Production of a high chromium containing ferrochrome

Claim 1

IN A CONTINUOUS TWO-STEP PROCESS FOR REDUCING CHROMITE ORE TO OBTAIN A LOW SILICON FERROCHRONIUM WHEREIN IN STEP 1 SILICON IS THE FORM OF A PRIMARY FERROCHROMESILICON ALLOY IS REACTED WITH A MOLTEN INTERMEDIATE SLAG FROM STEP 2 OF A PRECEDING HEAT TO FORM A SECONDARY FERROCHROMESILICON ALLOY AND A DISCARD SLAG AND IN STEP 2 THE SECONDARY FERROCHROMESILICON ALLOY IS REACTED WITH A CHROMITE ORE-LIME MELT OT PRODUCE THE LOW SILICON FERROCHROMIUM AND REPRODUCE THE INTERMEDIATE SLAG, THE AMOUNT OF PRIMARY FERROCHROMESILICON BEING SUBSTANTIALLY EQUAL TO THE EFFECTIVE STOICHIOMETRIC QUANTITY REQUIRED TO REDUCE THE CHROMIUM AND IRON OXIDES IN THE CHROME ORE-LIME MELT, THE IMPROVEMENT WHICH CONSISTS OF: (A) ADDING LESS THAN THE EFFECTIVE STOICHIOMETRIC QUANTITY OF PRIMARY FERROCHROMESILICON TO AT LEAST ONE HEAT TO ENRICH THE CHROMIUM CONTENT OF THE INTERMEDIATE SLAG AND (B) IN A SUBSEQUENT HEAT, (1) ADDING MORE THAN THE EFFECTIVE STOICHIONMETRIC QUANTITY OF PRIMARY FERROCHROMESILICON, A PORTION THEREOF BEING ADDED TO A CHROME ORE-LIME MELT TO BENEFICIATE THE ORE-LIME MELT AND A PORTION BEING ADDED TO THE INTERMEDIATE SLAG TO PRODUCE A CHROMIUM ENRICHED SECONDARY FERROCHROMESILICON, THE TOTAL EXCESS PRIMARY FERROCHROMESILICON BEING SUBSTANTIALLY EQUAL TO THE DEFICIENCY OF PRIMARY FERROCHROMESILICON IN THE PRECEDING HEATRS AND (2) REACTING THE BENEFICIATED CHROME ORE-LIME MELT WITH THE CHROMIUM ENRICHED SECONDARY FERROCHROMESILICON TO PRODUCE A HIGH CHROMIUM, LOW SILICON FERROCHROMIUM ALLOY AND REPORDUCE THE INTERMEDIATE SLAG.