brown coal mining engineering 15 surface mining 12 hard coal 12 opencast quarry mining 11 coal 11 metallurgy 9 more ... history 8 analytical chemistry 7 combustion 6 briquetting 5 environment protection 5 landscape recultivation 5 mining 5 coal energy sources 4 desulphurization 4 deposits mining 3 fluid boilers 3 geology 3 caustobiolite deposits 3 deposit geology 3 deposit prospecting 3 simulation and modelling 3 academic theses 3 biomass 2 mine fires 2 steam-gas cycles power stations 2 issues 2 power engineering 2 deep mining 2 less ...