Solubility of the Ternary System LiCl + NH 4 Cl + H 2 O

Self Cite

The water activities of the systems MSO 4 + H 2 O (M = Mn, Co, Ni, Cu, Zn) are essential data needed for simulating the hydrometallurgical process of these metals. In our previous work (J. Chem. Eng. Data, 2014, 59, 97−102), the experimental data of water activity for these binary systems have been reported at 323.15 K. As one part of this series of work, the experimental data of water activity for these systems are reported at 373.15 K. The reliability of the apparatus at 373.15 K was verified by measuring and comparing the water activities of the two reference systems, CaCl 2 + H 2 O and LiCl + H 2 O. The results showed that the maximal relative deviation of the water activities between the reference systems was 0.054%. The water activities for the concerned five systems were found to be approximately the same at a certain salt molality below 1 M. The water activities of these systems decrease at a certain salt molality more than 1 M in the following sequence: a MnSO 4 > a CuSO 4 (∼a ZnSO 4 ) > a CoSO 4 (∼a NiSO 4 ). Furthermore, the experiment data obtained in this work were compared with the model values reported in the literature.

Section: Experimental Sectionmentioning

confidence: 99%

Isopiestic Measurements on Aqueous Solutions of Heavy Metal Sulfates: MSO₄ + H₂O (M = Mn, Co, Ni, Cu, Zn). 2. T = 373.15 K

Yang

Zeng²,

Voigt

et al. 2016

Self Cite

“…After that, the composition of the brine can be summarized as the quinary system Li + , K + , Mg 2+ , Rb + //Cl − −H 2 O 1 O. Up to now, some ternary subsystems among them have been investigated in our previous research, such as the metastable phase equilibria of ternary system LiCl + RbCl + H 2 O at 298 K 2 and ternary systems KCl + MgCl 2 + H 2 O and KCl + RbCl + H 2 O at 298 K, 3 323 K, 4 and 348 K. 5 For the ternary systems LiCl + KCl + H 2 O and LiCl + MgCl 2 + H 2 O, some research has been done, such as the metastable phase equilibria of the ternary system LiCl + KCl + H 2 O at 298 K 6 and 323 K, 7 the stable phase equilibria of system LiCl + KCl + H 2 O at 348 K, 8 the stable phase equilibria of the ternary system LiCl + MgCl 2 + H 2 O at 273 K, 9 298 K, 10 333 K, and 348 K. 11 However, the metastable phase equilibria of these two ternary systems at 348 K have not been reported in the literature.…”

Section: ■ Introductionmentioning

confidence: 99%

Thermodynamics Phase Equilibria of the Aqueous Ternary Systems LiCl + KCl (MgCl₂) + H₂O at 348 K

Tan

et al. 2015

The thermodynamics phase equilibria of the aqueous ternary systems LiCl + MgCl 2 + H 2 O and LiCl + KCl + H 2 O at 348 K were investigated using an isothermal evaporation method. The solubilities and physicochemical properties such as density and refractive index of the equilibrated solution were determined. The compositions of solid phases were confirmed using the Scherinemakers' wet residue method. In accordance with the experimental data, the phase diagrams and physicochemical vs composition diagrams were constructed. The ternary system LiCl + MgCl 2 + H 2 O is of a complex type with double salt LiCl•MgCl 2 •7H 2 O (lithium carnallite) formed at 348 K, and its phase diagram consists of two invariant points, three univariant curves, and three crystallization fields corresponding to lithium chloride monohydrate (LiCl•H 2 O), magnesium chloride hexahydrate (MgCl 2 •6H 2 O), and lithium carnallite (LiCl•MgCl 2 •7H 2 O). The ternary system LiCl + KCl + H 2 O is of a simple eutectic type at 348 K, and its phase diagram is composed of one invariant point, two univariant curves and two crystallization fields corresponding to potassium chloride (KCl) and lithium chloride monohydrate (LiCl•H 2 O). Lithium chloride has a salting out effect on magnesium chloride or potassium chloride. Comparisons between the metastable and stable phase diagrams at 348 K of these two ternary systems have been drawn. In the system LiCl + MgCl 2 + H 2 O, the crystallization region of MgCl 2 •6H 2 O under the metastable equilibrium is smaller, while the crystallization region of the LiCl•MgCl 2 •7H 2 O is larger. In the system LiCl + KCl + H 2 O, the crystallization regions of LiCl•H 2 O and KCl under metastable equilibrium are both smaller. Comparisons between the metastable phase diagrams of system LiCl + KCl + H 2 O at (298, 323, and 348) K show that the crystallization region of LiCl•H 2 O increased with the rise of temperature, whereas the crystallization region of salt KCl is decreased.

“…The salt content of the NaCl (aq) reference solution was determined both gravimetrically by precipitation with AgNO 3 (aq), 18 and by the constant-weight evaporation method. 19 The content of the H 2 SO 4 (aq) stock solution was determined both by gravimetric precipitation with BaCl 2 (aq), 18 and by titration with NaOH (for H + ). 18 The composition of H 3 AsO 4 (aq) was determined by titration with NaOH (for H + ), 18 while the composition of NaOH was determined by titration with potassium hydrogen phthalate (KHP, C 8 H 5 KO 4 ).…”

Section: Methodsmentioning

confidence: 99%

“…The salt content of the NaCl (aq) reference solution was determined both gravimetrically by precipitation with AgNO 3 (aq), and by the constant-weight evaporation method . The content of the H 2 SO 4 (aq) stock solution was determined both by gravimetric precipitation with BaCl 2 (aq), and by titration with NaOH (for H + ) .…”

Section: Methodsmentioning

confidence: 99%

Isopiestic Measurements of Water Activities for an Arsenic Acid Aqueous Solution at 298.15 K

Yang¹,

Wang²,

Zhou

et al. 2017

The water activity of the H3AsO4–H2O system is quite important for controlling arsenic in the environment and modeling the hydrometallurgical processing related to arsenic. In this work, the water activity for this binary system, from extremely low concentrations to a molality of 18 mol·kg–1 at 298.15 K was determined by isopiestic measurements. The relative isopiestic molality deviation for parallel samples in each experimental run was better than 0.2%. When these water activity data were combined with the mean ionic activity coefficient (γm,±) calculated by the Gibbs–Duhem equation, the Pitzer model parameters for arsenic acid aqueous solution were fitted. The reliability of the data and the model parameters obtained in this work were also systematically discussed.