Chapter 3 – Raw Materials

The raw materials used in the formation of chemically bonded phosphate ceramics (CBPCs) are identified. Phosphoric acid and its acid phosphates are the major components. An overview of the extraction chemistry of phosphoric acid from apatite rocks is given and the candidate acid phosphates are identified. Also, the oxides required for formation of CBPCs are described briefly, and aggregates normally used in forming CBPC composites are discussed. Fly ash and wollastonite are of particular interest, and hence composition and particle structures of these two raw materials are given in detail. The detailed solution chemistry of these materials is discussed in Chapters 4 and 5, and the composites in Chapter 14.