Assessment of organic granulated manure fertilizers frictional properties

Abstract

Organic granulation and the use of granular organic fertilizers are usually used in organic farming for agricultural plant cultivation. Granulated organic manure fertilizer can be added locally by using a standard serial agricultural technique. These ecological fertilizers need smaller containers, are easier to transport, do not cause self-heating and self-ignition risk. The quality of the used granular fertilizers is determined not only by the chemical composition, but also by the physical and mechanical properties, such as: strength of the pellets, durability, friction, moisture and geometric characteristics of granules. Friction coefficients are one of the most important physical–mechanical properties of the material and affect all of their granulation and use processes: transportation, dosing, forming, spreading and etc. The paper provides the research results on static and dynamic friction of granular manure compost fertilizers. It was established that the static granular friction coefficient, in contact with the steel surface at a velocity of 100 mm/min, was about 25 % less than at a speed of 300 mm/min. It was obtained that the dispersion of the static friction coefficient is almost twice lower at bigger velocity of the ring. The inter-static and dynamic friction coefficients of organic fertilizer granules were similar and reached about 5. It can be argued that the method of use of two blades for determining the internal granulation friction was not completely suitable due to the size of the particles, fractions and forms.