Wako Pure Chemical Industries, Ltd.Wako Pure Chemical Industries, Ltd. - Laboratory Chemicals

New agent for extraction and recovery of palladium
Creastar Pd-EX

This is a thiodiglycolic acid amide (TDGA) newly introduced with a hexyl group. Having a high selectivity and rapidity for Pd ions, by only adding the small amount of this to DHS (dihexyl sulfide) used for Pd extraction, the extraction time can be drastically shortened.




1. Feature

Thiodiglycolic acid amide(TDGA) class developed by the National Institute of Advanced Industrial Science and Technology (patent 4,448,937) can extract Pd ions dissolved in the acidic aqueous solution into the organic phase with high selectivity and rapidity. Besides, with the excellent stability against air oxidation, by only adding the small amount of this to DHS (dihexyl sulfide) used for Pd extraction currently, the extraction time can be drastically shortened.
In addition, Pd ions taken into the organic phase in the form TDGA of two molecules is coordinating in Pd can be isolated and purified into the water phase with ammonia water.

2. The extraction time-dependency of extraction rate of palladium and platinum.

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Experimental condition

  • The organic phase for extraction:
    0.05M N,N'-dimethyl-N,N'-di-n-octyl-TDGA or DHS
    in 80 vol% n-dodecane-20 vol% 2-ethylhexanol
  • Water phase: 0.1g / L of Pd, Pt in 3M HCl

3. The reduction rate of palladium extraction associated with the extractant degradation due to strong acid.

image

Experimental condition

  • The organic phase for extraction:
    0.05M N,N'-dimethyl-N,N'-di-n-octyl-TDGA or DHS in 80vol% n-dodecane-20vol% 2-ethylhexanol
  • Water phase:
    Strong acid: 0.75M HNO3-2.25M HCl (2g / L of Pd)

4. The effect of adding to DHS

image

Experimental condition

  • The organic phase for extraction:
    N,N,N',N'-tetra-n-octyl-TDGA+(0.2-x)M DHS in 80vol%
    n-dodecane-20vol% 2-ethylhexanol
  • Water phase:
    1g/L of Pd in 3M HCl

Even by simply adding a small amount of TDGA to a conventional extractant DHS (15% molarity of total extractant), the rapid extraction of palladium was possible. In addition, the same back-extractive characteristics as the time when using 100% DHS (The ammonia solution was used.) and the extractive capacity (the palladium of half molarity of the extractant was extracted) have been shown.

5. Selectivity for metals of Creastar Pd-EX.

Experimental condition

  • The organic phase for extraction:0.1M Creastar Pd-EX in 80 vol%n-dodecane-20 vol% 2-ethylhexanol
  • Water phase (Metal-containing aqueous solution):
    50 ppm of Pd, Pt, Rh, Fe, Cu, Zn, Ni in 1M HCl
  • Extraction experiment:
    An organic solvent which the extractant was prepared to the prescribed concentration by the diluent and hydrochloric acid solution (1M) containing no metal were stirred in the test tube, and the pre-equilibration was conducted.
    The organic solvent of 1mL after the pre-equilibration was transferred to the plugged test tube of 10mL, then adding the hydrochloric acid solution (1M) containing the same volume of metal, and after one hour shaking in the vertical shaker, then it was centrifuged.
    The concentrations of the aqueous solution before and after extraction were measured by ICP emission spectroscope to determine the extraction rate.
    Pd (II) extracted into the organic layer with this extractant was back-extracted by being contacted with ammonia water of 28%.


※ 1. to 3. are the data of TDGA class except for Creastar Pd-EX. They have basically the same performance as Creastar Pd-EX.

6. Product List

Product Name Package Size Wako Catalog No.
Creastar Pd-EX
[CAS No. 201849-07-2] C18H36N2O2S
10 g 308-96101
25 g 306-96102