Ceramic microfiltration membranes based on natural silica

Abstract

The physicochemical features of preparation of macroporous ceramics and multilayer ceramic materials based on natural silica—quartz sand—from the Republic of Belarus, Qatar, Saudi Arabia, Mongolia, Azerbaijan, Turkmenistan, and Vietnam have been studied. It has been shown that the properties and structure of macroporous ceramic substrates are mostly determined by the phase composition of the natural sand and its quartz content. Membrane layers on the macroporous ceramic surface have been formed by the deposition of a suspension of fine natural silica in an aqueous solution of an aluminosilicate binder. The resulting microfiltration membranes with an average pore size of 3–5 μm, an air permeability coefficient of 10^–12–10^–13 m², a water permeability of 10–50 m³/(m² h bar), and a tensile strength of up to 10 bar are promising for wide practical use in the microfiltration of liquid media.