Abstract: Corrosion-inhibiting pigments based on cobalt are described that contain a trivalent or tetravalent cobalt/valence stabilizer complex. An inorganic or organic material is used to stabilize the trivalent or tetravalent cobalt ion to form a compound that is sparingly soluble in water. Specific stabilizers are chosen to control the release rate of trivalent or tetravalent cobalt during exposure to water and to tailor the compatibility of the powder when used as a pigment in a chosen binder system. Stabilizers may also modify the processing and handling characteristics of the formed powders. Cobalt/valence stabilizer combinations are chosen based on the well-founded principles of cobalt coordination chemistry. Many cobalt-valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium systems.

Abstract: Corrosion-inhibiting pigments based on manganese are described that contain a trivalent or tetravalent manganese/valence stabilizer complex. An inorganic or organic material is used to stabilize the trivalent or tetravalent manganese ion to form a compound that is sparingly soluble, exhibits low solubility, or is insoluble in water, depending upon the intended usage. Specific stabilizers are chosen to control the release rate of trivalent or tetravalent manganese during exposure to water and to tailor the compatibility of the powder when used as a pigment in a chosen binder system. Stabilizers may also modify the processing and handling characteristics of the formed powders. Manganese/valence stabilizer combinations are chosen based on the well-founded principles of manganese coordination chemistry. Many manganese-valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium or tetravalent lead systems.

Abstract: Corrosion-inhibiting pigments based on cobalt are described that contain a trivalent or tetravalent cobalt/valence stabilizer complex. An inorganic or organic material is used to stabilize the trivalent or tetravalent cobalt ion to form a compound that is sparingly soluble in water. Specific stabilizers are chosen to control the release rate of trivalent or tetravalent cobalt during exposure to water and to tailor the compatibility of the powder when used as a pigment in a chosen binder system. Stabilizers may also modify the processing and handling characteristics of the formed powders. Cobalt/valence stabilizer combinations are chosen based on the well-founded principles of cobalt coordination chemistry. Many cobalt-valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium systems.

Abstract: Rinsing or sealing solutions comprising a rare earth element and a valence stabilizer for barrier films. The treated films contain a rare earth/valence stabilizer complex. The rare earth element is selected from cerium, praseodymium, terbium, or combinations thereof, and at least one rare earth element is in the tetravalent oxidation state. The rinsing or sealing solution may also contain an optional preparative or solubility control agent. The oxidized rare earth element is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. A number of rare earth/valence stabilizer combinations that match the performance of conventional hexavalent chromium systems are presented.

Abstract: Conversion coatings comprising a rare earth element and a valence stabilizer combined to form a rare earth/valence stabilizer complex are described for substrate metals. The rare earth element is selected from cerium, praseodymium, terbium, or combinations thereof, and at least one rare earth element is in the tetravalent oxidation state. The coating bath may also contain a preparative or solubility control agent. The oxidized cerium, praseodymium or terbium is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. A number of cerium, praseodymium, or terbium/valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium systems.

Abstract: Conversion coatings based on cobalt are described for substrate metals such as aluminum, zinc, magnesium, titanium, cadmium, silver, copper, tin, lead, cobalt, zirconium, beryllium, or indium, their alloys, or items coated with these metals. The conversion coating contains a trivalent or tetravalent cobalt/valence stabilizer complex. The coating bath may also contain a preparative agent or solubility control agent. The oxidized cobalt is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. Cobalt/valence stabilizer combinations are chosen based on the well-founded principles of cobalt coordination chemistry. A number of cobalt/valence stabilizer combinations that match the performance of conventional hexavalent chromium systems are presented.

Abstract: A corrosion-inhibiting pigment comprising a rare earth element and a valence stabilizer combinded to form a rare earth/valence stabilizer complex. The rare earth element is selected from cerium, terbium, praseodymium, or a combination thereof, and at least one rare earth element is in the tetravalent oxidation state. An inorganic or organic material is used to stabilize the tetravalent rare earth ion to form a compound that is sparingly soluble in water. Specific stabilizers are chosen to control the release rate of tetravalent cerium, terbium, or praseodymium during exposure to water and to tailor the compatibility of the powder when used as a pigment in a chosen binder system. Stabilizers may also modify the processing and handling characteristics of the formed powders. Many rare earth-valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium systems.

Abstract: Rinsing or sealing solutions based on cobalt are described for barrier films such as anodic coatings, phosphate coatings, or “black oxide” coatings. The treated films contain a trivalent or tetravalent cobalt/valence stabilizer complex. The rinsing or sealing bath may also contain an optional preparative agent or an optional solubility control agent. The oxidized cobalt is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. Cobalt/valence stabilizer combinations are chosen based on the well-founded principles of cobalt coordination chemistry. A number of cobalt/valence stabilizer combinations that match the performance of conventional hexavalent chromium systems are presented.

Abstract: A process for recovery of hexavalent chromium from waste streams. The method includes providing a waste stream containing hexavalent chromium, reacting a soluble non-toxic precipitating reagent with the hexavalent chromium to form an insoluble precipitating reagent-chromate precipitate, and recovering the insoluble precipitating reagent-chromate precipitate. It may optionally include reacting the insoluble precipitating reagent-chromate precipitate with an acidic solution to form an insoluble precipitating reagent precipitate and a soluble hexavalent chromium compound, and recovering the soluble hexavalent chromium compound. The process may also include reacting the insoluble precipitating reagent precipitate with a solubilizing reagent to form the soluble non-toxic precipitating reagent.

