Dissolution behaviour of iron silicate glass

Abstract

A relationship between the water purifying effect and structure of 0.5xNa 2 O·0.5xCaO·5Fe 2 O 3 ·(95-x)SiO 2 glass (Na 2 O/CaO = 1; NCFS glass) with 'x' of 20 and 50 were investigated by means of 57 Fe-Mössbauer spectroscopy, X-ray diffraction (XRD), induced coupled plasma optical emission spectroscopy (ICP-OES), as well as absorption spectroscopy, pH and oxidation-reduction potential (ORP) measurements. In the case NCFS glass with 'x' of 20, dissolved amounts of total Fe, Na + , and Ca 2+ were respectively estimated to be 13.6, 39.1 and 36.7 mg/l, after 10 day-leaching test. On the other hand, the dissolved amounts of total Fe, Na + and Ca 2+ were determined to be 34.3, 647.6 and 667.6 mg/l, respectively when 'x' was 50. The original pH value of 6.0 was increased to 10.0 and 11.6 after leaching test of NCFS glasses with 'x' of 20 and 50, respectively. At the same time, the ORP value was decreased from 30.0 to −195.8 and −284.7 mV in the glasses with 'x' of 20 and 50, respectively.

Long-Term Leaching Effects on CaO-Modified Iron Silicate Slag

“…The long-term leaching effect on CaO-modified slags has not been extensively studied and can be simulated using dynamic leaching tests, such as dissolution and pH-dependent tests [12,[16][17][18][19][20][21]. One means of studying the long-term leaching effect is through the dynamic leaching test (CTG-LEACHCRETE) used for monolithic CaO-rich materials (cement paste), developed by Moudilou et al (2002), which is also suggested for slags [19].…”