用XPS研究高灰熔融温度煤灰的矿物结构转化

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武成利, 王蓓蓓, 陶然, 方刘伟, 李寒旭. 用XPS研究高灰熔融温度煤灰的矿物结构转化[J]. 光谱学与光谱分析, 2018,38(7): 2296-2301.
WU Cheng-li, WANG Bei-bei, TAO Ran, FANG Liu-wei, LI Han-xu. Study of Mineral Structure Transformation of Coal Ash with High Ash Melting Temperature by XPS[J]. Spectroscopy and Spectral Analysis, 2018,38(7): 2296-2301.
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用XPS研究高灰熔融温度煤灰的矿物结构转化

武成利, 王蓓蓓, 陶然, 方刘伟, 李寒旭

安徽理工大学化学工程学院, 安徽淮南 232001

作者简介: 武成利, 1976年生, 安徽理工大学化学工程学院副教授 e-mail: chlwu2@163.com

收稿日期: 2017-08-22

基金: 国家自然科学基金项目(21376006), 安徽省科技重大专项项目(15czz02045)资助

摘要

高灰熔点X煤通过添加钙镁复配( W_CaO/ W_MgO=1)助熔剂降低灰熔点, 在模拟煤气化过程中制备灰渣, 用X射线光电子能谱(XPS)分析不同温度点灰渣中O, Si, Al, Ca, Mg的存在形态及演化过程。认为钙镁复配助熔剂降低灰熔点主要是作用在硅、铝、氧结构变化上, 表现为铝元素结构中铝氧配位方式的变化, 即四配位的铝氧四面体[AlO₄]和六配位的铝氧八面体[AlO₆]随温度的变化而变化; 硅元素结构中SiO₂链的破坏, Ca²⁺和Mg²⁺加入会破坏SiO₂链, 使得桥氧硅变为非桥氧硅; 以及氧元素结构中桥氧键断裂和非桥氧键形成。结合Factsage热力学分析软件, 分析了添加钙镁复配助熔剂后, 煤灰渣的高温相平衡组成, 从矿物的结构变化研究助熔剂的助熔机理。结果表明, 添加钙镁复配助熔剂后, Ca²⁺和Mg²⁺易与硅氧和铝氧四面体以及铝氧八面体中非桥氧键结合, 生成低熔点的长石类矿物和镁质矿物, 从而降低煤灰熔融温度。

关键词: X射线光电子能谱; 煤灰渣; 复配助熔剂; 矿物结构转化; 高温相平衡

中图分类号:TQ53 文献标志码:A

Study of Mineral Structure Transformation of Coal Ash with High Ash Melting Temperature by XPS

WU Cheng-li, WANG Bei-bei, TAO Ran, FANG Liu-wei, LI Han-xu

School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, China

Abstract

The ash melting temperature of X coal with high ash melting temperature was reduced by adding calcium-magnesium compound flux ( W_CaO/ W_MgO=1). In the process of simulated coal gasification, the ash and slag were prepared, and the existence form and evolution process of oxygen, silicon, aluminum, calcium, magnesium at different temperature were analyzed by X-ray photoelectron spectroscopy (XPS). Calcium-magnesium compound flux can reduce ash melting temperature and mainly affect structure change of silicon, aluminum and oxygen. The change of the coordination mode of aluminum and oxygen was shown, namely aluminum-oxide tetrahedrons [AlO₄] and aluminum-oxide tetrahedrons [AlO₆] varied with temperature changes. The addition of Ca²⁺ and Mg²⁺ can destroy the silica chain, making bridging oxygen silicon change into non bridge oxygen silicon; Bridged oxygen bond fracture was broken and non bridging oxygen bond was formed in oxygen element structure. Combined with the Factsage thermodynamic analysis software, the high temperature phase equilibrium composition of coal ash was analyzed after adding calcium-magnesium compound flux, and the fluxing mechanism of flux was studied from the change of mineral structure. The results showed that Ca²⁺ and Mg²⁺ were easy to combine with the non bridging oxygen bonds in the silicon-oxide and aluminum-oxide tetrahedrons and aluminum-oxide octahedrons to produce low melting temperature feldspar minerals and magnesia minerals. Therefore the ash melting temperatures were reduced.

