機器
background
big
blade
brown coal
browncoal
bucket excavator
bucket wheel
buckets
chains
coal
coal mine
coal mining
concept
design
digger
digging
earth
efficiency
energy
environment
equipment
excavate
excavation
excavator
ground
heavy
heavy equipment
industrial
industry
large
lignite
load
machinery
marl
metal
mine
open pit
ore
power
quarry
site
steel
stone
surface mine
technology
tool
transportation
wheel
work