US 5,492,680 AGranted

Separation of scandium from tantalum residue using fractional liquid-liquid extraction

AssigneeThe United States of America as represented by the Secretary of the Interior

InventorMichael D. Odekirk

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Abstract

A process for separating scandium from an aqueous solution comprised of a first group of metals, scandium and a second group of metals includes the steps of: (a) providing a scandium-containing material and preparing therefrom an aqueous sulfuric acid solution containing a first group of metals, scandium and a second group of metals; (b) contacting the aqueous sulfuric acid solution with an organic liquid solution whereby scandium and the first and second groups of metals are extracted into the organic liquid solution to create a loaded organic solution; (c) scrubbing the loaded organic liquid solution first with an sulfuric acid solution to remove selected metals in the first group of metals from the organic liquid solution and then with a dilute HF solution to prepare the organic liquid solution for stripping; (d) stripping the remaining metals in the first group of metals from the loaded organic liquid solution with a HF solution so that only scandium and the second group of metals remain on the organic liquid solution; and (e) using a fractional stripping system to strip scandium from the loaded organic liquid solution with a HF solution so that the scandium is released from the organic liquid solution and only the second group of metals remains on the organic liquid solution.

Claims18

Dependent claims

A process for separating scandium from an aqueous solution including a first group of metals, scandium and a second group of metals, comprising the steps of:

(a) providing a scandium-containing material and preparing therefrom an aqueous sulfuric acid solution containing a first group of metals, scandium and a second group of metals;
(b) contacting said aqueous sulfuric acid solution with an organic liquid solution whereby said scandium and said first and second groups of metals are extracted into the organic liquid solution to create a loaded organic liquid solution;
(c) scrubbing said loaded organic liquid solution first with a sulfuric acid solution to remove metals selected in said first group of metals from said loaded organic liquid solution and then with an dilute HF solution to prepare said loaded organic liquid solution for stripping;
(d) stripping the metals remaining in said first group of metals from said loaded organic liquid solution with a HF solution so that only scandium and said second group of metals remain on said loaded organic liquid solution;
and
(e) using a fractional stripping system to strip said scandium from said loaded organic liquid solution with a HF solution so that said scandium is released from said loaded organic liquid solution and only said second group of metals remains on said loaded organic liquid solution.

3 more elements

Dependencies are inferred from the claim text.