Key Technologies for and Cases of Open-Stope-to-Backfill Transition in China’s Small and Medium Mines

Globally, the open-stope method is used in over 60% of small- and medium-sized mines because of its low cost and high initial efficiency, but it has issues like high ore loss and a great goaf-collapse risk, becoming a core bottleneck for mines’ green and sustainable development. Thus, accelerating its transition to the green backfilling method is an urgent industry need. This study focuses on Shishudi Gold Mine, Xingan Fluorite Mine, and Suichang Gold Mine, adopting a “problem diagnosis–scheme design–case verification–experience extraction” framework to analyze their economic and ecological indicators pre- and post-transition. Our results show remarkable effects: Shishudi’s ore recovery rose from 75% to 88.5%, with 300,000 tons of residual ore recovered and 100% tailing utilization; Xingan’s ore loss dropped by 12%, annual output increased by 60,000 tons, and 200,000 tons of tailings was consumed to achieve a “tailless mine”; and Suichang’s mining capacity rose from 30 tons per day (t/d) to 120 t/d, using 150,000 tons of cyanide-free tailings yearly. In this paper, the key problems of open-stope mining are identified and a transition path of “process innovation–system construction–tailing utilization–mechanization support” is summarized. Our results provide promotable technical solutions and practical references for global small- and medium-sized mines that are of great significance for driving their green and sustainable development.