Graphitic residue

Table 4. Analysis of Graphite Residues From Principal Sources...

Fig. 3.38 Typical graphitic residue, containing graphite flakes and some unattacked phosphide eutectic...

The presence of active sulphate-reducing bacteria usually results in graphitic corrosion and this has led to a useful method of diagnosing this cause of corrosion. The leaching out of iron from the graphitic residue which is responsible for the characteristic appearance of this type of corrosion leads to an enriched carbon, silicon and phosphorus content in the residue as compared with the original content of these elements in the cast iron. Sulphur is usually lost to some extent but when active sulphate-reducing bacteria are present, this loss is offset by the accumulation of ferrous sulphide in the residue with a consequent increase in the sulphur content of the residue out... 

Destroy the Zn(Ag)-graphite residues by slowly passing THT/isopropanol (1 1) (technical grade) (20 mL) through the funnel. 

Graphite residue compound 16.4.2.7.1, Reaction with S2O5F2 16,4,2.1.2... 

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