Process for the preparation of metal carbide and metal oxide microspheres

Claim 2

A PROCESS FOR PREPARING METAL CARBIDE MICROSPHERES HAVING A CARBON TO METAL RATIO OF ABOUT 1:1 TO 15 TO 1 WHICH COMPRISES: A. EXCHANGING ANION EXCHANGE RESIN SPHERES OR SULFUR FREE CATION EXCHANGE RESIN SPHERES WITH A SOLUTION OF A SOLUBLE SALT OF A METAL SELECTED FROM THE GROUP CONSISTING OF THE ACTINIDES, THE RARE EARTHS AND ELEMENTS OF GROUP IB, IIB, IIIB, IVB, VB, VIB AND VIIB OF THE PERIODIC TABLE, B. WASHING TO REMOVE EXCESS SOLUTION AND DRYING C. HEATING THE EXCHANGED RESIN SPHERES AT A TEMPERATURE OF 500* TO 1100*C. IN AN ATMOSPHERE OF STEAM, CARBON DIOXIDE OR OXYGEN FOR A PERIOD OF TIME SUFFICIENT TO REDUCE THE CARBON TO METAL RATIO TO ABOUT 3:1 TO 17:1, D. HEATING TO A TEMPERATURE OF 1200*C TO 1400*C. IN ARGON FOR 3 TO 6 HOURS TO EFFECT CARBOTHERMAL REDUCTION, E. SINTERING AT A TEMPERATURE OF 1000* TO 3000*C. FOR ABOUT 0.5 TO 28 HOURS IN HYDROGEN, AN INERT GAS OR UNDER VACUUM, AND F. RECOVERING THE METAL CARBIDE MICROSPHERES PRODUCT.

Claim 3

The process according to claim 1 wherein the spheres are exchanged with an aqueous chloride, nitrate, acetate, fluoride, perchlorate and sulfate solution.

Claim 4

A process for preparing metal carbiDe microspheres having carbon to metal ratios of from about 1:1 to 5:1 which comprises the steps of: a. exchanging sulfur containing cation exchange resins spheres with a solution of a soluble salt of a metal selected from the group consisting of the actinides, the rare earths and elements of Groups Ib, IIb, IIIb, IVb, Vb, VIb, and VIIb of the periodic table, b. washing to remove excess solution and drying, c. heating the exchanged resin spheres to a temperature of 400*-800*C. in an atmosphere of Hydrogen and steam for a period of 4 to 8 hours to reduce the sulfur content of the spheres to less than 0.5 percent, d. heating said exchanged resin spheres to a temperature of 500*-1100*C. in an atmospheres of steam carbon dioxide or oxygen for a period sufficient to reduce the carbon-to-metal ratio to about 3:1 to 17:1, e. heating to a temperature of 1,200* to 1,400*C. in argon for 3-6 hours to effect carbothermal reduction, f. sintering at a temperature of 1,000* to 3,000*C. for about 0.5 to 28 hours in hydrogen, an inert gas, or under vaccum and g. recovering the metal carbide microspheres.

Claim 5

A process for preparing metal carbiDe microspheres having carbon to metal ratios of from about 1:1 to 5:1 which comprises the steps of: a. exchanging sulfur containing cation exchange resins spheres with a solution of a soluble salt of a metal selected from the group consisting of the actinides, the rare earths and elements of Groups Ib, IIb, IIIb, IVb, Vb, VIb, and VIIb of the periodic table, b. washing to remove excess solution and drying, c. heating the exchanged resin spheres to a temperature of 400*-800*C. in an atmosphere of Hydrogen and steam for a period of 4 to 8 hours to reduce the sulfur content of the spheres to less than 0.5 percent, d. heating said exchanged resin spheres to a temperature of 500*-1100*C. in an atmospheres of steam carbon dioxide or oxygen for a period sufficient to reduce the carbon-to-metal ratio to about 3:1 to 17:1, e. heating to a temperature of 1,200* to 1,400*C. in argon for 3-6 hours to effect carbothermal reduction, f. sintering at a temperature of 1,000* to 3,000*C. for about 0.5 to 28 hours in hydrogen, an inert gas, or under vaccum and g. recovering the metal carbide microspheres.

Claim 6

The process according to claim 3 wherein the spheres are exchanged with an aqueous chloride, nitrate, acetate, fluoride, perchloriate or sulfate solution.

Claim 7

A process for preparing metal oxide microspheres which comprises: a. exchanging anion exchange resin spheres or sulfur free cation exchange resin spheres with a solution of a soluble salt of a metal selected from the group consisting of the rare earths, the actinides, elements of Group Ib, IIb, IIIb, IVb, Vb, VIb and VIIb. b. washing to remove excess solution and drying, c. heating the exchanged resin spheres at a temperature of 500* to 1100*C. in the pressure of steam, carbon dioxide or oxygen for a period of 3 to 8 hours to reduce the carbon-to-metal ratio to below about 0.5; d. sintering said microspheres to a temperature of 1,500* to 3, 000*C. for 3 to 8 hours in argon or under vaccum and recovering the product microspheres.

Claim 8

A process for preparing metal oxide microspheres which comprises: a. exchanging anion exchange resin spheres or sulfur free cation exchange resin spheres with a solution of a soluble salt of a metal selected from the group consisting of the rare earths, the actinides, elements of Group Ib, IIb, IIIb, IVb, Vb, VIb and VIIb. b. washing to remove excess solution and drying, c. heating the exchanged resin spheres at a temperature of 500* to 1100*C. in the pressure of steam, carbon dioxide or oxygen for a period of 3 to 8 hours to reduce the carbon-to-metal ratio to below about 0.5; d. sintering said microspheres to a temperature of 1,500* to 3, 000*C. for 3 to 8 hours in argon or under vaccum and recovering the product microspheres.

Claim 9

The process according to claim 5 wherein the spheres are exchanged with an aqueous chloride, nitrate, acetate, fluoride, perchlorate, or sulfate solution.

Claim 10

A process for preparing metal oxide microspheres which comprises: a. exchanging the sulfur containing cation exchange resin spheres with a solution of a soluble salt of a metal selected from the group consisting of the rare earths, the actinides, elements of Group Ib, IIb, IIIb, IVb, Vb, VIb and VIIb, b. washing to remove excess solution and drying, c. heating the exchanged resin spheres at a temperature of 500* to 1100*C. in the presence of steam, carbon dioxide or oxygen for a period of 3 to 8 hours to reduce the carbon-to-metal ratio to below about 0.5, d. sintering said microspheres to a temperature of 1,500* to 3, 000*C. for 3 to 8 hours in argon or under vaccum and recovering the product microspheres.

Claim 11

A process for preparing metal oxide microspheres which comprises: a. exchanging the sulfur containing cation exchange resin spheres with a solution of a soluble salt of a metal selected from the group consisting of the rare earths, the actinides, elements of Group Ib, IIb, IIIb, IVb, Vb, VIb and VIIb, b. washing to remove excess solution and drying, c. heating the exchanged resin spheres at a temperature of 500* to 1100*C. in the presence of steam, carbon dioxide or oxygen for a period of 3 to 8 hours to reduce the carbon-to-metal ratio to below about 0.5, d. sintering said microspheres to a temperature of 1,500* to 3, 000*C. for 3 to 8 hours in argon or under vaccum and recovering the product microspheres.

Claim 12

The process according to claim 7 wherein the spheres are exchanged with an aqueous chloride, nitrate, acetate, fluoride, perchlorate or sulfate solution.