In this study, cup-shaped copper sheets were developed to improve heat dispassion for high-power light emitting diodes (LEDs) array module (3 × 3, 4 × 4, and 5 × 5) using an electroplating technique. The cup-shaped copper sheets were directly contacted with sapphire to enhance the heat dissipation of the chip itself. The lateral emitting light extraction and heat dissipation of high-power LEDs ...

A simple and sensitive extraction-fluorimetric method for the determination of copper is reported. The 1,7-diaza-15-crown-5-copper-rose Bengal (DA15C5-Cu-RB) ternary complex is quantitatively extracted into chloroform, diluted with ammoniacal acetone and its fluorescence intensity is measured at 570 nm with excitation at 540 nm. A linear calibration graph was obtained over the copper concen...

Copper ore is a non-renewable resource with lower grades, which means that the extraction of more rock material required to produce same amount copper, implying greater consumption materials, reagents, water, and energy. Since there copper sulfide present in nature, concentration using bubble flotation method will generate number tailings. This article discusses environmental issues resulting f...

Processing of anodic slimes from an Egyptian copper electrorefining plant, exhibiting high contents of copper, lead, tin and silver has been presented. The proposed hydrometallurgical process consists of two leaching stages for extraction of copper with H2SO4 – O2 and silver with thiourea – Fe. Pyrometallurgical treatment of the leaching solid residue for production of Pb-Sn soldering alloy was...

This work aims to study the recovery of copper from ammoniacal aqueous solutions using hydrophobic propylene membrane contactors. The hydroxyoxime LIX 84-I and the β-diketone LIX 54 (both from Cognis) were used as extractants. The results obtained showed that practically all the copper content was removed from the ammoniacal feed solutions. The recovery of copper reached nearly 100% in several ...

an emission factor is a tool that is used to estimate air pollutant emissions to the atmosphere. it relates the quantity of pollutants released from a source to some activities associated with those emissions. to determine the quantity of pollutant released from copper and its alloys smelting furnaces, 63 samples from emission gases were collected on cellulose ester membrane filters in three 8-...

Latin American labor power has decreased dramatically in the 1990’s. In spite of this phenomenon, Chilean subcontracted laborers in the copper industry organized and forced the government to increase social protection for temporary workers. What circumstances allowed for the successful unionization? I argue that the unionization of subcontracted workers is due to a change in the labor instituti...