(49a) Use of Bentonite Binder to Optimize Granulation Process during Fertilizer Manufacture

Bentonite is one of the abundant natural clays that have caught the interest of many industrial applications as a binder and a filler. Varying quantities of bentonite were used in the wet granulation of Compound D (NPK) fertilizer from dry powders in the granulation plant at a local plant in Zimbabwe. Samples of the product were collected from the plant, after drying (prior screening), to analyze the effect of the binding properties of bentonite on the particle size distribution of the granulated fertilizer. Higher quantities of bentonite showed a reduction in gypsum losses, as less fines were obtained upon carrying out the grist test. Results proved that bentonite can be used as an effective binder in optimizing to the right target fertilizer granule size.