Nowadays in the world, due to the constant desire for recycling, many countries are considering the use of recycled plastics on roads. Modification of bitumen for roads in Kazakhstan is considered one of the most suitable and popular approaches. This paper presents the results of research on the modification of bitumen by recycled plastics from waste materials. The paper describes the details of the use of plastic waste as bitumen modifiers, with a specific focus on recycled plastics and how they can potentially be used to enhance bitumen performance and the road durability. The main physical and mechanical characteristics of the modified bitumen were determined after routine tests, penetration and plasticity, softening temperature, brittleness temperature on Fraas and microscopic analysis. The morphology of the modified bitumen was studied using scanning electron microscopy. The results confirm that the modified bitumen complies with the requirements for polymer-bitumen binder of Kazakhstani standards and is suitable for the production of modified bitumen by its physical and chemical characteristics.

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.

The article examines the characteristics of sewage sludge and its impact on the environment. The description of technical installations, sludge sites in the city's sewage treatment systems, which are sources of unfavorable sanitary and epidemiological condition of the studied territory,...

The use of rubber-polymer composites ELTC (End of Life Tire Compound) for bitumen modification was investigated. ELTC contains not only devulcanized rubber from used car tires, but also used plastics (polymers) such as polyethylene (PE) and polypropylene (PP). ELTC is obtained using the method of rubber devulcanization using a selective catalyst that allows selectively decomposing sulfide bonds at relatively low temperatures, while preserving most of the macromolecular chains. The characteristics of the asphalt binder improved after the modification of ELTC. After modification, the base asphalt binder became more homogeneous, and the thermal stability of the base asphalt binder increased. ELTC is evenly distributed, the compatibility between the components of the modified asphalt binder is good, which proves the uniformity of the modified asphalt binders. The results show that all ELTC formulations improve the softening temperature and increase their resistance to plastic deformation in the summer.

According to scientific research from different countries, crumb rubber obtained from end-of-life tires (ELT) during processing can improve the properties of the asphalt mixture, thereby extending the service life of the road surface. This paper presents the modification of bitumen with industrial rubber waste. The modification of bitumen for roads is considered one of the most suitable and popular approaches. This research paper describes the details of using different types of crumb rubber as bitumen modifiers. The modified bitumen’s main physical and mechanical characteristics were determined after conventional tests: penetration and ductility, softening point, and Fraas brittleness point. In order to obtain a rubber–asphalt concrete mixture with improved performance characteristics, the viscoelastic and rheological properties of rubber–bitumen binders and their comparison with polymer–bitumen binders were also studied. The research results show that with increasing temperature, the values of viscosity, shear stress and complex shear modulus of all studied bitumen systems decrease, the values of the phase shift angle increase, and the size of the rubber particles has a greater influence on the properties of bitumen systems.

Lead sludge from copper production is a source of rare metals, such as rhenium and osmium, whose content reaches 0.06–0.08% and 0.0025–0.0050%, respectively. The base of the sludge consists of lead sulfate. A method of reductive smelting of lead sludge from copper smelting production at 1000–1100 °C has been developed. Coke was used as a reducing agent and sodium sulfate as a slag-forming material. Optimal conditions for selective extraction of rare metals in smelting products were found: osmium in the form of metallic form into raw lead and rhenium in the form of perrhenate compound Na₅ReO₆ into sodium-sulfate slag. The developed technology makes it possible to extract rhenium with a high degree of extraction in the form of water-soluble compounds for the subsequent production of commercial salts of rhenium by the known hydrometallurgical methods. The content of rhenium in the slag phase is 0.18–0.25%, with its initial content in the slime of 0.06–0.08%. The degree of rhenium concentration at the first stage of processing is 3–3.2 times in the form of water-soluble perrhenate. Osmium and lead do not form solid solutions; osmium in crude lead is mainly concentrated in the lower zones of lead. A method of obtaining a concentrate containing 53–67% osmium from raw lead with an initial content of 0.0025–0.0050% in the slurry and a concentration number of 13,000–21,000 times has been proposed.