Off-spec and Reject Fertiliser: Management Guidelines

Keywords: Ammonium nitrate, Off-spec fertiliser, Reject fertiliser, Guidelines.

On 21 September 2001 a major explosion occurred in a bulk heap of ammonium nitrate (AN) in storage at the AZF factory, near Toulouse, France; causing 31 fatalities, injuries to more than 4,500 and extensive damage. The heap contained off-spec/reject AN materials of low density porous grade (used in explosives applications) and the high density fertilizer grade. The tragic event highlighted the need for effective management of off-spec and reject materials and work was undertaken by the European Fertilizer Manufacturers Association (EFMA) to produce a suitable guidance (to be published) for this purpose. This paper, drawing upon this work, describes the relevant factors, identifies the potential sources of off-spec and reject material and briefly outlines their potential hazards. Various general principles of good management and options available for utilisation of these materials are described. An investigation carried out by one of the EFMA companies for reduction of hazard sensitivity has been partly reported.

Kish D Shah MBE, B.Sc (Eng) Hons. F.IChemE. C.Eng. MIOSH., Terra Nitrogen (UK) Limited, Stockton-on-Tees, UK.

Hans van Balken, PhD., EFMA, Avenue E Van Nieuwenhuyse 4, Boite 7, B-1160 Brussels, Belgium.

22 pages, 2 figures, 8 tables, 5 references.