Recovery of gold from computer circuit board scraps: the study of the effect of different reductants

A b s t r a c t Computer circuit boards (CCBs) are valuable because of their precious metal contents. In this regard, the recovery of gold from CCBs has attracted great interest. In this work, we report the recovery of gold from CCBs with different reductants. The CCBs were first crushed mechanically to obtain particles with sizes less than 0.1 mm. The powders were then leached with nitric acid to remove undesired metals. The remaining was then treated with aqua regia to dissolve gold ion. The dissolved gold was then precipitated from the leachate with hydrazine, ferrous sulfate or oxalic acid and the effect of these reductants on the recovery of gold was studied. We were able to recover more than 99% of gold from CCBs with purity of about 99.5%.

[1]  D. Pilone,et al.  Prediction and measurement of multi-metal electrodeposition rates and efficiencies in aqueous acidic chloride media , 2006 .

[2]  K. Feldmann,et al.  The printed circuit board-a challenge for automated disassembly and for the design of recyclable interconnect devices , 1995 .

[3]  Paul T. Williams,et al.  Separation and recovery of materials from scrap printed circuit boards , 2007 .

[4]  K. Gloe,et al.  Recovery of precious metals from electronic scrap, in particular from waste products of the thick-layer technique , 1990 .

[5]  Katsutoshi Inoue,et al.  Recovery of Au(III) by using low cost adsorbent prepared from persimmon tannin extract , 2011 .

[6]  S. Herat.  International regulations and treaties on electronic waste (e-waste) , 2009 .

[7]  Eric Forssberg,et al.  Mechanical recycling of electronics scrap - the current status and prospects , 1998 .

[8]  Eric Forssberg,et al.  Mechanical separation-oriented characterization of electronic scrap , 1997 .

[9]  S. Syed,et al.  Recovery of gold from secondary sources—A review , 2012 .

[10]  D. Fray,et al.  Recovery of high purity precious metals from printed circuit boards. , 2009, Journal of hazardous materials.

[11]  Miss A.O. Penney.  (b) , 1974, The New Yale Book of Quotations.

[12]  Hirokazu Konishi,et al.  Influence of ammonium salt on electrowinning of copper from ammoniacal alkaline solutions , 2007 .

[13]  A. A. Jalil,et al.  Recovery of gold(III) from an aqueous solution onto a durio zibethinus husk , 2011 .

[14]  Lifeng Zhang,et al.  Metallurgical recovery of metals from electronic waste: a review. , 2008, Journal of hazardous materials.

[15]  Eric Forssberg,et al.  Aluminum recovery from electronic scrap by High-Force® eddy-current separators , 1998 .