Method of treating iron sulfide-containing ore or concentrates

Claim 1

A METHOD FOR THE TREATMENT OF IRON PYRITE OR OTHER IRON-SULFIDE CONTAINING ORES OR CONCENTRATES, COMPRISING THE STEPS OF (1) PREPARING A MIXTURE OF IRON-SULFIDE CONTAINING MATERIAL AND OF IRON-OXIDE CONTAINING MATERIAL WITHOUT ADDITION OF FLUXES, AND (2) HEATING THE MIXTURE TO MELTING IN A CLOSED ELECTRODE FURNACE UNDER THE EXCLUSION OF OXYGEN FROM THE OUTSIDE SO AS TO FORM (A) A SLAG IN WHICH SILICA AND GANGUE ARE INCLUDED TOGETHER WITH A SMALLER AMOUNT OF IRON, AND (B) A MATTER WHICH CONTAINS THE MAJOR PORTION OF THE IRON FROM SAID MIXTURE, PARTLY AS AN IRON SULFIDE CONTAINING LESS THAN 8 GRAM EQUIVALENTS OF SULFUR PER EVERY 7 GRAM EQUIVALENTS OF IRON AND PARTLY AS FERROUS OXIDE, FEO, WHICH IRON COMPOUNDS FORM AT LEAST A MAJOR PORTION OF SAID MATTE, SAID MATTE BEING OBTAINED IN A REACTIVE FORM, FROM WHICH THE MAJOR PORTION OF THE IRON CONTENT THEREOF CAN BE DISSOLVED SELECTIVELY BY LEACHING THE MATTE WITH DILUTED SULFURIC ACID AFTER CRUSHING THE SAME.

Claim 2

A METHOD FOR THE TREATMENT OF IRON PYRITE OR OTHER IRON-SULFIDE CONTAINING ORES OR CONCENTRATES, COMPRISING THE STEPS OF (1) PREPARING A MIXTURE OF IRON-SULFIDE CONTAINING MATERIAL AND OF IRON-OXIDE CONTAINING MATERIAL WITHOUT ADDITION OF FLUXES, AND (2) HEATING THE MIXTURE TO MELTING IN A CLOSED ELECTRODE FURNACE UNDER THE EXCLUSION OF OXYGEN FROM THE OUTSIDE SO AS TO FORM (A) A SLAG IN WHICH SILICA AND GANGUE ARE INCLUDED TOGETHER WITH A SMALLER AMOUNT OF IRON, AND (B) A MATTER WHICH CONTAINS THE MAJOR PORTION OF THE IRON FROM SAID MIXTURE, PARTLY AS AN IRON SULFIDE CONTAINING LESS THAN 8 GRAM EQUIVALENTS OF SULFUR PER EVERY 7 GRAM EQUIVALENTS OF IRON AND PARTLY AS FERROUS OXIDE, FEO, WHICH IRON COMPOUNDS FORM AT LEAST A MAJOR PORTION OF SAID MATTE, SAID MATTE BEING OBTAINED IN A REACTIVE FORM, FROM WHICH THE MAJOR PORTION OF THE IRON CONTENT THEREOF CAN BE DISSOLVED SELECTIVELY BY LEACHING THE MATTE WITH DILUTED SULFURIC ACID AFTER CRUSHING THE SAME.