The object of the invention is a method for dissolving carbon dioxide from flue or other gas and for the neutralization of the solution obtained. The gas, in which the partial pressure of carbon dioxide is at least 0.4 bar, is led to a dissolution process, where the major part of the carbon dioxide is dissolved into a flow of water. The aqueous solution of carbon dioxide thus obtained is neutralized by passing it through a material containing feldspar minerals, at which time the hydrogen ions of said solution are replaced by ions of alkali or alkaline earth metals, and the aluminum in said material is converted into aluminum compounds that can be separated and utilized.