Purification method
AssigneeOronzio deNora Impianti Elettrochimici S.p.A.
InventorsPlacido M. Spaziante, Luigi Giuffre, Aldo Castoldi, Giancarlo Sioli
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Abstract
A novel method of reducing metal impurities in aqueous alkali metal halide solutions, especially alkaline earth metal ions, and to novel organic solvent compositions having a synergistic activity for removal of metal impruties from aqueous solutions.
Claims19
A process for reducing metal ion concentration in aqueous alkali metal halide brines to a level below 0.2 mg/l comprising contacting an aqueous alkaline alkali metal halide brine having a pH of 10.5 to 12 and containing metal ion impurities with a water-immiscible organic solvent containing an effective amount of at least one complexing agent of the group consisting of 1-aryl-3-methyl-4-acylpyrazol-5-one wherein the acyl is derived from an organic carboxylic acid of 1 to 18 carbon atoms and a thenoyl-substituted keto compound and a complexing additive selected from the group consisting of trialkylphosphine oxides and trialkylphosphates.
A composition for reducing metal ion content of aqueous alkaline solutions comprising a solution of an water-immiscible organic solvent containing (a) 0.1 to 0.001 M of at least one complexing agent of the group consisting of 1-aryl-3-methyl-acyl-pyrazol-5-one wherein the acyl is derived from an organic carboxylic acid of 1 to 18 carbon atoms and a thenoyl-substituted keto compound and (b) 0.1 to 5% by volume of a complexing additive selected from the group consisting of trialkyl phosphine oxides and trialkylphosphates.
A composition consisting essentially of kerosene containing 0.1 and 0.001 moles of a member selected from the group consisting of thenoyl trifluoracetone and 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one and 0.1 to 5% by volume of a member of the group consisting of tributylphosphate and tri-n-octylphosphine oxide.
Dependencies are inferred from the claim text.