Factors affecting the equilibrium moisture contents of low-rank coals

✍ Scribed by H.N.S. Schafer

• Publisher: Elsevier Science
• Year: 1972
• Tongue: English
• Weight: 737 KB
• Volume: 51
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(72)90029-4

✦ Synopsis

The equilibrium moisture contents of various low-rank coals have been determined at a constant humidity and have been related to the carboxyl and phenolic hydroxyl contents.

The equilibrium moisture showed a highly significant correlation with the carboxyl group content, but the correlation with the phenolic group content was less significant. An equation relating moisture and acid group contents has been calculated. A study was also made of the moisture content of various salt-form coals, prepared from a Yallourn brown coal. It was found that the equilibrium moisture contents of salt-form coals are higher than those for the acid-form coals and depend on the type and amount of cation present; i.e. the equilibrium moisture contents, under similar conditions, vary with the cation in the order Fe* > Mg* > Ca++ > Cu++ > Ba* > Al-x Fe* x Na+ > K+. (This corresponds approximately to the degree of hydration of the cation in aqueous solution.) ' ' _ ,