Patent ID: 8702837

Claim:
A method of integrating n(≧1) blast furnaces with at least one air gas separation unit, comprising the steps of: feeding air with at least n+1 compressors to n blast furnaces and to an air gas separation unit producing oxygen with an oxygen purity of greater than 90 vol %, the air being fed to said air gas separation unit being fed at a pressure of at least about 5×10 5 kPa, each of said blast furnaces being fed by at least one compressor from said at least n+1 compressors, at least one of said at least n+1 compressors does not feed a blast furnace but instead is used to feed the air to said gas separation unit; as soon as one of said at least n+1 compressors that is feeding air to said n blast furnaces is producing air at a flow rate below a predetermined flow rate Dmin, it is disconnected from a respective one of said blast furnaces and the compressor that is feeding air to said gas separation unit is connected to said blast furnace.