Preparation of powders suitable for the manufacture of permanent magnets

Claim 1

A METHOD OF MANUFACTURING A MAGNETISABLE POWDER WHICH CONSISTS MAINLY OF METALLIC IRON AND WHICH IS COMPOSES OF PARTICLES OF MEAN ULTIMATE CRYSTAL SIZE SUCH THAT THE GREATEST DIMENSION OF EACH CRYSTAL IS NOT GREATER THAN 5,000 A., WHICH METHOD COMPRISES THE STEPS OF HEATING A MIXTURE OF AN IRON COMPOUND OF THE GROUP CONSISTING OF IRON OXIDES, HYDRATED IRON OXIDES AND IRON IRON HYDROXIDE, WITH AN ALKALINE EARTH METAL COMPOUND OF THE GROUP CONSISTING OF THE ALKALINE EARTH METAL OXIDES, HYDROXIDES AND CARBONATES, AND AN ALKALI METAL COMPOUND OF THE GROUP CONSISTING OF THE ALKALI METAL OXIDES, HYDROXIDES AND CARBONATES, THE PROPORTION OF SAID ALKALINE EARTH METAL COMPOUND BEING SUCH THAT THE FINAL PRODUCT CONTAINS FROM 0.1% TO 10% OF ALAKALINE EARTH METAL BY WEIGHT OF THE PRODUCT,AND THE HEATING BEING CARRIED OUT AT A LOW TEMPERATURE SUCH THAT REACTION TAKES PLACE BETWEEN SAID ALKALI METAL COMPOUND AND SUBSTANTIALLY ALL OF SAID IRON COMPOUND TO FORM AN ALKALI METAL FERRITE, AND THE ALKALINE EARTH METAL COMPOUND IS SUBSTANTIALLY UNIFORMLY DISTRIBUTED THROUGH THE MIXTURE, TREATING THE PRODUCT OF SAID HEATING WITH WATER, WHEREBY AN AQUEOUS SOLUTION IS FORMED AND AN IRON OXIDE CONTAINING SOLID RESIDUE IS LEFT, REMOVING SAID AQUEOUS SOLUTION AND HEATING SAID SOLID RESIDUE AT A TEMPERATURE BELOW 500*C. IN A REDUCING ATMOSPHERE UNTIL THE IRON PRESENT IN SAID RESIDUE IS MAINLY REDUCED TO THE METALLIC STATE.

Claim 2

A METHOD OF MANUFACTURING A MAGNETISABLE POWDER WHICH CONSISTS MAINLY OF METALLIC IRON AND WHICH IS COMPOSES OF PARTICLES OF MEAN ULTIMATE CRYSTAL SIZE SUCH THAT THE GREATEST DIMENSION OF EACH CRYSTAL IS NOT GREATER THAN 5,000 A., WHICH METHOD COMPRISES THE STEPS OF HEATING A MIXTURE OF AN IRON COMPOUND OF THE GROUP CONSISTING OF IRON OXIDES, HYDRATED IRON OXIDES AND IRON IRON HYDROXIDE, WITH AN ALKALINE EARTH METAL COMPOUND OF THE GROUP CONSISTING OF THE ALKALINE EARTH METAL OXIDES, HYDROXIDES AND CARBONATES, AND AN ALKALI METAL COMPOUND OF THE GROUP CONSISTING OF THE ALKALI METAL OXIDES, HYDROXIDES AND CARBONATES, THE PROPORTION OF SAID ALKALINE EARTH METAL COMPOUND BEING SUCH THAT THE FINAL PRODUCT CONTAINS FROM 0.1% TO 10% OF ALAKALINE EARTH METAL BY WEIGHT OF THE PRODUCT,AND THE HEATING BEING CARRIED OUT AT A LOW TEMPERATURE SUCH THAT REACTION TAKES PLACE BETWEEN SAID ALKALI METAL COMPOUND AND SUBSTANTIALLY ALL OF SAID IRON COMPOUND TO FORM AN ALKALI METAL FERRITE, AND THE ALKALINE EARTH METAL COMPOUND IS SUBSTANTIALLY UNIFORMLY DISTRIBUTED THROUGH THE MIXTURE, TREATING THE PRODUCT OF SAID HEATING WITH WATER, WHEREBY AN AQUEOUS SOLUTION IS FORMED AND AN IRON OXIDE CONTAINING SOLID RESIDUE IS LEFT, REMOVING SAID AQUEOUS SOLUTION AND HEATING SAID SOLID RESIDUE AT A TEMPERATURE BELOW 500*C. IN A REDUCING ATMOSPHERE UNTIL THE IRON PRESENT IN SAID RESIDUE IS MAINLY REDUCED TO THE METALLIC STATE.