Treatment of degraded oxime metal extractants in process organic solutions

Patent metadata

Field	Value
Publication number	US-2018073099-A1
Application number	US-201615558792-A
Country	US
Kind code	A1
Filing date	Mar 18, 2016
Priority date	Mar 20, 2015
Publication date	Mar 15, 2018
Grant date	—

Abstract

The invention relates to a method for regenerating the extractive potential of an organic hydroxyoxime-based extraction solution used in the recovery of metals by liquid-liquid extraction. The method is two-stage, in which a solid hydroxylamine is used in the reaction stage, and the removal of the undesirable compounds generated in the reaction occurs in the second stage by adsorption purification. The method of the invention is suitable for treatment of degraded oxime metal extractants in various process organic solutions both in aldehyde and ketoxime extractant solutions. The method can also be used to treat a mixture of degraded oxime extractants.

First claim

1 . A method of regenerating a degraded hydroxyoxime based organic extraction solution used in the recovery of metals by liquid-liquid extraction, comprising the step of (a) contacting the organic extraction solution with a wetted hydroxylamine or salt thereof in solid form in the presence of a solid alkaline salt and thereafter removing solid particles from the organic extraction solution, and the step of (b) purifying the organic extraction solution by adsorption purification by bringing said organic extraction solution into contact with an adsorption material in solid form,
wherein the method is performed without the use of a phase transfer catalyst.

2 . The method according to claim 1 , wherein in step (a) the solid-organic mixture is stirred and solid particles are dispersed into the organic phase.

3 . The method according to claim 1 , wherein the solid hydroxylamine or salt thereof is at least one selected from the group consisting of: hydroxylamine sulphate, hydroxylamine halide, hydroxylamine phosphate or hydroxylamine sulphonate.

4 . The method according to claim 1 , wherein the quantity of hydroxylamine used in step (a) is at least the equivalent of the total quantity of aldehyde and/or ketone formed in the extraction solution.

5 . The method according to claim 1 , wherein the solid alkaline salt is selected from the group consisting of: alkali metal hydroxide, earth alkali metal hydroxide, alkali metal carbonate, earth alkali metal carbonate and ammonia.

6 . The method according to claim 1 , wherein the solid alkaline salt is sodium carbonate.

7 . The method according to claim 1 , wherein solid particles are removed from the organic extraction solution by a decanter or filter.

8 . The method according to claim 1 , wherein after contacting the organic extraction solution with the wetted hydroxylamine or salt thereof in solid form in the presence of the solid alkaline salt and prior to the removal of the solid particles, the organic extraction solution is washed with an aqueous solution.

9 . The method according to claim 8 , wherein the washing is done at a pH of 2-5 and temperature of about 25-40° C.

10 . The method according to claim 8 , wherein the washing is carried out using a one stage mixer-settler unit or with only a mixer and the phases are separated with a centrifuge or decanter.

11 . The method according to claim 8 , wherein the hydroxylamine or its salt is recycled after the washing.

12 . The method according to claim 1 , wherein the adsorption material in a solid form is at least one selected from the group consisting of:
bentonite, diatomite, aluminium silicate, metal oxide, activated carbon, polymeric adsorbent and polymeric ion exchange resin.

13 . The method according to claim 1 , wherein the quantity of adsorption material is 0.01-10 weight %.

14 . The method according to claim 1 , wherein the quantity of adsorption material is 0.5-3 weight %.

15 . The method according to claim 1 , wherein the adsorption material is separated from the extraction solution by settling, filtration or centrifugation.

16 . The method according to claim 1 , wherein the adsorption material is in ground form.

17 . The method according to claim 1 , wherein the adsorption material is powder, spheres or filaments.

18 . The method according to claim 1 , wherein the step (a) and the step (b) take place as a batch operation.

19 . The method according to claim 1 , wherein the step (a) and the step (b) take place as a continuous operation.

20 . The method according to claim 1 , wherein the step (a) takes place as a batch operation and the step (b) takes place as a continuous operation.

21 . The method according to claim 1 , wherein the step (a) takes place as a continuous operation and the step (b) takes place as a batch operation.

Assignees

• Outotec Finland Oy

Inventors

• Kabugo James
• Paatero Erkki

Classifications

• C07C249/08

  by reaction of hydroxylamines with carbonyl compounds · CPC title

• B01D15/02 Primary

  with moving adsorbents · CPC title

• C22B3/12

  in inorganic alkaline solutions · CPC title

• B01J20/14

  Diatomaceous earth · CPC title

• B01J20/16

  Alumino-silicates (B01J20/12 takes precedence) · CPC title