Biogenic Silica and Cherts

Stepwise fluorination. Haimson and Knanth (1983) and Matheney and Knauth (1989) noted that the first fractions of oxygen were 0-depleted compared with oxygen recovered in later fractions, snggesting that the water-rich components of hydrous silica react preferentially in the early steps of fluorination. 

High temperature carbon reduction (Lucke et al. 2005). The technique is based on indnctive high temperatnre heating ( 1,500°C ) leading to carbon monoxide. It enables complete dehydration and decomposition in a single continuous process. 

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