Preparation of strontium hexaferrite magnets from celestite and iron ore fines by mechanochemical route

Abstract

In the present investigation celestite and iron ore fines have been used for the preparation of strontium hexaferrite powder. The mechanical alloying process has been adopted to prepare strontium hexaferrite powder. The mixture of celestite after chemical upgradation and physically upgraded iron ore fines along with sodium carbonate was milled for different duration in a high energy planetary ball mill with tungsten carbide jar and ball to prepare strontium hexaferrite powder. A long duration of ball milling for different duration has led to solid-state displacement reaction. At the end of each experiment the product was washed thoroughly and dried. The X-ray diffraction study of milled powder after annealing shows the development of single phase strontium hexaferrite. The resultant powder was compacted under magnetic field and sintered to prepare the magnet after annealing the ferrite powder. The moderate value of coercivity, remanence and energy product were observed in this sintered magnet. The work illustrates the feasibility to prepare strontium hexaferrite magnetic powders directly from natural ores.

Keywords:

• CELESTITE
• IRON ORE FINES
• MECHANOCHEMICAL ALLOYING
• MAGNETIC PROPERTIES