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1

Copper recovery from waste printed circuit boards and the correlation of Cu, Pb, Zn by ionic liquid

Li F., Chen M.

Environment Protection Engineering

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2017

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Vol. 43, nr 4

55--66

EN

Waste printed circuit boards (WPCBs) contain not only harmful materials but also many valuable resources, especially metals, which attracts more and more attention from the public. In this study, a sulfonic acid functionalized ionic liquid ([BSO₃HPy]OTf) was used to recycle copper from WPCBs. Zinc and lead, represented as typical heavy metals, were chosen to study the leaching behavior and their relation to copper. Five factors such as particle size, ionic liquid (IL) concentration, H₂O dose, solid to IL ratio and temperature were investigated in detail. The results showed that copper leaching rate was high, up to 99.77%, and zinc leaching rate reached the highest value of 74.88% under the optimum conditions. Lead cannot be leached effectively and the leaching rate was mostly low than 10%, which indirectly indicated that [BSO₃HPy]OTf has a good selectivity to lead. Besides, the interaction of copper, lead and zinc was characterized macroscopically by means of statistical methods. The Spearman correlation analysis showed that copper and zinc had a highly positive correlation. Lead had little relation to copper, which to some extent indicated that the effect of zinc on copper leaching behavior was bigger than that of lead.

2

Waste printed circuit boards nonmetallic powder as replacement for sand in cement mortar

Wang R., Zhang T., Wang P.

Materiały Budowlane

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2016

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nr 1

59--62

EN

The nonmetallic powder recycled from waste printed circuit boards (PCB) is used in cement mortar as replacement for sand. The results show that the waste PCB nonmetallic powder causes an increase in air content and improves the water-retention property of fresh mortar, decreases the bulk density of hardened mortar. There is a decrease in the compressive and flexural strengths with the addition of waste PCB nonmetallic powder and the decreasing degree depends on the substitution amount of the nonmetallic powder for sand. The tensile bond strength decreases slowly with the increase of the substitution amount from 0% to 35%. The water capillary adsorption of mortar is close to that of control when 10% and 20% sand is replaced. The use of mortar made with recycled waste PCB nonmetallic powder as sand replacement offers promise for applications as medium weight or light weight concrete, while adding value to a post-consumer electric and electronic material that is now generally treated as solid waste.

PL

W artykule analizowano możliwość wykorzystania niemetalicznego proszku pochodzącego z recyklingu płytek drukowanych PCB (ang. Printed Circuit Boards) jako zamiennika piasku w zaprawach cementowych. Uzyskane wyniki wskazują, że dodatek proszku PCB powoduje wzrost zawartości powietrza, poprawę zdolności do retencji wody świeżej zaprawy oraz zmniejszenie gęstości objętościowej stwardniałej zaprawy. Obserwowany spadek wytrzymałości na ściskanie i zginanie zależy od stopnia substytucji piasku proszkiem PCB. Przyczepność przy rozciąganiu spada stopniowo ze wzrostem substytucji od 0 do 35%. Adsorpcja kapilarna wody zapraw modyfikowanych jest zbliżona do wartości uzyskanej w przypadku próbki kontrolnej, jeśli stopień substytucji proszkiem PCB jest mniejszy niż 20%. Wyniki uzyskane dla zapraw z proszkiem PCB wskazują także na możliwość ich wykorzystania w betonach lekkich. Potwierdzają także, że zużyte elektryczne i elektroniczne płytki drukowane, uważane za produkty odpadowe, mogą być z powodzeniem wykorzystane w technologii materiałów budowlanych.

3

Recycling of non-metallic powder from printed circuit board waste as a filler material in a fiber reinforced polymer

Kanchanapiya P., Pinyo W., Jareemit S., Kwonpongsagoon S.

Environment Protection Engineering

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2015

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Vol. 41, nr 4

151--166

EN

Rapid growth in the electricity and electronics industry in Thailand has resulted in numerous problems with electrical waste management. Printed circuit board (PCB) components contain copper in an amount of approximately 10 wt. % and approximately 90 wt. % of non-conductive substrate made from fiberglass resin. In the recycling process, after copper is physically separated from PCB, only nonmetallic powder (NMP) will be left; that needs to be properly disposed of and managed. Therefore, this study is a proposal of suitable choices for NMP management. The results showed that NMP can be disposed in hazardous waste landfill. Furthermore, NMP can be recycled as a component in fiber- -reinforced polymer (FRP) of the following composition: coarse NMP 25%, fine NMP 25%, polyester 38.8%, hardener (Butanox type) 0.6%, catalyst (cobalt type) 0.6%, styrene monomer 10%. This FRP mixed with NMP can be properly processed into an artificial wall tile product in terms of mechanical properties, manufacturing processes and conditions of use.