Steelmaking process

Claim 1

A PROCESS FOR MAKING LOW PHOSPHOROUS LOW NITROGEN STEEL FROM PIG IRONS OF WIDELY VARYING PHOSPHOROUS CONTENT, SAID PROCESS COMPRISING INTRODUCING INTO A BASIC LINED REFINING ZONE THE IRON IN MOLTEN STATE, AN IRON-OXIDE BEARING MATERIAL, AND A LIME-CONTAINING BASE SLAG-FORMING REACTANT IN A PREDETERMINED AMOUNT SUFFICIENT TO OBTAIN A BASIC SLAG HAVING A WEIGHT PER CENT RATIO OF LIME TO SILICA OF AT LEAST ABOUT 1.5, INJECTING AN OXIDIZING GAS HAVING AN OXYGEN CONTENT IN EXCESS OF ABOUT 21% BY VOLUME SUBSTANTIALLY AT THE METAL SURFACE AND THEREBY TURBULENTLY INTERMIXING THE SLAG, FROM OXIDE, AND METAL PHASE WITH CONSEQUENT EARLY ELIMINATION FROM THE METAL OF PHOSPHOROUS TO NOT MORE THAN ABOUT .04% AND SIMULTANEOUS ELIMINATION OF AT LEAST ABOUT .4% CARBON BUT LEAVING AT LEAST ABOUT 1% CARBON IN THE METAL, SAID TURBULENT INTERMIXING BEING SUBSTANTIALLY ENHANCED BY THE GASES EVOLVED DURING SAID SIMULTANEOUS ELIMINATION OF CARBON AND AN OPERATING TEMPERATURE OF NOT LESS ABOUT 2500* F. BEING DEVELOPED WHEREBY OBTAINMENT OF SAID RATIO OF LIME TO SILICA IN THE SLAG AND ELIMINATION OF PHOSPHOROUS TO SUBSTANTIALLY THE EXTEND REQUIRED IN THE FINAL PRODUCT ARE BOTH ACCOMPLISHED WHILE THE CARBON CONTENT OF THE METAL IS NOT LESS THAN ABOUT 1%, AND CONTINUING THE INJECTION OF SAID GAS INTO THE MOLTEN METAL UNTIL THE CARBON CONTENT IS REDUCED TO THE DESIRED FINAL EXTENT BY OXIDATION THEREOF, THE HEAT EVOLVED DURING THE EXOTHERMIC REFINING AND SLAG-FORMING REACTIONS BEING THE SOLE SOURCE OF HEAT DURING THE PROCESS.