Olin Corporation

National Starch and Chemical Investment Holding Corporation

Maurice R Smith

Sanders H Moore

Harvey B Cochran

Alvie L Foster, Jr

Ivonne C Weidner

The present invention is directed to a solid chelating resin consisting of a reactive hydrophobic backbone having pendent carbodithioic groups. Preferably the resin is a poly(dithiocarbamate) containing no tertiary nitrogen groups. The invention is also directed to a novel process for making a chelating resin involving a) reacting a nucleophilic compound with carbon disulfide in a suitable solvent, to form a carbodithioic acid, b) neutralizing the carbodithioic acid with a base to form a carbodithioic acid salt; and c) reacting said carbodithioic acid salt with a crosslinking reagent in a suitable solvent to form a solid chelating resin. The chelating resin is useful in removing metals and cationic compounds from effluent streams.

Polydithiocarbamate resin

Vacuum cleaner hose coupling

An improved process for treating aqueous effluents and purge streams to selectively remove polluting elements such as iron, copper, lead and mercury therefrom is described. The procedure comprises contacting the effluent with a poly(dithiocarbamate) chelating agent whereby the polluting elements are absorbed. The resin is extracted with an acidic aqueous solution having a pH of from about 4 to about 6; and removing the resin. When this is done, the residual content of these polluting elements in the effluent is reduced to a level below EPA required levels so that the effluent can safely be discharged into the surrounding ecosystem. The poly(dithiocarbamate) resin containing the polluting elements can be disposed of, for example, by being deposited in an unsecured landfill.

Process for the purification of effluents and purge streams containing

A novel process is provided for producing a poly(dithiocarbamate) resin chelating agent which comprises dissolving a polyimine in an alcohol solvent to form a polyimine solution. A polyisocyanate is admixed in the polyimine solution to produce a cross-linked polyamine-polyurea precursor resin. The cross-linked polyamine-polyurea precursor resin is then reacted with a mixture of NH.sub.4 OH and CS.sub.2 to produce a poly(dithiocarbamate) resin chelating agent. The novel process can employ a polyimine in anhydrous or aqueous suspension form and uses non-hazardous solvents for the polyisocyanate reactant.

Process for producing poly(dithiocarbamate) chelating resins

A process is described for removing available chlorine from a depleted recirculating anolyte brine of a chlor-alkali cell. After the spent brine is removed from the cell, and typically after dechlorination, it is reacted with an amount of an organic hydroxyl moiety-containing compound soluble in said brine for a residence time sufficient to substantially reduce the residual dissolved chlorine and hypohalite ion remaining in said brine prior to resaturation and reuse in said cell. Suitable hydroxyl moiety-containing compounds include alcohols and saccharides.

Reduction of available chlorine in alkali brines

A process for removing chlorate ions from a recirculating anolyte brine as typically used in membrane chlor-alkali cells is disclosed. In this, a portion of the circulating brine after dechlorination and resaturation with additional alkali metal chloride is diverted and treated with an acidified aliphatic aldehyde to convert substantially all of the hypochlorite and chlorate to chlorine dioxide, chlorine gas and chloride ion. When performed in this manner, substantially lower quantities of acid are required as compared to prior art processes and the problems with the generation of excessive quantities of ClO.sub.2 are minimized.

Removal of chlorate and hypochlorite from electrolyte cell brine

A method for determining low level concentrations of alkaline earth metals in a concentrated aqueous alkali metal chloride brine containing alkaline earth metal ions comprises heating a sample of the brine to a temperature sufficient to remove water and form anhydrous alkali metal chloride. The anhydrous alkali metal chloride is then further heated to a temperature range in which the alkali metal chloride undergoes a change. The anhydrous alkali metal chloride is then vaporized and the alkaline earth metals atomized and passed through an analyzer where the concentration of alkaline earth metals are determined. Using the method of the present invention, alkaline earth metals such as calcium can be detected in concentrations as low as 1 part per billion, while magnesium can be detected in concentrations as low as 0.4 parts per billion.

Growing community of inventors

Cleveland, TN, United States of America

Maurice R Smith