Physical and Engineering Properties of Fertilzers and their Combination for the Design of Hopper

The physical and engineering properties of the urea (46-0-0), ammonium phosphate (16-20-0), potash (0-0-60), and their fertilizer combination were studied to design the hopper for the fertilizer application unit. The six important properties discussed were angle of repose, moisture content, particle size distribution, flowability, crushing strength and coefficient of kinetic friction. The largest angle of repose values was 33°, 35°, 41° and 47° for urea, ammonium phosphate, potash and their combination respectively. The bulk density value for fertilizer combination was considered for the design of hopper, as the mixture of three fertilizers were applied in the field and its value was 0.92 g cm-3. The urea has lowest coefficient of friction compared to others, which is 0.3. The flowability of the fertilizer was free and the crushing strength of ammonium phosphate and urea was having medium hardness compared to potash, which is very soft. The observed engineering properties viz., flowability, coefficient of friction, moisture content, angle of repose were satisfactory for designing the mechanical fertilizer applicator and bulk density for the volume required for the storage of fertilizer.