Fine and ultrafine particles are of growing importance for numerous industrial processes. Some examples are the use in the cement and sand industry, the production of explosives and pharmaceuticals, ore refining, the catalyst powders and fertilizers in the chemical industry, extenders in macromolecular compounds (paints, cosmetics, resins), and the use in space and nuclear industry. Ultrafine powders hence have widespread applications, due to their excellent properties: very high chemical activity due to their high specific surface area), low melting and sintering point, high specific heat among others. Different techniques can produce ultrafine particles. Mechanical production comprises crushing and grinding of solids, which remain the main techniques. There are however several other techniques available of so-called physic-chemical nature: thermal decomposition of solids, deposition from liquids, vapour phase methods and solid-state reactions. The energy consumption and obtained quality are often the selection criteria.