QUOTE(914werke @ Jul 14 2020, 11:23 PM)
no metal oxide, try to avoid sparks!
Solid Magnesium itself isn't going to be ignited by stray sparks.
However, what you really want to avoid is doing the mag blasting in an enclosed space. The small magnesium particles removed by the blasting, if consolidated, will become flammable dust.
Most industrial settings that do maching or grinding of magnesium that generates small shavings and grinding dust are deemed a potentially flamable or explosive environment and require preventative countermeasures to control risk.
Do the media blasting outdoors and don't try to recover the media for reuse and you'll be OK.