Method for quantifying the pyritic sulfur and the organic sulfur of a rock sample

A method for quantifying pyritic sulfur in a sedimentary rock sample, comprising:

• A. heating the sample in an inert atmosphere, between a first temperature ranging between 100° C. and 320° C. and a second temperature ranging between 600° C. and 700° C., to produce effluents by following a first temperature gradient ranging between 1° C./min and 30° C./min;
• B. continuously oxidizing at least part of the effluents obtained from heating the sample in an inert atmosphere and continuously measuring a first amount of SO2 released as a function of time of the heating in an inert atmosphere, and determining at least a pyrolysis sulfur content from a area under a curve of the measured first amount of SO2 released as a function of time and a pyrolysis pyritic sulfur content SPyrolPyrit from a area under a last peak of the curve of the measured first amount of SO2 released as a function of time;
• C. heating in an oxidizing atmosphere a residue of the sample resulting from the heating in the inert atmosphere between a third temperature ranging between 280° C. and 320° C. and a fourth temperature at least equal to 800° C., by following a second temperature gradient ranging between 1° C./min and 30° C./min;
• D. continuously measuring a second amount of SO2 released as a function of time of the heating in the oxidizing atmosphere and determining at least an oxidation sulfur content from a area under a curve of the measured second amount of SO2 released as a function of time and determining at least a total sulfur content STotal by a sum of the pyrolysis sulfur content and the oxidation sulfur content;
• and
• wherein at least a pyritic sulfur content SPyrit of the sample is determined from a formula:
• SPyrit=p(α,α,γ)·SPyrolPyrit, wherein
• p(α, β, γ) is a weighting function depending on a parameter α which represents a proportion of the pyrolysis pyritic sulfur relative to the total sulfur, parameter β which represents an effect of a mineral matrix of the sedimentary rock sample on the proportion, parameter γ which represents an effect of organic matrix of the sedimentary rock sample on the proportion with values of the parameters being predetermined.