Determination of the mineral-matter contents of coals by low-temperature ashing

✍ Scribed by Robert N. Miller; Richard F. Yarzab; Peter H. Given

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 832 KB
• Volume: 58
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(79)90044-9

✦ Synopsis

A new method is described for determining the mineral-matter content of coals, based on low-temperature ashing in an oxygen plasma. Unwanted side-reactions can occur during ashing, particularly oxidation of pyrite to haematite and fixation of organic sulphur as sulphate. These effects cannot be totally eliminated, but procedures are offered that minimize them, and are presented as accurate and rapid means of determining the mineral-matter content of bituminous coals. Data are presented to illustrate the magnitude of the effects under the recommended conditions of ashing. Duplicate determinations of the mineral-matter contents of 13 coals by acid demineralization and low-temperature ashing are reported in support of the new procedures. Statistical analysis of the data shows that the precision (*2 standard deviations) of the LTA procedure under the defined conditions is 0.20. Acceptance of the procedure is suggested for routine use with most coals of bituminous or anthracite rank. The procedure as proposed is unsuitable for use with HVC coals from Western provinces of the USA or with lignites and subbituminous coals.