THERMODYNAMIC ANALYSIS ON DECOMPOSITION OF FELDSPAR MINERAL UNDER ALKALI CONDITION

摘要

Many researches have reported that alkali-silica reaction (ASR) may be induced by alkali released from aggregates. Decomposition of potash feldspar, albite and nepheline under alkali condition were studied by thermodynamic analysis. The amount of alkali released from feldspar minerals was quantitatively discussed as well. It was indicated that the quantity of alkali released from nepheline was higher than it from potash feldspar and albite. Those alkalis will seriously react with reactive components in aggregates. With the increasing of initial OH~- concentration, the dissolution of albite and potash feldspars will increase, while the dissolution of nepheline will weaken slightly.