Vol 486, No 1 (2019)

In this work, the results of interpreting the variation of the magnetic signal of iron-rich marine sedimentary rocks were presented by the example of the Cretaceous–Paleogene section of the Bakchar iron ore deposit (Western Siberia). The anomalous values of the magnetic susceptibility are determined by two factors: first, a superimposed diagenetic process accompanied by the formation of pyrrhotite, greigite, and siderite among ooidal ironstones; and second, an increase in the continental runoff, causing the accumulation of terrigenous magnetite and ilmenite in the siltstone as the climate becomes increasingly humid and the weathering intensifies. It was shown that the elevated values of the magnetic susceptibility in iron-rich deposits can be due to the formation of ferrimagnetic iron sulfides, which is indicative of methane mobilization through ancient bottom sediments.

A one-step selective method for the synthesis of exo isomers of silicon-containing norbornenes by hydrosilylation of norbornadiene-2,5 with non-activated silanes in the presence of a Pd catalyst and bulky ligands has been developed. This approach leads to the formation of exo isomers only. The absence of stages of alkylation with organometallic reagents and photochemical rearrangement makes this approach attractive for directed design and synthesis of new polymeric materials showing required properties.

Compositions Li(Ni_0.33Mn_0.33Co_0.33)_1 – xFe_xO₂ (0 ≤ х ≤ 1) of the LiNiO₂–LiMnO₂–LiCoO₂–LiFeO₂ concentration tetrahedron have been studied. Samples were synthesized by gel combustion with starch, which afforded, for the first time, the impurity-free stable solid solution LiNi_0.2Mn_0.2Co_0.2Fe_0.4O₂ with an α-NaFeO₂ layered structure used as a cathode matrix of lithium-ion batteries. Electrochemical testing of homogeneous LiNi_0.2Mn_0.2Co_0.2Fe_0.4O₂ and the LiNi_0.3Mn_0.3Co_0.3Fe_0.1O₂ sample with the lowest iron content has been carried out. The results expand the understanding of the possibility of saturation with iron of Li(Ni,Mn,Co)O₂ with an α-NaFeO₂ structure and indicate the feasibility of further studying the homogeneity volume and properties of the Li(Ni,Mn,Co,Fe)O₂ solid solution.

A rapid heuristic computational algorithm for optimizing the energy and resource efficiency of a local process of multistage drying of a moving mass of phosphorite pellets was developed. The algorithm is distinguished by the use of heuristic computational procedures and heuristic rules of the iterative construction of a vector criterion of the efficiency of the chemical and energy engineering system. The criterion takes into account the energy consumption cost and the pellet quality indicators using both special barrier functions for deterministic constraints on control process variables (feed velocity and temperature of the carrier gas), and penalty functions for state variables of a local drying process (temperature gradient, heating rate, moisture content, moisture-transfer rate in pellets, temperature of the carrier gas at the outlet of the vertical multilayer pellet packing). Using the developed algorithm and software package, the scientifically grounded, optimal in energy consumption and dried pellet quality, operating conditions in local zones of drying of a travelling grate machine were determined.