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Transportation and refining of heavy metal-bearing oil are associated with the problems of localized destruction of metal structures and elements due to corrosion. In the process of equipment operation, it was revealed that premature failure of steel coils of heating tube furnaces at oil refineries and petrochemical plants was associated with insufficient strength and corrosion resistance of the steelwork. The study of the effect that structure and phase composition of 15KH5M-alloy steel elements of heating furnaces at oil refineries have on the corrosion properties, associated with mass loss and localized destructions in the process of heat treatment, allows to develop protective measures and determine heating modes with a rate-limiting step of oxidation. The rate of various corrosion types of 15KH5M steel is used as an indicator to assess the effectiveness of the applied modes of coil heat treatment in order to increase their corrosion resistance and improve their operational characteristics. Conducted experiments on heat treatment of certain steel coil sections allowed to determine rational heating modes for the studied coils, which made it possible to reduce their mass loss and increase corrosion resistance of working surfaces in the process of operation. Proposed heat treatment of steel coils at specified intervals of their operation in the tube furnaces creates conditions for their stable performance and affects the degree of industrial and environmental safety, as well as reduces material costs associated with the repair and replacement of individual assemblies and parts of tube furnaces.

Earlier, the authors had already successfully proposed a method for extracting minerals from crude oil as a first step, to be further developed in this second step in the direction of obtaining solid (metallic and / or oxide) phases of nickel and vanadium. The scientific, practical and strategic importance of the work is clearly-underlined with a general depletion of vanadium and nickel ores. In the current situation of mineral resources with a general depletion of vanadium and nickel ores, it becomes necessary to search for new and alternative resources to obtain these strategic and important metals and their compounds from available resources. Taking into account that vanadium and nickel ores are practically absent in the raw material resources base of some countries, such as Middle East's countries. Thus, a high percentage of imports of this metal product remains, which worsens the economic situation that has developed during political conflicts. The scientific approach was based on a combination of hydrometallurgical and electrometallurgical experiments, consistently carried out through the processes of sorption and desorption during cathodic electrodeposition. Sorption processes for vanadium and nickel were carried out using a mixture of Syrian sorbing materials (incense-type resins and surface-activated natural clays) with finely ground glass SiO 2 . Cathodic electrodeposition experiments were carried out on a copper cathode plate, and on the other hand, an insoluble glassy carbon electrode was used as the anode. All batch experiments were carried out to determine the best conditions for vanadium and nickel sorption by studying six different parameters affecting the sorption capacity of vanadium and nickel. As a result, the maximum sorption capacity of vanadium and nickel was 87.5 % and 91.3 % consistently under the predetermined conditions. Eventually, 7.6 % Ni (with a purity of 97 %) was recovered from the solution after the desorption process by the electrolytic method (during electrolysis); 15.6 % (99.3 % pure) V 2 O 5 and 11.5 % (79 % pure) NiO chemically.

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The presence of precious metals in electronic waste such as gold, silver, platinum and palladium, as well as non-ferrous metals (copper, nickel, zinc, tin, etc.) make it attractive for recycling. In industry, both hydrometallurgical and pyrometallurgical methods are used to extract valuable metals from electronic waste. Universal method for processing of electronic scrap waste does not exist nowadays.