A study on the effect of silica nanoparticles (SNPs) dispersion in bitumen is herein reported. First, the size of the nanoparticles was finely tuned by controlling the experimental conditions during their synthesis, obtaining spherical SNPs with diameter ranging from 95 up to 900 nm. Subsequently, SNPs were embedded with peripheral amine groups by using APTES (3-aminopropyltriethoxysilane) as functionalized agent (NH2@SNP), and ultimately long alkyl chains were grafted by reacting the free amine with an alkylated aldehyde (C14N@SNP). All SNPs (ca. 1 wt%.) were dispersed in bitumen to probe their effect on the rheological properties of bitumen. No significant change in the thermorheological properties of bitumen was observed upon varying the size of the SNPs. Slight improvement was observed when using NH2@SNPs, while the best results were obtained by using C14N@SNPs, showing the crucial role that hydrophobic substituents play in bitumen binders which leads to significant improvements.

This paper considers the effect of aging processes on viscoelastic characteristics of vacuum residue oxidation products modified with crumb rubber. Viscoelastic properties were compared to original bitumen raw material-vacuum residue and vacuum residue oxidation products during short-term and long-term aging. The complex shear modulus of the vacuum residue and its oxidation products decreased with an increase in temperature. Short-term aging resulted in increased shear modulus for all samples.The vacuum residue oxidation product modified with crumb rubber had the maximum values of the rutting parameter and fatigue parameter. There was an expansion of the temperature range of plasticity: for the vacuum residue oxidation product with crumb rubber, its value was 67.2 °C. The curves of the black diagram of the modified vacuum residue oxidation product are shifted towards smaller phase angles with the increase in the shear modulus, which indicates the increase in the stiffness and elasticity of the rubber bitumen binders. The vacuum residue oxidation product modified with crumb rubber corresponded to the rubber bitumen binder of the grade RBB 60/90, according to its physical and mechanical indicators.

Аннотация. В работе изучено влияние механохимической активации на элементный состав шунгитовых пород месторождения Коксу. Использование наноструктурированного порошка шунгита в сорбентах может привести к улучшению их сорбционных свойств. В результате механохимической активации в образцах шунгитовых пород карбонатного и сланцевого происхождения уменьшается массовая доля углерода, массовая доля кремния увеличивается. В составе пород также увеличивается содержание кислорода, алюминия и железа, что способствует улучшению сорбционных свойств шунгита. Снижение скорости вращения шаров приводит к незначительному изменению содержания элементов, наблюдается уменьшение содержания углерода, кислорода и натрия, а содержание кремния, алюминия, железа и калия увеличивается. Увеличение соотношения массы образца и массы шаров с 1:1 до 1:3 при скорости измельчения 400 об/мин не привело к значительным изменениям содержания элементов.

The actual problem of the oil refining industry is to improve the process of oxidation of heavy oil residues and the properties of oil bitumen. One way to solve the problem is to add modifiers. The addition of modifiers leads to an intensification of the oxidation process and an increase in the characteristics of the bituminous binders. The work aims to study the effect of adding rubber crumb on the process of vacuum residue oxidation and the properties of the obtained rubber-bitumen binders (RBB). The influence of the size of crumb rubber and its content, the mixing stage and oxidation modes on the properties of rubber-bitumen binders are determined. Vacuum residue from the Omsk oil refinery was used as a raw material, which was modified with crumb rubber with a dispersion of 0.6‒1.0 mm and less than 0.6 mm. The novelty of the research is the addition of crumb rubber to the vacuum residue and the oxidation process to obtain bitumen. The product of vacuum residue oxidation for 2 h at 260 °С with preliminary mixing of 2 wt.% crumb rubber with particle sizes less than 0.6 mm at 180 °С and additional mixing of 8 wt.% crumb rubber after oxidation corresponds to the brand of rubber-bitumen binder RBB 60/90. The rubber-bitumen binder is characterized by high elasticity and low Fraas point. Рrepared аsphalt concrete mixture based on RBB corresponded to type B according to physical and mechanical parameters. The complex shear modulus of the samples decreases with the temperature increase. Short-term aging resulted in increased shear modulus for all samples.

In this study, we aimed to select the optimal solvents for the removal of asphaltene–resin–paraffin deposits. The effectiveness of various solvents was determined based on the asphaltene–resin–paraffin deposits (ARPDs) of the Zhanaozen (Ozen) crude oil field. These deposits affect the geological, physical, and technological conditions of the oil field, thus influencing its development. According to the results, we found that the most effective composite solvent is a composition comprising a 50% gasoline fraction and a 50% kerosene fraction. This composition showed mass loss of deposits of 97.7% and a dissolving power of 93.5 g/cm3 after 5 h. We confirmed the effectiveness of this composition by the paraffinic type of the deposits, which is explained by the high content of paraffin in the oil from the Zhanaozen field. Aromatic solvents showed a relatively low dissolving power compared with aliphatic solvents, which also confirms the low content of resins and asphaltenes in the ARPD.