Method for converting iron oxide to magnetic oxide

Claim 1

IN THE BENEFICIATION OF LOW GRADE, IRON BEARING ROCK, THE METHOD OF CONVERTING NON-MAGNETIC IRON MINERALS INTO A MAGNETIC STATE WHICH COMPRISES CONTINUOUSLY CARRYING OUT EACH OF THE FOLLOWING STEPS: DEPOSITING A SHALLOW GAS PERMEABLE LAYER OF NON-MAGNETIC IRON ORE ON A TRAVELING GRATE, MOVING SAID GRATE THROUGH SUCCESSIVELY ARRANGED SEAL CLOSED, COMMUNICATING HEATING, REDUCING AND COOLING CHAMBERS, FLOWING GAS THROUGH A CLOSED CIRCUIT EXTENDING SUCCESSIVELY THROUGH THE HEATING, COOLING AND REDUCING CHAMBERS, BRINGING A COMBUSTIBLE GAS INTO THE CIRCUIT IN ADVANCE OF THE HEATING CHAMBER AND BURNING SAID GAS THEREIN, PASSING THE BURNING GAS THROUGH THE ORE ON THE GRATE IN THE HEATING CHAMBER, DISCARDING PART OF THE BURNED SPENT GAS FROM THE CIRCUIT AFTER LEAVING THE HEATING CHAMBER, MIXING A COOL GAS SUBSTANTIALLY FREE FROM UNCOMBINED OXYGEN WITH THE REMAINDER OF THE BURNED SPENT GAS AND PASSING SAID MIXTURE THROUGH THE COOLING AND REDUCING CHAMBERS AND THROUGH THE ORE ON THE GRATE IN BOTH CHAMBERS AND BRINGING GAS FROM THE REDUCING CHAMBER INTO THE HEATING CHAMBER.