Some physical and chemical characteristics of hexa(thiocyanate-N)chromate complexes of cerium lanthanides with 3-pyridine-3-carboxylic acid are studied. It was shown by IR spectroscopy that the compounds are N-thiocyanate, the organic ligand is bidentate. It was established by X-ray diffraction analysis that substances have an isle structure, crystallize acoording the same structural type, and their crystallographic parameters change regularly in accordance with the change in the radii of Ln3+ ions. The compositions of the substances differ only in the content of crystallization water in the molecules. The magnetic characteristics and thermal behavior of substances in an inert atmosphere and oxidizing atmospheres are presented.

New compounds (HOOC(CH2)5NH3)2SiF6 (1) and [Cu(Cpl)2(H2O)2SiF6]·2Cpl (2), where Cpl = ε-caprolactam ε-C6H11NO and (HOOC(CH2)5NH3)+ is the 5-carboxypentylammonium ion, were prepared from aqueous solutions and characterized by chemical analysis, IR spectroscopy, and single-crystal X-ray diffraction. In the structure of compound 1, the coordination surrounding of a Si atom is a nearly regular octahedron. The crystals of 1 are triclinic, space group P 1 . The caprolactam is hydrated and protonated upon crystallization. Hydrogen bonds F…Н–N between SiF_6^2 - anions and organic cations and acidic hydrogen bonds between the carboxy groups of cations were found to exist in the structure of 1. Compound 2 crystallizes in triclinic crystal system, space group P 1 , and has a chain-polymeric structure. The coordination polyhedra of the two unique copper ions are tetragonally distorted octahedra formed by the O atoms of two Cpl molecules and two F atoms of the hexafluorosilicate ions, which perform as bridges between nearest neighboring cations. The coordination surrounding around a Si atom is a slightly distorted octahedron. Hydrogen bonds between the H atoms of coordinated water molecules and the O atoms of uncoordinated Cpl molecules exist in the structure. The hexafluorosilicate ions in the structures of 1 and 2 have identical geometries.

Synthesis conditions were developed, new compounds of compositions (HOOC(CH2)5NH3)2SiF6 (1) and [Cu(Cpl)2(H2O)2SiF6]·2Cpl (2), where (Cpl – ɛ-caprolactam, ɛ-C6H11NO, (HOOC(CH2)5NH3)+ – cation 5-carboxypentylammonium) were obtained from aqueous solutions and studied by chemical, IR spectroscopic and X-ray diffraction analyses. In the structure of compound 1, the coordination environment of the Si atom is an almost regular octahedron. Crystals are triclinic sistem, space group P1¯. During crystallization, caprolactam undergoes a hydration reaction and protonation. In structure 1, hydrogen bonds F...H–N were found between anions and organic cations, as well as “acidic” hydrogen bonds between carboxyl groups of cations. Compound 2 crystallizes in the triclinic system, space group P1¯ and has a polymer chain structure. The coordination polyhedron of two independent copper cations is a tetragonally distorted octahedron formed by the O atoms of two Cpl molecules and two F atoms of hexafluorosilicate anions acting as bridges between neighboring cations. The coordination environment of the Si atom is a slightly distorted octahedron. The structure contains hydrogen bonds between the H atoms of coordinated water molecules and the O atoms of uncoordinated Cpl molecules. The geometry of hexafluorosilicate anions in structures 1 and 2 is identical.

The coal waste from power stations in the north and south of the Kuznetsk Basin are compared in terms of their suitability for concrete production and as a source of valuable components. The mean aggregate content of rare and rare-earth metals in ash and slag waste in the Kemerovo region is 0.02–0.04%; the content of matrix elements is up to 65%. Such waste is promising for the extraction of matrix, rare, and rare-earth metals.

During their operation, thermal power plants (TPP) produce a huge amount of ash and slag waste, which pollutes the environment. The present paper considers the dumps of the Kemerovskaya State District Power Plant in terms of mineral deposits located on the surface. Dump samples of various ages were analyzed for the content of matrix and microcomponents. Based on the performed analysis, measures for the comprehensive separation of valuable components from waste are proposed.

