The extractlon of fluoslilclc acid from dilute aqueous solutions by high-molecular-weight amines in kerosene has been studied. Extraction equlllbrium curves for various commercial amines are presented for room temperature, an amine concentration of 0.2 M, and aqueous acid concentrations up to 1 M. Formation of stable suspensions, coextraction of water, and aggregation of amine salts are discussed. Amine extraction of fluosilicic acid is compared with that of other mineral acids.
The enthalpy, entropy, and equilibrium constant of the reversbble binding of NO to FeI'NTA in an aqueous solutionhave been determined to be AHo = -11.9 kcal/mol, AS = -11.1 eu, and K = 4.6 X lo5 M-' at 50 OC, respectively. The formation and dissociation rate constants of Fe"(NTAXN0) are k 1 7 X 10' M-l s-l a nd k -, 2 35 s-', respectively, at 25 OC. The rate of binding of NO to form the complex is much faster than the mass transfer rate at typical wet scrubber conditions.