During automatic and intelligent cutting at the coal mining face, complex geological conditions (fold structure, fault structure and magmatic intrusion) easily cause distinct occurrence conditions of coal rock seams (gangue, inclusion, or fault in the coal and rock), which induces different coal-rock cutting performances of shearer picks. Therefore, the objective of the present study is to review the selected solutions on the evaluation of coal-rock cutting performances of shearer picks under complex geological conditions. Occurrence conditions of coal rock seams were classified according to different criteria. Mechanical coal-rock breakage of coal rock by shearer picks were introduced. Shearer pick forces during coal-rock cutting (load spectrums of the pick and the mechanical model of the pick force) and coal-rock cutting mechanism (coal-rock cutting process by the pick and pick failure mechanisms) were discussed. The service safety evaluation of the pick based on wear and fatigue (pick wear, quantitative evaluation of service safety, and methods to improve the service safety) was presented. Finally, research prospects were outlined to propose the future research focus of shearer picks under complex geological conditions, such as the adaptive cutting of shearers, the fusion detection method of coal-rock interface by automatic shearers, the effects of geological conditions on coal-rock cutting mechanisms, the selection of systems suitable for different geological conditions, and shearer pick reliability evaluation. Results of this study are of great significance in understanding failure modes and the cutting mechanisms of shearer picks, quantitatively evaluating pick safety, promoting the automatic and intelligent cutting of coal rock seams, and thereby improving the production efficiency of shearers.

In this study, a dynamic–discrete element-finite element coupling method is proposed to investigate the influence of structural parameters on the excavation performance and stress deformation of the bucket. The main research work is as follows: through ADAMS-EDEM co-simulation of the digging process of the bucket, the digging resistance and the loose force of each part of the bucket are obtained. The influence law of the change of the structural parameters of the excavator bucket on the digging resistance, filling rate and energy consumption is revealed. Through the coupling simulation of EDEM-ANSYS, the loose force is introduced into the finite element model of the bucket to enable the coupling of ADAMS-EDEM-ANSYS. The influence of the change of the bucket structure parameters on the stress and deformation of the bucket components is explored. The results show that the cutting angle and angle of throat of the bucket has a major influence on the digging performance of the bucket. While the angle of the throat and the thickness of the ear plate have a minor influence on the digging performance of the bucket. In the process of excavation, the teeth of the bucket are subjected to the largest digging resistance, resulting in relatively large deformation. All of the components of the bucket are subjected to different degrees of excavation resistance, but the stress concentration at the ear plate is the most obvious. The deformation and stress of the whole bucket can be reduced, to some extent, by reducing the thickness of the ear plate along with increasing the thickness of the stiffening plate. The results can be used to improve the digging performance of the bucket and reduce the stress and deformation of the bucket.

As a component directly in contact with materials in the excavation process of the excavator, the structure and performance of the bucket directly affect the efficiency of the excavator. With the increasingly prominent environmental and energy problems, it has become a research difficulty to optimize the bucket structure of excavators so as to reduce the digging resistance and energy consumption of excavators. Therefore, an orthogonal optimization method of bucket structure that couples Adams with EDEM was proposed to explore the excavation performance of buckets with different structures under different geological conditions. The particle size distribution and mass proportion of various ores under different geological conditions were obtained through geological investigation, and particle models with different shapes and sizes were constructed. The friction coefficient and collision recovery coefficient between bucket and ore and between ore and ore were measured using a self-made testing device. The results show that the excavation resistance of the bucket teeth during the excavation process is much greater than that of other components, and optimizing the bucket structure can effectively reduce the excavation resistance of the bucket teeth. Under different geological conditions, the optimization parameter combinations of bucket structure obtained through orthogonal experiments are different. In addition, after structural optimization, the excavation resistance and energy consumption of the bucket were reduced, and the filling rate was also improved.

The coal structure deformation attributed to actions of tectonic stresses can change characteristics of nanopore structure of coals, affecting their CO₂ adsorption. Three tectonically deformed coals and one undeformed coal were chosen as the research objects. The isotherm adsorption experiments of four coal specimens were carried out at the temperature of 35 °C and the pressure of 0 to 7 MPa. Nanopore structures were characterized using the liquid nitrogen adsorption method. The results show that there exist maximum values of excess and absolute adsorption capacity, which increase with increasing coal deformation degree. As the degree of coal deformation increases, the pore volume and specific surface area present an obvious increasing trend in the case of micropores, exhibiting an increase at first (cataclastic coal and ganulitic coal) and then stabilization (crumple coal), in the case of mesopores, and showing a gradual decrease in the case of macropores. The mesopores are the key factor of CO₂ adsorption of tectonically deformed coals, followed by the micropores and the limited effect of macropores at the strong coal deformation stage.

Large-scale mining hydraulic shovels are critical loading equipment in open-pit mines, where bucket–coal/rock interaction governs digging resistance, bucket filling, energy demand, dynamic structural loading, and tribological wear. This review synthesizes evidence on coal–rock properties, digging trajectories, local fracture, granular filling, load transfer, field measurement, wear, and structural and operating-parameter optimization. Its contribution is a mechanism-based comparison of methods, assumptions, validation evidence, and limits of transfer across material, tool, bucket, and machine scales. The reviewed studies show that material properties, bucket geometry, and kinematics jointly influence fragmentation, filling, and load transfer, but reported optima and numerical predictions remain condition-dependent. Particularly important gaps are calibration after particle or geometric scaling and full-scale validation linking cycle-resolved load, fill, energy use, and structural response with cumulative wear. A staged validation framework and coupled structure–operation evaluation are proposed as research directions; they are not presented as experimentally established improvements for large mining shovels.