Keyword: X-ray photoelectron spectroscopy; Coal ash and slag; Compound flux; Transformation of mineral structure; High temperature phase equilibrium

文章图片

引言

目前, 煤炭是中国最重要的一次能源^[1], 而煤气化是一种高效的洁净煤技术, 水煤浆和粉煤气化工艺均采用液态排渣技术^{[2, 3]}, 要求入炉煤的灰熔点温度小于1 400 ℃, 而中国煤炭中煤灰熔融温度FT> 1 400 ℃的煤分别占到中国煤炭年产量、保有储量的55%和57%左右^[4]。通过添加助熔剂降低煤灰熔融温度, 是一种使高灰熔点煤达到液态排渣气化用煤标准的有效方法。

国内外许多专家学者利用了不同现代分析手段, 从其表观形貌、矿物组成、键能键角等方面, 进行了添加助熔剂降低煤灰熔融温度及其机理的研究。李继炳等^[5]利用XRD研究了添加助熔剂后煤灰的矿物组成, 与硅铝酸盐矿物生成低温共熔物降低煤灰熔融温度。 Wu等^[6]研究三元及多元复杂相图与添加助熔剂后煤灰中矿物转变之间的关系。李瑞连等^[7]利用量子化学计算方法研究了高灰熔点煤添加助熔剂后, 煤气化过程中灰分矿物与助熔剂发生的作用。

X射线光电子能谱(XPS)作为一种表面分析技术, 不仅能探测表面的化学组成, 而且还可以确定各元素的化学状态, 并通过积分峰面积确定其相对百分含量, 样品无需处理等优点, 适用于研究添加助熔剂后煤气化过程中煤灰渣表面官能团特征。目前利用XPS进行研究的大多是研究煤燃烧过程中碳、氧、硫等存在形态及变化规律^{[8, 9, 10, 11]}, 对气化过程中相关元素存在形态的研究比较少。本研究利用XPS测定添加助熔剂后煤气化过程中主要元素(O, Al, Si, Ca, Mg)的存在形态及变化规律, 并结合热力学计算, 对比煤气化过程中相组成的变化, 从而确定矿物结构的变化, 为助熔剂助熔机理提供理论基础。

2 实验部分

2.1 煤样基础分析

选择X煤为原料, 考察钙镁复配助熔剂对煤灰熔融性的影响。 X煤的基础分析如表1, 其煤灰化学组成如表2。

表1 X煤的基础分析 Table 1 Basis analysis of X coal

表2 X煤灰成分分析(Wt%) Table 2 Ash composition analysis of X coal (Wt%)

由表中数据可知, X煤灰的硅铝总和(SiO₂+Al₂O₃)大于90%, 硅铝比大于为1.8, 碱性氧化物含量仅为5.64%, 故X煤的灰熔融温度较高, 不适合气化炉液态排渣, 需添加助熔剂降低灰熔点。

根据前期实验研究, 针对X煤样, 在钙镁复配为6%(W_CaO/W_MgO=1)时, 煤灰熔融温度降低最多, 助熔效果达到最佳。

从表3的煤灰特征温度可知, X煤的灰熔融温度较高, 超过1 500 ℃, 不适合气化炉液态排渣, 而添加6%(W_CaO/W_MgO=1)后流动温度为1 290 ℃, 满足液态排渣气化用煤。

表3 X煤灰特征温度 Table 3 Ash characteristic temperatures of coal samples

2.2 样品制备

采用X煤添加钙镁复配助熔剂6%(W_CaO/W_MgO=1), 用国标法烧制成灰, 结合高温管式炉模拟气化炉过程, 使用程序升温至1 500 ℃, 在CO:N₂=6:4的弱还原性气氛下, 烧制得到不同温度点(1 000, 1 200, 1 290, 1 400, 1 500 ℃)的渣样, 磨成粉末。

2.3 仪器及其参数

实验使用X射线光电子能谱仪, 美国赛默飞世尔科技, 型号为Thermo ESCALAB 250XI, 其仪器参数为: 180° 半球能量分析器; 能量范围: 0~5 000 eV; 单色Al Ka (hν =1 486.6 eV), 功率150 W; 结合能以C(1s) 284.8校准。

