Study on the Adsorption Behavior of Co(II), Pb(II) on Modified Sodium Trititanate Whisker and Its Application to Wastewater
The modification of sodium trititanate whisker surface was performed by means of impregnation procedure to fabricate the modified sodium trititanate whisker, which was characterized by scanning electron microscopy(SEM) and infrared spectroscopy(IR). Its adsorptive performance for Co(II), Pb(II) in a static system was investigated by inductively coupled plasma atomic emission spectrometry(ICP-AES). The main factors affecting adsorption and desorption of Co(II), Pb(II), the adsorptive capacity of Co(II), Pb(II) in optimal condition and adsorption isotherm and the influence of coexistent ions were examined. The comparative test for selectivity was done. The adsorptive rate for Co(II) and Pb(II) on 0.2500 g of modified sodium trititanate whisker at PH 5.0 was the best. Co(II), Pb(II) adsorbed on the modified sodium tretitanate whisker could be eluted with 10 mL of 3.0 mol/L HCl. The adsorptive performance of modified sodium trititanate whisker was better than that of unmodified sodium trititanate whisker. The sobent has been applied to the enrichment and separation of Co(II), Pb(II) in water sample to determine Co(II), Pb(II).
The influence of temperature on the structural behaviour of sodium tri- and hexa-titanates and their protonated forms
Abstract The thermal stability of Na 2 Ti 3 O 7 and Na 2 Ti 6 O 13 , together with that of their protonated forms was investigated. The influence of temperature on the structural behaviour of tri- and hexa-titanates was studied using DTG, XRD, FTIR and FT-Raman. These results were correlated with the nature of the exchangeable cations using elemental analysis and N 2 -sorption. The tunnel structure of Na 2 Ti 6 O 13 revealed a higher thermal stability compared to the layered structure of Na 2 Ti 3 O 7 that shows traces of dimerisation above 800 °C. The sodium forms were observed to be more thermally stable compared to their protonated forms. However, analysis show that ‘H 2 Ti 6 O 13 ’ is much more thermally stable than the layered H 2 Ti 3 O 7 which go through structural changes above 250 °C and suffer a complete structural collapse into anatase/rutile above 800 °C. It was obvious that thermal stability was significantly influenced by the nature of the exchangeable cations and the degree of ion-exchange.
Thermodynamics on the Carbochlorination of Titanium-bearing Ores
The equilibrium compositions of the multi-component, multi-phase and multi-reaction system of carbochlorination of titanium-bearing ores are calculated with HSC, a computational chemistry software. The thermodynamic equilibrium calculation of the reaction system shows that a complete conversion of titanium-bearing ores is feasible at a temperature near 200oC. At temperatures ranging from 800 to 1600oC, the products of the reaction system are all in gaseous phase. Thermodynamic analysis accords with the industrial practice. The simulated results provide reasonable scientific basis for improving suitable technological conditions of the carbochlorination reduction.