A polyaluminum chloride (PAC) solution, used in the coagulation sedimentation process during water treatment, was proposed to prepare hydrotalcite-like compound (HT) for industrial processes. HT was also prepared with PAC and calcined dolomite as magnesium and alkali sources. The dolomite calcination was carried out in an electric furnace at 1000°C for 1 hour. The contents for CaO and MgO in the calcined dolomite was 55.2% and 41.8% by weight indicating that the composition of calcined dolomite is CaO·MgO. The mixture was stirred continuously at 25°C for 12 hour and the resulting suspension was washed with deionized water and centrifuged repeatedly. The calcined dolomite was hydrated after its addition to the mixed solution of MgCl2 and PAC. The proposed method mainly produced Cl--HT, which can be used for anion exchange and can be transformed by calcination at 400-600°C for the wastewater treatment application.