无煤柱护巷
Protection roads without pillars
无煤柱开采
non-pillar extraction
Non-pillar Mining
mining without pillar left
无煤柱开采技术
mining technique without coal pillar
立柱无土栽培
columnar soilless culture
卵叶无柱兰
Amitostigma hemipilioides
煤无烟燃烧
coal-smokeless combustion
Coal smokeless combustion
煤无烟燃烧锅炉
coat-sootless combustion boiler
煤无烟燃烧技术
Coal-sootless combustion technology
无烟煤煤气化
gasification of anthracite
无柱钢骨架
steel skeleton without column