Describe the steps in fractional distillation of air which is used to separate oxygen, nitrogen, noble gases

1) Air is pumped in and filtered to remove the dust 2)Water vapour, carbon dioxide and pollutants are removed 3)The air is compressed which makes it hot, it is cooled down again by recycling cold air 4)The cold compressed air is passed into a larger space where it expands rapidly making it very cold . 5) The mixture is slowly warmed up where each liquid boils one by one