Pyrohydrolysis for the rapid determination of small and large amounts of fluorine in fluorides, silicate minerals and rocks using an ion-selective electrode.

Pyrohydrolytic-ion chromatographic determination of fluorine, chlorine, and sulfur in geological samples

“…Tin alone oxidized too rapidly to be an effective accelerator. Other workers have postulated that metal fluorides are hydrolyzed to HF (19), or in the presence of silicon to H2SiF6 (13), in a pyrohydrolytic system, and pH studies of our trapping solution indicate that at least some of the fluorine in our system is being trapped in an acidic form. While some of the other combinations reached higher maximum temperatures, only the Fe-Sn mixtures were able to consistently maintain temperatures greater than 1000 °C for a full 20-min burn.…”

Hydropyrolytic-ion chromatography determination of fluoride in coal and geological materials

“…In a hydropyrolytic system, metal fluorides are thought to react with silica and water to form volatile H2SiF6 (19). Si02 has been added to geological samples to promote this reaction (20).…”