Keywords Ammonium nitrate, Nitram, Ammonium nitrate safety, Ammonium nitrate manufacture.

INTRODUCTION
Ammonium nitrate has played a major role in the development of fertilisers during the past 10-15 years, during which time the manufacturing process has seen a number of stages of development. In the basic process now used by all manufacturers considerable detail improvements have been made during recent years. In this paper we describe the recent process developments made by the Agricultural Division of ICI; we do not attempt to review or compare the many processes in use throughout the world. We have used this particular process as a basis to discuss variations which are in use and explain why, at each stage, ICI chose its particular techniques.

The process and techniques used do not always lead to the cheapest possible plant. Emphasis has been laid by ICI on the safety aspects of plant and product and on the elimination of the effluent problem always attendant on ammonium nitrate plants. It will become clear that the know-how involved can be used to design plants to satisfy a number of different sets of criteria, including low capital cost plants where appropriate.

R W R Carter and A G Roberts, ICI Ltd, Billingham, UK.

48 Pages, 12 Figures.