Compositions involving CR sub 2 -O sub 3 V sub 2 O sub 3 -TiO sub 2

Patent · Tue Oct 29 04:00:00 EST 1991

OSTI ID:5771152

Muan, A; Najjar, M S

This patent describes a method of preparing a composition from Cr{sub 2}O{sub 3}, V{sub 2}O{sub 3} and TiO{sub 2} wherein the composition falls within the shaded area circumscribed by ABCDF as shown in the disclosed FIGURE. It comprises heating V{sub 2}O{sub 5} powder having a particle size of less than about 50 microns in an atmosphere in which the partial pressure of oxygen is in the range of 10{sup {minus}8} to 10{sup {minus}10} atmospheres while starting at a temperature of 600{degrees} C and gradually increasing the temperature over a period in the range of about 12 to 24 hours to about 1300{degrees} C for a period to ensure complete reduction of all vanadium to V{sup 3+}; separately heating TiO{sub 2} and Cr{sub 2}O{sub 3} powders each having a particle size of less than about 50 microns for a period of about 10 to 14 hrs at a temperature in the range of about 600{degrees} C to 800{degrees} C for TiO{sub 2} and about 1000{degrees} C to 1200{degrees} C for Cr{sub 2}O{sub 3}; thoroughly grinding together about 35 to 98 wt. % of V{sub 2}O{sub 3} from, with about 0 to 55 wt. % of TiO{sub 2} and about 2 to 45 wt. % of Cr{sub 2}O{sub 3} to produce a mixture having a grain size of less than about 50 microns; pelletizing the mixture at a pressure of about 5,000 psi; and heating and reacting together the pellets at a temperature in the range of about 1100{degrees} C to 1800{degrees} C for a period in the range of about 1/2 to 48 hrs in an atmosphere in which the partial pressure of oxygen is in the range of 10{sup {minus}10} to 10{sup {minus}5} atmosphere. This patent also describes composition produced from Cr{sub 2}O{sub 3}, V{sub 2}O{sub 3} and TiO{sub 2}, wherein the composition is a solid solution.

• Assignee: Texaco Inc., White Plains, NY (United States)
• Patent Number(s): A; US 5061673
• Application Number: PPN: US 7-531-608
• OSTI ID: 5771152
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CHALCOGENIDES
CHEMICAL COMPOSITION
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
ELEMENTS
HEAT TREATMENTS
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PARTIAL PRESSURE
PARTICLE SIZE
POWDERS
SIZE
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES