Experimental Study of Pollutant Removal Chemical Techniques in the Bayer Process

Document Type : Original Articles

Authors

• Mostafa Mahmoudian ¹
• Ahad Ghaemi ²
• shahrohk Shahhosseini ²

¹ Shahroud university

² Iran university of science and technology

10.22067/ma.v28i2.38395

Abstract

In this work, carbonate and oxalate creating factors were determined in the Bayer process. In the chemical removal of carbonate and sodium oxalate soluble in sodium aluminate liquor, barium aluminate with structures of Ba2Al2O5, Ba2Al4(OH)16 and BaAl2O4, calcium aluminate (Ca3Al2(OH)12), sodium phosphate (Na3PO4) and lime were separately used. Investigation of temperature, concentration of caustic soda, Al2O3 and sodium carbonate revealed that using barium aluminate with the structure of Ba2Al4(OH)16 with the removal efficiency of carbonate equal to 80.2% and sodium phosphate (Na3PO4) and lime with the removal efficiency equal to 66.9% in oxalate removal, have maximum efficiency. The results also showed that lime and bauxite lead to 66.9 and 99.9% of carbonate and oxalate pollutions in Bayer process liquor, respectively.

Keywords

• Bayer Process
• Carbonate
• Oxalate, Pollutant
• Chemical Technique

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References

1. Sonthalia R., Behara P., Kumaresan T., Thakre S., "Review on alumina trihydrate precipitation mechanisms and effect of Bayer impurities on hydrate particle growth rate", Journal of Colloids and Surfaces, Vol. 125, pp. 137–148, (2013).

2. Hind A.R., Bhargava S.K., Grocott S.C., "The surface chemistry of Bayer process solids", Journal of Colloids and Surfaces, Vol. 146, pp. 1-3, (1999).

3. Shin H.J., Lee S.O., Kim S.J., Tran T., Kim M.J., "Study on the effect of humate and its removal on the precipitation of aluminum trihydroxide from the Bayer process", Journal of Minerals Engineering, Vol. 13, pp. 387–391, (2004).

4. Xiao J.B., Jiang X.Y., Chen X.Q., "Identification of Organic Acids in Bayer Liquors By GC–MS: A Comparison Using Butylation and Methylation", Journal of Chromatographic Science, Vol. 183, pp. 183-188, (2007).

5. Armstrong L., Hunter J., McCormick K., Warren H., "Bound Soda Incorporation during Hydrate Precipitation", 14th International Symposium on Industrial Crystallization, pp. 283–292, (1993).

6. Technoexport P., "Alumina plant jajarm process and operating manual", (1997).

7. Zhang Y.F., Cao S.T., Zhang Y., Zheng S.L., "A method to produce alumina from Chinese diasporic bauxite", China patent, Appl. No. 200810227930.5, (2008).

8. Power G., Loh J., "Organic compounds in the processing of lateritic bauxites to alumina: Part 1: Origins and chemistry of organics in the Bayer", Journal of Hydrometallurgy, Vol. 105, pp. 1–29, (2010).

9. McSweeney N.J., Tilbury A.L., Nyeboer H.J., McKinnon A.J., Sutton D.C., Franzmann P.D., Kaksonen A.H., "Molecular characterization of the microbial community of a full-scale bioreactor treating Bayer liquor organic waste", Minerals Engineering, Vol. 24, pp. 1094–1099, (2011).

10. Machold T., Macedi E., Laird D.W., May P.M., Hefter G.T., "Decomposition of Bayer process organics: Low-molecular-weight carboxylates", Journal of Hydrometallurgy, Vol. 99, pp. 51-57, (2008).

11. Whelan T.J., Ellis A.V., Kannangara G.S.K., Marshall C.P., Smeulders D.E., Wilson M.A., "Macromolecules in the Bayer process", Reviews in Chemical Engineering, Vol. 19, pp. 431– 471, (2003a).

12. Ellis A.V., Wilson M.A., Kannangara K., "Bayer poisons: degradation of angiosperm and gymnosperm water-soluble extracts in sodium hydroxide at 145°C", Industrial Engineering Chemistry Research, Vol. 41, pp. 2842–2852, (2002b).

