Oxidation Enhancement of Gaseous Elemental Mercury Using Waste Steel Slag under Various Experimental Conditions

Abstract

In this study, the oxidation characteristics of elemental mercury were assessed based on the input gas environment, temperature, and particle size distribution of the steel slag. Experiments were performed at room temperature, 100 °C and 200 °C, under air and simulated gas environments. The oxidation reaction of elemental mercury was conducted using steel slag samples of 1 mm, 2.36 mm, and 4.75 mm at various conditions. From the basic characteristic analysis of the steel slag, it was found that the steel slag exhibits a similar composition to that of fly ash, and it can be utilized as an oxidizing agent. Results show that regardless of the temperature and the particle size distribution of steel slag, the oxidation reaction of elemental mercury rarely occurred in the air environment. However, in the case of the HCl gas environment, it was observed that the smaller the steel slag particle size, the stronger the oxidation reaction. It is believed that the oxidation efficiency of the steel slag increased as the contact area between the gas and particles increased. The oxidation reactivity was nearly two times higher in the temperature range of 100 °C to 200 °C than it was at room temperature. It is advised that further research be undertaken in order to determine the precise temperature range at which the oxidation reaction occurs.