GRINDABILITY AND MAGNETIC PROPERTY OF CHROMITES FROM VARIOUS LOCALITIES IN RELATION TO THEIR MINERALOGICAL PROPERTIES: FUNDAMENTAL STUDIES ON MINERAL PROCESSING OF CHROMITES (3RD REPORT).

Mineralogical properties of eight kinds of chromites from various localities, and their effects on the grindability and magnetic property were investigated. It was found that there are great differences in the chemical composition, lattice constant, specific gravity, crystallinity, and surface structure in the chromites investigated. Vicker's hardness becomes higher, as the Cr//2O//3 content of chromite decreases. The adequate correlation is not observed between the hardness and grindability. The lower the homogeneity of the surface and internal structure is, the higher the grindability of chromite becomes. All chromites investigated show the paramagnetic property at room temperature and their susceptibilities have the apparent positive correlation with Fe**2** plus content of chromite. Some chromites have the relatively large spontaneous magnetization at liquid nitrogen temperature. It is supposed that the distribution of magnetic ions is not uniform in the crystal structure and so the ferrimagnetism is generated in some higher concentrated parts.