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AssigneeAmoco Corporation
InventorYuehsiung Chang
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Cobalt and manganese oxidation catalyst metals are recovered from trimellitic anhydride process residue by extracting the residue with water and using the extract solution as a diluting solution in an electrodialyzer the separation stack of which comprises an anode channel and at least one three channel repeating unit wherein each repeating unit having in sequence channels A, B, and C. In this separation stack the anode channel is formed by an anode and a cation permeation membrane, Channel A is formed by two cation permeation membranes, Channel B is formed by a cation permeation membrane and an anion permeation membrane, and Channel C is formed by an anion permeation membrane and either a cation permeation membrane or a cathode. A suitable anolyte flows through the anode channel. The diluting solution is fed to the A channels. An electrolyte is fed to the B channels. A suitable catholyte is fed to the C channels. Concentrating solution of cobalt and manganese substantially free of metal and organic contaminants is effluent from the B channels. The metals cobalt or cobalt and manganese can be recovered as an aqueous solution of acetate salts from an aqueous solution containing aromatic compounds including benzoic acid and one or more of the toluic acid, phthalic acid, and carboxybenzaldehyde isomers by electrodialysis using acetic acid and the catholyte, water as the metal acetate solvent, and the aqueous solution acid oxygen-containing aromatic compounds, and the metal ions as a more efficient than precipitating the metals from such solution as their carbonates and dissolving the carbonate precipitate in acetic acid.
An electrodialysis process for recovery of cobalt and manganese ions from a diluting solution comprising said ions and contaminants, which comprises feeding said solution to an electrodialyzer separation stack which comprises an anode channel formed by an anode and a cation permeation membrane and at least one, three-channel repeating unit wherein each repeating unit having in sequence channels A, B, and C wherein this repeating unit comprises a Channel A formed by two cation permeation membranes, a Channel B formed by a cation permeation membrane and an anion permeation membrane, and a Channel C formed by an anion permeation membrane and either a cation permeation membrane or a cathode, passing an anolyte comprising an aqueous solution of an acid through the anode channel, feeding diluting solution through the A channels, feeding an electrolyte through the B channels, feeding a catholyte comprising an aqueous solution of a carboxylate produced by reaction of a metallic hydroxide and an organic acid selected from a group consisting of formic, acetic, oxalic, lactic, tartaric, citric, benzoic and phthalic acids in a concentration of at least about 0.01N, through the C channels and removing a concentrate comprising a solution of cobalt and manganese substantially free of contaminants as an effluent from the B channels.
The process of claim 7, wherein each cation permeation membrane is polytetrafluorethylene modified by sulfonic acid groups bonded to carbon atoms of the polymer chain and each anion permeation membrane is an aminic sulfate modified polymer and the separation unit is operated at a current density of from about 5 mA/cm.sup.2 to about 25 mA/cm.sup.2.
A process for recovery of cobalt and manganese ions from a diluting solution comprising said ions and contaminant ions of at least one metal selected from iron, copper, and nickel which recovery process comprises adding a complex forming compound to the diluting solution containing the metal ions;
A method of separating cobalt ions or cobalt and manganese ions from an aqueous solution thereof also containing oxygen-containing aromatic compounds including benzoic acid, and one of the isomers of toluic acid, phthalic acid, and carboxybenzaldehyde which method comprises feeding such aqueous solution to an electrodialyzer separation stack which comprises an anode channel formed by an anode and a cation permeation membrane and at least one, three-channel repeating unit wherein each repeating unit having in sequence channels A, B, and C wherein this repeating unit comprises a Channel A formed by two cation permeation membranes, a Channel B formed by a cation permeation membrane and an anion permeation membrane, and a Channel C formed by an anion permeation membrane and either a cation permeation membrane or a cathode, passing an anolyte comprising an aqueous solution of about 4 percent to about 20 percent of acetic acid through the anode channel, feeding said aqueous solution through the A channels, feeding a dilute electrolyte comprising at least 0.1N HBr through the B channels, feeding an aqueous acetic acid solution at about 4 percent to about 20 percent concentration through the C channels and removing an aqueous effluent of decreased metal ion content from the A Channels, an aqueous solution of metal acetates as effluent from the B Channels and aqueous acetic acid of decreased acetic acid content as effluent from the C Channels.
Dependencies are inferred from the claim text.