Mine conveyor belt fire classification

This article presents a conveyor belt fire classification model that allows for the determination of the most effective firefighting strategy. In addition, the effect of belt design parameters on the fire classification was determined. A methodology that involves the use of numerical simulations and artificial neural networks was implemented. An approach previously proposed for modeling fires over conveyor belts was used. With the objective of obtaining some required modeling input parameter and verifying the capacity of this approach to get realistic results, computational fluid dynamics model calibration and validation were carried out using experimental test results available in the literature. Results indicated that scenarios with belt positions closer to the mine roof and greater tunnel heights require a higher longitudinal air velocity to be attacked directly. Furthermore, the belt fire classification model provided by the artificial neural network had an accuracy around 95% when test scenarios were classified.

EXTRACTION OF OPEN PIT BOTTOM RESERVES BY ROOM-AND-PILLAR METHOD USING HYBRID BACKFILL

For the transition from open pit to underground mining in thin and steeply dipping ore bodies, it is proposed to use the room-and-pillar method with hybrid backfill. The geotechnology assumes bottom-up mining within levels which are generally sequenced top downward. The hybrid backfill is waste rock and rubble concrete. The authors discuss the multivariate problem on the stability of structural elements of the geotechnology with ranking of basic parameters in the field of natural tectonic stresses. The geotechnology safety is proved by the 3D FEM-based stress-strain analysis of the limiting case of mine roof spans. The stress patterns in the structural elements of the technology are determined, and the areas of instability are identified. The rubble concrete pillars effectively ensure mining safety with the discussed technology. The hybrid backfill as against rock fill is a more reliable method of ground control, especially in case of increasing thickness of ore bodies.

Safety evaluation of mine roof accident based on grey fuzzy comprehensive evaluation

By analyzing the risk assessment methods of roof accidents at home and abroad, this paper summarizes the research status of risk assessment in this area, and analyzes the significance of risk assessment of mine roof accidents. The risk identification of roadway collapse accident is carried out from four aspects -- human, material, environment, and management, and the risk evaluation index system is established, including human unsafe behavior, material unsafe state, management factors and environmental factors. On this basis, the weight of index set is determined by grey relation analysis, and the fuzzy comprehensive evaluation model is obtained by combining the fuzzy comprehensive evaluation method. Taking a coal mine as an example, this paper makes an empirical study of risk assessment and puts forward corresponding countermeasures according to the results of comprehensive assessment. The results show that the safety level of the mine is very safe, so it is feasible to use the grey fuzzy comprehensive evaluation method to evaluate the safety of the mine, which can provide reference for the same kind of mine.