Abstract: The invention relates to a compound of two main components, a polysaccharide and a borate provider, that form a flowable, penetrating liquid when mixed, then cross-link and gel to form a stable, flexible crust when applied to a substrate. The crust stabilizes the substrate and prevents loss of particulate matter, but can be softened or mechanically worked to allow access to the substrate, for example for further processing. Additives may be used to control specific properties of the crust.

Abstract: Filter systems that are effective against a broad range of contaminants including HCN, cyanogen chloride (CK), acid contaminants. and basic contaminants such as ammonia without the need (but with the option, if desired) for using molybdenum or chromium containing materials. The filtering systems of the present invention include a tungsten-based material and other impregnants incorporated into a substrate such as filter media particles.