Double complexes [Ln(DMSO)8][Cr(NCS)6], where Ln = Nd (1), Eu (2), Gd (3), Dy(4), Ho (5), Lu (6), Tb (7), or Yb (8), synthesized by the reaction between aqueous solutions of Ln(NO3)3 and K3[Cr(NCS)6] and dimethyl sulfoxide C2H6SO (DMSO) have been studied by IR spectroscopy and single-crystal X-ray diffraction. Single crystals of compounds for XRD were obtained by isothermal recrystallization of complex powders from DMSO solutions. Compounds 1–8 are isostructural, crystallize in the triclinic system, space group P $$\overline 1 $$ . The crystal structure is island with [Ln(DMSO)8]3+ cations and [Cr(NCS)6]3– anions. The asymmetric unit comprises two cations and two anions. The coordination environment of the Ln atom consists of eight O atoms of DMSO molecules located at the vertices of a distorted square antiprism. In isolated [Cr(NCS)6]3– anions, the chromium(III) coordination polyhedron is close to a regular octahedron and consists of N atoms of six NCS ions. The center packing of complex cations and anions is a distorted NaCl structure.

The paper presents certain aspects of applying equilibrium-kinetic modeling to preliminarily assess the formation of the chemical composition of sewage subdump waters during upcoming mining at the Udokan deposit. The mineral dissolution rates, including oxidative dissolution of sulfides, and sorption of strontium, cobalt, zinc, and nickel on calcite are taken into account. It is shown that the chemical composition of water during interaction with dump rocks changes very slowly. However, such heavy metals as nickel, zinc, cobalt, and molybdenum should accumulate in the aqueous solution of the settling pond within 50 years.

We carried out equilibrium-kinetic modeling the interaction of the integrated technological sample from the Pavlovskoe ore deposit with atmospheric precipitates to estimate the potential environmental contamination during mining. Accumulation of major (Zn, Pb) and trace (Cu, Co, Cd, As, Hg, Se, Hg, Sb) ore elements in aqueous solution during summer period has been calculated. It has been shown that the aqueous solution after the interaction acquires sulfate–calcium composition and accumulates Zn, Sb, and Hg in concentrations exceeding the maximum permissible concentrations.

Chemical interactions in carbonate rock–seawater, silty sand–seawater, clay rock–seawater, basalt–seawater, and granite–seawater systems, where the term “seawater” denotes the compositions of halite, epsomite, and sylvinite stages of seawater densification, were simulated at 25, 100, 200, and 300°С and various pressures in order to assess the ability of rocks to generate hydrocarbons. Based on the efficiency of hydrocarbon generation, the rocks are arranged in the following series: clay > silty sandstone > carbonate > mafic rocks; felsic rocks are unproductive. It is shown that with an increase in the weight rock/water ratio (R/W), which may be taken as the conditional time (degree) of metamorphism, the reduction potential (lgfH2) of rocks, i.e., their ability to generate hydrocarbons, increases. At R/W → 1, the reduction potentials (lgfH2) for carbonate, clay, and silty sandstone are –2.74, –2.45, –2.57 at 100°С, –1.2, –1.1, –1.0 at 200°С, and –0.5, +0.3, –1.2 at 300°С, respectively, which shows a clear advantage of clay at high temperatures (pressures) in terms of its ability to reduce chemical elements and generate hydrocarbons. Thermodynamic modeling of interactions in a closed water–mineral precipitate–natural organic matter system at the T–P parameters of diagenesis was performed. A mature type of kerogen and associated substances (water-dissolved hydrocarbons, nitrogen compounds) are formed in the system in the course of the reactions. It is shown that the removal of CO2 (g) and N2 (g) from the system promotes hydrocarbon and kerogen formation reactions. It was found that the water phase changes insignificantly during kerogen formation. In general, the effect of desalination and changes in pH and Eh, as well as the increase in the content of CO2 dissolved in the water, is significant.

