The influence of the internal structure and dispersity to structural-mechanical properties of oil systems

Some oils and oil products are dispersed systems with composite internal organization. The dynamical model of dispersed particle, named complex structural unit (CSU), with complicated internal structure is suggested. A nucleus surrounded by solvate shell contains high-molecular mass components of different natures. Sizes of nuclei and solvate shells change in accordance with the magnitude of external influence. An optimal correlation between parameters of CSU and the value of external factor can be fixed for every technological process. The results of determination of the dispersity degree in oil systems are presented. Connection of nonmonotonous extremal dependence macroscopic parameters (viscosity, stability, etc.) and microscopic ones (particle sizes) with external influence value changing is shown. These regularities are basic for the intensification of technological processes. Technology is tested in practice with good results. For managing structural-mechanical properties, the addition of heavy residue, containing significant amount of resin-asphaltene substances (RAS), has been chosen together with thermal treatment and regulation of speed of cooling. Speed of cooling determines sizes and number of interacting particles. Connections between particles could be realized through the solvate shells formed from RAS or directly with each other. Finally, the structure of coalescence or condensation type is formed. These kinds of structures differ in their structural-mechanical properties. Such oil compositions are basis for specific products, which are used in mining industry for dust depressing and preventing adherence of granular materials to the walls of transportation equipment. The optimal combination of influencing of external factors gives an opportunity to include bigger amount of heavy residues for decreasing the cost. (C) 2000 Elsevier Science B.V. All rights reserved.