Manufacturing methods and anisotropic ferrite magnet and hexagonal ferrite particles and a method of manufacturing the same anisotropic ferrite magnet

摘要

PURPOSE:To improve specially the degree of orientation of a molded material and to obtain very high magnet characteristics by a method wherein a surface active agent is made to exist in a slurry. CONSTITUTION:An iron oxide (an Fe2O3) and sodium carbonate (Na2CO3) are ground by an attritor along with water. Then, an aqueous solution consisting of a strontium chloride (an SrCl26H2O) dissolved in water is dripped in the attritor holding a slurry and moreover, is ground. This slurry is cleaned until NaCl is reduced to 0.5% or lower and thereafter, is dehydrated, dried and granulated and these grains are calcined in the air to obtain calcinated powder. This calcinated powder is subjected to dry grinding. In this case, a stearic acid is used as a surface active agent and a toluene is used as a non-aqueous solvent. At this time, iHc of ferrite powder is ground and is reduced to 3.5 or lower by introducing a strain. Thereby, the degree of orientation of a molded material can be specially improved and very high magnet characteristics can be obtained.