Abstract: The present application relates to methods for leaching and extraction of precious metals. For example, the present application relates to methods of leaching gold, palladium and/or platinum from a substance comprising gold, palladium and/or platinum (such as a gold-containing ore or a platinum group metal (PGM) concentrate) using an organic solvent that is water-miscible or partially water-miscible.

Abstract: Clogging of membrane by slime adhesion is efficiently prevented and stable treatment can be carried out for a long period of time at a low cost by a small amount of chemicals without membrane deterioration and trihalomethane formation, even if applied to the water having a large number of viable cell counts and a harsh water quality by supplying water to be treated to a membrane separation apparatus 4, adding intermittently to the water to be treated a combined chlorine agent containing sulfamic compound, and repeating a non-addition feeding period in which water to be treated is supplied for 6-120 hours without addition of the combined chlorine agent, and an intermittent addition feeding period in which water to be treated is supplied for 0.5-40 hours under the addition of a combined chlorine agent at a biofilm exfoliating concentration in an early stage of biofilm formation during the non-addition feeding period.

Abstract: A flue gas additive is provided that includes both a nitrogenous component to reduce gas phase nitrogen oxides and a halogen-containing component to oxidize gas phase elemental mercury.

Abstract: This invention comprises a lightweight, portable chemical combination of reagents for sterilizing or disinfecting objects in the absence of electrical power or fire. The chemical combination includes a chemical oxidant with the capacity to liberate a biocidal intermediate, a chemical reductant of the oxidant with the capacity to react with the oxidant, and an effector to induce a reaction between the oxidant and reductant. In one embodiment, the oxidant comprises chlorite, the reductant comprises sulfite, and the effector comprises ascorbate. In another embodiment, the chemical combination comprises the oxidant, reductant, effector and iron-activated magnesium. When water or water solutions are added to either embodiment, the chemical combination generates heat, steam and a biocidal intermediate that can destroy contaminating microorganisms. In one embodiment, the biocidal intermediate is a halogen-based biocidal intermediate, such as chlorine dioxide.

Abstract: A composition for anti-microbial effect in a water system such as a pulp and paper processing line with an aqueous slurry. The composition comprises a free chlorine-generating biocide comprising a chlorine source, urea, and an alkali in a concentration sufficient to provide a pH greater than 10, and typically at least pH 11.

Abstract: This invention comprises a lightweight, portable chemical combination of reagents for sterilizing or disinfecting objects in the absence of electrical power or fire. The chemical combination includes a chemical oxidant with the capacity to liberate a biocidal intermediate, a chemical reductant of the oxidant with the capacity to react with the oxidant, and an effector to induce a reaction between the oxidant and reductant. In one embodiment, the oxidant comprises chlorite, the reductant comprises sulfite, and the effector comprises ascorbate. In another embodiment, the chemical combination comprises the oxidant, reductant, effector and iron-activated magnesium. When water or water solutions are added to either embodiment, the chemical combination generates heat, steam and a biocidal intermediate that can destroy contaminating microorganisms. In one embodiment, the biocidal intermediate is a halogen-based biocidal intermediate, such as chlorine dioxide.

Abstract: A solid composition in the form of a tablet that generates and releases a biocidal solution comprising at least chlorine dioxide with an enhanced weight percent yield is presented. The composition comprises reactants capable of in-situ generation of chlorine dioxide comprising a chlorite donor that is coated with a gel-forming material that slows the rate of dissolution of the high solubility chlorite donor, a free halogen donor, and an acid source, resulting in an unexpectedly high weight percent yield and providing a controlled release of biocidal solution. The compositions of the invention show improved environmental stability which can reduce the cost of packaging and significantly increase the utility of the composition. The controlled release allows the use in multi-tablet chemical dispensers which may otherwise induce potentially explosive conditions or allow rapid release of the biocidal solution thereby inducing a spike in chemical concentration rather than a controlled and sustained release.

Abstract: A solid composition in the form of a tablet that generates and releases a biocidal solution comprising at least chlorine dioxide with an enhanced weight percent yield is presented. The composition comprises reactants capable of in-situ generation of chlorine dioxide comprising a chlorite donor that is coated with a gel-forming material that slows the rate of dissolution of the high solubility chlorite donor, a free halogen donor, and an acid source, resulting in an unexpectedly high weight percent yield and providing a controlled release of biocidal solution. The compositions of the invention show improved environmental stability which can reduce the cost of packaging and significantly increase the utility of the composition. The controlled release allows the use in multi-tablet chemical dispensers which may otherwise induce potentially explosive conditions or allow rapid release of the biocidal solution thereby inducing a spike in chemical concentration rather than a controlled and sustained release.

Abstract: An efficient cyclic process and related compositions for the in-situ generation of chlorine dioxide from dilute solutions of chlorite anions at near neutral pH. The cyclic process provides a means of safe and effective use of chlorine dioxide with reduced concern of chlorite accumulation in the aqueous system. The disclosed chemistry used to support the cyclic process can be applied independently or in various combinations that are effectively inert. This dramatically reduces safety concerns since the chlorine dioxide is produced in-situ to the application and in dilute concentrations. Also, the process allows for regeneration of inert anions such as bromide and chlorite thereby reducing operating cost.

Abstract: An efficient cyclic process and related compositions for the in-situ generation of oxyhalogens from anions of chloride, bromide and chlorite in an aqueous system using in-situ generated sulfate free radicals. The cyclic process and compositions enhance the rate of inactivation of microbiological organisms especially those resistant to inactivation from free halogen based sanitizers, and oxidation of oxidation resistant organic based compounds in aqueous solution. Aquatic facilities susceptible to accumulation of organic N-chloramines and other oxidation resistant compounds, as well as oxidation resistant parasitic organisms such as cryptosporidium and Giardia, obtain dramatic improvements in the rate of oxidation and subsequent inactivation of these undesirable contaminants.

