Restoration of plant communities on various dump substrates

The results of field studies in 2018 and 2019 at the pilot production site on the territory of the external dump “Zarechny” of JSC SUEK-Kuzbass are presented. The ecological and coenotic characteristics of plant communities formed in the areas with the filling of the fertile soil layer (FSL) (0.5 m thickness), with the application of potentially fertile rocks (PFR) (1 m thickness), in the area with the filling of technogenic eluvium, as well as in the area with the layer-by-layer filling of PFR (0.6 m thickness) and FSL (0.4 m thickness) were studied. Geobotanical descriptions were carried out according to standard methods, taking into account iterations. It is established that in the first years after the end of the formation of the pilot production site, the number of herbaceous plant species increases in all areas. However, the use of lithogenic resources in the frame of reclamation accelerates the development of plant communities on man-made landscapes, but does not allow reaching the stages of zonal formations.

Plugging slurry (backfill) and surface cavity closure technology

The purpose of the study is to study mining and environmental emergencies associated with the formation of sinkholes of the earth’s surface over mining workings after the mass closure of coal mines and to develop a new method for eliminating the sinkhole. The study used a method of physical modeling, which investigated the influence of humidity on the deformation properties of burnt rocks used as a filler in the manufacture of plugging and filling suspensions, while establishing the dependence of the relative deformation of dump rocks on the load at their natural humidity and water saturation. The main results of the research are: a new method for eliminating dips in the earth’s surface over the inclined opening workings of the liquidated coal mines of the Eastern Donbass; formulations of plugging and filling suspensions used for layer-by-layer filling of sinkholes and providing non-shrink laying.

Multiscale Study of Interactions Between Corrosion Products Layer Formed on Heritage Cu Objects and Organic Protection Treatments

In the framework of the protection of copper objects exposed to atmospheric corrosion, different solutions are envisaged, among them carboxylate treatments (HC10). In this study, an analytical approach based on complementary techniques from micrometer to nanometer scale (μRS, SEM-EDS, SAM) is used to describe the properties of the corrosion products layer (CPL) and determine the penetration depth of the HC10 protection treatment inside the CPL of copper samples issued from the roof of the Saint Martin church in Metz. The CPL consists in a thick brochantite layer (20 to 50 μm), mainly composed of Cu4SO4(OH)6, on top of a thinner (1 to 5 μm thick) cuprite layer, Cu2O, acting as a natural corrosion barrier on the metal. Application of the organic treatment is implemented by immersing the corroded samples in HC10 solution, consistent with future requirements for large scale applications. Even for short-term duration (one minute), the HC10 treatment penetrates to the cuprite/brochantite interface, but Cu(C10)2 precipitate is only detected locally, whereas for a longer immersion of thirty minutes, it is present in higher proportions in the whole brochantite layer, filling the pores, up to the cuprite/brochantite interface. Cu(C10)2 acts as a second inner barrier and prevents liquid infiltration.

Mathematical Modeling of Process of Obtaining the Solid Uranium Hexafluoride

A non-stationary mathematical model of desublimation UF6 in vertical tanks considers the movement of gaseous uranium hexafluoride contains in the article. Results of calculation of time dependence of the linear velocity desublimation, the thickness of the resulting layer of the solid phase, the temperature distribution in the tank wall - desublimation layer, filling dynamics of vertical tank B-12 by solid UF6 are presented. Calculations have shown that the 70% of B-12 tank is filled desublimation UF6 by 250 hours, which is in good agreement with the experimental data

Stipulation of Conditions of CMF with Required Allocation of Tool Materials

The existing production techniques of CMF (changeable multi-faceted plates) are not sufficient for production of tools with enhanced hardness parameters. In order to implement the production technique of composite CMF using layer by layer filling of press mold the research was conducted of the rotation speed of the press mold on the interface form of powdered materials phases. The suggested production method of composite CMF allows to enhance the hardness of cutting plates by 10–15%.