Distribution of elements between copper and FeO x –CaO–SiO 2 slags during pyrometallurgical processing of WEEE

Abstract

The rapidly increasing rate of creation of electronic waste (WEEE) requires the development of effective processing strategies so that the valuable (minor) metals and compounds in WEEE can be kept within the materials cycle while the possibly harmful elements and compounds can be kept out of the environment. Pyrometallurgical processing currently offers the most attractive routes to perform the initial separation before the usual hydrometallurgical refining steps to produce high purity metals and compounds. There is a lack of information on the way valuable metals in WEEE behave during smelting because the combination of metals in WEEE is frequently different to that found in natural ores. In this first paper the slag/metal distribution ratio of tin between FeO_x–CaO–SiO₂ slags and copper was examined at an oxygen partial pressure of 10⁻⁸ MPa (10⁻⁷ atm) and at 1300°C. The distribution ratio of tin was unaffected by the Fe/SiO₂ ratio of the slag, over the range examined, but strongly dependant on the CaO content. The higher the CaO content the smaller the slag/metal distribution ratio and, consequently, the greater the activity coefficient of SnO(l) in the slags. Iso-distribution ratio lines and iso-SnO(l) activity coefficient lines were presented on the copper-saturated FeO_x–CaO–SiO₂ phase diagram. Tin volatilisation during the converting stage of WEEE processing in a black copper smelter would be improved by using slag with a high CaO content for the given slag system. The distribution of indium, mostly found in liquid crystal displays, will be examined in a subsequent paper.

Keywords

WEEE Black copper FCS slag Minor element distributions Tin

Get full access to this article

View all access options for this article.

References

Anindya

. 2012. Minor elements distribution during the smelting of WEEE with copper scrap, PhD thesis (unpublished), RMIT University, Melbourne, Australia.

Anindya

, Swinbourne DR , Reuter

and Matusewicz

. 2009. Tin distribution during smelting of WEEE with copper scrap, European Metallurgical Congress 2009, (ed. Harre

), 555–568, GDMB-Informationsges, Clausthal-Zellerfeld.

Antrekowitsch

, Potesser

, Spruzina

and Prior

. 2006. Metallurgical recycling of electronic scrap, in EPD Congress 2006, (ed. Howard

S M

), 899–908, The Minerals, Metals & Materials Society.

Aurubis . 2013. Recycling technology – Aurubis’ multi-metal recycling, http://www.aurubis.com/en/our-business/raw-materials/recycling/technology (accessed on 4 January 2013).

Azakami

and Yazawa

. 1976. Activity measurements of liquid copper binary alloys. Can. Metall. Q, 15, (2), 111–122.

Bale

, Chartrand

, Degterov

, Eriksson

, Hack

, Ben Mahfoud

, Melançon

, Pelton

and Petersen

. 2002. FactSage thermochemical software and databases, Calphad, 26, (2), 189–228.

Cui

and Forssberg

. 2003. Mechanical recycling of waste electric and electronic equipment: a review, J. Hazard. Mater., 99, (3), 243–263.

E-wasteguide.info . 2009. Material composition, http://ewasteguide.info/node/4074, (accessed 14 December 2012).

Gortais

, Hodaj

, Allibert

and Welter

. 1994. Equilibrium distribution of Fe, Ni, Sb, and Sn between liquid Cu and a CaO-rich slag, Metall. Mater. Trans. B, 25B, (5), 645–651.

10.

Hager

, Howard

and Jones

. 1970. Thermodynamic properties of the Cu-Sn and Cu-Au systems by mass spectrometry, Metall. Mater. Trans. B, 1, (2), 415–422.

11.

Hagelüken

. 2005. Recycling of electronic scrap at Umicore's integrated metals smelter and refinery, in European Metallurgical Congress 2005, (ed. Waschki

), 307–324, GDMB-Informationsges, Clausthal-Zellerfeld.

12.

Hagelüken

and Kerckhoven

. 2006. Coping with challenges in WEEE - Recycling by using state-of-art smelting and refining processes, Proc. 5th Int. Electronics Recycling Congress, Hamburg, January 2006.

13.

Hultgren

, Desai

, Hawkins

1973. Selected values of the thermodynamic properties of binary alloys, 795–800, Ohio, American Society for Metals.

14.

Juckes

. 2002. Dicalcium silicate in blast-furnace slag: a critical review of the implications for aggregate stability. Min. Proc. Extr. Met., 111, 120–128.

