The paper outlines the consequences with respect to physical quality of the continuing development of storage and handling of fertilisers in bulk. Dispatching bulk fertilisers all the year round from the W-European continent to destinations all over the world requires high standards of quality.
Whereas the chain of actions to move fertiliser from production-facility to application on the farm is done partly or wholly in bulk, the physical quality of the fertiliser is threatened by a number of actions which do not play a part if the fertiliser is bagged.
The most detrimental of these actions are:
— transhipment with danger of crushing, abrasion and segregation and increase of caking tendency as a consequence.
— exposure to climatic conditions of rain, humidity and sunshine.
— prolonged storage of large heaps.
Good fertiliser quality means: “fitness for use under modern farming and distribution methods”:
— good storage quality.
— good handling and transport quality.
— well balanced nutrients to supply crop requirements.
These objectives, seen from the point of view of the ultimate users of fertilisers, mean that certain strict requirements are to be set for a range of physical properties of the product.
High physical quality of fertiliser means good ability to withstand these actions. The physical quality can be measured by a number of physical properties i.e.:
• particle size distribution (mean diameter and spread)
• hygroscopic behaviour
• mechanical strength
• bulk density
• flow behaviour
By comparison of test results before, after and during the bulk distribution chain, the influence of bulk handling on the physical quality can be determined and analysed. This has enabled us to define the production control quality standards necessary to preserve the required quality for application, even at high throughput rates and in humid climates.
In the paper, UKF’s answer to these strict requirements for the handling storage and transport of bulk fertilisers is explained. Therefore, the actual criteria set by UKF for bulk fertiliser quality are presented as far as they are determined through routine sampling and analysis of the regularly changing product-mix.
The numerous factors influencing the quality of bulk fertilisers make the subject rather complex. Therefore, so-called Ishikawa-diagram, demonstrating the relationships between the different factors and the bulk quality, is presented.
It is expected that this diagram will support the understanding of how to manage quality of bulk fertilisers. To accept this challenge successfully, it will be necessary to exploit the best from all the employees throughout the company. In this way “quality” may be the key to success.
At least in W-Europe the development from bagged to bulk fertilisers will continue for economic reasons. Important markets like India and Pakistan are almost completely switched over to receive fertilisers in bulk.
Good quality of fertilisers nowadays means:
“Fitness for use under modern fanning and distribution methods”.
In other words good physical quality of fertiliser means:
* good transport and handling properties in (trans)shipment
* maintaining good physical quality during long-term storage
* effective application of essential nutrients through good distribution of particles
As a consequence the physical quality of bulk fertiliser must meet the following requirements:
* free flowing
* free of harmful substances
* constant and narrow range of particle size distribution
* constant bulk density for each sort of fertiliser
* smooth, strong and spherical particles
Considering the harmful effects of handling, storage and transport in bulk on physical quality of fertilisers, these quality requirements are even higher.
Constant attention and expertise and specific measures, based on long-term experience and extensive know-how, are essential ingredients for successful production and delivery to end-users of fertilisers in bulk with a constant high standard of quality. Adequate quality test methods and defined standards are essential for an effective quality control system based on a generally accepted company quality policy. These standards should take into account the “quality consumption” by the distribution chain for bulk fertilisers.
Nowadays UKF is able to offer and distribute, throughout European countries and countries with similar climates, a wide range of fertilisers in bulk which can cope with the most severe quality requirements.
Also for overseas markets, CAN, urea, sulphate of ammonia, mono- and diammonium phosphate and many compound fertilisers are dispatched in bulk all the year round by UKF as a matter of routine without major difficulties.
CAN, other NP-’s and NPK-’s do still have to be delivered to some of our overseas export markets in bags because one is not equipped for transshipment and bagging of fertiliser in bulk.