This article performs a comparative analysis of noise generated by conveyor belts with different design parameters. The study was conducted for belts with the same tensile strength, differing in the physical parameters of the cover rubber. Noise emission measurements were performed on a laboratory belt conveyor. The test on the stand allowed for the determination of the noise emission as a function of variable operating parameters: the tensioning force and linear speed of the belt. Research results indicated a significant impact of speed on the emitted noise. The effect of belt tension on noise emission is small, and it is definitely less significant than the effect of linear speed. The results also show that it is possible to select a conveyor belt that emits less noise under the same operating conditions. The analysis of the results allowed us to determine the impact of the physical parameters of the belt covers on the emitted noise.

In compliance with ecological policies, activities undertaken by surface mines in relation to environment protection should be comprehensive and must take into account the principle of sustained development. One of the most basic tasks in this area is to reduce the nuisance caused by the noise emitted to the environment. The problem of above-standard noise levels caused by transportation systems operated in mines can be solved only after major noise sources are identified and analyzed in detail. This article first focuses on the literature studies to describe the possible sources of noise generated by a belt conveyor and in its second part it presents exploratory research into noise sources. The research was performed under laboratory conditions with the use of an acoustic camera as a tool for spatially identifying and classifying individual noise sources. The article identifies some phenomena related to the operation of main belt conveyor components and describes their characteristic frequency ranges.

The size distribution and fragmentation level of the blasted rock mass are crucial factors in enhancing the efficiency of loading, transportation, crushing, and milling processes. This article provides a comparative analysis of grain size distribution curves derived from image analysis using various methods. The first method compares representative fragments of the muck pile through manual analysis, commercial software, and an open-source algorithm. The second method evaluates the grain size distribution curves of the entire muck pile, utilizing both commercial software and an open-source algorithm.

Poland is a country with significant lignite resources. Prospecting for and exploring lignite deposits, as well as lignite extraction, requires prior acquisition of an appropriate concession. As concessions serve as instruments for regulating economic activity—and thereby constitute a form of permissible restriction on such activity under the Polish Constitution—the legal provisions governing them must be enacted by statute. This article analyzes the role of state policies relating to lignite extraction and its use in electricity generation, and examines the concession procedure as a regulatory instrument, with a particular focus on one specific ground for refusing to grant a concession: inconsistency with the state’s raw material interest. The main research question addresses whether the incorporation of the state’s raw material interest as grounds for refusal complies with constitutional standards and whether policy documents—specifically the State Raw Materials Policy and the State Energy Policy—can effectively guide its interpretation. The analysis concludes that, while the constitutional framework permits such a ground for refusal, current policy documents require updates and greater specificity to ensure legal certainty and consistency in administrative practices.

The article presents the results of the numerical experiments were designed to determine the effect of obstacles in the form of the drainage wells/piezometer on the basic efficiency parameters of the excavator’s work. Simulation research on built model included defining the basic parameters of...

The article presents the results of the numerical experiments were designed to determine the effect of obstacles in the form of the drainage wells/piezometer on the basic efficiency parameters of the excavator’s work. Simulation research on built model included defining the basic parameters of...