选用热力学软件5.1版本Equilib 模块中的FACT-SLAG数据库, 计算X煤添加钙镁复配助熔剂后的煤灰渣相平衡组成。气氛设置为弱还原性气氛CO:N₂=3:2, 换算为质量比为168:112; 体系压力为1 atm; 计算800~1 500 ℃下的高温灰渣相平衡组成。

3 结果与讨论

3.1 X煤添加6%(W_CaO/W_MgO=1)煤灰渣的XPS分析

将制备好的样品压片制样, 对不同样测试其X射线光电子能谱, 得到不同温度点的X射线光电子能谱图。用XPS4.1、 Origin8.5进行数据处理和分析, 对O(1s), Al(2p), Si(2p), Ca(2p), Mg(1s)五种元素进行分峰拟合, 选择Shirley 类型去除基线; 添加峰, 选择峰类型为p; 添加好峰后点击XPS Peak Processing中的Optimise All进行拟合, 将拟合好的数据用Origin8.5制图, 得到如下结果: 图1为X煤添加6%(W_CaO/W_MgO=1)1 000 ℃时煤灰渣的XPS分析, 表4为五种元素分峰拟合后的峰位置、半高宽、面积等。

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	图1 X煤添加6%(W_CaO/W_MgO=1)1 000 ℃渣样的XPS分析Fig.1 XPS analysis of X coal adding 6% (W_CaO/W_MgO=1) of 1 000 ℃ slag sample

表4 X煤添加6%(W_CaO/W_MgO=1) 1 000 ℃渣样的XPS分析 Table 4 XPS analysis of X coal adding 6% (W_CaO/W_MgO=1) of 1 000 ℃ slag sample

由图1和表4的数据, 对O(1s), Al(2p), Si(2p), Ca(2p), Mg(1s)五种元素的拟合结果为: 煤渣中的氧主要是无机氧, 主要形态包括非桥氧Si— O— M(其中M为金属阳离子)、桥氧Si— O— Si以及自由氧M— O— M中的氧, 对应的结合能分别是非桥氧(530± 0.5) eV、氧化铝(531.1± 0.3) eV、桥氧(531.8± 0.3) eV、氧化硅(532.65± 0.3) eV。其中结合能为(530± 0.5) eV的还有可能是Mg— O或Ca— O中的氧。通过对每个小峰的面积积分可以得到不同官能团的相对含量。

氧化铝作为一种两性氧化物, 起着连接网络生成体和网络外体之间的桥梁作用。由标准结合能表可知: 铝氧四面体[AlO₄]的结合能约为(73.8± 0.4) eV, 铝氧八面体[AlO₆]的Al(2p)结合能约为(74.5± 0.4) eV。而图1中Al(2p)的谱峰均处于(74± 1) eV之间, 说明煤灰渣中的铝都是以Al₂O₃的形式存在, 但是有两种不同的配位方式。

煤灰渣的硅主要以硅酸盐的形式存在, 而硅酸盐中硅的存在形态是桥氧硅和非桥氧硅, 其中结合能为(102.4± 0.3) eV的是Si— O, 而(103± 0.4) eV是Si— O₂; Ca(2p)电子存在Ca(2p_1/2)和Ca(2p_3/2)两个自旋分裂峰, 双峰是Ca(2p)的特征现象, 主要是Ca— O结构; Mg(1s)结合能为1 304.3 eV是Mg— O结构。

图2— 图5分别为X煤添加6%(W_CaO/W_MgO=1) 1 200, 1 290, 1 400和1 500 ℃时煤灰渣的XPS分析, 由于煤灰渣中的钙和镁以Ca— O和Mg— O单一的形式存在, 所以主要对O(1s), Al(2p), Si(2p)三种元素进行分峰拟合, 拟合结果为: O(1s)主要存在形态为非桥氧、桥氧以及自由氧(Al₂O₃和SiO₂中的氧); Al(2p)的主要存在形态为氧化铝, 有两种不同的配位方式即: 铝氧四面体和铝氧八面体; Si(2p)的XPS分析反映煤灰渣中主要是以硅酸盐的形式存在, 有Si— O和Si— O₂两种结构, 因此添加钙镁复配助熔剂后, Ca— O和Mg— O的结构无变化, 主要是影响O, Si和Al的存在形态。

