Increasing force is applied to the grains to assess the crushing resistance of pellets until their breaking point.
|Hardness, crash resistance||> to 30 Newton||> to 35 Newton on average|
|Resistance to mass-taking||< to 50 Newton||< to 30 Newton|
|Resistance to moisture intake||close to 0||close to 0|
A fertilizer sample is subjected to a load of 17 kg for 3 days at 40oC. The force needed to break the clod is then measured.
A 1-litre test tube is filled with the sample to be tested, packed and weighed.
|Nitrogen fertilizer density||0,85 to 0,95 kg/l||0,8 to 1,1 kg/l|
|Compound fertilizer density||0,90 to 1,20 kg/l||1 to 1,15 kg/l|
|Dust rate||less than 1 per 1000||less than 0.5 per 1000|
A fertilizer sample is introduced into a counter-airflow column to remove the dust. The weighing differential before and after the column passages is used to calculate the dust level.
A sample of fertilizers was passed through smaller and smaller grids to assess the different granulometric slices of the sample.
This test is used to determine the median diameter (D50) of the sample.
|Median diameter||minimum 3 mm||80% des granulés entre 2,5 et 4 mm|
3,35 mm on average
3 < D50 < 3,5 mm
2,5 < 80% < 4 mm
2 < 96% < 4,75 mm
|Sphericity||> to 60%||> to 70%|
The pellets are poured on a moving disc.
The round pellets roll towards a receptacle, the others are ejected by wind tunnel.
We weigh the proportion of round pellets.