AN ANALYSIS OF THE INFLUENCE OF CARBON NANOPARTICLES ADDITIVE ON SELECTED PROPERTIES OF LUBRICATING OILS

This paper presents the results of an analysis of the influence of the addition of various types of carbon nanoparticles on selected essential physical and operational properties of lubricating oils. Two selected oils, i.e. the mineral base oil without additives and the typical marine lubricating circulating oil Marinol RG 1240, were modified with the addition of shungite nanoparticles, graphite nanotubes, and C60 fullerenes. The mass fraction of modifiers was 0.2% wt for each of the additives. As part of the experimental tests, measurements were made of the impact of the above-mentioned modifiers on the change in the value of the ignition temperature of oils, the effect on the changes in the value of the dynamic viscosity coefficient in the aspect of changes of temperature and shear rate, as well as the impact on the changes in the friction coefficient and the size of the wear size scar. These tests were carried out on an EraFlash automatic apparatus for determining ignition temperature using the closed cup method, with a Haake Mars III research rheometer, and a T-02U tribometer with a four-ball head.

ANALYSIS OF GRAPHITE MINERAL-ROW MATERIAL BASE OF THE UKRAINIAN SHIELD USING ECONOMIC METHODS

The analysis of the mineral base of graphite of the Ukrainian shield with the use of geological and economic eassessment methods was carried out. Directions of the rational development are outlined. The main problems of sustainable development of graphite mineral raw-material base in modern conditions are determined. Geological and technological factors of economic value of graphite deposits and occurrences are characterized. A scheme of comparative assessment estimation of graphite deposits was proposed. This scheme allows to establish the most promising objects for further exploration in the initial stages of mineral deposits prospecting. The analysis includes the main geological, economic, technological and industrial factors of economic value of graphite deposits, such as reserves / resources, graphite content in ores, depth of ores, exploration degree and complexity of the deposit and others. The following methods were used in the work: the method of rapid assessment of the minerals value for determining the potential economic value of objects and the method of scoring. At the first stage, the deposits and occurrences included in the state balance, were ranked according to geological and industrial parameters. Each of the parameters rated according to its qualitative characteristics. The number of points obtained for graphite deposits with proven development efficiency (Burtynske, Balakhivske) and the developed field (Zavalivske) were used as optimal indicators. According to them, the most promising for further exploration works graphite occurrences with the best geological and industrial indicators were selected. The commodity value of these deposits was calculated using the method of coefficients. The results of the calculation were also taken into account for determining the most promising deposits for investment. According to the obtained data, a map of potentially promising graphite deposits of the Ukrainian shield was constracted.

Main nonfuel mineral exploration results in 2020 and planned activities for 2021

The most significant aspects of nonfuel mineral base reproduction in the period under review are characterized.

Interactive map of knowledge as an opportunity to unify all types of geological research

The paper addresses the issues of qualitative improvement of information systems which support subsurface use, monitoring, and control of the Russian mineral base through the development of information technologies. Based on material processing, contained in the registration cards of geological studies, in which the main geological study data are summarized, a model of an interactive study map is proposed. The proposed interactive map of verified materials provides a great opportunity for creating a catalog of works, as well as compiling specialized maps and cartograms to reflect the geological study of any given territory.

Examination of lubricity properties of mineral base oil, containing nanoparticles of hexagonal boron nitride, and evaluation of the influence of surfactants on their sedimentation

The article presents the results of tests on the lubricity properties of SN150 base oil containing hexagonal boron nitride (h-BN) of different granulation. The boron nitride with a particle size below 100 nm and the second one with a particle size below 25 μm were used. The lubricity tests were carried out on a four-ball apparatus. The methodology of these tests was determined on the basis of the normative document PN-EN ISO 20623: 2018-02, which contains the following parameters characterising the lubricity: initial seizure load ISL [N], weld load WL [N], load-wear index LWI [N], mean wear scar diameter MWSD [mm] obtained in a long duration wear test under a specified load; wear-load curve, i.e., the dependence of the mean wear scar diameter on the load, was also performed. Tests were also carried out to check the influence of selected surfactants on the sedimentation process of hexagonal boron nitride in the SN150 mineral base oil. Based on the conducted research and their analysis, it was found that hexagonal boron nitride has a positive effect on the lubricating properties of the base oil; better results were obtained for the boron nano-nitride with a particle size below 100 nm. It was also found that the problem of sedimentation of the solid particles of hexagonal boron nitride was solved by the addition of succinimide dispersant. Keywords: tribology, lubricity, boron nitride, surfactants, sedimentation

RESEARCH THERMODYNAMICS OF VISCOUS FLOW OF BASE OILS THAT ARE THE BASIS FOR LUBRICANT COMPOSITIONS

The thermodynamic characteristics of the process of viscous flow of mineral base lubricating oils (SGK grade AU, naphthenic T-110) and synthetic (Synfluid PAO 6 cSt) were found. It was found that the activation energy and the change in the activation entropy of the viscous flow of mineral oils, considered trade marks, are higher than that of synthetic oil. The obtained thermodynamic data made it possible to establish the mechanism of the flow of lubricating oils.

Influencia mineragráfica en la recuperación de oro en los procesos metalúrgicos de la Minera Qero´s Gold de Paucartambo- Cusco

Los estudios mineragráficos permitieron seleccionar el proceso metalúrgico más adecuado para una óptima recuperación de oro, cuya caracterización tanto microscópica y macroscópica, permitió experimentar pruebas metalúrgicas en moliendabilidad, cianuración en botellas, concentración centrífuga, flotación rougher. Como resultado de estas pruebas metalúrgicas en el mineral base permitió una recuperación del 94.48% en flotación selectiva con una mezcla (blending) de 36% de veta Inkaracay y 64% de veta mina Sanca 2.

Chemical Characterization Using Different Analytical Techniques to Understand Processes: The Case of the Paraffinic Base Oil Production Line

Mineral base oils are used to produce commercial lubricants and are obtained from refining vacuum residue. Lubricants are used to reduce friction in industry devices, so their viscosity is a key characteristic that needs to be optimized throughout the process. The purpose of this study is to show how global chemical characterization of samples from the base oil production chain can facilitate a better understanding of the molecular impacts of processing and their effect on macroscopic properties like viscosity. Eight different samples were characterized by different analytical techniques, including liquid chromatography and mass spectrometry techniques, to understand their chemical evolution through the different process units at the molecular level. Furthermore, a statistical treatment allowed for the identification of parameters that influence viscosity, mainly sulfur and polyaromatics content. This study demonstrates the importance and effectiveness of cross-checking results from different complementary analytical techniques to acquire valuable data on lubricating oil base samples.

Polyacrylate-magnetite nanocomposite as a potential multifunctional additive for lube oil

The application of polymer nanocomposites (PNCs) in lubricant industry has attracted considerable interest due to their much enhanced properties compared to neat polymers. In this study, magnetite (Fe3O4) nanoparticles (NPs) were synthesized. Then PNCs were prepared by reinforcing these NPs in the homopolymer of dodecyl acrylate in different percentages. The characterization of the prepared NPs and PNCs was done by different analytical techniques. Thermal stability is determined through thermogravimetric analysis (TGA). Performance evaluation of the PNCs as viscosity index improver, pour point depressant and antiwear additive was carried out by blending them with a mineral base stock at different percentage ratios. Standard ASTM methods are followed to carry out the evaluations. It is found that with increasing the percentage of nanocomposites in the base stock, the overall performance of the furnished lubricant is enhanced.