Abstract: A corrosion-inhibiting pigment comprising a rare earth element and a valence stabilizer combinded to form a rare earth/valence stabilizer complex. The rare earth element is selected from cerium, terbium, praseodymium, or a combination thereof, and at least one rare earth element is in the tetravalent oxidation state. An inorganic or organic material is used to stabilize the tetravalent rare earth ion to form a compound that is sparingly soluble in water. Specific stabilizers are chosen to control the release rate of tetravalent cerium, terbium, or praseodymium during exposure to water and to tailor the compatibility of the powder when used as a pigment in a chosen binder system. Stabilizers may also modify the processing and handling characteristics of the formed powders. Many rare earth-valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium systems.

Abstract: Conversion coatings comprising a rare earth element and a valence stabilizer combined to form a rare earth/valence stabilizer complex are described for substrate metals. The rare earth element is selected from cerium, praseodymium, terbium, or combinations thereof, and at least one rare earth element is in the tetravalent oxidation state. The coating bath may also contain a preparative or solubility control agent. The oxidized cerium, praseodymium or terbium is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. A number of cerium, praseodymium, or terbium/valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium systems.

Abstract: Rinsing or sealing solutions comprising a rare earth element and a valence stabilizer for barrier films. The treated films contain a rare earth/valence stabilizer complex. The rare earth element is selected from cerium, praseodymium, terbium, or combinations thereof, and at least one rare earth element is in the tetravalent oxidation state. The rinsing or sealing solution may also contain an optional preparative or solubility control agent. The oxidized rare earth element is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. A number of rare earth/valence stabilizer combinations that match the performance of conventional hexavalent chromium systems are presented.

Abstract: Corrosion-inhibiting pigments based on manganese are described that contain a trivalent or tetravalent manganese/valence stabilizer complex. An inorganic or organic material is used to stabilize the trivalent or tetravalent manganese ion to form a compound that is sparingly soluble, exhibits low solubility, or is insoluble in water, depending upon the intended usage. Specific stabilizers are chosen to control the release rate of trivalent or tetravalent manganese during exposure to water and to tailor the compatibility of the powder when used as a pigment in a chosen binder system. Stabilizers may also modify the processing and handling characteristics of the formed powders. Manganese/valence stabilizer combinations are chosen based on the well-founded principles of manganese coordination chemistry. Many manganese-valence stabilizer combinations are presented that can equal the performance of conventional hexavalent chromium or tetravalent lead systems.

Abstract: Conversion coatings based on cobalt are described for substrate metals such as aluminum, zinc, magnesium, titanium, cadmium, silver, copper, tin, lead, cobalt, zirconium, beryllium, or indium, their alloys, or items coated with these metals. The conversion coating contains a trivalent or tetravalent cobalt/valence stabilizer complex. The coating bath may also contain a preparative agent or solubility control agent. The oxidized cobalt is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. Cobalt/valence stabilizer combinations are chosen based on the well-founded principles of cobalt coordination chemistry. A number of cobalt/valence stabilizer combinations that match the performance of conventional hexavalent chromium systems are presented.

Abstract: Rinsing or sealing solutions based on cobalt are described for barrier films such as anodic coatings, phosphate coatings, or “black oxide” coatings. The treated films contain a trivalent or tetravalent cobalt/valence stabilizer complex. The rinsing or sealing bath may also contain an optional preparative agent or an optional solubility control agent. The oxidized cobalt is present in the coating in a “sparingly soluble” form. The valence stabilizers can be either inorganic or organic in nature. Cobalt/valence stabilizer combinations are chosen based on the well-founded principles of cobalt coordination chemistry. A number of cobalt/valence stabilizer combinations that match the performance of conventional hexavalent chromium systems are presented.

Abstract: Corrosion-inhibiting pigments based on manganese are described that contain a heptavalent (permanganate), hexavalent (manganate), or pentavalent (manganate) compound. An inorganic or organic material is used with the heptavalent, hexavalent, or pentavalent manganese ion to form a compound that is sparingly soluble in water. Specific solubility control cations are chosen to control the release rate of heptavalent, hexavalent, or pentavalent manganese during exposure to water and to tailor the compatibility of the powder when used as a pigment in a chosen binder system. Solubility control agents may also modify the processing and handling characteristics of the formed powders. Many permanganate or manganate compounds are presented that can equal the performance of conventional hexavalent chromium systems. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure.

Abstract: A process for recovery of hexavalent chromium from waste streams. The method includes providing a waste stream containing hexavalent chromium, reacting a soluble non-toxic precipitating reagent with the hexavalent chromium to form an insoluble precipitating reagent-chromate precipitate, and recovering the insoluble precipitating reagent-chromate precipitate. It may optionally include reacting the insoluble precipitating reagent-chromate precipitate with an acidic solution to form an insoluble precipitating reagent precipitate and a soluble hexavalent chromium compound, and recovering the soluble hexavalent chromium compound. The process may also include reacting the insoluble precipitating reagent precipitate with a solubilizing reagent to form the soluble non-toxic precipitating reagent.