NATURE OF POROSITY IN AMERICAN COALS
NATURE OF POROSITY IN AMERICAN COALS
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DOI：
10.1016/0016-2361(72)90003-8
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发表时间：
1972-01-01
期刊：
影响因子：
7.4
通讯作者：
NANDI, SP
中科院分区：
文献类型：
--
作者：
GAN, H;WALKER, PL;NANDI, SP
使用以下表征技术研究了许多40 × 70（即-40 +70）目大小的美国煤（从无烟煤到褐煤）的孔隙度性质：气体吸附、氦和汞置换以及汞孔隙度测定法。在298 K下从二氧化碳吸附计算的表面积始终高于在77 K下从氮气计算的表面积，表明煤的分子筛性质。在直径范围12-29 600 μ m内测量了总孔体积，然后将其分为大孔（300-29 600 μ m）、过渡孔（12-300 μ m）和微孔（4-12 μ m）。煤的总孔隙体积变化很大（孔隙率在4.1%和23.2%之间）。在低阶煤（碳含量小于75%）中，孔隙度主要是由于大孔隙的存在。在具有76- 84%范围内的碳含量的煤中，总开孔体积的约80%是由于微孔和过渡孔，而在较高碳含量的煤中微孔占主导地位。具有约35-55%的其总开孔体积在过渡范围内的煤预期最适合用于从溶液中吸附有机分子。因此，它们作为用于水净化的可能材料是令人感兴趣的。一般来说，这些结果被认为是重要的，在理解的程度和速率的相互作用的煤与气体和液体。
The nature of the porosity in a number of 40 × 70 (i.e. − 40 + 70) mesh size American coals, varying in rank from anthracite to lignite, has been studied using the following characterization techniques: gas adsorption, helium and mercury displacement, and mercury porosimetry. Surface areas calculated from carbon dioxide adsorption at 298 K are consistently higher than those calculated from nitrogen at 77 K, indicating the molecular sieve character of the coals. Total pore volumes have been measured in the diameter range 12–29 600 Å and then divided into macropores (300-29 600 Å), transitional pores (12–300 Å), and micropores (4–12 Å). Coals vary widely in their total pore volumes (porosities range between 4.1 and 23.2%). In the lower-rank coals (carbon content less than 75%), porosity is primarily due to the presence of macropores. In coals having a carbon content in the range 76–84%, about 80% of the total open pore volume is due to micro and transitional pores, whereas in the coals of higher carbon content microporosity predominates. Coals having about 35–55% of their total open pore volume in the transitional range are expected to be most suitable for use for adsorption of organic molecules from solution. Thus, they are of interest as possible materials to be used in water purification. In general, these results are considered to be of importance in understanding the extent and rate of interaction of coals with gases and liquids.