Early detection of spontaneous combustion disaster of sulphide ore stockpiles

Abstract

Original scientific paper The fire hazards induced by the spontaneous combustion of sulphide ores pose safety, environmental, and economic concerns to the mining and metallurgical industries and have become one of the most important problems in mining, particularly when sulphide ores have to be stored for a long time or transported for a long distance. The first purpose of this paper is the selection of a suitable detection indicator for running through the entire process of spontaneous combustion from oxidation to fire and accurately determining the position of the fire source of the spontaneous combustion of sulphide ore stockpiles at an early stage. We conducted on-site and laboratory experiments by using five indices to assess the oxidation characteristics of sulphide ores. Experimental results show that the change of surface temperature on sulphide ore stockpiles could indirectly reflect the nature of sulphide ore oxidation and is closely related to the various stages of spontaneous combustion. On the basis of the temperature anomaly analyses and infrared thermal imaging technology, a new fire source detection method, which can monitor the highest temperature point on the surface of self-igniting ores, was proposed. The investigation result shows that the maximum temperature differences are 0,5; 0,16 and 0,04 °C at the detection depths of 2, 3, and 5 m, respectively, and a scope of 1 × 1 m when close to the self-ignition duration. Under the same condition, the maximum temperature differences are 1,39; 0,53 and 0,14 °C at a scope of 2 × 2 m. Therefore, the infrared thermal imaging system with a sufficiently high accuracy can be used to measure the temperature differences on the surface of ore stockpiles, thus resulting in the determination of fire source position. Keywords: mine safety; sulphide ore stockpiles; spontaneous combustion; detection of fire source; infrared thermal imaging Rano otkrivanje katastrofe nastale spontanim izgaranjem naslaga sulfidne rudeIzvorni znanstveni članak Opasnost od vatre izazvane spontanim izgaranjem sulfidnih rudača važno je sigurnosno, ekološko i ekonomsko pitanje za rudarstvo i metalurgiju, a postalo je jedan od najvažnijih problema u rudarstvu, posebice kada je potrebno dugotrajno uskladištiti sulfidne rudače ili ih prenositi na velike udaljenosti. Osnovna je svrha ovoga rada odabir odgovarajućeg indikatora detekcije kroz cjelokupni proces spontanog izgaranja od oksidacije do vatre uz točno određivanje mjesta nastanka vatre kod spontanog izgaranja naslaga sulfidne rude u ranom stadiju. Proveli smo terenske i laboratorijske eksperimente koristeći pet pokazatelja kako bi odredili karakteristike oksidacije sulfidnih rudača. Eksperimentalni rezultati pokazuju da bi promjena površinske temperature na naslagama sulfidne rudače mogla indirektno odražavati prirodu oksidacije sulfidne rudače te da je usko povezana s različitim stadijima spontanog izgaranja. Na temelju analiza temperaturnih anomalija i tehnologije infracrvene termografije, predložena je nova metoda za otkrivanje iz...

Thermodynamic Model and Kinetic Compensation Effect of Spontaneous Combustion of Sulfur Concentrates

“…During the mining of sulfur-bearing metals, exfoliated and accumulated sulfide ores easily oxidize in air, releasing heat, and under heat storage conditions, the ore temperature can reach the ignition point, thereby causing spontaneous combustion of sulfide ores. − Sulfur concentrates are an abbreviation of selected sulfide metal ore powders. Sulfur concentrates are the granular form obtained by separating undesired components from raw sulfide metal ore (such as iron sulfide, copper sulfide, zinc sulfide, and lead sulfide) substances.…”