The recovery of phosphorus from sewage sludge and sewage sludge ashes provides a sustainable solution for the provision of this finite resource. For this purpose, a variety of methods are available, which differ in concept and products. The RecoPhos-Process provides a new approach for the recovery of phosphorus from sewage sludge ash by the use of a graphite bed in an inductively heated packed bed reactor. As part of the RecoPhos project a bench scale plant was designed and built to allow meaningful results regarding the RecoPhos-Process. For the development of the process and further industrial implementation it is necessary to get a mathematical description of the inductively heated graphite packing. In this thesis an approach is presented, which allows to calculate the inductive heating of the packed bed of graphite.