Quantitative risk assessment of thermal hazardous reactions with case study

Abstract

Thermal hazards constitute menace to the exploration, processing and their allied industries. This work presents quantitative risk assessment of these thermal hazards via a simplified model, probability and severity determination with quantitative risk and proposed risk ranking for thermal runaway reactions using a case study of self-heating mineral ores. -- A number of sulphide-containing mineral ores supplied by Vale Inco from Reid deposit were already investigated for self-heating thermal hazardous behaviour on the effect of mineralogy, particle size distribution and moisture contents using combined state-of-the-art instruments like Mineral Liberation Analysis, Thermal Gravimetric Analysis and Differential Scanning Calorimetry. The obtained results are then analyzed using AKTS software with the final data used for the risk assessment by first validating the developed kinetic model. -- A continuous probability function, Gaussian probability distribution, is used to determine the associated chances of occurrence of the thermal hazards having fitted the representative data of thermal hazards into continuous distribution using Matlab. The probability of the hazards is determined under seven major classes of activation energy and Arrhenius’ constant. -- Similarly, severity of the defined thermal hazards is evaluated using the ratio of enthalpy of reaction of the ore under specific investigated effect to a referenced thermally hazardous material under four major categories of low, medium, high and extremely high risk classes using well-studies referenced materials. The associated risks are then determined as product of probability and consequences. -- Finally, the numerical values of the associated risks are evaluated for consistency on a predefined scale with the risk ranked and coded by means of colour legend. The associated risk with these mineral ores is found to be of medium class category and can be managed effectively. Recommendations are made for further work on the subject and approach for improvements.