Carbonyl iron powder production process

Carbonyl iron powder reacts with iron at high temperature and high pressure to produce 5-carbonyl iron oil. After low pressure separation, the product can be delivered after annealing and oxidation prevention treatment. Under the condition of 200 and 200bar, carbonyl synthesis reaction formula is as follows.

Fe+5CO  Fe( CO)5 

Carbonyl iron is decomposed into Fe and CO at 300 ℃ and 1 bar. 

Fe( CO)5  Fe+5CO

Because in the process of decomposition, Fe has the effect of catalytic CO and CO2, usually on NH3 as shielding gas is used to inhibit the reaction so that carbonyl iron powder is inevitable there will be in the presence of N elements from the collected in the cyclone collector products generally around the iron content of 97%, among them the content of C and N are less than 1% with Fe2O3, the existence of impurities such as Fe3N, at the same time, the iron powder show will be on CO and NH3 gas adsorption to a certain extent, these factors caused by iron powder hardness is larger, often referred to as hard powder. 

When the iron powder is reduced with H2 gas for 1 hour, the iron content will increase to about 99.0%, while the content of other elements will also significantly reduce the reduced carbonyl iron powder with slightly lower hardness, which is also known as soft powder. 

Carbonyl iron powder has a high activity. After being placed for a period of time under normal conditions, due to the increase of entropy, the iron powder particle size of automatic agglomeration will increase and the particles will be sticky, which has a great impact on the application of injection molding. 

Carbonyl iron powder has very high requirements on the process. The carbonyl iron powder size and carbon content can be significantly changed by a temperature change of 3 degrees and a gas flow rate increase of 5% during decomposition of 5 carbonyl iron powder.