Production of geopolymer foams from Tunisian clay for heat resistance application

摘要

This invention presents the in situ method of preparation of eco-friendly foam (geopolymer) using natural or calcined Tunisian clay rich in kaolinite and hematite. This material has higher thermal stability to ensure safety for life and property in the case of fire. The manufacturing process consists: 1) to prepare and mix a natural or thermally activated clay (between 550 °C- 950 °C) with basic solution composed of sodium hydroxide (NaOH) and sodium silicate (Na2Si03.5H20); 2) to add foaming agent (silica fume) to the reactant mixture; 3) to carry out the moulding of fresh product in standardized moulds; 3) to place the moulded mixture in an oven at a temperature less than 100 °C until constant weigh; 4) The obtained geopolymer foams resists to the exposure of high temperatures (between 1 OO °C and 1100 °C).