Ultrafine iron oxide is produced in a controlled atmosphere furnace using reducing gases. While getting the reduced iron powder out of the controlled atmosphere furnace, iron powder immediately catches fire, this phenomenon is called pyrophoric tendency.
The main cause of the pyrophoric behaviour of the iron powder is the very fine size (<30 microns) of the particles in proportion to the surface area, wherein the highly active surface of iron readily reacts with oxygen in the air, to form a stable iron oxide. This pyrophoric tendency of the powder was prevented by using inert gas like nitrogen. However, the powder gets rapidly oxidised in the downstream processes like pulverizing, blending, packaging and storing leading to poor quality low grade iron powder.
We tried to increase the size by reducing the powder at slightly higher temperatures. While we were successful in preventing the pyrophoric tendency of the powder by increasing its particle size, the quality of the powder deteriorated.
We are looking for solutions that will enable us to arrest/eliminate the oxidation of fine and ultra-pure Iron powder during its further processing, handling and storage and shipment. We are seeking solutions that involve physical/ chemical/ metallurgical/mechanical solution for the aforementioned issue of iron powder without affecting its final quality.
Critical Success Factors/ Measures:
1) A technological process design and working model that demonstrates the capability of handling highly pyrophoric iron powder, without getting oxidized during its processing, handling and storage.
2) We prefer low cost solution for packaging the iron powder in nitrogen or any other inert gas.