Fertilizer Granule Formation with Recovered Phosphorus by PHOS4green

Using continuous spray granulation to produce phosphate-containing fertilizer

Spray granulation in the fluid bed refines the digested phosphate into a marketable product. This enables you to produce round pellets with a compact, homogeneous particle structure. The process allows the drying of liquids – like suspensions from sewage sludge ash – to produce dust-free, flowable, easy-to-dose granules with high bulk density and a narrow particle size distribution.

Fluidized bed processes are used for thermal treatment and drying to form granules from powders or liquids and to coat particles. A fluidized bed is formed when process air lifts and fluidizes a layer of solid particles. The process air simultaneously provides the thermal energy required for particle production. The process time varies depending on the raw materials and the end product, for example, if substances in the formulation tend to stick together. Once the target size of the fertilizer granules is reached, the product is discharged. It is immediately ready for use and can be directly packaged, shipped and dosed.

The phosphate suspension is sprayed into the fluidized bed in the process chamber and dries on to the particles already in the bed, initiating layer-by-layer particle growth. The small solid particles required to maintain the granular structure are generated in the process itself. These serve as carrier nuclei for the formation of new fertilizer granules.  The liquid raw material suspension is the only required raw material.

Watch the video on Continuous Spray Granulation in the Fluid Bed on the Glatt Youtube Channel here.