title: Minimum ignition energy of nano and micro Ti powder in the presence of inert nano TiO₂ powder.
abstract: The inerting effect of nano-sized TiO2 powder on ignition sensitivity of nano and micro Ti powders was investigated with a Mike 3 apparatus. "A little is not good enough" is also suitable for micro Ti powders mixed with nano-sized solid inertants. MIE of the mixtures did not significantly increase until the TiO2 percentage exceeded 50%. Nano-sized TiO2 powders were ineffective as an inertant when mixed with nano Ti powders, especially at higher dust loadings. Even with 90% nano TiO2 powder, mixtures still showed high ignition sensitivity because the statistic energy was as low as 2.1 mJ. Layer fires induced by ignited but unburned metal particles may occur for micro Ti powders mixed with nano TiO2 powders following a low level dust explosion. Such layer fires could lead to a violent dust explosion after a second dispersion. Thus, additional attention is needed to prevent metallic layer fires even where electric spark potential is low. In the case of nano Ti powder, no layer fires were observed because of less flammable material involved in the mixtures investigated, and faster flame propagation in nanoparticle clouds.
authors.affiliation: Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines, Northeastern University, Shenyang 110819, China. Electronic address: yuanchunmiao@mail.neu.edu.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Chunmiao
authors.affiliation: Process Engineering & Applied Science, Dalhousie University, 1360 Barrington Street, Halifax, NS B3J 2X4, Canada.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Amyotte
authors.affiliation: Process Engineering & Applied Science, Dalhousie University, 1360 Barrington Street, Halifax, NS B3J 2X4, Canada.
authors.forename: Md Nur
authors.initials: MN
authors.lastname: Hossain
authors.affiliation: Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines, Northeastern University, Shenyang 110819, China; Department of Civil Engineering, Shenyang Jianzhu University, Shenyang 110168, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Li
mesh_terms: D004391:Dust; D005107:Explosions; D005390:Fires; D053768:Metal Nanoparticles / Q000737:chemistry*; D011208:Powders; D014025:Titanium / Q000737:chemistry*
chemical_list: D004391:Dust; D011208:Powders; C009495:titanium dioxide; D014025:Titanium
keywords: Dust explosion; Layer fire; Minimum ignition energy; Nano titanium; Solid inertants