Related by context. Frequent words. (Click for all words.) 61 sulfur coal 54 lignite coal 54 bituminous coal 53 coal 52 sulfur fuels 52 grade ores 50 sulfur 47 Sulfur dioxide 47 coal seams 47 thermal coal 47 dewatered 46 NOx 46 SO2 emissions 46 lignite 46 oxide ore 46 NOx emissions 46 tonnages 45 particulate emissions 45 sulfur oxide 45 stockpiled ore 45 renewable feedstocks 45 nitrous oxides 45 UG2 45 nitrogen oxide emissions 45 sulphide ore 44 ores 44 particulate matter emissions 44 baseload electricity 44 Coking coal 44 calorific value 44 sulfur dioxide emissions 44 dissolved solids 44 Powder River Basin 44 diesel fuel 44 feedstock 44 mill tailings 43 baseload generation 43 Metallurgical coal 43 hydrofluoric acid 43 tonnage 43 flue gases 43 coal seam 43 natural gas 43 SO2 43 tailings 43 ash 43 pellet stoves 43 flotation circuit 43 CONSOL 43 ferrous metal 43 nitrogen oxides NOx 42 briquettes 42 metallurgical coal 42 syngas 42 sulfur dioxide 42 ore 42 soot particles 42 absorbents 42 nitrogen fertilizers 42 Activated Carbon 42 sulfur dioxide SO2 42 woody biomass 42 ferrosilicon 42 petroleum coke 42 spodumene 42 carbonaceous 42 evaporation ponds 41 furnaces 41 wood pellets 41 sulfide 41 mined ore 41 metallurgical recoveries 41 Wyoming Powder River 41 coal gasification 41 taconite 41 fly ash 41 fluorspar 41 fine particulates 41 coal fired 41 coking coal 41 chlorides 41 heap leach pad 41 saprolite 41 Ovoot Tolgoi 41 synthetic fuels 41 nitrogen oxide NOx 41 radioactive wastes 41 manganese 41 Coal seam 40 steam boilers 40 contaminated soils 40 Niobium 40 heap leach operation 40 reformulated gasoline 40 phosphate fertilizer 40 SOx 40 coal ash 40 incomplete combustion 40 kaolin 40 harmful pollutants 40 ore mined