Fertiliser Coatings

Keywords: Caking, anticaking, dusting, coating agent, anticaking agent, fertiliser, surface active agent.

Since the start of the industrial production of fertilisers about one hundred years ago, the fertiliser industry has made tremendous progress in developing ever more efficient fertilisers and improved production methods.

In spite of these improvements certain problems are still encountered in the manufacture, handling and application of industrial fertilisers. The main problems can be listed as caking, dusting and moisture pick-up, and have attracted a great deal of attention in the past, but although progress has been made, the task of finding cost-effective solutions will still continue.

Increased mechanised bulk handling and spreading techniques, occupational health and safety plus environmental considerations will demand higher quality fertilisers.

The scope of this paper covers the mechanisms of caking, factors affecting caking, dusting and moisture pick-up, anticaking by using coating agents. The process of selecting a coating agent, laboratory methods used for determining the efficiency and application of these agents, are also covered.

Internally added anticaking agents are only briefly mentioned and coating by slow release is not covered.

Agne Ohlsson, Akzo Nobel Surface Chemistry AB, Sweden.

32 pages, 9 plates, 4 figures, 2 tables, 23 refs.