13. Power G., Loh J., "Organic compounds in the processing of lateritic bauxites to alumina. Part 1: Origins and chemistry of organics in the Bayer process", Journal of Hydrometallurgy, Vol. 105, pp. 1–29, (2010)

14. Machold T., Laird D.W., Rowen C.C., May P.M., Hefter G.T., "Decomposition of Bayer process organics: Phenolates, polyalcohols, and additional carboxylates", Journal of Hydrometallurgy, Vol. 107, pp. 68-73, (2011).

15. Power G., Loh J., "Organic compounds in the processing of lateritic bauxites to alumina", Journal of Hydrometallurgy, Vol. 127, pp. 125-149, (2012).

16. Cao S., Zhang Y., Zhang Y., "Preparation of sodium aluminate from the leach liquor of diasporic bauxite in concentrated NaOH solution", Journal of Hydrometallurgy, Vol. 98, pp 298-303, (2009).

17. The P.J., "The effect of glucoisosaccharinate on the Bayer process of alumina trihydrate", Light Metals, pp. 122–131, (1980).

18. Gerais S., "Organic control technologies in bayer process", Alcan Bayer company report, (2004).

19. Atkins P., Grocott S.C., "Impact of organic impurities on the product of refined alumina", Proceedings of Science, Technology and Utilisation of Humic Acids, CSIRO Division of Coal and Energy Technology, Sydney, Australia. pp. 85–94, (1988).

20. Power G., Loh J.S.C., Vernon C., "Organic compounds in the processing of lateritic bauxites to alumina Part 2: Effects of organics in the Bayer process", Journal of Hydrometallurgy, Vol. 127, pp. 125-149, (2012).

21. Jones F., Farrow J.B., Bronswijk W.V., "Effect of caustic and carbonate on the flocculation of hematite in synthetic Bayer liquors”, Colloids and Surfaces A: Physicochemical and engineering aspects, Vol. , pp. 65-73, (1998).

22. Strominger M.G., Malito J.T., "Purification of Bayer process liquors using cationic polymeric quaternary ammonium salts", United States Patent, Patent No: US5284634 A, (1994).

23. Power G., Tichbon W., "Sodium Oxalate in the Bayer Process: Its Origin and Effects", 2nd International Alumina Quality Workshop. Perth. Australia, pp. 99–115, (1990).

24. Loh J., Brodie G., Power G., Vernon C., "Mechanisms of Degradation of Hydrate Yield Inhibitors by Wet Oxidation", Proceedings of the 8th International Alumina Quality Workshop, Darwin, Australia, pp. 199–205, (2008a).

25. Brady J.P., "An examination of the applicability of hydrotalcite for removing oxalates anions from Bayer process solutions", (2011).

26. Grocott S.C., Rosenberg S.P., "Possible mechanisms for soda incorporation in smelter grade alumina", 1st International Alumina Quality Workshop, pp. 271–287, (1988).

27. Dong J., Loh J.S.C., Tardio J., Vernon C., Bhargava S., "Fundamentals of wet oxidation of bayer liquor organics: Effect of oxygen on malonates", Engineering a Better World: Sydney Hilton Hotel, NSW, Australia, 18-21, (2011).

28. Smith T, "Practical thermometric titrimetry", Metrohm Ltd. CH-9101 Herisau/Switzerland, (2006).

29. Standard Test Methods for Chemical Analysis of Limestone, Quicklime, and Hydrated Lime, Active Standard ASTM C25 Developed by Subcommittee: C07.05, Book of Standards Volume: 04.01

30. Greg P., Joanne S.C, Lohb, Chris V., "Organic compounds in the processing of lateritic bauxites to alumina", Journal of Hydrometallurgy, Vol. , pp. , (2012).

31. Technoexport P., "Alumina plant jajarm process and operating manual", (1997.(

32. Palmer S.J., Smith M., Frost R.L., "Implication of calcium hydroxide in the seawater neutralisation of bauxite refinery liquors", (2012).

33. Dunstan G., Charmaine R., Riley G.W., "Method for the causticization of bayer process solutions", PCT, International publication number: WO 2006/081626-A1,)2006.(