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	图2 X+6%(W_CaO/W_MgO=1) 1 200 ℃煤渣的XPS拟合结果Fig.2 XPS analysis of X coal adding 6% (W_CaO/W_MgO=1) of 1 200 ℃ slag sample

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	图3 X+6%(W_CaO/W_MgO=1) 1 290 ℃煤渣的XPS拟合结果Fig.3 XPS analysis of X coal adding 6% (W_CaO/W_MgO=1) of 1 290 ℃ slag sample

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	图4 X+6%(W_CaO/W_MgO=1) 1 400 ℃煤渣的XPS拟合结果Fig.4 XPS analysis of X coal adding 6% (W_CaO/W_MgO=1) of 1 400 ℃ slag sample

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	图5 X+6%(W_CaO/W_MgO=1) 1 500 ℃煤渣的XPS拟合结果Fig.5 XPS analysis of X coal adding 6% (W_CaO/W_MgO=1) of 1 500 ℃ slag sample

表5和图6分别为XPS测得模拟气化过程煤灰渣在不同温度时元素的含量, 以及模拟气化过程中X煤灰渣含氧官能团、铝和硅不同结构的变化行为。由表5可知, 温度低于1 290 ℃时灰渣表面Al和Si的浓度随着温度的升高而增加, 此时, 铝和硅的含量达到最大, 说明在升温过程中铝和硅由物质内部向表面迁移; 1 290~1 400 ℃煤灰渣表面Al和Si的含量降低并逐渐平稳, 表明在1 290 ℃时灰渣生成了共熔物, 矿物逐渐被包裹于熔渣中, 导致表面Al和Si的含量降低, 直至平稳。钙和镁的含量相对较少, 1 000~1 500 ℃整体出现降低的趋势, 复配助熔剂中CaO和MgO会产生Ca²⁺和Mg²⁺, 高温下容易进入莫来石晶格中, 破坏莫来石的结构, 生成钙长石、镁尖晶石、镁堇青石、镁橄榄石等, 出现八元[Si/AlO₄]四面体、 [SiO₄]四面体、 [AlO₄]四面体、 [AlO₆]八面体结构。氧元素的含量较多, 占总元素组成的五分之三左右。 1 400~1 500 ℃时, 五种元素的含量基本不变, 是由于熔渣共熔体的形成。

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	图6 X+6%(W_CaO/W_MgO=1)煤灰渣中元素不同结构的含量变化Fig.6 X add 6% (W_CaO/W_MgO=1) contents changes of different structure in coal ash slag

表5 XPS测得煤灰渣元素组成 Table 5 Elements composition in coal ash slag measured by XPS

图6(a)— (c)分别是不同含氧结构(桥氧、非桥氧、自由氧)、铝氧四面体和八面体结构、硅的两种结构单元。由图6(a)可以看出非桥氧的含量低于百分之二十, 1 200 ℃之前非桥氧含量呈现降低的趋势, 在1 200~1 500 ℃时非桥氧的含量是逐步上升的, 而对应的桥氧整体呈下降趋势; 结果显示到1 500 ℃时, 非桥氧含量达到最大, 桥氧含量达到最小, 这种现象解释为: 随着温度的升高, 钙镁复配助熔剂的加入增加了非四次配位的金属阳离子, 促进了桥氧键的断裂, 非桥氧键的生成。由图6(b)可以看出在1 000~1 200 ℃时X煤灰渣中铝氧四面体的结构呈现大幅度上升, 达到一个最大值, 而相应的铝氧八面体结构达到一个最小值, 这一过程中钙长石的生成促使铝进入四配位, 形成含有Al和Si原子的[Si/AlO₄]四面体结构; 而到1 290 ℃时, [AlO₄]四面体和[AlO₆]八面体结构的含量分别达到最低和最高, 结合表5, 铝元素的含量在1 290 ℃时最高, 可以解释为[AlO₄]的电负性对网络结构的影响增大, 为了保证结构的稳定, 部分未转化为[AlO₆]。由图6(c)可知, 在1 000~1 200 ℃时, Si— O含量逐渐降低, Si— O₂含量对应增加; 而1 200~1 290 ℃时, Si— O含量逐渐增加; 当温度达到1 500 ℃时, Si— O含量达到最高, Si— O₂含量达到最低; Si— O含量的增加会促进Si— O— M的生成, 这与氧中的非桥氧和桥氧的变化相对应。

