A pyrohydrolytic method for the determination of low fluorine concentrations in coal and minerals

✍ Scribed by K.J. Doolan

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 928 KB
• Volume: 202
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)85902-4

✦ Synopsis

Techniques are described for the pyrohydrolysis of a range of sample materials in a silica tube furnace. Samples are mixed with a catalyst and combusted at 1200°C in a stream of oxygen and steam, and the liberated fluorine is absorbed in solutions appropriate to either ion-selective electrode or ion-chromatographic measurement. Catalyst composition, furnace temperature, and gas flow rates are particular variables discussed with respect to recovery of fluorine at concentrations up to about 5% (w/w). Recovery and precision are favourable compared with those obtained by the alternative peroxide fusion and oxygen bomb combustion methods for coal analyses. Relative standard deviation is less than 0.05 for most samples. Results agree with certified values of available reference materials including ores and rocks, while new data are provided for several noncertified reference materials.