Mining complex geology, mitigation of float dust, and developing autonomous machine capability using horizon sensing technology for coal seam boundary detection

Chief Executive Officers of the National Mining Association (NMA) for the Mine of the Future (MOF) and their prioritized Technology Development Road Map, together with a 2010 Section 11 National Research Council/National Engineering Academy Study, confirmed that boundary detection in coal and metal/nonmetal mining remains a mining technology gap. The National Aeronautical and Space Administration (NASA) Automated Coal Extraction (ACE) programme determined in 1971 that a horizon sensor (HS) installed on a rotating coal cutting drum and geological vision ahead of mining technologies were beyond the state-of-the-art. Remote control of mining machines assisted by ‘last cut’ machine control algorithms has enabled machine operation from a distance. The technology, when augmented with helmet-mounted air filters, has significantly improved machine operator health and safety. In idealistic coal deposits without meandering paleochannels, faults, and other types of anomalous seam geology, the prevailing state-of-the-art is highly useful. In the real world of sedimentary deposits, meandering paleochannels and differential compaction cause seam rolls, floor ‘horsebacks’, rapidly-thinning coal seams, and fractured roof rock. Paleochannels, faults, and dykes cause very high nonlinear stress fields in the seam and boundary rock. The thin boundary layers of a coal seam are commonly contaminated by heavy metals and radioactive elements that precipitate by biochemical reduction during the deltaic or strandline peatcoal forming processes. Gradational deposition is partly responsible for the higher density, sulphur, and ash observed in the thin boundary layer (Chyi and Chou, 1986). Researchers now believe that heavy metals in the cutting dust plume are a contributing Mining complex geology, mitigation of float dust, and developing autonomous machine capability using horizon sensing technology for coal seam boundary detection