Abstract: A process for producing a substantially non-explosive powder containing finely divided metallic particles suitable for being incorporated in a refractory mixture, comprising simultaneously grinding a mixture of pieces of metal with pieces of an inert refractory material to produce a premixture containing finely divided metallic particles and finely divided refractory particles which are intimately mixed together. The refractory particles are present in such particle sizes and quantities as ensure that the Minimum Explosible Concentration, as tested in a 20-L vessel with a chemical igniter, is greater than 100 gm/m.sup.3. The inert particles comprise at least 40% of the mixture, and preferably 50% to 75%. The invention also includes a premixed powder, produced by this process, especially as contained in drums or impermeable bags.