Method of beneficiating tantalum- and niobium-containing tin slags

Claim 1

THE METHOD OF BENEFICIATING THE TANTALUM AND NIOBIUM OXIDE CONTENTS OF AN IRON-BEARING TIN SLAG OR OTHER METALLUGICAL BY-PRODUCT WHICH COMPRISES HEATING THE SLAG IN THE PRESENCE OF SUFFICIENT CARBON TO CONVERT THE TANTALUM AND NIOBIUM OXIDES TO A HEARTH PRODUCT CONTAINING THE TANTALUM AND NIOBIUM AS CARBIDES IN ADMIXTURE WITH A CARBON-CONTAINING IRON ALLOY, SEPARATING OXIDIC GANGUE CONSTITUENTS FROM SAID HEARTH PRODUCT, REACTING SAID HEARTH PRODUCT WITH AN AMOUNT OF SODIUM NITRATE SUCH AS TO INSURE OXIDATION OF ALL METALLIC CONSTITUENTS OF SAID HEARTH PRODUCT TO THEIR RESPECTIVE HIGHEST-VALENCE HEAT-STABLE OXIDIC FORM OF SODIUM SALT, TOGETHER WITH A SOURCE OF ADDITIONAL SODIUM OXIDE IN AMOUNT OF AT LEAST ABOUT 25% BY WEIGHT OF SAID SODIUM NITRATE, LEACHING THE RESULTING REACTION PRODUCT WITH HOT WATER, SUBJECTING THE HOT WATER-INSOLUBLE CONSTITUENTS OF SAID REACTION PRODUCT TO REACTION WITH AN AQUEOUS MINERAL ACID TO CONVERT THE TANTALUM AND NIOBIUM CONSTITUENTS TEREOF TO THEIR HYDRATED OXIDES AND TO DISSOLVE THE SODIUM AND IRON CONSTITUENTS, AND SEPARATING THE RESULTING AQUEOUS PHASE FROM SAID HYDRATED OXIDES TO LEAVE AS A RESIDUE A BENEFICIATED MASS OF THE TANTALUM AND NIOBIUM OXIDE CONSTUENTS OF THE STARTING TIN SLAG.

Claim 2

THE METHOD OF BENEFICIATING THE TANTALUM AND NIOBIUM OXIDE CONTENTS OF AN IRON-BEARING TIN SLAG OR OTHER METALLUGICAL BY-PRODUCT WHICH COMPRISES HEATING THE SLAG IN THE PRESENCE OF SUFFICIENT CARBON TO CONVERT THE TANTALUM AND NIOBIUM OXIDES TO A HEARTH PRODUCT CONTAINING THE TANTALUM AND NIOBIUM AS CARBIDES IN ADMIXTURE WITH A CARBON-CONTAINING IRON ALLOY, SEPARATING OXIDIC GANGUE CONSTITUENTS FROM SAID HEARTH PRODUCT, REACTING SAID HEARTH PRODUCT WITH AN AMOUNT OF SODIUM NITRATE SUCH AS TO INSURE OXIDATION OF ALL METALLIC CONSTITUENTS OF SAID HEARTH PRODUCT TO THEIR RESPECTIVE HIGHEST-VALENCE HEAT-STABLE OXIDIC FORM OF SODIUM SALT, TOGETHER WITH A SOURCE OF ADDITIONAL SODIUM OXIDE IN AMOUNT OF AT LEAST ABOUT 25% BY WEIGHT OF SAID SODIUM NITRATE, LEACHING THE RESULTING REACTION PRODUCT WITH HOT WATER, SUBJECTING THE HOT WATER-INSOLUBLE CONSTITUENTS OF SAID REACTION PRODUCT TO REACTION WITH AN AQUEOUS MINERAL ACID TO CONVERT THE TANTALUM AND NIOBIUM CONSTITUENTS TEREOF TO THEIR HYDRATED OXIDES AND TO DISSOLVE THE SODIUM AND IRON CONSTITUENTS, AND SEPARATING THE RESULTING AQUEOUS PHASE FROM SAID HYDRATED OXIDES TO LEAVE AS A RESIDUE A BENEFICIATED MASS OF THE TANTALUM AND NIOBIUM OXIDE CONSTUENTS OF THE STARTING TIN SLAG.