Abstract: The present invention relates to a method for producing a bonded article by press-moulding and carbonating a granular, carbonatable material. The granular material is applied in a mould, is press-moulded therein under a compaction pressure of at least 25 MPa, and is carbonated during said press-moulding step by means of a gas which contains at least 1 vol. % of carbon dioxide. By carbonating the material when press-moulding it, high compressive strengths can be achieved in a short period of time.

Abstract: A method of producing a mainly carbonate bonded article includes a step of providing an alkaline granular material having one or more alkaline earth metal silicate phases. The method includes a step of compacting the granular material to obtain a compact of the granular material. The porosity of the compact is smaller than or equal to 37% by volume. The intrinsic permeability of the compact is at least 1·10?12 cm2. The method also includes a reacting step arranged to form at least 5% by weight of carbonates (CO32?), by reacting the granular material with carbon dioxide in the presence of water, thus transforming the compact into the article. In the reacting step, the compact, being unsaturated with moisture at the beginning of the reacting step, is brought in an atmosphere having carbon dioxide. The atmosphere is at a temperature of at least 70° C. and at a pressure of at least 0.5 MPa. The pressure is also higher than the saturated vapor pressure of water at the temperature.