Fertilizer Formulation, Influence of Formulation on Physical Properties of Fertilizers

Abstract

This work was undertaken to determine to what degree caking in fertilizers could be controlled by formulation. A method for determining caking tendencies was devised. The composition of ammoniating solution and the solution phase of a 3-12-12 fertilizer were studied to determine their influence on caking. The work indicated that improvement in the condition of mixed fertilizer could be obtained by controlling ammoniation solution composition. Metathesis contributed markedly to the amount of objectional salts in solution and to crystal forms deposited from the solution phase, and, within the range normally found in mixed fertilizer, degree of ammoniation and moisture content contributed little to caking. Until drying becomes common practice in fertilizer manufacture, it appears that physical condition can be improved by selection of proper raw materials. The caking of mixed goods during the time between bagging and application is a problem, long recognized in the fertilizer industry. Various facets of .the problem have been studied and Worth-while information has been obtained. Adams and Ross (2) reported on the caking tendency of pure salts, Lawrence (8) discussed the factors considered most detrimental to well conditioned goods, and Rader (77) markedly increased the knowledge of the solution phase composition. Other authors have studied hygroscopicity (7, 70, 75, 76), chemical reaction (5, 6, 9, 73), and similar topics concerned with or closely related to caking of fertilizer.Study of the reported work indicated that many factors influence caking: loss of moisture, change in temperature,