Behavior of CO₂ Absorption in Wet-grinding of Electronic Arc Furnace Reducing Slag by Vibration Ball Mill

Abstract

A fundamental study was carried out in order to fix CO₂ on slag. The electronic arc furnace reducing slag was wet-ground by a vibration ball mill under CO₂ atmosphere. The effect of grinding conditions on the behavior of CO₂ absorption was investigated.
The rate of the absorption of CO₂ under wet grinding was larger than that under dry grinding. The total amount of CO₂ absorption increased with the increase in total amount of the slag and water in case that the weight ratio of the water to the slag was kept constant. The CO₂ was fixed as CaCO₃ and Ca₄Si₂O₆(CO₃)(OH, F)₂. Any compounds of Mg were not detected by XRD after the experiment. In the early stage of grinding, the CO₂ was absorbed even if the grinding was stopped. The concentration of Ca in the water was larger than the solubility of Ca(OH)₂. Hence, the absorption of CO₂ was determined by the surface reaction that consisted of chemical reaction and mass transfer in liquid. In the latter stage of grinding, the CO₂ was not almost absorbed immediately after the grinding was stopped. The concentration of Ca in water was small. Accordingly, the absorption of CO₂ was influenced by the dissolution of slag into water.
The amount of the exhausted CO₂ was calculated from the electronic power which was necessary for operating this experimental apparatus. The amount of CO₂ absorption was larger than that of the exhausted CO₂ from a solar, an atomic, a wind and a water power plant.