Recycling ferrous-nickel slag in blast cleaning

The aim of this study is the development of a procedure for the recycling of the ferrous-nickel slag that is widely used in open dry blast cleaning operations in Greek shipyards thus annually generating thousands of tons of blast cleaning waste. Laboratory tests were carried out, based on the reclamation of the material fraction with size a distribution within the range -1400+150 μm, in order to determine the number of the effective uses (life cycles) of the abrasive material. It is demonstrated that the reclamation yield in the first three life cycles is more than 80%. Laboratory tests also proved that the recycled ferrous-nickel slag has properties comparable to the fresh material’s ones in terms of particle size distribution, consumption and other physical-chemical properties.

A semi-industrial recycling unit of used ferrous-nickel slag was also designed and installed in a Greek shipyard (Neorion New SA of Syros Shipyards). The operation of the semi-industrial recycling unit verified the conclusions resulting from the laboratory tests, and most important, it was proved profitable for the shipyard.