Porous refractory ceramics using agrowastes and some kaolinitic clays

Abstract

In the purpose of making low cost porous refractories bricks, two kaolin named MY3 and KG from the locality of Foumban in Cameroon are used together with a rice husks (Br) and coffee residues (Rc). The formulations made of mixture of chamotte, raw clay as a binder and agricultural wastes in varying proportions, are fired at 1200 °C for 4 h. The addition of chamotte from 10 to 60 % in the studied clays, contributes to a reduction of firing shrinkage. The mineralogy of the products is made of mullite (34–38 %) which is associated to cristobalite (10–19 %), quartz (14–20 %) and amorphous phase (23–39 %). The addition of 10–20 % of agrowastes causes a reduction in the apparent density of 13 % and an increase in the open porosity of 14 %.