The effect of cation content of some raw and ion-exchanged Victorian lignites on their equilibrium moisture content and surface area

Six Victorian lignites of known inorganic content have been water and acid-washed. The acid-washed form of one of these lignites (LYLA(R)) was subsequently exchanged with Na, Mg, Ca and Al salts. The equilibrium moisture contents (EMC) of all samples have been determined across a range of relative vapour pressures (RVP) extending previous observations in the case of a single lignite exchanged with a series of cations. Previous measurements for a single lignite exchanged with a series of cations have only been made at a single RVP. The effects of the different metal cations on the EMC values varied depending on the RVP. The surface areas determined by CO2 adsorption also showed an effect of cation content.