Moisture in coal: 1. Differentiation between forms of moisture by n.m.r. and microwave attenuation techniques

✍ Scribed by John F. Unsworth; Colin S. Fowler; Nigel A. Heard; Vincent L. Weldon; Vincent J. McBrierty

• Book ID: 103091109
• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 943 KB
• Volume: 67
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(88)90379-1

✦ Synopsis

Microwave attenuation, and both pulsed and continuous wave nuclear magnetic resonance techniques have been used to examine the complex behaviour of water in a range of coals, as a function of temperature and water content. The results support the view that there is a range of heterogeneous water sites and environments in coal. Evidence is shown of tightly bound water exhibiting glass-like character at low temperatures (x -8O"C), more loosely bound water exhibiting unusually complex behaviour between -20°C and 0°C and essentially bulk-like water in samples with high water content. There is efficient chemical exchange between sites. It is shown that continuous wave n.m.r. line-width measurements provide a rapid and reasonably accurate method of determining the inherent moisture content in wet coal samples.