Abstract: Process for the manufacture of aerated concrete construction materials comprising the following steps: (a) mixing a composition comprising at least water, a cementitious material, calcium oxide, a compound comprising reactive silicon dioxide, a source of oxygen, and a compound selected from sodium carbonate, sodium bicarbonate and sodium hydroxide; (b) pouring the mixture of step (a) into a mould and allowing the mixture to set, thus forming a stiffened body; (c) removing the stiffened body from the mould; (d) optionally cutting and shaping the stiffened body, and (e) curing the stiffened body.

Abstract: A process for the bleaching of mechanical paper pulp with one or more peroxide oxidizing agents, in which the pulp is pretreated in a pretreatment step with one or more chelating agents chosen from aspartic acid and its derivatives, substituted on the nitrogen atom, characterized in that the initial pH of the pretreatment step, just before adding the one or more chelating agents, is above 8.

Abstract: Process for the bleaching of paper pulp in which : (a) an aqueous suspension of the paper pulp is first subjected to a chelating treatment with at least one aminopolycarboxylic acid, its salt or their mixtures in order to reduce at least partially the metallic ion, especially manganese, content of the suspension, and (b) the aqueous suspension of the paper pulp thus obtained is subjected to a bleaching treatment with hydrogen peroxide in the presence of i. at least one poly-?-hydroxyacrylic acid, its salt or their mixtures, the function of which is to chelate at least partially iron present in the aqueous suspension, and ii. at least one aminopolycarboxylic acid, its salt or their mixtures, the function of which is to chelate calcium present in the aqueous suspension thereby improving the performance of the poly-?-hydroxyacrylic acid, its salt or their mixtures.