A novel method of fuzzy fault tree analysis combined with VB program to identify and assess the risk of coal dust explosions

Cyber-Attacks Risk Analysis Method for Different Levels of Automation of Mining Processes in Mines Based on Fuzzy Theory Use

The rising automation level and development of the Industry 4.0 concept in the mining sector increase the risk of cyber-attacks. As a result, this article focuses on developing a risk analysis method that integrates Kaplan's and Garrick's approach and fuzzy theory. The proposed approach takes into account the level of automation of the operating mining processes. Moreover, it follows five main steps, including identifying the automation level in a selected mine, definition of cyber-attack targets, identification of cyber-attack techniques, definition of cyber-attack consequences, and risk ratio assessment. The proposed risk assessment procedure was performed according to three cyber-attack targets (databases, internal networks, machinery) and seven selected types of cyber-attack techniques. The fuzzy theory is implemented in risk parameter estimation for cyber-attack scenario occurrence in the mining industry. To illustrate the given method's applicability, seven scenarios for three levels of mine automation are analyzed. The proposed method may be used to reveal the current cybersecurity status of the mine. Moreover, it will be a valuable guide for mines in which automation is planned in the near future.

Safety Risk Assessment of a Pb-Zn Mine Based on Fuzzy-Grey Correlation Analysis

Improving safety management and risk evaluation methods is important for the global mining industry, which is the backbone of the industrial development of our society. To prevent any accidental loss or harm to human life and property, a safety risk assessment method is needed to perform the continuous risk assessment of mines. Based on the requirements of mine safety evaluation, this paper proposes the Pb-Zn mine safety risk evaluation model based on the fuzzy-grey correlation analysis method. The model is compared with the risk assessment model based on the fuzzy TOPSIS method. Through the experiments, our results demonstrate that the proposed fuzzy-grey correlation model is more sensitive to risk and has less effect on the evaluation results under different scoring attitudes (cautious, rational, and relaxed).

Flow field characteristics and coal dust removal performance of an arc fan nozzle used for water spray

Dust source that presents a ring shape is frequently observed in mining engineering. An arc fan nozzle used for water spray is designed to improve the dust removal efficiency. Based on a study of the spray field characteristics of an arc fan nozzle using volume of fluid (VOF) analysis, it is found that the section of arc fan flow gradually increases, and its mean width of the impact zone is 3.1 times that of the free jet zone. After leaving the guiding object, the central axis velocity of the arc fan flow rapidly increases and then gradually decreases. Based on dimensionless analysis, the calculation formula of the jet speed near the wall is achieved. The relationship between the section geometric features of arc fan flow and the structural parameters of the arc fan nozzle is analysed. A field test completed in the Fucun coal mine indicates that the dust removal efficiency obviously improved with the use of arc fan nozzles. Compared to the full cone nozzles used before, the average removal efficiency for total dust increased by 34%, and the average removal efficiency for respirable dust increased by 32%.