Magnesium-aluminum layered double hydroxides (Mg-Al LDHs) possess anion-exchange properties that can potentially be utilized for water preservation and purification. Therefore, a simple and convenient method for preparing Mg-Al LDHs is required. In this chapter, we developed new preparation methods of Mg-Al LDH by using seawater and Ca(OH)2 as magnesium and alkali resources. Furthermore, dolomite and polyaluminum chloride were examined as potential magnesium, aluminum, and alkali resources for the production of Mg-Al LDHs. In addition, we analyzed the formation of Mg-Al LDH, as below. Mg-Al solution, together with alkali (used for pH control), was added dropwise to deionized water. In the local environment, where the droplets of alkali were added, the pH was very high. This high pH resulted in the formation of Al(OH)4- from Al(OH)3; this Al(OH)3 formed in solution with the addition of Mg-Al solution. The Al(OH)4- quickly reacted with Mg2+ and other anions present in the solution, thereby leading to the formation of Mg-Al LDH. Moreover, we examined the characteristics of anion intercalation during Mg-Al LDH precipitation and investigated the Mg-Al LDH particle properties for the various preparation methods.
|Title of host publication||Precipitation|
|Subtitle of host publication||Prediction, Formation and Environmental Impact|
|Publisher||Nova Science Publishers, Inc.|
|Number of pages||18|
|Publication status||Published - 2012 Jan|