Production of Calcium Phosphate Particles from Marine Wastes by Gas Jet Assisted Laser Heating

Abstract

There are many manufacturing techniques to form metallic particles with certain size and properties. The laser heating method has been successfully applied to generate metallic particles when a supersonic gas flow is assisting this process. The metallic target is heated, melted and vaporised and micro-particles are carried away by a gas flow stream. The high-velocity gas is used to solidificate molten particles and to condensate the metallic vapour resulting in the formation of fine particles. Several attempts were carried out for the production of metallic particles by laser supersonic heating method, obtaining spherical micro-particles (1- 50 "m) of copper, steel, or aluminium. This work presents the application of this method to generate particles from fish bone, in order to obtain a material with a composition close to the inorganic part of the bones. A pulsed Nd:YAG laser has been used to obtain calcium phosphate micro- and nanoparticles. Microparticles size ranges from 10 to 100"m, whereas the nanoparticles have diameters as small as 2 nm. High resolution transmission electron microscopy (HRTEM) allowed us to identify the nanoparticles as whitlockite.