Technology of preparation of carbonyl iron powder by high-pressure gas phase synthesis

High pressure gas consistency on the diagnosis of industrial production of carbonyl iron powder in the most mature technology for the high pressure gas method, the synthesis pressure more than 20 mpa, reaction temperature is 150-200 ℃, reaction time > 120 h, divided into two large, high pressure synthesis and thermal decomposition of coal pulverizing process.
High pressure synthesis process: Fe + 5 CO (20-30 MPa, 150-150 ℃) - > Fe (CO) 5.
Industry with sponge iron (about 95%) iron piece or as a feedstock for synthetic iron oxide scales, the ball grinding into powder, and then the reduction under hydrogen atmosphere, into the synthesis reaction kettle, CO gas after high-pressure press pressure into the reaction kettle, heated the kettle body at the same time, the synthesis reaction, production of Fe (CO) 5 and the decompression for liquid cooling.
Thermal decomposition process, Fe (CO) 5 (190-300 ℃) - > Fe + 5 CO.
In a wall heat type electric heating or gas of vertical cylinder spiral heating furnace body heat solution, Fe (CO) 5 q after gasification, from importing the pyrolysis furnace tube on the top of the center, in the 300 ℃, under the pressure of 1 bar, the gaseous Fe (CO) 5 break down to form iron core to grow up, finally to obtain the required technical performance of carbonyl iron powder.
This process usually with NH3 as protective gas, so the carboxyl iron powder will contain less than 1% of N elements.