Senior Engineer, Bechtel Corporation, San Francisco, CA
Corrosion Specialist, Teledyne Wah Chang Albany, Albany, OR
Pages: 12 Published: Jan 1993
Titanium and its alloys offer superior corrosion resistance in the oxidizing sulfuric acid environments present in sulfide pressure leaching operations. Their use is limited due to their pyrophoricity in high-pressure oxygen environments. We investigated the ignition resistance of several titanium alloys in oxygen using a tensile rupture technique. A commercial titanium alloy, niobium-55 wt. % titanium (Nb-55 Ti), was found not to ignite at pressure and temperature conditions under which Grade 2 titanium and other standard titanium alloys ignite. The decreased ignitability of titanium when alloyed with niobium is discussed in terms of a burn factor (the ratio of heat of oxidation to thermal diffusivity) and alloy microstructure. Nb-55 Ti, selected for its corrosion resistance, mechanical properties and reduced pyrophoricity compared to standard titanium alloys, has been successfully used in sulfide pressure oxidation equipment.
gold, pressure oxidation, autoclaves, titanium, niobium, ignition testing, oxygen, flammability
Paper ID: STP24858S