Leachability of iron ions from binary and ternary phosphate glasses

Abstract

With a view to using glasses as a source of iron, which is one of the micronutrients required by plants, a systematic study on leachability of iron ions from binary and ternary phosphate glasses having molar composition (40+X)FeO.(60-X)P2O5 and (55-X)FeO. XR2O.45P2O5 (where X = 0–9 mol% and R = Li, Na, K) was carried out. Leaching of iron ions has been studied as a function of pH and the results show that leaching increases with increasing pH of the solutions. The concentration of iron ions in the leachate decreases with increasing bond strength between non-bridging oxygen ions and the cations in glasses. The leaching of iron ions enhances with increase in leaching time as well as an increase in the concentration of P2O5 in the glass. It decreases further with an increase in particle size of glasses. © 2009 Taylor and Francis Group, LLC.