TITLE:
Effect of Different Kinetic Factors on the Thermochemistry of Sulfophosphoric Attack Reaction of Natural Phosphate Tunisian by DRC
AUTHORS:
Olfa Lachkar-Zamouri, Khemaies Brahim, Faten Bennour, Ismail Khattech
KEYWORDS:
Thermochimique, Phosphate Ore, Differential Reaction Calorimetry, Concentration, String Speed, Particle Size
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.8 No.11,
November
16,
2018
ABSTRACT: Mixture of phosphoric and sulfuric acid solutions
has been used to investigate the dissolution of natural phosphates (PN) by DRC.
The effect of concentration, particle size and stirring speed reaction is
examined. Thermochimique properties of each kinetic parameters reaction are
determined. It was found that these parameters have a considerable effect on
the thermochemical aspect of the attack reaction. It is known that the process
of PN sulphophosphoric acid attack leads to the formation of dihydrate (CaSO4.2H2O:
DH). The present work shows the precipitation of other residues their formula
depends on factors studied. The increase in concentration leads to the
formation of hemihydrate (CaSO4v1/2H2O:HH) beside DH for the low values of% H2SO4 due to the solubility of dihydrate on the etching solution and the
precipitation of (Ca (H2PO4)2.2H2O)
next of DH for low agitation values because of the lack of turbulence between
the liquid phase and the solid phase which favors the precipitation of this
latter compound.