Major Oxides and Oxide Minerals

The literature review in Chapter 2 reveals that divalent metal oxides such as oxides of calcium, magnesium, and zinc (CaO, MgO, and ZnO) are the major candidates for forming phosphate ceramics. These oxides are sparsely soluble in acidic solution, and as we shall see in Chapter 4, they are the most suitable ones to form ceramics. In addition, following the methods discussed in subsequent chapters in this book, aluminum oxide (alumina, AI2O3) and iron oxide (Fe203), which are abundant in earth s crust have excellent potential to form low cost CBPCs. For this reason, we have provided relevant information on these oxides. Table 3.2 gives some details. 

Candidate Metal Oxides, Abundance of their Metals in Earth s Crust, their Solubility, and CBPC Forming Temperature. 

Metal Oxide Metal Abundance (wt%) [13] Aqueous Solubility Potential to Form CBPC CBPC Forming Temperature (°C) 

09 Sparingly soluble. Higher in acidic solutions and decreases with pH High volume structural products, and in waste management Ambient and cold 

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