X煤添加钙镁复配助熔剂, 其中Ca²⁺和Mg²⁺会进入莫来石晶格中, 破坏莫来石的结构, 即破坏Si— O共价键, 并且Ca²⁺和Mg²⁺会与非桥氧结合生成SiO₂链, 且Ca²⁺和Mg²⁺易与生成的[AlO₄]^-, [AlO₆]^-以及[SiO₄]^-结合, 生成钙长石、镁橄榄石、镁尖晶石、镁堇青石等低熔点矿物, 从而导致煤灰熔融温度降低。

3.2 X煤添加6%(W_CaO/W_MgO=1)煤灰渣的热力学计算

图7为X煤添加6%(W_CaO/W_MgO=1)煤灰渣的高温相平衡组成, 表示随着温度的升高, 煤灰渣中各种矿物相对含量的变化; 以及煤气化过程中, 液态渣的变化过程。

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	图7 X+6%(W_CaO/W_MgO=1)煤灰渣的高温相平衡组成Fig.7 The high temperature phase equilibrium composition of X coal adding 6% (W_CaO/W_MgO=1) ash

从图中可以看出: 煤灰渣在800~1 500 ℃时, 主要由钙长石、钙黄长石、橄榄石、镁堇青石等相平衡组成。 800 ℃时, 煤灰渣中存在的主要矿物是钙长石、镁堇青石、镁橄榄石、钙黄长石、硅酸镁, 随着温度的升高, 钙黄长石、镁堇青石、橄榄石分别在1 100, 1 250和1 300 ℃后便消失不见; 在1 000~1 200 ℃时, 钙长石和镁堇青石的大量存在导致[Si/AlO₄]^-结构多, 与XPS分析结果相符, 在1 100~1 300 ℃时, 液相熔渣与镁橄榄石、钙长石、镁堇青石共存, 低温下含镁矿物镁堇青石、黄长石和橄榄石首先发生共熔; 随着温度的升高, 钙长石的含量在1 200 ℃时骤减, 而液态渣含量骤增, 主要是由于钙长石与镁橄榄石、镁堇青石等镁质矿物发生低温共熔, 这是钙镁复配在降低煤灰熔融温度方面较为显著的主要原因, 这与XPS分析X煤添加6%(W_CaO/W_MgO=1)后煤渣中矿物结构的变化相一致。

4 结论

(1)利用XPS对高灰熔点X煤添加6%(W_CaO/W_MgO=1)助熔剂后, 模拟气化炉气化过程中Al, Si, O, Ca和Mg五种元素进行研究, 煤灰渣中铝主要以Al₂O₃的形式存在, 分为[AlO₄]四面体结构和[AlO₆]八面体结构; 氧主要是以桥氧、非桥氧、自由氧三种形式存在; 硅主要以硅酸盐形式存在, 包括与桥氧链接的硅和与非桥氧链接的硅两种结构; 钙和镁主要以Ca— O和Mg— O的形式存在。

(2)钙镁复配助熔剂的加入是通过作用在铝氧四面体、铝氧八面体和硅氧四面体结构上, 促进桥氧键的断裂, Ca²⁺和Mg²⁺碱土金属离子破坏莫来石晶格, 促进SiO₂链断裂, 与非桥氧离子结合, 生成钙长石、镁橄榄石、镁尖晶石、镁堇青石等低灰熔点矿物, 容易发生低温共熔, 能够有效的降低煤灰熔融温度。

The authors have declared that no competing interests exist.

参考文献

文献列表

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[10]	MA Ling-ling, QIN Zhi-hong, ZHANG Lu, et al(马玲玲, 秦志宏, 张露, 等). Journal of Fuel Chemistry and Technology(燃料化学学报), 2014, 42(3): 277. [本文引用:1]
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2016

0.0

... 引言目前, 煤炭是中国最重要的一次能源^[1], 而煤气化是一种高效的洁净煤技术, 水煤浆和粉煤气化工艺均采用液态排渣技术^[2,3], 要求入炉煤的灰熔点温度小于1 400 ℃, 而中国煤炭中煤灰熔融温度FT#cod#x0003E ...