15.

Kongoli

, McBow

, Yazawa

2006. Liquidus relationships of calcium ferrite and ferrous calcium silicate slag in continuous copper converting, in Sohn Int. Symp. Advanced Processing of Metals & Materials, (ed. Kongoli

and Reddy

R G

), 69–87, 2006, Warrendale, PA, TMS.

16.

Kuehr

. 2010. E-waste: not your normal trash, http://ourworld.unu.edu/en/e-waste-not-your-normal-trash/# (accessed 10 December 2012).

17.

Lehner

. 2011. Boliden AB, Ronnskar, Sweden, Personal communication, 13 September 2011.

18.

LME . 2012. LME tin, http://www.lme.com/tin.asp (accessed on 9 December 2012).

19.

Louey

, Swinbourne DR and Lehner

. 1999. Silver and tin distribution between copper matte and fayalite slag, Proc. AusIMM, 304, (2), 31–36.

20.

Nagamori

and Mackey

. 1977. Distribution equilibria of Sn, Se and Te between FeO-Fe₂O₃-SiO₂-Al₂O₃-CuO_0·5 slag and metallic copper, Metall. Mater. Trans. B, 88B, 39–46.

21.

Nikolic

, Hayes

and Jak

. 2008. Phase equilibria in ferrous calcium silicate slags: Part IV, Liquidus temperatures and solubility of copper in ‘Cu₂O’-FeO-Fe₂O₃-CaO-SiO₂ slags at 1250°C and 1300°C at an oxygen partial pressure of 10⁻⁶ atm, Metall. Mater. Trans. B.

22.

Outotec Research Oy . 2009. New simulation tool for process engineers and research scientists, http://www.outotec.com/39468.epibrw (accessed on 9 December 2012).

23.

Pink

. 2010. Australia's environment: issues and trends 2010, Australian Bureau of Statistics, Cat. no. 4613·0, 58.

24.

Rankin

. 2011. Minerals, metals and sustainability – Meeting future material needs, Melbourne, CSIRO Publishing, 189–213.

25.

Rentz

, Krippner

, Hähre

and Schultmann

. 1999. Best available techniques (BAT) in copper production, French-German Institute for Environmental Research, University of Karlsruhe, Germany.

26.

Reuter

and Van Schaik

. 2012. Opportunities and limits of recycling: a dynamic-model-based analysis, MRS Bull., 37, (4), 339–347.

27.

Van Schaik

and Reuter

. 2012. Shredding, sorting and recovery of metals from WEEE: linking design to resource efficiency, in Waste electrical and electronic equipment (WEEE) handbook (ed. Goodship

and Stevels

), Cambridge, Woodhead Publishing Ltd, 163–211.

28.

Sigworth

and Elliott

. 1974. Thermodynamics of dilute liquid copper alloys, Can. Metall. Q, 13, (3), 455–461.

29.

Takeda

, Ishiwata

and Yazawa

. 1983. Distribution equilibria of minor elements between liquid copper and calcium ferrite slag. Trans. Jpn Inst. Metal., 24, (7), 518–528.

30.

Takeda

and Yazawa

. 1989. Dissolution loss of copper, tin and lead in FeO_n-SiO₂-CaO slag, in Productivity and technology in the metallurgical industries, (ed. Koch

and Taylor

J C

), 227–240, The Minerals, Metals & Materials Society.

31.

US Geological Survey . 2012. Minerals information: tin. http://minerals.usgs.gov/minerals/pubs/commodity/tin/ (accessed on 12 January 2013).

32.

Widmer

, Oswald-Krapf

, Sinha-Khetriwal

(2005). Global perspectives on e-waste, Environ. Impact Assess. Rev., 25, (5), 436–458.

33.

Woerz

and Wallner

. 1988. Copper recycling plant at Brixlegg (Austria), in World survey of nonferrous smelters (ed. Taylor

J C

and Traulsen

H R

), 281–288, The Minerals, Metals & Materials Society.

34.

Wood

, Creedy

, Matusewicz

and Reuter

. 2011. Secondary copper processing using Outotec Ausmelt TSL technology, in Proceedings of MetPlant 2011, 460–467, The Australasian Institute of Mining & Metallurgy: Carlton South.

35.

Yazawa

. 1994. Thermodynamic interpretation on oxide dissolution in slag, in Pyrometallurgy for complex materials and wastes (ed. Nilmani

), 61–72, Warrendale, PA, The Metallurgical Society.