ChemInform Abstract: Growth of High-Purity Potassium Dihydrogen Phosphate Crystals from Nonstoichiometric Aqueous Solutions.

ChemInform ◽  
2010 ◽  
Vol 28 (49) ◽  
pp. no-no
Author(s):  
YU. N. VELIKHOV ◽  
O. V. DEMIRSKAYA
Keyword(s):  
Aqueous Solutions ◽  
High Purity ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Potassium Dihydrogen

scholarly journals KH2PO4 crystallisation from potassium chloride and ammonium dihydrogen phosphate

2016 ◽  
Vol 18 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Kristina Jančaitienė ◽  
Rasa Šlinkšienė
Keyword(s):  
Aqueous Solutions ◽  
Potassium Chloride ◽  
Solid Phase ◽  
Potassium Dihydrogen Phosphate ◽  
Molar Ratio ◽  
Dihydrogen Phosphate ◽  
Ammonium Dihydrogen Phosphate ◽  
Potassium Dihydrogen ◽  
Increasing Temperature ◽  
Nitrogen Phosphorus

Abstract Seeking to obtain bulk (NPK – nitrogen, phosphorus, potassium), chlorine-free fertilizers, the influence of interaction between potassium chloride and ammonium dihydrogen phosphate in aqueous solutions at temperature of 20, 40, 60 and 80°C has been investigated. Components of the solid phase have been identified by methods of chemical and instrumental analysis: radiography (X – ray), infra – red molecular absorption spectroscopy (IR) and scanning electron microscopy (SEM). It has been observed that the largest amount of solid state potassium dihydrogen phosphate was obtained at 60–80°C, when the potassium chloride and ammonium dihydrogen phosphate molar ratio is equal 0.8:0.2. Changing the molar ratio of 0.5:0.5 to 0.8:0.2, and with increasing temperature, various shaped crystals have developed in the remaining aqueous solutions with a morphology shifting from sharp needles to tetragonal prism.

scholarly journals Effect of cyclohexane diamine tetraacetic acid on micro morphology of rapidly grown potassium dihydrogen phosphate crystals

RSC Advances ◽  
2017 ◽  
Vol 7 (37) ◽  
pp. 23102-23108
Author(s):  
Weidong Li ◽  
Shenglai Wang ◽  
Guangwei Yu ◽  
Duanliang Wang ◽  
Pingping Huang ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Rapid Growth ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Tetraacetic Acid ◽  
Growth Technique ◽  
Potassium Dihydrogen ◽  
Micro Morphology ◽  
Kdp Crystals ◽  
Point Seed

Potassium dihydrogen phosphate (KDP) crystals were grown from aqueous solutions with different concentrations of cyclohexane diamine tetraacetic acid (CDTA) by the “point seed” rapid growth technique.

Activity Coefficients of Potassium Dihydrogen Phosphate in Aqueous Solutions at 25°C and in Aqueous Mixtures of Urea and this Electrolyte in the Temperature Range 20–35°C

2003 ◽  
Vol 217 (6) ◽  
pp. 723-738 ◽  
Author(s):  
Jaakko I. Partanen ◽  
Yuko Mori ◽  
Marjatta Louhi-Kultanen ◽  
Juha J. Kallas
Keyword(s):  
Aqueous Solutions ◽  
Osmotic Coefficients ◽  
Potassium Dihydrogen Phosphate ◽  
Dihydrogen Phosphate ◽  
Pitzer Equation ◽  
Aqueous Mixtures ◽  
Potassium Dihydrogen ◽  
Parameter Estimations ◽  
Aqueous Urea ◽  
Parameter Values

AbstractSimple two-parameter Hückel and Pitzer equations were determined for the calculation of the activity and osmotic coefficients of aqueous solutions of potassium dihydrogen phosphate at 25°C up to a molality of the saturated solution (= 1.83 mol kg−1). The isopiestic data measured by Stokes (1945) were used in the parameter estimations. The resulting parameter values were tested with all thermodynamic data found in the literature for this electrolyte at this temperature. In these tests it was observed, that the Hückel equation applies to the data within experimental error up to a molality of 1.0 mol kg−1, and the Pitzer equation applies well to the data in the molality range 1.0–1.83 mol kg−1 but not very well in dilute solutions. Therefore, also a three-parameter Pitzer equation was determined that applies to all data. The activity and osmotic coefficients calculated by these three models were compared to the values suggested by Robinson and Stokes (1959) and to those calculated by the equations of Hamer and Wu (1972) and of Pitzer and Mayorga (1973) for this electrolyte. Solubility measurements of KH2PO4 at 20, 25, 30 and 35°C were made in aqueous urea solutions, and the molality of urea varied in these measurements from 0 to 2.5 mol kg−1. The thermodynamics of these studies were analyzed by using the Pitzer formalism. It was observed that only one interaction parameter between urea molecules and ions (this parameter is linearly dependent on the temperature) was needed to describe almost completely the new solubility data.

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