mining 764 mining engineering 315 history 157 deep mining 70 surface mining 52 metallurgy 48 ore deposits 47 more ... mines (mining) 45 coal 44 crude oil 41 uranium 38 landscape recultivation 36 natural gas 34 brown coal 33 mineral deposits 33 deposits mining 32 hard coal 27 safety of work 23 environment protection 23 opencast quarry mining 23 silver 21 mining law 17 geological survey 16 geology 16 ores 16 environment 16 caustobiolite deposits 13 gold 13 environmental pollution 13 industry 12 less ...