Étude cinétique et thermodynamique de l’attaque d’une fluorapatite par des mélanges d’acides sulfurique et phosphorique À 25°C

Modelling of a solid dissolution in liquid with chemical reaction: Application to the attack reaction of phosphate by sulphuric acid

“…The enthalpy value is related to the fluoroapatite mole number. This value is close to that reported in the literature by Antar et al: Δ H reaction = −224.5 kJ mol −1 .…”

“… The low value of activation energy enables us to ensure that the chemical regime is not the limiting step and thus the mass transfer is the rate‐controlling step. Furthermore, the activation energy value is in the interval of the values reported in literature, whose values lie between 15 and 29 kJ mol −1 …”

Calorimetric and Potentiometric Studies of Ag+ Complexation With Tris(Dimethylamino)Phosphine Sulfide in Acetonitrile Solution

“…The recorded signals were processed according to the procedure developed in previous papers [24][25][26][27][28] in order to get the deconvoluted curves and to calculate iteratively both thermodynamic and kinetic parameters from the thermogenesis curves.…”

Dissolution of Tunisian phosphate ore by a mixture of sulfuric and phosphoric acid: Kinetics study by means of differential reaction calorimetry

“…Several studies on the dissolution of synthetic phosphate [5][6][7][8][9][10][11][12] or phosphate ore [13][14][15][16][17][18][19][20][21][22][23] in acid solutions have been carried out such as phosphoric acid [5,[15][16][17], succinic acid [18], acetic acid [19], and hydrochloric acid [6,[20][21] to illustrate the kinetics and process mechanism as well as enhancing the yield of the phosphate attack. Nevertheless, phosphate ore dissolution by sulfuric acid remains the most extensively used process [22] and over 90% of the phosphoric acid produced globally is manufactured through the decomposition of phosphate ore with sulfuric acid as an acidulate [23].…”

“…However, another study by Amira et al [17] studied the phosphoric acid acidulation of Tunisian phosphate and established that the attack rate increased with increasing temperature and the experimental results fit the shrinking-core model with an ash layer diffusion control with an activation energy equal to 25.4 ± 1.8 kJ mol -1 . The attack of the natural phosphates being complex, is the reasonthat our team initially used synthetic phosphate for the modelization of the reaction of acid attack of phosphates [5][6][7][8][9][10][11].…”