Non-Segregating Blended Fertiliser Development: A New Predictive Test for Optimising Granulometry

Keywords Segregation, Micronutrient, Boron, QPM, SGN, Blended fertilisers.

Particle segregation is a very broad and complex phenomenon that can occur in various areas of plants in industries which handle particulate materials. Segregation is of particular importance in the fertiliser industry and can occur when filling storage silos, during transport and in field application itself. It has special importance for blended fertilisers since with these the segregation can lead to uneven distribution of the different nutrients in the field. Segregation is the separation of particles due to differences in physical characteristics. Of these characteristics, the most influential by far, as far as fertilisers are concerned, is particle size. This paper describes a novel methodology for assessing the level of segregation of bulk solid components to be expected, using the segregation properties of micronutrient boron granules within NPK blends as a model. Results of actual segregation in terms of intensity and distribution within the blends are compared to those predicted using the existing industry method of Size Grade Number (SGN) derived from particle size measurements of the components. The test shows very good correlation between the two methods and that the SGN method can be used to calibrate the new test. In addition the new methodology offers a practical test prediction of segregation in many other material storage and transport situations.

I A Bridle, M S A Bradley and A R Reed, The Wolfson Centre for Bulk Solids Handling, School of Engineering, University of Greenwich, London, UK.

H Abou-Chakra and U Tüzün, Chemical and Process Engineering, School of Engineering, University of Surrey, Guildford, UK.

I Hayati and M R Phillips, Borax Europe Limited, 1A Guildford Business Park, Guildford, UK.

27 Pages, 17 Figures, 13 Plates, 3 Tables, 13 References