# A Review of the Impact of Spontaneous Combustion on Slope Stability in Coal Mine Waste Dumps
## 5 Discussion
A coupled thermo-mechanical modeling to bridge the gap between existing studies and real-world conditions is needed for accurate predictions. This integrated approach is crucial for managing the long-term safety and environmental risks associated with mine waste dumps prone to spontaneous combustion. **Long-Term Material Behavior**: A number of research studies have been conducted to gain a better understanding of the mechanisms underlying spontaneous combustion. While the impact of spontaneous combustion on slope stability is critical, there remains a significant lack of geotechnical investigations at many affected sites. This gap in the research may be attributed to the heterogeneous nature of materials comprising mine waste dumps, as well as the substantial costs and logistical challenges associated with conducting such studies. Moreover, there is currently no comprehensive research focusing on the post-combustion residual strength and creep behavior of materials within mine waste dumps. This is a crucial oversight, as these properties are essential for evaluating long-term slope stability and the risk of delayed failures following combustion events. It appears that mine waste dumps are often not given sufficient attention in terms of geotechnical assessment until spontaneous combustion or spontaneous combustion-induced consequences have already occurred. To address this issue proactively, it is imperative to conduct long-term experimental research into the behavior of mine waste materials under elevated thermal conditions. Such studies should aim to characterize changes in the mechanical properties, deformation behavior, and overall structural integrity over time, thereby enabling the more effective prediction, prevention, and mitigation of spontaneous combustion hazards. **Sustainability**: A number of methods have been developed and applied worldwide over the years. The effectiveness of these techniques is dependent on individual site situations. Fuel is removed when it is physically separated from the burning mass; therefore, in surface subjects such as spoil piles or mine waste dumps, the removal of carbonaceous or sulfide minerals is normally unrealistic. The removal of heat can be accomplished by injecting a heat-absorbing material; i.e., water, inert gas, foam, grout, etc. ; however, it is usually impractical. Additionally, these materials can have effects on the environment surrounding dumps, such as the air, surface/underground water, noise, vegetation and eco-system. Hence, most strategies for the control and prevention of spontaneous combustion focus on removing oxygen, or rather, preventing it from accessing the fuel. This is usually best accomplished by applying cover layers of inert material, which reduce the rate at which oxygen can penetrate the mine waste dump. The effectiveness of a cover is generally dependent on the composition, particle size and bulk density, water content of the cover, air-filled void space, heat transfer capacity, oxygen transfer, and cover thickness. However, the cover layer can make the slope instable because it adds mass to the slope. The excavation of heated or burning material is one of the primary methods used to control spontaneous combustion in mine waste dumps. The effectiveness of this approach depends on several factors, including the layout of the waste dump, the extent of the combustion problem, and site-specific conditions. When implemented properly, this method results in the complete elimination of burning zones and facilitates the relatively rapid cooling of adjacent areas, typically within a few hours to several days. However, despite its effectiveness, excavation has several drawbacks. The process generates significant amounts of dust, which can have adverse environmental and health impacts, leading to complaints from nearby communities. Moreover, excavation alters the shape and size of the dump,necessitating design and operational modifications to maintain stability and ensure continued waste disposal efficiency.