Natural phosphate sources low in heavy metals are getting scarce. Containing about 15 mass-% of P2O5, sewage sludge ash can be considered as secondary phosphorus (P-) source. The P-content in the European sewage sludge could replace roughly 15% of the phosphate imports into the EU. The RecoPhos project will use an innovative reactor in order to recover phosphorus from sewage, sludge and ashes. The reactor was originally designed for the reductive recovery of steel work dusts. By the use of ashes the material flow will be minimal; if only sludge is available, it can be also used as input, adding flexibility to the concept. If additives are needed, suitable industrial wastes can be used.