In our research, we analyzed the energy and water consumption in diamond mining and laboratory synthesis operations. We used publicly available reports issued by two market leaders, DeBeers and ALROSA, to estimate water and energy use per carat of a rough diamond. The efficiency of the two most popular synthesis technologies for artificial diamonds—High-Pressure-High-Temperature (HPHT) and Microwave-assisted Chemical Vapor Deposition (M-CVD)—was examined. We found that the modern HPHT presses, with open cooling circuits, consume about 36 kWh/ct when producing gem-quality and average-sized (near-) colorless diamonds. ALROSA and DeBeers use about 96 kWh/ct and 150 kWh/ct, respectively, including all energy required to mine. Energy consumption of M-CVD processes can be different and depends on technological conditions. Our M-CVD machine is the least energy-efficient, requiring about 215 kWh/ct in the single-crystal regime, using 2.45-GHz magnetron for the support synthesis. The M-CVD methods of individual synthetic companies IIa Technology and Ekati Mine are different from our results and equal 77 and 143 kWh/ct, respectively. Water consumption for the HPHT and M-CVD methods was insignificant: approximately zero and 0.002 m³/ct, respectively, and below 0.077 m³/ct for ALROSA-mined diamonds. This study touches upon the impact of the diamond production methods used on the carbon footprint.

The paper presents a method of applying a protective coating from ultrahigh molecular weight polyethylene to rubber products. A distinctive feature of the presented method is the prevulcanization of a rubber compound in order to form it into the desired shape and remove an excess rubber material. The application of an ultrahigh molecular weight polyethylene powder to the prepared surface ensures a uniform coating thickness. To achieve an optimal combination of rubber properties, we study how the scorch time affects its physical and mechanical properties, hardness, corrosion, abrasion and thermal resistance. We find the scorch time range in which a spatial elastomeric network forms that influences the penetration of ultrahigh molecular weight polyethylene into butadiene-nitrile rubber.

The article describes the research findings on the development of polymeric composite materials based on ultra-high molecular polyethylene (UHMP) which possesses extremely high impact toughness, wearability, corrosive medium resistance, hydrophobic behavior and wet strength, and is capable to retain these properties under low temperature. As modifiers, thermally expanded graphite, basalt fiber and vermiculite were used. It has been found that modification of UHMP with thermally expanded graphite in amount from 1 to 6 mass percent increases wearability of the composite material to 28 times and decreases abrasive wear 10 times at the same or slightly lower mechanical properties as compared with the initial matrix. The resultant composition is protected by RF patent. Modification of UHMP using short-cut and activated basalt fibers exhibits their advantage over nonactivated fibers. Wearability of the composites modified by activated basalt fibers in a mount of 5 mass percent is increased 7.7 times at the higher strength and elasticity modulus by 30–40%, while the short-cut fiber enhances wearability of the composite material by 2.5–5.4 times. In modification of UHM by basalt fibers using joint activation technology, the total wear rate is reduced by 4 times with a decrease in the friction factor at the retained physical properties. The same effect is observed in joint mechanical activation of UHMP with vermiculite. The total wear rate is decreased by 3.5 times and the friction factor is lowered 1.5 times at the preserved physical characteristics. The developed polymeric composites having improved tribotechnical characteristics are recommended for the use in friction assemblies and mechanisms of mining equipment.

The article presents the results of a study of the structure of humic acids isolated from brown coals of Yakutia and oxidized coals of Kuzbass using nuclea