PYROPHORIC NATURE OF IRON SULFIDES

Hydrogen sulfide, often present in crude oil tankers, can react with r ust to form various sulfides including mackinawite (FeS), greigite (Fe 3S4), and pyrite (FeS2). The tendency for these compounds to react wit h oxygen in air to form potentially explosive mixtures depends upon th eir morphology and the environmental conditions. The experimentally de termined heat of size and smaller surface area the values measured wer e lower due to incomplete oxidation of the sulfide. All the sulfides p roduced, whether from magnetite or acicular, prismatic or spherical ge othite, were approximately spherical in form. The heat of oxidation of greigite was found to be approximately -2100 kJ mol(-1), and be appro ximately the heat of formation of greigite is approximately -320 kJ mo l(-1).