Abstract: The invention provides a novel light-weight building material suitable for heat and sound insulation from an aluminum hydroxide sludge, which is a very noxious industrial waste material, and disintegrated scrapped paper as the base components. The sludge is first alkalized by the addition of sodium hydroxide to dissolve the gel-like aluminum hydroxide in the form of sodium aluminate and then admixed with the disintegrated scrapped paper to give a slurried mixture which is next neutralized to a weakly acidic condition by adding phosphoric acid whereby insoluble phosphates are deposited on the cellulosic fibers. The slurried mixture is further admixed with a coagulating agent to give a coagulated mass of the fibrous material with deposition of the phosphates. The coagulated mass is then separated from the liquid portion and dried to give a light-weight mass which is used as a blow-on insulating material for buildings or as a material for shaping an insulating board or slab.

Abstract: The building material of the invention, which is in a disintegrated fluffy form and suitable for shaping into a board for walls and ceilings or as a blow-on or blow-in insulating material having excellent performance as heat and sound insulation, comprises essentially a disintegrated organic fibrous material, e.g. disintegrated scrapped paper and gel-like aluminum hydroxide uniformly blended with the fibrous material together with a flame retardant agent which is preferably an inorganic phosphate such as sodium phosphate and disodium hydrogen phosphate and, optionally, with a waterproofing agent. The building material is prepared by first mixing the organic fibrous material with an aqueous solution of the phosphate and then with an aluminum hydroxide sludge obtained as a noxious industrial waste in aluminum-processing industries employing surface anodization followed by drying and disintegration.

Abstract: The invention provides a novel aluminum hydroxide-based spray-on insulating material which is workable by blowing to form a layer on the ceiling or wall of a building effective for heat and sound insulation. The inventive material is prepared by first blending an organic fibrous material, e.g. reclaimed pulp from scrapped papers, with a gel-like amorphous aluminum hydroxide sludge, available in large quantities as a waste in the anodization treatment of aluminum articles, with adjustment of the pH of the mixture to weakly acidic whereby the organic fibers are entrammeled by the coagulated aluminum hydroxide and then a powdery aluminum hydroxide, which is prepared by drying and pulverizing the gel-like aluminum hydroxide sludge, is admixed with the mixture followed by drying and disintegrating the blend into fluffs. The spray-on insulating material is worked by blowing as such or may be blown together with an adhesive so as to increase the mechanical stability of the insulating layer.