Ore-bearing rocks and natural waters of the Pitkäranta ore district (near the “Arsenic” shaft, the Hopunvaara mine field) were sampled and analyzed. The permanganate value as well as iron and manganese contents in surface water are higher than MPC values, while water samples from the “Arsenic” shaft have the elevated contents of zinc, copper, and arsenic. The Fe, Mn, Cu, Zn, Cr, As, and Ni speciation in waters have been determined by thermodynamic calculations, taking into account the possibility of the formation of metal complexes with humic and fulvic acids. The fulvic acid is almost completely consumed for the formation of the complex Fe(OH) 2 Fu - . Ni, Cd, Co occur mainly in the ionic form, and the fraction of Mn and Zn in the ionic form is also significant.

The new complexes [M(NKA)2(NCS)2(H2O)2], where M2+ = Co2+ (I), Ni2+ (II); NKA = C10H14N2O (N,N-diethylpyridine-3-carboxamide, nicotinic acid diethylamide, nikethamide), have been synthesized and studied by chemical and X-ray diffraction analyses and IR spectroscopy. The single-crystal X-ray diffraction analysis of these complexes has shown that they crystallize in triclinic system with space group $$P\bar {1}.$$ Despite similar molecular structures of the two complexes, the orientation of molecules in a crystal cell is different in them. The coordination polyhedron of the metal atom is a distorted octahedron built of the O atoms of two coordinated water molecules, the two N atoms of the pyridine rings of two NKA molecules, and the two N atoms of rhodanide groups. The packing of molecules leads to the appearance of additional stacking interactions with the formation of a branched network of hydrogen bonds between coordinated water molecules and NKA carbonyl groups in the structures of these complexes.

The new complexes [M(NA)2(H2O)4]SiF6 ⋅ 2H2O, where M2+ = Co, Ni, Zn (complexes I, II, and III, respectively), and NA = C6H6N2O is nicotinamide, [Cu(NA)2(SiF6)(H2O)2] ⋅ 2H2O (IV), and (HNA)2SiF6 (V) have been synthesized from aqueous solutions and studied by chemical, IR spectroscopic, and X-ray diffraction analyses. Their unit cell parameters are a = 16.2448(18) Å, b = 6.8834(8) Å, c = 10.0767(11) Å, β = 102.765(3)°, V = 1098.92 Å3, space group C2 for I; a = 16.1591(7) Å, b = 6.8777(3) Å, c = 10.0314(5) Å, β = 102.410(1)°, V = 1088.82 Å3, space group C2 for II; a = 16.2265(6) Å, b = 6.8965(3) Å, c = 10.0696(5) Å, β = 102.390(1)°, V = 1100.60 Å3, space group C2 for III; a = 6.5915(4) Å, b = 7.7670(4) Å, c = 10.1506(5) Å, α = 110.7390(10)°, β = 105.824(2)°, γ = 95.448(2)°, V = 456.868 Å3, space group P $$\overline{1}$$ for IV; and a = 14.1904(7) Å, b = 9.0468(4) Å, c = 11.8160(7) Å, β = 106.277(2)°, V = 1456.1 Å3, space group C2/c for V. Complexes I–III are isostructural and represent ionic compounds formed by hexafluorosilicate anions and complex cations. The coordination polyhedron of the metal is a slightly distorted octahedron built of the O atoms of four coordinated water molecules and the two N atoms of two pyridine rings of two nicotinamide molecules in trans positions of the polyhedron. Complex IV has a polymeric chain structure. The coordination polyhedron of the copper cation represents an octahedron, which is elongated along its axis and built of the two N atoms of two pyridine rings of two nicotinamide molecules, the two O atoms of coordinated water molecules, and the two F atoms of hexafluorosilicate anions acting as bridges between neighboring cations. In the structure of complex V, the nitrogen atom of the pyridine ring HNA+ is protonated. The geometry of hexafluorosilicate anions is identical in all the five complexes. The structures have branched networks of hydrogen bonds.