Factors affecting the formation of Fe₃O₄ through the method of precipitation and oxidation

In order to prepare magnetic.particles having high qualities in their shape, size and magnetic property etc. satisfying the needs for a duplicating developer, the effects of process selection and conditions in the fabrication of ultrafine Fe₃O₄ particles through the alkaline method are studied. These include the relationship among the raw materials, alkalinity ratio, tempreature, rate of air-flow and time of oxidation etc. Properties of particles of Japanese and Chinese origin are compared with those made with the optimized process under discussion. It is shown that properties of products made with this process has attained or surpassed the standard of domestic products and are on a par with the level of imported magnetic particles from Japan.