| 摘要 |
PURPOSE:To obtain the iron powder carrier of a binary developer by reducing and oxidizing an iron ore to form a porous iron powder having a resistivity of a specified value or more. CONSTITUTION:The porous iron powder to be used here is obtained by reducing the iron ore with a reducing agent, such as carbon, at about 1,000 deg.C and after treatment including pulverization, oxidizing it at about 800 deg.C. Since oxygen is released by the reduction treatment, such an iron powder is made porous. This powder is low in electric resistivity, and it can be enhanced to a resistivity of >=1X10<8>OMEGA.cm by subjecting it to oxidation treatment in a rotary mill. |
