T. Kinoshita, S. Akita, S. Ozawa, S. Nii, F. Kawaizumi, K. Takahashi
Department of Chemical Engineering, Nagoya University, Chikusa-ku,Nagoya 464-8603, Japan.
Nagoya Municipal Industrial Research Institute, 3-4-41 Rokuban, Atsuta-ku, Nagoya 456-0058, Japan.
DOI: 10.4236/jmmce.2004.31006   PDF    HTML     5,201 Downloads   6,630 Views   Citations

Abstract

A continuous recovery of Au(III) via foam separation from its hydrochloric acid solutions was studied using a nonionic surfactant: polyoxyethylene nonyl phenyl ether having 20 ethylene oxide units (PONPE20). The surfactant showed a strong affinity to Au(III) in HCl media, and successfully played a dual role for foamproduction and metal-collection in the system. Experimental parameters examined were the feed flow rate, the foam height and the depth of bulk liquid phase. Under a standard condition, the percent recovery and the enrichment ratio of Au(III) were 54 % and 4.5, respectively. Using the adsorption isotherm of Au(III) obtained in a batch operation, these two values could be estimated against the feed flow rate which are in good agreement with the experimental ones. It was also found that about 90 % of Au(III) recovered in the foamate phase was transferred onto the foam surface and the rest was conveyed to the interstitial water between the foam. Highly selective recovery of Au(III) was achieved from multi-metals solution.

Keywords

foam separation, nonionic surfactant, gold(III), continuous operation, surface excess, Freundlich’s adsorption isotherm

Share and Cite:

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Maurice, C. F., et al. 1995, Mineral Processing, In: Flotation Science and Engineering, Part 2, pp.89-259, (Matis, K. A., Eds.), N.Y., Dekker.
[2]	Thomas, E., et al. 1992, Separations Based on Foams, In: Surfactant-Based Separation Processes, Part IV, pp. 233-320, (Scamehorn, J. F., et al. Eds.), N.Y., Dekker.
[3]	Maruyama, H., Suzuki, A., Seki, H., 2000, “Adsorption of Water Soluble Proteins onto Bubbles in Continuous Foam Separation”, J. Coll. Int. Sci., Vol. 224, pp. 76-83.
[4]	Bhattacharya, P., Ghosal, S. K., and Sen, K., 1991, “Effect of Physicochemical Parameters on the Separation of Proteins from Human Placental Extract by Using a Continuous Foam Fractionating Column”, Sep. Sci Technol., Vol. 26(10&11), pp. 1279-1293.
[5]	Malcolm D. E., Leahy G. J., Neville T. M. and Stuart K.N. 1991, “Selective Ion Flotation of Gold from Alkaline Cyanide Solutions”, AisIMM World Gold '91 Conference Cairns 21th to 26th April, pp. 121 - 131.
[6]	Tharapiwattananon, N., Scamehorn, J.F., Osuwan, S., Harwell, J.H., and Haller, K.J., 1996, “Surfactant Recovery from Water Using Foam Separation”, Sep. Sci. Technol., Vol. 31(9), pp.1233-1258.
[7]	Koczo, K., and Racz, G., 1991, “Foaming Properties of Surfactant Solution”, Colloids Surf., Vol. 56, pp. 59-82.
[8]	Uraizee F., and Ganesan, N., 1992, “Effect of Coalescence on the Performance of Continuous Foam Fractionation Column”. Sep. Sci. Technol., Vol. 27(7), pp. 937-953.
[9]	Konduru, R., 1992, “Adsorption studies of Aqueous Zinc Ions by Foam Fractionation in Simple Mode”, J. Chem. Eng. Japan, Vol. 25, No. 5, pp. 555-560.
[10]	M. Hiraide, 1995, Foam Fractionation and Flotation, In: Encyclopedia of Analytical Science, pp. 1453, (Townshend, A., Eds.), F.L., Academic Press.
[11]	Akita, S. and Takeuchi, H., 1996, “Cloud Point Extraction of Gold(III) from Hydrochloric Acid Solution, in Value Adding through Solvent Extraction”, ISEC ’96, Vol.1, pp. 529-534.
[12]	Kinoshita, T., Akita, S., et al., 2003, “A study on gold(III) recovery via foam separation with nonionic surfactant in batch mode”, J. Min. & Mat. Char. & Eng., 2003, Vol. 2, No. 2, pp. 71-82.
[13]	Akita, S., Yang, L. and Takeuchi, H., 1996, “Solvent Extraction of Gold(III) from Hydrochloric Acid Media by Nonionic Surfactant”, Hydrometallurgy, Vol. 43, pp. 37-46.
[14]	Akita, S., Rovira, M., Sastre, A. M. and Takeuchi, H., 1998, Cloud Point Extraction of Gold(III) with Nonionic Surfactant – Fundamental Studies and Application to Gold Recovery from Printed Substrates”, Sep. Sci. Technol., Vol. 33 (14), pp. 2159-2177.
[15]	Akita, S., Yang, L. and Takeuchi, H., 1997, “Micellar-enhanced Ultrafiltration of Gold(III) with Nonionic Surfactant”, J. Membrane Science, Vol. 133, pp. 189-194.