The article presents the results of research on the production of polymer-bitumen binder (PBB) based on mixtures of non-oxidized and oxidized petroleum products, namely high-viscosity tar, darkened vacuum distillate, and oxidized petroleum bitumen 70/100, obtained at technological installations of Limited Liability Partnership (LLP) “JV Caspi Bitum’’ and styrene-butadiene-styrene (SBS) block copolymer brand L 30-01A modifier in the presence of a stabilizer. The results obtained show that the introduction of the SBS modifier in the presence of a sulfur stabilizer improves the performance characteristics of PBB, such as elasticity, ductility, softening temperature, penetration, and brittleness temperature.

This study examines the influence of virgin polyethylene (vPE), recycled polyethylene (rPE), and Aerosil (A) on the performance of bitumen binders modified with partially devulcanized rubber (DVR). The experimental program included morphology analysis, determination of devulcanization degree, dynamic viscosity measurements, shear stress–shear rate analysis, load–displacement (F–Δl) testing, storage-stability evaluation, ring and ball softening point (R&B), penetration (P), and elastic recovery (ER) testing. The results show that DVR-rPE-modified bitumen binders exhibit 20–35% higher viscosity and up to 25% greater elongation at the break compared to DVR-vPE-modified bitumen systems, indicating more effective interaction with the bitumen matrix. The incorporation of Aerosil increased viscosity ca. 1.5–2 times for DVR-rPE and DVR-vPE-modified systems, respectively. Meanwhile, top and bottom differences in R&B decreased by a factor of 1.6–5 for DVR-rPE and DVR-vPE-containing composites, respectively, demonstrating significant enhancement in structural stability during storage. Mechanical testing further revealed that DVR-rPE + A binders absorbed 10–20% more deformation energy and consistently maintained ER values above 70–80%, corresponding to a higher elastic recovery grade at 25 °C. Overall, the DVR-rPE + A system provided the most balanced improvements in rheological, mechanical, and thermal properties, confirming its potential for use in high-performance, thermally stable, and environmentally sustainable bituminous materials for pavement applications.

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This study presents a hydrogeochemical assessment of oilfield formation waters from the Karazhanbas, Zhetybay, and Uzen oil fields in the Mangystau Region of Kazakhstan, with the aim of elucidating lithium distribution, identifying the geochemical factors controlling its accumulation, and providing a preliminary resource-oriented evaluation. The study investigated pH, total dissolved solids (TDS), ionic–salt composition, lithium (Li) concentration, and the relationships between Li, TDS, major cations, and geochemical ratios, including Ca/Li and Mg/Li. Major ions were determined using standard hydrochemical methods, while Li was analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES). The investigated waters were predominantly classified as chloride–calcium type according to their hydrochemical composition. In terms of TDS, the waters follow the sequence Uzen > Zhetybay > Karazhanbas, whereas Li concentrations follow the sequence Zhetybay > Uzen > Karazhanbas. The highest Li concentrations were detected in Zhetybay waters (1.40–1.85 mg/dm³); in Uzen waters, Li reached 1.51 mg/dm³; and in Karazhanbas waters, it ranged from 0.30 to 0.70 mg/dm³. The highest Mg/Li and (Na⁺ + K⁺)/Li ratios were characteristic of Uzen waters, indicating a more complex salt matrix. Compared with internationally reported lithium-enriched brines, the Mangystau formation waters contain relatively low Li concentrations and cannot currently be considered a commercially viable lithium source. The scientific significance of this study lies in establishing a regional hydrogeochemical baseline for oilfield formation waters and demonstrating that maximum mineralization does not necessarily correspond to the highest Li concentration.

Introduction: This paper represents the results of exploratory research on the production of ammonium-potassium sulfate salt and by-products. Information on the use of the results of fundamental research for the creation of new technological processes is provided. The increase in the range of products based on ammonium salts is a priority task for the industrial enterprise “KazAzot” JSC (Kazakhstan, Aktau). Another task is to expand the areas of application of products with derivatives based on ammonium hydrosulfate. Furthermore, combined fertilizers can be included in the list of products. The aim of the work is to scientifically substantiate physicochemical transformations in reaction mixtures, such as obtaining ammonium-potassium sulfate-fertilizer with three target components. Methods: The experimental work was conducted in a laboratory shaft electric furnace, with observations of changes in the reaction mass and determination of the pH of the gas phase. The produced products were subjected to an X-ray phase analysis on the diffractometer Miflex 600 (Japan) with CuKɑ. In addition, the physicochemical changes of reaction mixtures and synthesized salts were studied with the help of the derivatograph of the Q-1000/D system by “MOM” F. Paulik, J. Paulik, L. Erdey and LabSys Evo TG-DTA/DTG (Setaram, France), NETZSCH STA 443 F3 in the nitrogen atmosphere. The thermodynamic evaluation of the probability of reactions was obtained using the Astra-4 program complex HCS-5.1 Chemistry (Outokumpu). Results: It has been established that in the temperature range 157 - 260 °C at equal molar ratios of NH₄HSO₄÷KSO₄ the condensed product of the reaction is a double salt ammonium-potassium sulfate (NH₄KSO₄) and its decomposition into constituent sulfates occurs above 260 °C with simultaneous pyrolysis of ammonium sulfate to complete formation of ammonium hydrosulfate and ammonia. At incomplete pyrolysis of ammonium sulfate in the cooled residue is present (NH₄)₃HS₂O₈, so salt formed from 2 ammonium sulfates: (NH₄)₂SO₄∙NH₄HSO₄ and similarly, the product of incomplete decomposition of ammonium-potassium sulfate - NH₄KSO₄ is KHSO₄∙K₂SO₄. Conclusion: An increase in the stoichiometric molar ratio in the system «NH₄HSO₄ ÷ KCl» leads to the formation of more complex hydrated salts and the basic salt of ammonium - ammonium sulfate, and, on the contrary, a decrease in the ratio - to a more basic compound of potassium sulfate.

This paper presents the research data aimed at resolving the problem of soil purification from high-paraffin crude oil using microorganisms.Samples of oilcontaminated soil were taken from the walls of the oil storage pit at the Uzen oilfield. According to the analysis of the oilcontaminated soil samples, the share of oil was 28 %, the share of mechanical impurities – 9.7 %, and the share of water – 60 %.It has been found that according to the API(American Petroleum Institute) indicators, that oil chemical composition may contribute to its rapid decomposition during bioremediation. Paraffin hydrocarbons are also easily decomposed by bacteria. The bacterial preparation «SHER» was used in laboratory experiments.The method of bacteria immobilization with the «SHER» biological product on the medium made from screenings of shell limestone wastes has been chosen.The conditions for conducting experimental laboratory studies on cleaning oil-contaminated soils by biological remediation are described.According to the results of the research, it was established that the immobilization of bacteria of the biological product "Sher" by a carrier in the form of sifting limestone-shell rock showed a high degree of purification of oil-contaminated soil (88.63%).To study the further activity of bacteria, experiments were conducted on the secondary use of thesolution of residual mother waterof the biological product "SHER", used in the process of cleaning oil-contaminated soil.The results of experimental studies using solution of residual mother water and immobilization by screening showed the degree of soil purification (45.7%). Thus, based on the results of studies of the drug "SHER", it can be concluded that this drug can effectively neutralize oil products in the soil.