The high affinity of Mg/Al hydrotalcite for carbonate anions means that it cannot be reversibly exchanged and so prevents its use as an anion-exchange material. However, carbonate can be removed by thermal decomposition, evolving CO2. The resultant material sorbs anions when placed in solution and returns to the hydrotalcite structure. This work showed that hydrotalcite can be used as an anion absorbent by firing, anion sorption, exchanging in carbonate, and repeating the cycle. Ion exchange, XRD, TGA/MS, and Al-27 NMR results showed that after the first firing and rehydration cycle, the hydrotalcite structure becomes disordered, with its sorption capacity reduced by approximately 50%. Further firing/sorption cycles cause only a slow degradation in structure.