2016

0.0

2006

0.0

2015

0.0

Rong-sheng

, WANG

Yong-gang

, LIN

Xiong-chao

, et al(徐荣声, 王永刚, 林雄超, 等). Journal of Fuel Chemistry and Technology(燃料化学学报), 2015, (11): 1303.

In order to understand the slagging properties of blended coal, different coal blending and flux agent were added to Jincheng anthracites. The X-ray diffraction (XRD), thermodynamic software FactSage and ash fusion temperature (AFT) test were employed to analyze the ash fusion characteristics of blended coals and the mineralogical properties of the blended coal ashes. The results show that the content of ash in coal has an important role in the AFT change of blended coals. The lower the ash contained in raw coal is, the easier the AFT of blended coal lowers. The addition ratio of coal blending is 20% and 30% when the AFT decreases significantly for coal C with low ash content and G with high ash content, respectively. There is more significant fluxing effect of K on C than that on G. It is found that the feldspar mineral is formed at the deformation temperature. The decreasing in contents of mullite as well as the appreciably increasing for feldspar is the main reason for the decreasing of AFT. The thermodynamic analyses indicate that the producing of liquid matter is related to the rapidly decreasing in the contents of anorthite and quartz, as well as slowly decreasing for mullite at high temperature. The anorthite takes part in the formation of liquid matter. The fluxing effect of anorthite depends on the contents of matter which can react with anorthite to produce a melt with lower fusion point.

School of Chemical and Environmental Engineering, China University of Mining and Technology(Beijing), Beijing 100083, China

主要研究添加助熔剂或配煤降低晋城无烟煤的灰熔融温度。通过X射线衍射(XRD)、热力学计算以及灰熔点测试等手段,研究混煤灰熔融特性及其在变形温度时的矿物学特征,解析其结渣特点。结果表明,原煤灰含量越低,混煤灰熔点降低效果越明显。在配煤添加量为20%时,低灰煤C灰熔点降低趋势最明显,对于高灰煤G,则为30%;助熔剂K对C的灰熔点降低效果比对G的更明显。在混煤灰的变形温度处,出现了长石类矿物质。长石类矿物含量的上升和莫来石含量的下降促使灰熔点快速降低。热力学计算表明,高温下,煤灰中液相物质的产生伴随着钙长石和石英含量的快速下降以及莫来石含量的缓慢降低。钙长石参与了煤灰中液相物质的产生。能够与钙长石作用形成低熔点共熔体的物质的含量决定了它的助熔效果。

... 1 400 ℃的煤分别占到中国煤炭年产量、保有储量的55%和57%左右^[4] ...

2010

0.0

Ji-bing

, SHEN

Ben-xian

, ZHAO

Ji-gang

, et al(李继炳, 沈本贤, 赵基钢, 等). Journal of China Coal Society(煤炭学报), 2010, (1): 140.

The effect of flux on the melting characteristics of coal ash for the Liuqiao No.2 Coal Mine in North Anhui Province (AQ) was investigated.The change of the compositions of mineral under various temperatures with the atmosphere of N 2 and H 2 mixture before and after adding flux into AQ was analyzed by XRD.The results show that mullite formed over 1 000 ℃ has an effect on increasing the ash fusion temperature of coal,and this is the major reason which leads to high ash fusion temperature of AQ.The coal ash fusion temperature is obviously reduced by adding calciumbased flux,magnesiumbased flux and ferrumbased flux respectively.While the adding mass amount of calciumbased flux is 6.2%(coal as reference),or the adding mass amount of magnesiumbased flux is 2.8%,or the adding mass amount of ferrumbased flux is 5.6%,the ash fusion temperature( T F ) of AQ can be reduced to below 1 350 ℃to meet the requirements of the shell gasifier slagtapping process.The low temperature eutectic mixtures are easily formed between flux with aluminium silicate minerals under high temperature,which will remarkably decrease coal ash fusion temperature.

