Determination of the Settling Rate of Aggregates Using the Ultrasound Method during Paraffinic Froth Treatment

摘要

This paper presents results of a study on the settling rate of aggregates formed during paraffinic treatment of bitumen froth. Experiments were performed at temperatures ranging from 30 to 90 degrees C and various solvent/bitumen ratios, using n-pentane, isopentane, and n-hexane as paraffinic solvents. Characteristic settling curves of diluted bitumen froth were obtained by two independent methods: visual observation and an ultrasound technique. The ultrasound study showed that the hindered settling zone interface can be accurately tracked in place using an ultrasound velocity profiler. Problems associated with determining the settling rate by fitting a linear function to the initial part of the settling curve of the upper interface at higher temperatures were avoided by applying the so-called lower interface method. Settling rates determined using the upper and lower interface methods showed good agreement, confirming interchangeability of the methods.