Method of forming uniform uncontaminated iron oxide for pigment and other uses

Claim 1

THE METHOD OF MANUFACTURING IRON OXIDE FOR PIGMENT AND OTHER USES, COMPRISING THE STEPS IN COMBINATION OF: FORMING A STARTER SOLUTION OF A SULPHATE OF IRON WITH AN ALKALI TO FORM A FINE PARTICLE SUSPENSION OF AN HYDROXIDE OF IRON CONTAINING ACTIVE AND INACTIVE CONTAMINANTS; OXIDIZING SAID SUSPENSION TO FORM PIGMENT SEEDS, CONTACTING THE PIGMEMT SEEDS WITH METALLIC IRON IN THE PRESENCE OF A SULPHATE OF IRON AND OXYGEN TO FORM A COLLOIDAL IRON OXIDE GEL; AND BEFORE CONTACTING SAID PI MENT SEEDS WITH METALLIC IRON SUBSTANTIALLY REMOVING SAID ACTIVE AND INACTIVE CONTAMINANTS BY CENTRIFYING SAID SUSPENSION TO RENDER SAID COLLOIDAL IRON OXIDE MORE UNIFORM AND MORE ACTIVE IN GROWTH WHEREBY TO PROVIDE SUBSTANTIALLY UNIFORM UNCONTAMINATED IRON OXIDE.

Claim 2

THE METHOD OF MANUFACTURING IRON OXIDE FOR PIGMENT AND OTHER USES, COMPRISING THE STEPS IN COMBINATION OF: FORMING A STARTER SOLUTION OF A SULPHATE OF IRON WITH AN ALKALI TO FORM A FINE PARTICLE SUSPENSION OF AN HYDROXIDE OF IRON CONTAINING ACTIVE AND INACTIVE CONTAMINANTS; OXIDIZING SAID SUSPENSION TO FORM PIGMENT SEEDS, CONTACTING THE PIGMEMT SEEDS WITH METALLIC IRON IN THE PRESENCE OF A SULPHATE OF IRON AND OXYGEN TO FORM A COLLOIDAL IRON OXIDE GEL; AND BEFORE CONTACTING SAID PI MENT SEEDS WITH METALLIC IRON SUBSTANTIALLY REMOVING SAID ACTIVE AND INACTIVE CONTAMINANTS BY CENTRIFYING SAID SUSPENSION TO RENDER SAID COLLOIDAL IRON OXIDE MORE UNIFORM AND MORE ACTIVE IN GROWTH WHEREBY TO PROVIDE SUBSTANTIALLY UNIFORM UNCONTAMINATED IRON OXIDE.