機器
ball
business
capacity
chemical
closeup
concentrating
contemporary
copper
danger
development
dust
energy
engineering
equipment
factory
gold
grind
heavy
huge
industrial
industry
manufacturing
material
metal
mill
mine
mineral
mining
operate
ore
plant
power
powerful
process
production
raw
refinery
rotate
safety
spin
steel
tank
technology
tool
tube
work
workshop