Computer simulation of calcareous deposition

Formation of calcareous deposits on marine structures under cathodic protection reduces the current required to protect the surface, as time progresses. Computer aided design methods to date rely heavily on polarization data obtained from laborious and expensive in situ experiments. The present approach lays the foundation for a new design method in which the formation of calcareous deposits is modeled from first principles, based on precipitation and diffusion of ions of the constituent compounds in the boundary layer. Calcareous deposition in a one dimensional boundary layer was modeled and this model was used successfully to simulate the cathodic protection of a rotating cylinder in artificial sea water. Precipitation rate constant of Mg(OH)$\sb2$ was determined and the pH on the cylinder surface was estimated to be one tenth of a pH unit higher than that required for the precipitation of magnesium hydroxide from sea water.