Removal of gas-phase As₂O₃ in dry process by metal oxide adsorbents

The adsorption of gas-phase As₂O₃ by metal oxides like CaO, Fe₂O₃ and Al₂O₃ was investigated in a fixed bed reactor with an arsenic continuous generation facility. The results indicated that the adsorption of As₂O₃ on metal oxides is dominated by chemical adsorption at a temperature between 600 and 900 ℃; the adsorption quantity and efficiency are decreased with the increase of temperature. The arsenic adsorption ability of three metal oxide follows the order of Fe₂O₃ > CaO > Al₂O₃. The saturation adsorption phenomenon will not occur under the current conditions with the concentration of arsenic in the gas phase in the range between 4.5×10^-6 and 13.5×10^-6 (volume ratio); the adsorption efficiency for each adsorbent is only affected by the adsorption temperature and the same adsorption efficiency can be achieved with different arsenic concentrations.