Investigation of grinding-aid effect on the fineness, particle size distribution, surface area and color properties of calcite powder in dry vertical stirred mill

Abstract In this study, the effect of some chemical additives such as methanol, ethanol, sodium oleat and chloroform on the dry ultrafine grinding of calcite powder (X₅₀= 33 µm, Sv=0.95 m²/cm³) was investigated by using a stirred mill. The experiments were carried out by a batch operation, and the change in average particle size (X₅₀), particle size distribution (PSD) width, surface area (Sv) and color properties (lightness, whiteness) of calcite powder. The results show that the lightness (L) values of the ground calcite products slightly increased from 97.67 to 97.94 with grinding aids (methanol and ethanol) increased from 0.25% to 1%. The whiteness index (WI) value of the ground calcite products satisfactorily increased from 93.88 to 97.51 with grinding aids (ethanol) at a rate of 0.5%.

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