研究了钙基、镁基和铁基等3种助熔剂对皖北刘桥二矿煤（AQ）灰熔融特性的影响，在添加助熔剂前后在氢气和氮气的混合气氛下对AQ煤灰进行不同温度的热处理，对矿物组成进行了XRD分析。结果表明：导致AQ煤灰熔融温度高的主要原因是1 000 ℃以上形成的莫来石引起的；加入钙基、镁基和铁基等助熔剂均可以降低AQ煤灰的熔融温度，当钙基助熔剂的添加量达到6.2%时(以煤基计)，或镁基助熔剂的添加量达到2.8%时，或铁基助熔剂的添加量达到5.6%时，均可使AQ的煤灰流动温度降到1 350 ℃以下，满足Shell气化炉的液态排渣要求；在高温下助熔剂与煤灰中其他铝硅酸盐矿物发生反应，生成低温共熔化合物，从而使煤灰熔融温度明显下降。

... 李继炳等^[5]利用XRD研究了添加助熔剂后煤灰的矿物组成, 与硅铝酸盐矿物生成低温共熔物降低煤灰熔融温度 ...

2010

0.0

... Wu等^[6]研究三元及多元复杂相图与添加助熔剂后煤灰中矿物转变之间的关系 ...

2016

0.0

... 李瑞连等^[7]利用量子化学计算方法研究了高灰熔点煤添加助熔剂后, 煤气化过程中灰分矿物与助熔剂发生的作用 ...

2009

0.0

... 目前利用XPS进行研究的大多是研究煤燃烧过程中碳、氧、硫等存在形态及变化规律^[8,9,10,11], 对气化过程中相关元素存在形态的研究比较少 ...

2013

0.0

Mei

, YANG

Jun-he

, ZHANG

Qi-feng

, et al(李梅, 杨俊和, 张启锋, 等). Journal of Fuel Chemistry and Technology(燃料化学学报), 2013, 41(11): 1287.

X-ray photoelectron spectroscopy (XPS) was used to investigate the nitrogen and sulfur functional forms present in New Zealand coal (NXL) and its pyrolysis char prepared under argon atmosphere at 8 different temperatures between 300 and 1 000℃. The N 1 s spectra obtained were curve-resolved into 4 peaks: pyridinic-N (398.8±0.4 eV), pyrrolic-N (400.2±0.3 eV), quaternary-N (401.4±0.3 eV) and nitrogen oxides (402.9±0.5 eV); and S 2 p peaks into 6 peaks: pyrite (162.5±0.3 eV), sulphidic (163.3±0.4 eV), thiophenic (164.1±0.2 eV), sulfoxide (166.0±0.5 eV), sulfones (168.0±0.5 eV) and sulfate (169.5±0.5 eV). The results show that nitrogen present in coal in pyrrolic forms is converted into pyridinic functionalities upon heat treatment and nitrogen oxides disappeared above 900℃. The major organic sulfur form in NXL is thiophene and its content is over 50%. Pyrite is decomposed completely into troilite at 600℃.

1. School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; 2. School of Chemistry and Chemical Engineering, Beifang University of Nationalities, Yinchuan 750021, China; 3. Baoshan Iron & Steel Co., Ltd, Shanghai 201900, China; 4. School of Science, University of Shanghai for Science and Technology, Shanghai 200093, China

选择一种高硫新西兰煤(NXL)作为研究对象,高纯Ar气氛中,以5℃/min的升温速率在管式炉中热解,热解终温为300~1 000℃。用XPS研究煤及不同温度下半焦中氮、硫的赋存形态。将N 1 s 谱图用Lorentzian-Gaussian拟合分为四个峰:N-6(398.8±0.4)eV、N-5(400.2±0.3)eV、N-Q(401.4±0.3)eV和N- X (402.9±0.5)eV;S 2 p 谱图分为六个峰:硫铁矿(162.5±0.3)eV、硫化物(163.3±0. 4)eV、噻吩(164.1±0.2)eV、亚砜(166.0±0.5)eV、砜(168.0±0.5)eV和硫酸盐硫(169.5±0.5)eV。结果表明,煤中氮元素的主要存在形式是吡啶、吡咯、质子化吡啶和氮氧化物;低于600℃,半焦中的氮元素主要以吡啶和吡咯形式存在;随温度的升高,吡咯向吡啶转化;当温度超过900℃,氮氧化物这一形态消失。该煤中的硫以有机硫为主,其中,噻吩硫占50%以上;随着热解温度的升高,煤中的硫铁矿硫逐步转化为无机硫化物,600℃时分解完全。

... 目前利用XPS进行研究的大多是研究煤燃烧过程中碳、氧、硫等存在形态及变化规律^[8,9,10,11], 对气化过程中相关元素存在形态的研究比较少 ...

