACS Omega,2022,7(2):2023−2030.

[12] DU Gang,ZHUANG Xinguo,QUEROL X,et al. Ge distribution in the Wulantuga high−germanium coal deposit in the Shengli Coalfield,Inner Mongolia,northeastern China[J]. International Journal of Coal Geology,2009,78(1):16−26.

[13] WEI Qiang,RIMMER S M. Acid solubility and affinities of trace elements in the high–Ge coals from Wulantuga (Inner Mongolia) and Lincang (Yunnan Province),China[J]. International Journal of Coal Geology,2017,178:39−55.

[14] WEI Qiang,DAI Shifeng,LEFTICARIU L,et al. Electron probe microanalysis of major and trace elements in coals and their low–temperature ashes from the Wulantuga and Lincang Ge ore deposits,China[J]. Fuel,2018,215:1−12.

[15] 魏强,代世峰. 中国煤型锗矿床中的关键金属和有害元素:赋存特征与富集成因[J]. 煤炭学报,2020,45(1):296−303

WEI Qiang,DAI Shifeng. Critical metals and hazardous elements in the coal–hosted germanium ore deposits of China:Occurrence characteristics and enrichment causes[J]. Journal of China Coal Society,2020,45(1):296−303

[16] DAI Shifeng,FINKELMAN R B. Coal as a promising source of critical elements:Progress and future prospects[J]. International Journal of Coal Geology,2018,186:155−164.

[17] DAI Shifeng,YAN Xiaoyun,WARD C R,et al. Valuable elements in Chinese coals:A review[J]. International Geology Reviews,2018,60(5/6):590−620.

[18] DAI Shifeng,WANG Xibo,SEREDIN V V,et al. Petrology,mineralogy,and geochemistry of the Ge–rich coal from the Wulantuga Ge ore deposit,Inner Mongolia,China:New data and genetic implications[J]. International Journal of Coal Geology,2012,90/91:72−99.

[19] BELKIN H E,ZHENG Baoshan,ZHOU Daixing,et al. Chronic arsenic poisoning from domestic combustion of coal in rural China:A case study of the relationship between earth materials and human health[J]. Environmental Geochemistry,2008:401−420.

[20] CHENG Wei,ZHANG Qin,YANG Ruidong,et al. Occurrence modes and cleaning potential of sulfur and some trace elements in a high−sulfur coal from Pu’ an Coalfield,SW Guizhou,China[J]. Environmental Earth Science,2014,72:35−46.

[21] DUAN Piaopiao,WANG Wenfeng,LIU Xiaohua,et al. Distribution of As,Hg and other trace elements in different size and density fractions of the Reshuihe high−sulfur coal,Yunnan Province,China[J]. International Journal of Coal Geology,2017,173:129−141.

[22] KOLKER A,SENIOR C,ALPHEN C V,et al. Mercury and trace element distribution in density separates of a South African Highveld (#4) coal:Implications for mercury reduction and preparation of export coal[J]. International Journal of Coal Geology,2017,170:7−13.

[23] LUO Guangqian,MA Jingjing,HAN Jun,et al. Hg occurrence in coal and its removal before coal utilization[J]. Fuel,2013,104:70−76.

[24] WANG Wenfeng,QIN Yong,SANG Shuxun,et al. Partitioning of minerals and elements during preparation of Taixi coal,China[J]. Fuel,2006,85:57−67.

[25] WANG Wenfeng,QIN Yong,WEI Chongtao,et al. Partitioning of elements and macerals during preparation of Antaibao coal[J]. International Journal of Coal Geology,2006,68(3/4):223−232.

[26] WANG Wenfeng,QIN Yong,WANG Junyi,et al. Partitioning of hazardous trace elements during coal preparation[J]. Procedia Earth and Planetary Science,2009,1(1):838−844.

[27] 代世峰,任徳贻,周义平,等. 煤型稀有金属矿床:成因类型、赋存状态和利用评价[J]. 煤炭学报,2014,39(8):1707−1715

DAI Shifeng,REN Deyi,ZHOU Yiping,et al. Coal–hosted rare metal deposits:Genetic types,modes of occurrence,and utilization evaluation[J]. Journal of China Coal Society,2014,39(8):1707−1715

[28] 中华人民共和国国家质量监督检验检疫总局,中国国家标准化管理委员会. 煤炭浮沉试验方法:GB/T 478—2008[S]. 北京:中国标准出版社,2008.

[29] DAI Shifeng,WANG Xibo,ZHOU Yiping,et al. Chemical and mineralogical compositions of silicic,mafic,and alkali tonsteins in the Late Permian coals from the Songzao Coalfield,Chongqing,southwest China[J]. Chemical Geology,2011,282(1/2):29−44.

[30] American Society for Testing and Materials. Standard test method for total fluorine in coal and coke by pyrohydrolytic extraction and ion selective electrode or ion chromatograph methods:ASTM D5987—1996(2007)[S]. ASTM International,West Conshohocken,1996.

[31] Annual book of ASTM standards:ASTM D 388–99,2005[S]. Standard Classification of Coals by Rank. Gaseous Fuels:Coal and Coke. vol. 05,p. 06.

[32] 中国煤炭工业协会. 煤炭质量分级 第1部分:灰分:GB/T 15224. 1—2018[S]. 北京:中国标准出版社,2018.

[33] 中国煤炭工业协会. 煤炭质量分级 第2部分:硫分:GB/T 15224. 2—2010[S]. 北京:中国标准出版社,2010.

[34] WARD C R. Analysis and significance of mineral matter in coal seams[J]. International Journal of Coal Geology,2002,50:135−168.

[35] WARD C R. Analysis,origin and significance of mineral matter in coal:An updated review[J]. International Journal of Coal Geology,2016,165:1−27.

[36] 韩吟文,马振东,张宏飞,等. 地球化学[M]. 北京:地质出版社,2003.

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