Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning 2017-03-23T09:55:18+00:00
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Octylphenyl acid phosphate (OPAP) to extract Gallium (11 replies and 1 comment)

Paul Morrow
1 year ago
Paul Morrow 1 year ago

I am looking for this extractant (for the recovery of gallium from sulphuric acid), does anyone know a supplier?

I contacted several suppliers, Exxon Mobil Chemicals, Cytec, Daihachi and Solvay-Rhodia, but none seems to have this product in their portfolio.

Marshal Dienes
1 year ago
Marshal Dienes 1 year ago

How much extractant do you need?

Paul Morrow
1 year ago
Paul Morrow 1 year ago

For initial tests 100 g will suffice, however if successful we would require more for pilot testing.

Carmen Ibanz
1 year ago
Carmen Ibanz 1 year ago

Have you read this paper?http://web.ornl.gov/info/reports/1980/3445605115595.pdf

you will see that OPAP is not really one reagent and that it probably varies with whoever is making it and how they felt that day. So, if you do find any, your results may not be reproducible by others or even yourself some time later. Proceed with caution.

I would suggest Kelex 100 for your application. It is available from some Chinese sources.

Whatever, you do, you will need to characterize the reagent that you receive to determine what mix you are working with.

Paul Morrow
1 year ago
Paul Morrow 1 year ago

I didn't found this paper, I was aware of the fact that OPAP is a mixture of mono-OPAP and di-OPAP, however the other impurities mentioned in your reference would require me to purify such a product before testing.

The reason to consider OPAP as potential extractant is due to its extraction ability in acidic environment (see Harbuck: stacks.cdc.gov/view/cdc/10144/cdc_10144_DS1.pdf). Is Kelex 100 also able to extract gallium from sulphuric acid solutions?

Carmen Ibanz
1 year ago
Carmen Ibanz 1 year ago

D2EHPA will extract Ga at pH 2. How acidic is your system?

If you have to purify the reagent, then you are no longer dealing with a commercial system, unless the company that might be applying your technology will also be purifying any reagent they buy - a significant extra operating expense. Screen the organo-P extractants, D2EHPA, Cyanex 272 (Ion quest 290) and Ion quest 801 (P507). They are more readily available than Kelex 100 and I can't remember any more whether that works from acidic solutions (would have to dig in my files).

Maya Rothman
1 year ago
Maya Rothman 1 year ago

D2EHPA will work reasonably well; as to OPAP - chances are whoever makes D2EHPA (e.g., Asia-based suppliers) may also have OPAP on their product list.

Sugar Watkins
1 year ago
Sugar Watkins 1 year ago

I think this is the thesis you are talking about:

Gallium solvent extraction from sulphate solutions using organ phosphoric acid reagents (D2EHPA, OPAP)

http://digitool.library.mcgill.ca/R/-?func=dbin-jump-full&object_id=70338&silo_library=GEN01

you can download/read for free.

Paul Morrow
1 year ago
Paul Morrow 1 year ago

My system is quite acidic, pH < 0, which should enable extraction of gallium using OPAP, while D2EHPA is less efficient. D2EHPA was inefficient as was PC88A (Ion quest 801) and Cyanex 272 for gallium extraction at these low pH values. Tests at higher pH values are planned, but would in practice require leaching at reduced acid strength (increased leaching time) and/or pH adjustment after leaching (increased chemical usage).I am also performing tests with hydrochloric acid solutions to test solvating extractants, however I suspect that selectivity would be poorer in such a system.Up till now we have no response from Asia-based suppliers.

Carmen Ibanz
1 year ago
Carmen Ibanz 1 year ago

So, what about a 2-stage countercurrent leach? Add fresh feed in stage 2 and fresh acid in stage 1. Consume the free acid in stage 2 to produce a less acidic PLS. Advance the residue to stage 1 where you can complete the leach by adding strong acid. Requires some intermediate L/S but you get the most out of your acid, produce a PLS with lower acidity and avoid neutralizing the PLS (waste of acid).

Paul Morrow
1 year ago
Paul Morrow 1 year ago

A countercurrent leach (or similar) will be applied; however the metal concentration is very low. This due to the fact that we use secondary sources (WEEE), so called urban mining. See also the projects website for more background information: http://www.re-claim.eu.

Furthermore, we also extract indium selectively from the strong acidic PLS (prior to gallium recovery) giving additional restrictions to the acid strength of the PLS (due to selectivity of indium extraction).

Wayne
1 year ago

Hi all,
I too am now trying to source OPAP for gallium extraction Paul, did you have any luck finding a source?

David
1 year ago
David 1 year ago

Try chemnet.com at http://bit.ly/1MFi7kW?

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