Recovery of precious metals from scrap printed circuit boards through pyrolysis

Bidini, Gianni; Fantozzi, Francesco; Bartocci, Pietro; D’Alessandro, Bruno; D’Amico, M.; Laranci, Paolo; Scozza, E.; Zagaroli, M.

doi:10.1016/j.jaap.2014.11.020

Cited by 74 publications

(30 citation statements)

References 15 publications

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“…Ru, Ir, and Os remain in the solid residue.H eating the residue with sodium hydroperoxide at 500 8 8Cconverts Ru and Os into their water-soluble ruthenates and osmates,t hus allowing them to be separated from insoluble IrO 2 ,w hich is further processed to give iridium metal. [182] In contrast to PGM-containing ores,t hese wastes are mixed with acollector metal, such as Cu and smelted in ashaft furnace to extract the PGMs from the waste material by forming an alloy with the added metal ( Figure 14). Gas scrubbing with hydrochloric acid produces water-soluble OsCl 4 and [RuCl 6 ] 2À .The addition of nitric acid yields volatile OsO 4 .T he remaining chlororuthenate is further processed to Ru metal.…”

Section: Extraction Technologiesmentioning

confidence: 99%

“…[181] In addition to WEEE processing, pyrolysis is being discussed as an alternative to combustion. [182] In contrast to PGM-containing ores,t hese wastes are mixed with acollector metal, such as Cu and smelted in ashaft furnace to extract the PGMs from the waste material by forming an alloy with the added metal ( Figure 14). The resulting Cu alloy contains up to 20 wt %PGMs.Slag-forming Figure 14.…”

Section: Reviewsmentioning

confidence: 99%

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Valuable Metals—Recovery Processes, Current Trends, and Recycling Strategies

et al. 2017

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This Review provides an overview of valuable metals, the supply of which has been classified as critical for Europe. Starting with a description of the current state of the art, novel approaches for their recovery from primary resources are presented as well as recycling processes. The focus lies on developments since 2005. Chemistry strategies which are used in metal recovery are summarized on the basis of the individual types of deposit and mineral. In addition, the economic importance as well as utilization of the metals is outlined.

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Section: Extraction Technologiesmentioning

confidence: 99%

Section: Reviewsmentioning

confidence: 99%

Valuable Metals—Recovery Processes, Current Trends, and Recycling Strategies

et al. 2017

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“…5 Increasing attention on precious metals recovery such as gold, silver and platinum from waste PCBs (WPCBs) has boosted the development of new processes including physical [18][19][20] and thermochemical techniques. 12,18,19,21 Hydrometallurgical methods are one of the key technologies in metal recycling because they enable a fine separation between chemically-similar metals in small-scale operation. 1,[22][23][24][25][26] The base metals recovery has a substantial impact on the economics of the process due to larger available amount in WPCBs.…”

Section: Introductionmentioning

confidence: 99%

Recovery of Lead and Noble Metals After Processing Printed Circuit Boards From Cell Phones by Leaching With Mixtures Containing Hydrogen Fluoride

Silva¹,

Corrêa²,

Gismonti³

et al. 2018

Quim. Nova

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This work examines the leaching of printed circuit boards (PCBs) from cell phones in aqueous solutions containing HF + H 2 O 2 or HF + NaClO under mild experimental conditions. The PCBs were not ground but were previously treated with 6 mol L -1 NaOH at 50 o C for 1 h to remove their soldering mask. , respectively. The processing of the solid residue is also described in detail. It was leached with water at ~90 o C followed by HNO 3aq. at 25 o C. Lead, palladium and silver were recovered in this order, leaving gold as final solid. After 1 h at [35][36][37][38][39][40] o C, 5 mol L -1 HF + 0.3 mol L -1 NaClO mixtures leached the base metals, copper, gold and palladium. Gold was recovered by liquid-liquid extraction with methyl isobutyl ketone. Silver precipitated as chloride. This salt was isolated by leaching with NH 3aq . Loss of fluoride ions (as HF) was below 0.5 wt.% after leaching and handling the solid residue.

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“…although waste PCBs present potentially serious long-term environmental and health implications, previous studies have focused only on the current status of sites polluted by waste EEE and precious metal recycling [19,[21][22][23][24][25][26]. Scientific information regarding the transfer of heavy metals from waste PCBs to the environment, particularly through aR washing, remains limited.…”

mentioning

confidence: 99%

Investigation of the Leaching Characteristics of Heavy Metals from Waste Printed Circuit Boards through Column Testing with Simulated Acid Rain

Zhao¹,

Luo²,

Qiao³

et al. 2017

JRST

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Waste printed circuit boards (PCBs) contain various heavy metals; hence, randomly discarded PCBs in open fields induce probable environmental risks when precipitation occurs, particularly acid rain (AR). We applied the column leaching method under simulated AR leaching to study the leaching characteristics of Cu, Pb and Zn in waste PCBs. Cu and Pb were easily leached by AR (pH 2 and 3) but not by distilled water (pH 5.6; CK treatment). By contrast, Zn could be leached readily even in CK treatment. AR with low pH exerted good leaching effects on Cu, Pb, and Zn. The heavy metal contents in the leachates were in the order of Cu > Pb > Zn. The maximum leaching concentrations of Cu, Pb, and Zn were 34.7, 4.06, and 1.15 mg/L, respectively, which are higher than drinking water standard set by the US Environmental Protection Agency. Therefore, waste PCBs can be considered a new source of heavy metal and pose potential environmental risks.

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Recovery of precious metals from scrap printed circuit boards through pyrolysis

Cited by 74 publications

References 15 publications

Valuable Metals—Recovery Processes, Current Trends, and Recycling Strategies

Valuable Metals—Recovery Processes, Current Trends, and Recycling Strategies

Recovery of Lead and Noble Metals After Processing Printed Circuit Boards From Cell Phones by Leaching With Mixtures Containing Hydrogen Fluoride

Investigation of the Leaching Characteristics of Heavy Metals from Waste Printed Circuit Boards through Column Testing with Simulated Acid Rain

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