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

作　　者：黄少青 宁树正 刘大锐 刘亢 张莉 HUANG Shaoqing;NING Shuzheng;LIU Darui;LIU Kang;ZHANG Li(General Prospecting Institute,CNACG,Beijing 100039;State Energy Zhunneng Resources Comprehensive Development Co.,Ltd.,Ordos,Inner Mongolia 017100)

机构地区：[1]中国煤炭地质总局勘查研究总院,北京100039 [2]国能准能资源综合开发有限公司,内蒙古鄂尔多斯017100

出　　处：《中国煤炭地质》2023年第2期22-27,共6页Coal Geology of China

基　　金：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)。

摘　　要：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。Jungar coalfield in Inner Mongolia is a typical case of metal enrichment in coal measures,which can be used as a new source of rare earth elements,coal combustion residues are the direct raw materials for extraction and smelting of coal-type metals.Coal residues from vulcanizing bed combustion of Ordos Zhunneng gangue power plant in Inner Mongolia were analyzed and tested by means of inductively coupled plasma mass spectrometry(ICP-MS),X-ray diffraction analyzer(XRD),scanning electron microscopy(SEM-EDX) and other instruments,the results show that:(1)The content of rare earth elements in stokehold feed coal in Zhunneng gangue power plant is 190.42 μg/g,compared with world coal,it is slightly enriched,however,after combustion,there are obvious differences between fly ash and bottom ash,there are about 80% of the rare earth elements in coal go into fly ash,it makes the content of rare earth elements in fly ash reach to 865.37 μg/g,when it is converted into rare earth oxide(REO),the content of it is about 1 081 μg/g,according to the industrial grade requirements of China's Rare earth Geological Exploration Code(DZ/T 0204—2002),it is valuable for development and utilization.(2)The mineral types of coal bottom ash and fly ash in Zhunneng gangue power plant are basically the same,but there is only a difference in content.The main minerals of coal combustion residues include mullite,quartz,hematite,vitreous and so on.Thereinto,the content of mullite is 16.3% to19.8%,the content of amorphous vitreous is 65.7% ~ 69.1%,the mullite content in fly ash minerals is relatively low compared with the nearby Guohua Power Plant( former Jungar Power Plant) and other power plants,but the content of amorphous vitreous is higher,the possible reason is that the main mineral kaolin( 74.7%) in the stokehold feed coal( Heidaigou coal No.6) is transformed into amorphous metakaolin.(3)The fly ash was studied by means of scanning electron microscope,on the whole,fly ash is composed of irregular shape and size particles,its main compositi

关 键 词：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 

分 类 号：P618.11[天文地球—矿床学]