To solve the problem of controlling mining in the open-pit mine end slope fire-burned area, applying multivariate function fitting to the roof and floor modeling of multi-coal seam open pit mines, introducing the factor of coal quality changes in the fire-burned area, determining coal quality information at each location through proximate analysis of coal, to establish the net profit model of the mining area, it is determined the net profit of each mining position by numerical integration, the final mining position was determined without failure by calculating the slope stability based on the numerical simulation of strength reduction. Taking the Dananhu No. 2 open-pit mine in Hami, Xinjiang, China as the engineering background, the fire-burned area III within the southern end slope boundary of the first mining area is 240 m. It was finally determined that the optimal mining position is when the advancement degree is 182 m, the ultimate pit slope angle is 25°, the three-dimensional slope stability is 1.305, the profit is 671.96 million yuan, The deep boundary of the southern end slope fire-burned area of the slope is reduced by 58 m. This paper solves the problem of end slope mining in Dananhu No. 2 mine, and maximizes its net profit under the condition of ensuring safe production.

In response to the problems of developed rock fractures and unsatisfactory bench blasting effects in open-pit coal mines in Xinjiang, China, By using on-site research, theoretical analysis, numerical simulation and other methods, the main influencing factors of burnt rock blasting are analyzed, and the impact of joint cracks in burnt rock on its blastability is quantitatively evaluated and graded. Research shows: the main influencing factors on the blastability of burnt rock are the density of original rock joint fractures, the length of original rock joint fractures, the radius of crack propagation after blasting, and the peak blasting stress. We have established quantitative mathematical models for various influencing factors, established a classification evaluation model and evaluation standards for the blastability of burnt rocks in Xinjiang region. The comprehensive evaluation index G of blastability is divided into five levels: Level I (G > 20.7) extremely easy to blast, Level II (G = 16.7–20.7) easy to blast, Level III (G = 12.7–16.6) difficult to blast, Level IV (G = 8.7–12.6) difficult to blast, and Level V (G < 8.7) extremely difficult to blast. And a study was conducted on the blastability evaluation and classification of burnt rocks in six open-pit coal mines in Xinjiang region, and the results of blastability classification were obtained: open-pit mine 1: G = 13.3 is level III difficult to blast, open-pit mine 2: G = 13.0 is level III difficult to blast, open-pit mine 3: G = 13.3 is level III difficult to blast, open-pit mine 4: G = 13.1 is level III difficult to blast, open-pit mine 5: G = 12.8 is level III difficult to blast, and open-pit mine 6: G = 12.5 is level IV difficult to blast.

To address key challenges during the capacity expansion of the Baoqing Chaoyang Open-Pit Coal Mine from 7 to 11 Mt/a—such as insufficient working-line length, excessive advancing intensity, poor coordination between mining zones, elevated internal dump slope risks, and constrained dumping capacity—this study develops a zoning optimization method based on Unascertained Measure Theory (UMT). A working-line optimization model, constructed from coal seam thickness, density, production targets, and advancing dynamics, indicates a rational length range of 1350–2050 m at 11 Mt/a. Guided by coal seam occurrence and the original layout, the initial longitudinal-mining area is reorganized into four transverse primary zones. An eight-dimensional evaluation index system is established, covering geological, geotechnical, hydrogeological, topographic, engineering, economic, environmental, and social factors. Combined weighting using the Analytic Hierarchy Process and the Entropy Weight Method, together with multiplicative normalization, yields a hybrid subjective–objective weighting set. On this basis, four-level UMT evaluation functions and an evaluation matrix are constructed, and comprehensive assessments are performed using a confidence recognition criterion. The results show that Scheme II achieves the best overall performance in terms of economic efficiency, transportation, safety, and resource utilization, with a V₁-level confidence of 0.7058, significantly higher than the other schemes. Under Scheme II, the four zones provide 971.2 Mt of recoverable raw coal, an average stripping ratio of 5.8, and a maximum service life of 34.3 years. The proposed integrated framework of working-line design, mining-zone zoning, and uncertainty-based evaluation offers a practical decision-support tool for capacity expansion planning in large-scale open-pit coal mines.

Inclined coal-seam open-pit mines with internal dumping commonly reserve an end-side retaining ditch when turning from horizontal advance to along-strike excavation. Selecting a single fixed ditch level is straightforward but ignores year-to-year variability in stripping volumes and haulage distances, which can inflate the combined transportation and secondary stripping costs. This study proposes a two-stage optimization framework for planning the ditch-height trajectory during the turning period. First, a maximum economic ditch height is derived via an economic-compensation model that balances the revenue from overlying coal recoverable after turning against the added costs of longer haulage and increased external dumping, with cost/revenue streams discounted using a compound-interest formulation. Second, within this upper bound, a total-cost minimization model couples annual stripping transportation costs during turning with the secondary stripping cost after turning. The model enforces annual waste-volume balance among inner dumping, ditch storage, and external dumping, preferred waste-flow directions, bounds on ditch height, and limits on height differences between adjacent years. Haulage distances are calculated from centroid locations of stripping and dumping stages extracted from 3DMine, and the resulting dynamic program is solved using a sequential recursion method. A seven-year case study (2023-2029) outputs an optimized fluctuating ditch scheme with yearly ditch heights of 214.5, 190.5, 206.7, 201.3, 189.6, 181.2, and 166.0 m, reducing the cumulative cost by 148.32 million CNY compared with the conventional constant-level ditch plan. The framework offers a practical decision tool for parameterizing retaining ditches and improving the overall economics of gentle-slope turning in inclined coal-seam open-pit mines.