EFFECT OF SULFATE-IONS ON THE FORMATION AND PHYSICOCHEMICAL PROPERTIES OF FERRIC-OXIDE HYDROXIDES PREPARED BY A HOMOGENEOUS PRECIPITATION METHOD .1.

The effects of sulfate ions on the formation and physico-chemical prop erties of ferric oxide hydroxides were studied using various technique s. Samples prepared from 0.1 M Fe(NO3)(3) solution without sulfate ion s contain mixtures of goethite and hematite, whereas basic sulfates of varying composition were formed from solutions containing sulfate: ir on [III] ratio greater than and equal to one. Goethite samples of very narrow particle size range, spherical shape, microporous nature, high surface area, high true density and low packing density and surface a cidity, which are very necessary for good catalysts and ferrite making , were obtained at low sulfate: iron [III] ratios (0.25: 0.5).