Granulation by Extrusion and Compaction Methods

1. PRODUCTION OF MIXED FERTILISERS BY EXTRUSION INCORPORATING BY-PRODUCT MATERIALS.

Conclusions.

Producing fertilisers by extrusion is practical and has value for the particular operation of incorporating organic by-products. It is not a cheap method of production but has the virtue of not being a continuous process so that fertiliser prescriptions can be dispensed according to the need of the soil, the plant and the idiosyncratic desire of the farmer. The fertilisers so produced are efficient and effective.

These types of organic fertilisers are produced in the UK for agriculture and particularly for the horticulture, and for turf dressing.

Pelleted fertiliser or agriculture is best applied by a spreader and not drilled into the ground. Hence, there is some limitation in its application to cereal crops.

The process is capable of development by improving both the pelletiser and the die performance as these apply to producing fertilisers.

The capital cost of pelletising plant is low compared with an equivalent granulation plant. The plant is compact and light-weight so that the housing and civil work involved is not onerous.

The largest single criticism of the process is the very heavy utilisation of electricity.

A Stephenson, Humber Fertilisers plc., UK.

13 pages, 2 figures, 6 tables.

2. GRANULATION OF FERTILISERS IN COMPACTION/GRANULATION PLANTS.

Summary.

The today’s intensive farming requires natural or synthetic mineral fertilisers which can be applied to as single- or multi-component types. Besides the chemo-physical properties of the fertilisers their mechanical characteristics play an important role in the fertiliser technology.

Therefore granulation techniques were developed to transform the pulverulent material into a shape being suitable for handling and final use by means of enlarging the grain size. One of these techniques is the binderless compacting with subsequent crushing and sizing.

The principle of this compaction/granulation system will be described whereby the compaction process is of much importance. The parameters influencing the compacting process are discussed. Finally, some typical examples of application serve the purpose of illustrating the compaction/granulation plants.

R Zisselmar, Koppern GmbH, Germany.

20 pages, 7 figures, 2 tables, 3 refs.