2014

0.0

Ling-ling

, QIN

Zhi-hong

, ZHANG

, et al(马玲玲, 秦志宏, 张露, 等). Journal of Fuel Chemistry and Technology(燃料化学学报), 2014, 42(3): 277.

By analyzing the organic sulfur content in the model compounds and the Xinyu refined coking coal, the curve fitting methods and setting parameters of XPS spectra were discussed. The results indicate that when analyzing the content of different sulfur forms in coal with XPS, the curve fitting methods of 2 p 3/2 and 2 p 1/2 splitting peaks and some other parameters are set as follows: an approximate 2:1 relative area separated by 1.18 eV with equal L-G% and FWHM level. In addition, the 2 p 3/2 peak of each organic sulfur is fixed as: mercaptan/thioether 162.1~163.6 eV, thiophene 164.0~164.4 eV, and sulfoxide 165.0~166.0 eV. Good reproducibility and fitting level are achieved when the curve fitting parameters are adjusted finely and dynamically within a certain range.

School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China

通过对含硫模型化合物和新峪焦精煤中的有机硫含量的分析，对XPS谱图的分峰拟合方法和参数设置进行了探讨。结果表明，用XPS解析煤中不同形态硫含量时，应按2 p 3/2 和2 p 1/2 劈裂峰分峰方法进行，并设置劈裂峰的面积比约为2：1，裂距为1.18 eV，L-G%相同，FWHM值也相同；限定各有机硫2 p 3/2 峰峰位分别为：硫醇硫醚类硫162.1~163.6 eV；噻吩类硫164.0~164.4 eV；亚砜类硫165.0~166.0 eV，同时对分峰拟合参数在一定范围内进行动态微调，可实现良好的数据重现性和较佳的拟合度。

... 目前利用XPS进行研究的大多是研究煤燃烧过程中碳、氧、硫等存在形态及变化规律^[8,9,10,11], 对气化过程中相关元素存在形态的研究比较少 ...

2016

0.0

ZHANG

Lan-jun

, LI

Zeng-hua

, YANG

Yong-liang

, et al(张兰君, 李增华, 杨永良, 等). Safety in Coal Mines(煤矿安全), 2016, 47(5): 85.

We use XPS technology to research Xinchen fat coal low temperature oxidation experiment. The XPS results of sulfur on the coal surface before and after oxidation show that the sulfide and pyrite content is highest for raw coal sample; thiophenic sulfur content is the highest in organic sulfur, followed by sulfoxide and sulfone; there is also some sulfate existing on the coal surface. The result of oxidized coal is different from raw sample; the relative contents of thiophenic sulfur is reduced; the sulfide oxide into sulfoxide which further oxidized to sulfone, that is the reason why sulfone relative concentration increased meanwhile sulfoxide disappeared. The nitrogen spectrogram of raw coal analysis shows that the nitrogen mainly exists on the edge of coal molecules; about 21% of nitrogen is embedded into coal molecular structure in the quaternary nitrogen form; the pyrrole nitrogen content is the highest. The XPS results of oxidation sample show that the oxygen atom linked to nitrogen removal in the process of oxidation; the oxidation nitrogen changes into other forms and most parts of it change into pyridine.

利用XPS测试技术对兴成肥煤低温氧化规律进行实验研究。硫元素XPS氧化前后测试结果对比分析表明原煤硫元素中硫化物硫和硫铁矿硫占比最高，而有机硫中噻吩硫含量最高，其次为砜和亚砜。氧化后煤表面噻吩硫相对含量降低，有机硫中的部分硫化物硫氧化成亚砜，亚砜进一步氧化成砜，导致砜相对浓度增加，而亚砜缺失。原煤氮元素谱图分析可知兴成煤中氮主要存在于煤分子的边缘，约21%氮以季氮形式镶嵌于煤分子芳香结构中，煤中吡咯氮含量最高。氧化后XPS结果表明在氧化过程中与氮相连的氧原子脱除，氧化型氮转变为其他形态，且很大一部分转化为吡啶。

... 目前利用XPS进行研究的大多是研究煤燃烧过程中碳、氧、硫等存在形态及变化规律^[8,9,10,11], 对气化过程中相关元素存在形态的研究比较少 ...