Modeling of hydroxyapatite precipitation in a rotating diskreactor

In this work the use of a Rotating Disk Reactor for the precipitation of hydroxyapatite is investigated. The adopted device is able to produce nanoparticles in a continuous mode whit relatively low energy consumptions. The required conditions of micromixing can be established in correspondence of the reagents feeding point. The experimental work was mainly devoted to investigate the effect of the reagents feed location over the rotating disk surface. This operating parameter has a great influence on the particle size distribution of the produced HAP and only the optimized position allows the production of particles smaller than 100 nanometers. The obtained experimental results were interpreted on the light of a hydrodynamic simulation model. The model provided the map of the specific dispersed energy and the flow regimes in the liquid films, thus allowing the identification of the disk zones where micromixing may occur.