Abstract: An aqueous slurry of gypsum plaster is stabilized by an organic, polymeric, hydrophilic stabilizer for more than 30 days without setting.Upon activation with a Lewis acid the slurry becomes hydrated. The plaster form or the hydrated form may be employed to impregnate a substrate to form insulating sheeting. The substrate may be fabric, felt, paper, nonwoven, or sponge.Open-cell, foamed gypsum may be used alone or molded to shaped articles such as bricks for a firewall.

Abstract: A filter composition is formed from a foamed gypsum combined with fine particulate carbonaceous material such as activated carbon, dried blood and comminuted vegetable matter. The combination of activated carbon with dried blood provides a particularly effective human user filter system. A broad range of filter uses are contemplated such as face masks and cigarette filters.

Abstract: Sequestering compositions are described which utilize two water dispersible polymers, the first having pendant carboxy groups and the second containing hydroxy, amino or imino groups within the polymer. The compositions sequester various metals, are inexpensive to prepare and are easily handled and recovered. A representative embodiment is a mixture of polyacrylic acid and polythyleneimine. Additional chelating agents can be present.