A new method for testing the self-heating character of sulphide concentrates

A rapid, inexpensive, and quantitative method has been developed to quantify the self-heating potential of sulphide concentrates. The method consists of measuring the sulphur dioxide evolved when a concentrate is heated and oxidized in air at 300 °C. Sulphur dioxide is the reaction product of the oxidation of elemental sulphur present in the concentrate. We found a strong correlation between the output of the sulphur method (i.e. the elemental sulphur grade) and the output of the United Nations self-heating protocol (i.e. the temperature rise). Both methods provide evidence of the extent of prior oxidation of the sulphide concentrate, but do not inform about the rate at which the concentrate was oxidized.