Abstract: An efficient cyclic process and related compositions for the in-situ generation of chlorine dioxide from dilute solutions of chlorite anions at near neutral pH. The cyclic process provides a means of safe and effective use of chlorine dioxide with reduced concern of chlorite accumulation in the aqueous system. The disclosed chemistry used to support the cyclic process can be applied independently or in various combinations that are effectively inert. This dramatically reduces safety concerns since the chlorine dioxide is produced in-situ to the application and in dilute concentrations. Also, the process allows for regeneration of inert anions such as bromide and chlorite thereby reducing operating cost.

Abstract: This invention relates to a method for enhanced sanitation and oxidation of aqueous solutions at aquatic facilities. The method provides a means for the in-situ generation of chlorine dioxide from dilute solutions of chlorite anions at near neutral pH, and enhanced inactivation rates of microbiological organisms including cryptosporidium.

Abstract: A composition for anti-microbial effect in a water system such as a pulp and paper processing line with an aqueous slurry. The composition comprises a free chlorine-generating biocide comprising a chlorine source, urea, and an alkali in a concentration sufficient to provide a pH greater than 10, and typically at least pH 11.

Abstract: Microbiological control is achieved by continuously and inexpensively dosing water in contact with biofilm, or that comes into contact with biofilm, using a highly effective biocide that provides very effective microbiocidal control of planktonic microorganisms and of biofilm species, even where the biofilm infestations have been in existence for long periods of time and thus have encased themselves in a substantial quantity of slimy defensive polysaccharide layers or films. In addition, the biocide used makes possible significant reduction in copper and/or iron surfaces in contact with the water as compared to N,N?-bromochloro- 5,5-dimethyl hydantoin. Still other advantages are made possible by the described technology.

Abstract: A cost-effective process is described for the preparation of a stable and non-hazardous brominating reagent containing 2:1 stoichiometric ratio of alkali bromide to alkali bromate. The process comprises of reacting alkaline bromine intermediate mixture, obtained from bromine recovery plant, with chlorine gas in the presence of a strong alkali to oxidize the bromide ions to bromate ions. This brominating reagent is useful for the bromination of aromatic compounds by substitutions.

Abstract: Microbiological control in aqueous media and/or eradication or reduction of biofilm on a surface in contact with such media is achieved by introducing into the aqueous medium a microbiocidally effective quantity of one or more 1,3-dibromo-5,5-dialkylhydantoins where one of the alkyls is methyl and the other is a C1-4 alkyl, wherein (i) the molar quantity of 1,3-dibromo-5,5-dialkylhydantoin introduced is less than the molar quantity of N,N?-bromochloro-5,5-dimethylhydantoin that would be required to effect the same degree of microbiological control in that medium, (ii) the molar quantity of the 1,3-dibromo-5,5-dialkylhydantoin introduced releases an amount of “free chlorine” that is greater than the amount of “free chlorine” that would be released in that medium by an equimolar quantity of N,N?-bromochloro-5,5-dimethylhydantoin, and (iii) the amount of “free chlorine” released by the quantity of the 1,3-dibromo-5,5-dialkylhydantoin introduced is greater than the amount of “free chlorine” that could be predicte

Abstract: The present invention is directed to frozen biocidal compositions. Specifically, the biocidal compositions comprise a frozen aqueous solution of a plurality of ions selected from the group consisting of halide and oxyhalide ions. The frozen biocidal compositions are useful in preserving or extending the shelf-life of perishable articles.

Abstract: A new method is described to produce large volumes of low cost sterile, Water-for-Injection (WFI) grade water on-line, on-demand from potable water in order to meet the needs of dialysis therapies and other biological applications for sterile, injectable grade water. The source water is processed by a combination of membrane and column chromatographic methods including reverse osmosis, chemical sterilization, reduction of iodine sterilant to iodide, deionization, endotoxin-specific adsorption and polishing filtration in order to reduce contaminant levels below those specified by the US Pharmacopoeia.

Abstract: Stabilized bromine solutions are prepared by combining a bromine source and a stabilizer to form a mixture, and then adding an oxidizer to the mixture.

Abstract: A non-chrome containing composition and process are disclosed for enhancing the corrosion resistance of zinc or zinc alloy surfaces. The composition comprises a source of titanium ions or titanates, an oxidant and fluorides or complex fluorides. The composition also preferably comprises an organic acid and/or a Group II metal compound, preferably a Group II metal chloride.

Abstract: Among the enhanced properties of the 1,3-dibromo-5,5-dimethylhydantoins described are their larger average particle sizes, their compactibility even though devoid of a binder, their excellent free-flowing and low-dust properties, and their more appealing aesthetic qualities, as compared to previously known 1,3-dibromo-5,5-dimethylhydantoins. These novel 1,3-dibromo-5,5-dimethylhydantoins can be produced, for example, by concurrently feeding (i) an aqueous solution or slurry formed from an inorganic base and 5,5-dimethylhydantoin, and (ii) a brominating agent, in proportions such that each nitrogen atom is substituted by a bromine atom, thereby forming product which precipitates in an aqueous reaction mixture. The pH of the reaction mixture is maintained in the range of about 5.5 to about 8.5.

Abstract: Stabilized bromine solutions are prepared by combining a bromine source and a stabilizer to form a mixture, adding an oxidizer to the mixture, and then adding, an alkaline source to adjust the pH of the mixture to at least 13.