USE OF BSC AFTER ACID SOLUTION TO DEVELOP THE EXPANSION PROPERTIES OF CEMENT

Abstract

Formation of hydroxyl complexes in the Fe(0)-Fe(II)-glycine-water system from pH at I=0.5 mol/l, temperature 298.15 K, СFe(II)=1×10-4 and СGly=3×10-3 mol/l were studied by the Clark–Nikolsky oxidative potential method. Experimental curves of the dependence of the EMF of the system on the concentrations of hydrogen, iron(II) and glycine ions: рН, рСох, pCL, respectively, are obtained. They allowed us to establish that the processes of complexation in the studied system proceed stepwise in a wide pH range from 1.0 to 8.2. The type and number of coordinated ligands and the total composition of the complex compounds formed were determined. Chemical models of complex formation reactions and model parameters of coordination compounds have been compiled. The values of the angular coefficients, the domain of dominance and the constants of the formation of complexes are determined. The formation of the following coordination compounds is shown: [Fe(OH)(H2O)5]+; [FeHL(H2O)5]2+; [Fe(HL)(OH)(H2O)4]+; [Fe(OH)2(H2O)4]0 and [Fe2(HL)2(OH)2(H2O)8]2+.