Process for the production of steel

Claim 1

A PROCESS FOR MANUFACTURING STEEL OF LOW OXYGEN CONTENT COMPRISING BLOWING SUBSTANTIALLY PURE OXYGEN FROM ABOVE AGAINST THE SURFACE OF A BATH OF MOLTEN CRUDE IRON CONTAINING IMPURITIES INCLUDING CARBON, SULFUR AND SILICON AND HAVING A FLUID SLAG COVER IN A CONVERTER TYPE VESSEL AT A RATE HIGH ENOUGH TO OXIDIZE SULFUR, SILICON AND OTHER IMPURITIES IN SAID METAL AND PROVIDE AN AMOUNT OF OXYGEN IN EXCESS OF THE THEORETICAL OXYGEN REQUIREMENT PER UNIT OF TIME BASED ON CARBON COMBUSTION RATE, CONTINUING BLOWING AT SAID RATE UNTIL THE BATH OF MOLTEN IRON HAS REACHED A TEMPERATURE BETWEEN ABOUT 1450* AND 1600*C., THEN REDUCING THE FLOW OF OXYGEN AGAINST THE SURFACE OF THE BATH TO A LOWER RATE NOT EXCEEDING 2.0 NORMAL CUBIC METERS PER MINUTE PER TON OF A METAL, AND CONTINUING BLOWING THE BATH WITH OXYGEN AT SAID LOWER RATE UNTIL AT LEAST ABOUT 90% OF THE BLOWING TIME HAS ELAPSED, AND DISCONTINUING BLOWING WHEN NOT MORE THAN 112% OF THE THEORETICAL VOLUME OF OXYGEN REQUIRED TO OXIDIZE SAID IMPURITIES TO THE DEGREE DESIRED IN THE FINISHED STEEL HAS BEEN BLOWN INTO SAID VESSEL.