Chemical composition and liberation characterization of printed circuit board comminution fines for beneficiation investigations

Abstract

a b s t r a c tChemical composition and liberation are critical attributes in characterizing a resource stock for beneficiation investigations. Though end-of-life printed circuit board is recognized as a valuable secondary resource stock, no procedural standard exists for the determination of its chemical composition, nor for the À75 lm fines generated during its comminution. The effect of the digestion procedure on the final assays in wet spectroscopic analyses was assessed in this work. Liberation was also explored against literature background. Determination of assays of all constituent elements in printed circuit board comminution fines was found to require comparison of data from more than one digestion condition, while composite particles still persist at the fines sizes, though very few. The discussion reflects how these impact the beneficiation investigations.

Assessment of gold and silver in assorted mobile phone printed circuit boards (PCBs): Original article

“…Aqua regia digests almost all the base and noble metals (Ogunniyi et al, 2009). The residue left on the filter paper denotes that some metals still remained un-dissolved in the conc.…”

“…An important and related fact is that the life of the mobile phone is getting reduced drastically. The life is less than two years in developed countries and three years in developing countries (Ogunniyi et al, 2009). Hence, a copious mobile phone waste of more than 8.2 billion mobile phones is expected to be accumulated worldwide in the coming years.…”

“…After the end of life of the mobile handset, people deem it as of nil monetarist items and proceed on its disposal without much thought. The end of life mobile phone poses health hazards due to the presence of toxins in it (Ogunniyi et al, 2009). The contents of precious metals are much richer in printed circuit board than natural ores as the metals in printed circuit boards are used in several layers.…”

Challenges in legislation, recycling system and technical system of waste electrical and electronic equipment in China

“…According to the United State Environmental Protection Agency, approximately 5 million tons of WEEE are generated in the US with an annual increase of 3-5% and 7 million tons in European Union (Tanskanen, 2013). WEEE contains lots of valuable copper and precious metal elements (Ogunniyi et al, 2009), along with plenty of hazardous heavy metals, flame retardants and refrigerants (Eric Williams et al, 2008;Wienold et al, 2011), which make it an attractive secondary resource and an environmental contaminant simultaneously.…”

Valorization of Printed Circuit Boards from Waste Electrical and Electronic Equipment by Pyrolysis

“…Recycling of printed circuit boards is difficult due to the complex structure of the boards and wide material composition. It has been estimated that a typical printed circuit board is composed of 40 wt% metals, 30 wt% plastics and 30 wt% of ceramic material [16]. The metals present include large amounts of copper, aluminium and iron, but also precious metals such as gold, silver and palladium which increase the interest in recycling technologies to recover such metals.…”