iSET Journal X:X

SURFACE STABILISATION FOR THE PREVENTION OF SPONTANEOUS COMBUSTION IN COAL SPOIL HEAPS: LABORATORY AND SEMI‑INDUSTRIAL EVALUATION

Spontaneous combustion of coal spoil heaps and post‑mining waste dumps represents a persistent environmental and safety challenge in many European coal regions. One of the key mechanisms driving self‑heating processes is the unrestricted access of oxygen to coal‑bearing materials deposited at the surface of spoil heaps. Surface stabilisation treatments therefore represent a promising preventive approach to limit oxidation processes and reduce the risk of smouldering and endogenous fires. \r\nThis study presents the results of laboratory and semi‑industrial investigations aimed at evaluating the effectiveness of selected surface stabilisation treatments in restricting oxygen access to deposited materials. Three types of surface treatments were examined: a polymer‑based stabilisation agent, a chemical iron‑based agent, and a reference application of clean water. Semi‑industrial field tests were conducted under real operational conditions at a lignite mine spoil heap, while laboratory experiments enabled controlled assessment of surface crust formation, cohesion, and resistance to air flow. \r\nThe results demonstrate significant differences in performance between the tested treatments. \r\nThe polymer‑based agent exhibited the most balanced combination of surface cohesion, flexibility, and mechanical stability, effectively limiting air ingress even under mild mechanical disturbance. The chemical stabilisation agent proved effective primarily at higher application rates, forming a compact but less flexible surface crust. In contrast, the application of water provided only a short‑term stabilisation effect, with limited durability after drying. \r\nThe findings confirm that surface stabilisation treatments can play an important role in the prevention of spontaneous combustion in coal spoil heaps, particularly when applied as part of a preventive risk‑management strategy. The combination of laboratory testing and semi‑industrial validation is shown to be an effective approach for evaluating surface treatments and optimising their application in post‑mining environments.

spontaneous combustion; coal spoil heaps; surface stabilisation; polymer-based sealing; oxygen \r\ningress; semi-industrial testing

Received: March 31, 2026; Revised: April 29, 2026; Accepted: June 22, 2026; Prepublished online: August 7, 2026