准能矸石电厂燃煤产物稀土元素分异规律及矿物特征研究Study on Differentiation and Mineral Characteristics of Rare Earth Elements in Coal Combustion Residues from Zhunneng Gangue Power Plant
黄少青,宁树正,刘大锐,刘亢,张莉
摘要(Abstract):
内蒙古准格尔煤田是煤系金属富集的典型,可以作为新的稀土元素来源,燃煤产物是煤型稀有金属提取冶炼的直接原料。运用电感耦合等离子体质谱仪(ICP-MS)、X射线衍射分析仪(XRD)、能谱扫描电镜(SEM-EDX)等对内蒙古鄂尔多斯准能矸石电厂流化床燃煤产物进行了分析测试,结果表明:(1)准能矸石电厂炉前煤稀土元素含量190.42μg/g,与世界煤相比表现为轻度富集,但在燃烧后,在粉煤灰和底灰中发生明显的分异,煤中稀土元素约80%进入粉煤灰,使得粉煤灰中稀土元素含量达到865.37μg/g,换算为稀土元素氧化物(REO)含量约为1 081μg/g,参照《稀土矿产地质勘查规范》(DZ/T 0204—2002)规定的稀土元素工业品位要求,具有开发利用价值;(2)准能矸石电厂燃煤底灰与粉煤灰中的矿物种类基本一致,仅存在含量上的差别。燃煤产物的主要组成矿物包括莫来石、石英、赤铁矿、玻璃体等。其中莫来石含量16.3%~19.8%,非晶质玻璃体含量65.7%~69.1%,粉煤灰矿物中莫来石含量与附近的国华电厂(原准格尔电厂)及其他电厂相比相对较少,而非晶态玻璃体含量较高,可能的原因是其炉前煤(黑岱沟6号煤)中主要矿物高岭土(74.7%)转化为非晶态的偏高岭土所致;(3)利用扫描电镜对粉煤灰进行了研究,整体看粉煤灰由形状、大小不规则的颗粒组成,主要成分为硅铝矿物,但基本看不到煤粉炉粉煤灰中常见的玻璃微珠,主要原因是样品所采集的流化床炉燃烧温度较低;在粉煤灰中观察到了稀土元素矿物独居石及稀土元素氟氧化合物,独居石矿物可能源于原煤,在煤炭燃烧过程中矿物结构没有发生改变,煤中的氟碳铈矿物可能在燃烧过程中结构发生了改变,形成稀土元素氟氧化合物附着于硅铝矿物边缘,粉煤灰中稀土元素的其他赋存形式可能存在于硅酸盐玻璃相中。
关键词(KeyWords): 准格尔煤田;燃煤产物;粉煤灰;稀土元素;分异规律;稀土元素矿物;独居石
基金项目(Foundation): 国家重点研发计划项目(2021YFC2902005);; 中国煤炭地质总局科技创新项目(ZMKJ-2019-J02)
作者(Author): 黄少青,宁树正,刘大锐,刘亢,张莉
参考文献(References):
- [1]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.
- [2]朱世飞,曹泊,王佟,等.广西上林县万福矿区煤中稀土元素地球化学特征[J].中国煤炭地质,2020,32(9):64-69.
- [3]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.
- [4]黄少青,张建强,张恒利.东北赋煤区煤中锗元素分布特征及富集控制因素[J].煤田地质与勘探,2018,46(3):6-10.
- [5]宁树正,黄少青,张莉,等.中国北方不同成煤时代煤中金属矿点(床)分布及资源前景[J].煤田地质与勘探,2020,48(2):42-48.
- [6]刘大锐,高桂梅,池君洲,等.准格尔煤田黑岱沟露天矿煤中稀土及微量元素的分配规律[J].地质学报,2018,92(11):2368-2375.
- [7]DAI S,SEREDIN V V,WARD C R,et al.Enrichment of U-Se-Mo-Re-V in coals preserved within marine carbonate successions:geochemical and mineralogical data from the Late Permian Guiding Coalfield,Guizhou,China[J].Mineral Deposita,2015,50(2):159-186.
- [8]KETRIS M P,YUDOVICH Y E.Estimations of Clarkes for carbonaceous biolithes:World averages for trace element contents in black shales and coals [J].International Journal of Coal Geology,2009,78(2):135-148.
