Calcium Phosphates in Biological and Industrial Systems

Research on calcium phosphates has attracted considerable attention in recent years. Calcium phosphates are the major inorganic constituents of biological hard tissues such as teeth and bones and other pathological minerals. Calcium phosphates have been widely produced in industry, in such forms as, ceramics, nutrient supplements, medicines, dentifrices, and stabilizers for plastics. They are utilized in solid state chemistry as fluorescent lamp phosphors and play a role in waste water treatment processes. Calcium phosphates are important in industrial water treatment (Le. , boiler and cooling) where deposition of these salts on heat exchanger surfaces can lead to loss of system efficiency, overheating, unscheduled shutdown time, and ultimately heat exchanger failures. Effective control of calcium phosphate deposits continue to challenge the industrial scientist. Calcium phosphate deposits have also been encountered during pasteurization of milk. Calcium phosphates of interest include: dicalcium phosphate dihydrate (DCPD, CaHP0-2H0), brushite; dicalcium phosphate anhydrous (DCP, CaHP0), 4 2 4 monetite; octacalcium phosphate (OCP, CasH2(P04)6-SH20); tricalcium phosphate (TCP, Ca3(P04h), whitlockite; and hydroxyapatite (HAP, Cas(P04h0H). Other calcium compounds of biological and industrial interest include: amorphous calcium phosphate (ACP); fluorapatite (FAP, CaS(P04)~); calcium pyrophosphate dihydrate (CPPD, CaP07-2H0); calcium fluoride; and calcium phosphonates. 2 2 2 This book is intended to provide a comprehensive discussion on calcium phosphates in the diverse areas of their investigations.