Development of graphite-like particles from the high temperature treatment of carbonized anthracites
Development of graphite-like particles from the high temperature treatment of carbonized anthracites
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DOI：
10.1016/j.coal.2010.11.007
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发表时间：
2011-02
影响因子：
5.6
通讯作者：
S. Rodrigues;I. Suárez‐Ruiz;M. Marques;D. Flores;I. Cameán;A. García
中科院分区：
文献类型：
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作者：
S. Rodrigues;I. Suárez‐Ruiz;M. Marques;D. Flores;I. Cameán;A. García
本研究的目的是对无烟煤高温处理（HTT）过程中形成的颗粒进行光学和结构（显微拉曼光谱和X射线衍射）表征。将来自Peñarroya-Belmez-Espiel盆地（PBEB，西班牙）（Rr=2.62%）和Douro盆地（DB，葡萄牙）（Rr=6.25%）的两种不同等级的无烟煤在氮气流下在管式炉中在1000 ℃下煅烧，然后在石墨炉中在2000 ℃和2500 ℃的温度下处理。在这些高温下处理后，所获得的残余物显示出各种石墨结构，即薄片、微球和结晶聚集体，其百分比取决于前体（无烟煤）的类型和温度。这些结构是从致密颗粒中生长出来的，致密颗粒是所研究样品的主要成分。薄片、微球和结晶聚集体在2000°C下形成并获得其性质，并且随着温度的升高而发生微小变化。此外，这些结构表现出与石墨边缘平面相似的特性。两种样品的致密颗粒显示出随着温度的升高其微观结构的改善。这种改进在来自于C40 DB无烟煤的致密颗粒中更大。事实上，在2500°C下，这些致密颗粒显示出与天然石墨相似的光学和结构特性。这是没有发现的情况下，致密的颗粒，从无烟煤的PBEB。这些观察结果也得到了X射线衍射参数的支持，这些参数赋予了2500°C下的C4 H2 DB样品的最高结晶度。
The aim of this study is the optical and structural (micro-Raman spectroscopy and X-ray diffraction) characterization of particles formed during the high temperature treatment (HTT) of anthracites. Two anthracites of different rank, from the Peñarroya–Belmez–Espiel Basin (PBEB, Spain) (Rr=2.62%), and the Douro Basin (DB, Portugal) (Rr=6.25%), were carbonized at 1000°C in a tube furnace, under nitrogen flow, and then treated at temperatures of 2000°C and 2500°C, in a graphite furnace. After treatment at these high temperatures, the residues obtained show various graphite structures, namely, flakes, microspheres and crystalline aggregates, in percentages that depend on type of the precursor (carbonized anthracite) and temperature. These structures grow from the dense particles, which are the major component of the studied samples. Flakes, microspheres and crystalline aggregates develop and acquire their properties at 2000°C, and minor changes occurring with the rise in temperature. Moreover, theses structures exhibit similar characteristics to those of graphite edge planes. Dense particles from both samples show an improvement in their microstructure with the rise in temperature. This improvement is greater in dense particles from the carbonized DB anthracite. In fact at 2500°C these dense particles show optical and structural properties similar to those found in natural graphite. This was not found in the case of dense particles from the carbonized PBEB anthracite. These observations are also supported by the X-ray diffraction parameters which confer the highest degree of crystallinity for the carbonized DB sample at 2500°C.