- [9]全国地质矿产标准化技术委员会.稀土矿产地质勘查规范:DZ/T 0204-2002[S].北京:地质出版社,2003.
- [10]MEIJ R.Trace element behavior in coal-fired power plants[J].Fuel Processing Technology,1994,39(1):199-217.
- [11]DAI S,REN D,CHOU C,et al.Mineralogy and geochemistry of the No.6 Coal (Pennsylvanian) in the Junger Coalfield,Ordos Basin,China[J].International Journal of Coal Geology,2006,66:253-270.
- [12]赵蕾,代世峰,张勇,等.内蒙古准格尔燃煤电厂高铝粉煤灰的矿物组成与特征[J].煤炭学报,2008,33(10):1168-1172.
- [13]钱觉时,吴传明,王智.粉煤灰的矿物组成(上)[J].粉煤灰综合利用,2001(1):26-31.
- [14]刘汇东.重庆主要电厂燃煤产物的物质组成及粉煤灰的资源化利用[D].北京:中国矿业大学(北京),2015.
- [15]邵培.高铝煤与煤灰中Li-Ga-REE等多元素共生组合特征及协同分离[D].江苏徐州:中国矿业大学,2019.
- [16]黄礼煌.稀土提取技术[M],北京:冶金工业出版社,2006.
- [17]吴志颖,孙树臣,吴文远,等.氟碳铈矿焙烧过程中空气湿度对氟逸出的影响[J].稀土,2008,29(5):1-4.
- [18]杨英,孙树臣,涂赣峰,等.我国氟碳铈矿焙烧分解过程与机理研究进展[J].稀土,2014,35(4):98-102.
- [19]潘金禾.粉煤灰中稀土元素赋存机制及富集提取研究[D].江苏徐州:中国矿业大学,2021.
- [20]侯丽敏,乔超越,王甜甜,等.稀土尾矿中氟碳铈矿分解反应动力学研究[J].中国稀土学报,2022,40(3):493-499.
- [21]杨英,孙树臣,涂赣峰.氟碳铈矿分解脱氟过程研究[J].有色金属科学与工程,2021,12(4):126-132.
- [22]孙树臣,高波,吴志颖,等.氧化钙对混合稀土精矿分解气相中氟的影响[J].稀有金属,2007(3):400-403.
- [23]代世峰,任德贻,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.
- [24]SEREDIN V V,DAI S.Coal deposits as potential alternative sources for lanthanides and yttrium[J].International Journal of Coal Geology,2012,94:67-93.
- [25]CROWLEY S S,STANTON R W,RYER T A.The effects of volcanic ash on the maceral and chemical composition of the C coal bed,Emery Coal Field,Utah[J].Organic Geochemistry,1989,14:315-331.
- [26]SEREDIN V V.Rare earth elements in germanium-bearing coal seams of the Spetsugli Deposit (Primor’e Region,Russia)[J].Geology of Ore Deposits,2005,47(3):238-255.
- [27]HUANG S,NING S,ZHANG J,et al.REE characteristics of the coal in the Erlian Basin,Inner Mongolia,China,and its economic value[J].China Geology,2021(4):256-265.
- [28]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.
- [29]HOWER J C,GROPPO J G,HENKE K R,et al.Notes on the potential for the concentration of rare earthelements and yttrium in coal combustion fly ash[J].Minerals,2015,5(2):356-366.
- [30]HOWER J,GROPPO J,JOSHI P,et al.Location of cerium in coal-combustion fly ashes:Implications for recovery of lanthanides[J].Coal Combustion and Gasification Products,2003,5(1):73-78.
- [31]KOLKER A,SCOTT C,HOWER J C,et al.Distribution of rare earth elements in coal combustion fly ash,determined by SHRIMP-RG ion microprobe[J].International Journal of Coal Geology,2017,184:1-10.
- [32]DAI S,ZHAO L,HOWER J C,et al.Petrology,Mineralogy,and chemistry of size-fractioned fly ash from the Jungar Power Plant,Inner Mongolia,China,with Emphasis on the Distribution of Rare Earth Elements[J].Energy & Fuels,2014,28(2):1502-1514.