The Synthesis and Properties of High Pure δ Layered Sodium Disilicate

Abstract

Abstract δ layered sodium disilicate (δ-Na2Si2O5) is a single layer silicate and has good properties as detergent builder. However, it is difficult to synthesize high pure δ-Na2Si2O5. In this paper, a feasible and simple technology was found by decreasing Na content in liquid sodium silicate (water glass). The crystalline time was short and no seed needed. The suitable synthesis conditions were Si/Na = 1.05–1.10, calcining at 720 °C for 5 minutes. The synthesis conditions are of industrial value. XRD and 29Si NMR data proved that synthesized samples were δ-Na2Si2O5 without impure phase. High pure δ-Na2Si2O5 exhibited good ions binding ability and reached 312 to 338 mg CaCO3/g.