INERTING OF FINE METALLIC POWDERS

Minimum explosible concentration (MEG) tests were carried out on mixtu res of 50:50 Al-Mg dust, Al dust, and 70:30 Mg-Ca dust. MgO dust was a dded to these mixtures as an inertant. The results indicate that betwe en 70 and 75% fine MgO dust is required to completely inert the 50:50 Al-Mg dust, which is in the same range as the levels of rock dust need ed for coal dust inerting. Use of a coarser MgO dust raises the quanti ty of MgO required to inert. Minimum oxygen concentration tests on the 50:50 Al-Mg dust with added MgO correlated with the MEC results. Prep aration of inert/metal dust mixtures is a novel method of decreasing t he explosion hazard in manufacturing, transportation and for the end-u ser.