Abstract: A filter cake formed of a glass precursor material and impregnated with a normally leachable toxicant can be heated, preferably with at least one other glass precursor material, at a sufficiently high temperature to form a molten composition which solidifies, upon cooling, to form a glass. The normally leachable toxicant becomes fixed within the glass rendering it substantially more non-leachable allowing for a more environmentally sound means for disposal, e.g., by landfill techniques. The process can be used to treat the arsenic sulfide-impregnated filter cake derived from the manufacture of food grade phosphoric acid.

Abstract: Filter cake waste media from a phosphoric acid purification process containing contaminating amounts of arsenic is treated in the process of this invention to remove the arsenic therefrom and to render the filter media suitable for reuse. The process of the invention comprises separating the arsenic contaminant from the filter material by treating the material with sufficient amount of a base, such as soda ash, to dissolve the contaminating arsenic compounds into solution and separating and recovering the filter media from the arsenic-containing solution. The separated arsenic can be recovered by reprecipitation utilizing an acid and a source of soluble sulfide ions.

Abstract: This invention is concerned with improving adhesion, friction and wear properties of sputtered refractory coatings on substrates of materials that form stable nitrides.Each substrate (10) is placed directly below a titanium carbide target (16) of a commercial radiofrequency diode apparatus (14) in a vacuum chamber (26). Nitrogen is bled into the system through a nozzle (3) resulting in a small partial pressure of about 0.5% to 2.5% during the first two minutes of deposition. The flow of nitrogen is then stopped, and the sputtering ambient is reduced to pure argon through a nozzle (28) without interrupting the sputtering process.When nitrogen is deliberately introduced during the crucial interface formation, some of the titanium at the interface reacts to form titanium nitride while the metal of the substrate also forms the nitride. These two nitrides atomically mixed together in the interfacial region (38) act to more strongly bond the growing titanium carbide coating (12) as it forms on the substrate (10).

Abstract: This invention is concerned with improving adhesion, friction and wear properties of sputtered refractory coatings on substrates of materials that form stable nitrides.Each substrate (10) is placed directly below a titanium carbide target (16) of a commercial radiofrequency diode apparatus (14) in a vacuum chamber (26). Nitrogen is bled into the system through a nozzle (30) resulting in a small partial pressure of about 0.5% to 2.5% during the first two minutes of deposition. The flow of nitrogen is then stopped, and the sputtering ambient is reduced to pure argon through a nozzle (28) without interrupting the sputtering process.When nitrogen is deliberately introduced during the crucial interface formation, some of the titanium at the interface reacts to form titanium nitride while the metal of the substrate also forms the nitride. These two nitrides atomically mixed together in the interfacial region (38) act to more strongly bond the growing titanium carbide coating (12) as it forms on the substrate (10).