Department of Mining Machines and Machine-Building Technology, Saint-Petersburg State Mining University

V. I. Bolobov, Professor

Science and Technology Centre “Gidrometallurgiya” Ltd

Ya. M. Shneerson, General Director
A. Yu. Lapin, Technical Director

The state of the problem referring to the application of titanium alloys as construction materials for autoclaves operating with oxygen gas has been considered. The instructions on safe operation of titanium alloys in nonferrous autoclave processes, as well as scientific background for setting the limit values of oxygen partial pressures, Рs.o in vapor-gas mixtures precluding ignition of autoclave titanium elements even at failure have been analyzed. It has been concluded that the set values of Рs.o are correct only for the autoclaves with no moving parts, as for those fitted with moving elements (agitators) along with the accidental structural failure there exists a risk of another emergency situation when friction work Аf contributes to the juvenile surface temperature Т*. Under such conditions, the potential ignition of materials will be determined by the temperature Т** to which the surfaces of elements under friction get heated. The latter (Т**) may considerably exceed the temperature reached only due to fracture energy of a construction (Т*). The conclusion has been drawn that eliminating a possibility of titanium alloy ignition in the oxygen environment of autoclaves equipped with agitating units can be provided by the development of technical measures preventing heating the potential friction points of titanium constructions up to the alloy ignition temperature Т* at given partial pressures of reactant gases.

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