Influence of cellulose additive on the granulation process of potassium dihydrogen phosphate

Abstract

KH2PO4, which was manufactured using conversion of KCl and NH4H2PO4, is concentrated crystalline chlorine-free phosphorus and potassium fertilizer. It is usually used as a component of liquid complex fertilizer, because KH2PO4 crystals melt very easily, have very high hygroscopicity and caking effect. Granulated products are considerably more convenient than powders, but KH2PO4 crystals are pure, hardly agglomerate, therefore they need a proper binder. This study aims to investigate the influence of cellulose additive and other different conditions on the granulation process and on the properties of the granulated product. Potassium dihydrogen phosphate was granulated using three different types of granulators (rotary, a fluidized bed and a drum) and by changing the amount of water used for irrigation purposes. The achieved results indicate that in order to obtain granulated potassium dihydrogen phosphate with optimal properties the use of water does not suffice; therefore, another binder (cellulose) was used in order to improve physical and mechanical properties of the granules. Was determined that cellulose additive (5%) improves some properties of the fertilizer such as, the amount of marketable fraction, SGN, pH, also reduces the hygroscopicity of the fertilizer granules about 2 times. But cellulose additive does not improves the static strength of granules and bulk density. Highlights1. Fluidized bed and rotary granulators cannot be used to obtain granulated PDP.2. For PDP granulation can be used drum-granulator-dryer.3. PDP cannot be granulated by using water.4. MC addition improving the most important properties of fertilizer.

Equilibrium Solubility Behavior and Thermodynamic Properties of Potassium and Ammonium Di-Hydrogenophosphate Aqueous Solutions at T = 298.15 K

“…were evaluated in the range of ionic strength fraction (y) from 0.00 to 1.00 using the developed models of Pitzer and CPB. The solubility m s of potassium and ammonium dihydrogenophosphates in aqueous solutions is calculated using eq 1 and the above two models with parametrization to determine the osmotic coefficients; however, in terms of the precipitated phase, the solid solutions are composed of a mixture of binary systems (K, NH )H PO (s) 4 2 4…”

“…The aqueous mixed solutions of potassium and ammonium dihydrogenophosphates were prepared by dissolving anhydrous materials extra pure by Sigma-Aldrich (SA) and Riedel-de-Haen (RH), respectively, with mass fraction purity of KH 2 PO 4 (≥0.99, SA), (NH )H PO 4 2 4 (≥0.99, RH) (Table 1), and double-distilled water (conductivity <5 μS•m −1 ). The molality is made at the considered value in the mixed system, and its standard uncertainty is u(m) = 0.01 mol•kg −1 .…”

“…Phosphoric acid salts are of great commercial and scientific importance. They are broadly employed in several industries, such as agrifood and pharmaceuticals. , Potassium and ammonium orthophosphates can be used as food additives, stabilizers, antioxidants, and water retention agents. – Ammonium and potassium dihydrogenphosphate are important in fertilizers and industrial materials. The physicochemical properties of electrolyte solutions are very useful for understanding their behavior.…”