• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.513-515
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• 2008

Due to the rapid development of telecommunication industry, most telecom operators are investing to upgrade their access networks by using optical cables instead of copper cables. Building new telecom ducts for optical cable installation requires so huge capital expenses that most telecom operators need to remove unused copper cables in order to secure enough space to in-stall optical cables. In this paper, we will present a alternative method to extract copper from removed copper cables.

• Membrane Journal
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• v.23 no.1
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• pp.92-99
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• 2013

In this study the nanofiltration (NF) membrane treatment of a sulfuric acid waste solutions containing copper ion ($Cu^{+2}$) discharging from the etching processes of the printed circuit board (PCB) manufacturing industry has been studied for the recycling of acid etching solution. SelRO MPS-34 4040 NF membrane from Koch company was tested to obtain the basic NF data for recycling of etching solution and separation efficiency (total rejection) of copper ion. NF experiments were carried out with a dead-end membrane filtration laboratory system. The pure water flux was increased with the increasing storage time in sulfuric acid solution and lowering pH of acid solution because of the enhancement of NF membrane damage by sulfuric acid. The permeate flux of acid solution was decreased with the increasing copper ion concentration. Total rejection of copper ion was decreased with the increasing storage time in sulfuric acid solution and copper ion concentration, and lowering the pH of acid solution. The total rejection of copper ion was decreased from initial 37% to 15% minimum value.

• Resources Recycling
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• v.17 no.3
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• pp.48-55
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• 2008

Leaching of copper and silver from mobile phone PCBs(printed circuit boards) with nitric acid was performed to investigate the effects of nitric acid concentrations, leaching temperatures, agitation speeds, and pulp densities on the leaching behaviors of Cu and Ag. The leaching rate considerably increased with increasing acid concentration and temperature. The leaching ratios of Cu and Ag were found to be 96.4% and 96.5%, respectively, under the optimum condition; at $80^{\circ}C$ with 2mol/L $HNO_3$ and 120g/L in pulp density within 39minutes. The kinetic parameters were determined based on the shrinking core model with reaction control corresponding to small particles. The activation energies for the leaching of copper and silver were found to be 45.5kJ/mol and 60.5kJ/mol at $35{\sim}80^{\circ}C$ with 2mol/L $HNO_3$, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1729-1734
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• 2009

About 40 million automotive vehicles all over the world and 0.55 million in Korea were retired from use annually. Every nation is desperate to decrease environmental pollution by ELVs(End of Life Vehicles) and try to tighten the regulations. Europe passed laws requiring OEMs to increase vehicles' recovery and reuse rate to 95% by 2015 from current 84%. The ferrous parts, 75% of total automobile weight, are almost recycled whereas the remaining 25% of the non-metal -predominantly plastics as well as form, glass and rubber- and the non-ferrous materials -copper, nickel and aluminium- end up in landfills. The recycling status of non-ferrous materials represented by copper and nickel is reviewed and how much the recycling rate will be improved is calculated.

• Resources Recycling
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• v.3 no.3
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• pp.7-11
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• 1994

The recovery of copper from $\alpha$-Etchent waste and pure copper solution was studied by the $H_2$reduction process. The results of test were as following: 1) The recovery of copper was increased with increasing hydrogen pressure and stirring speed up to 300 psi and 500 rpm, respectively, and was decreased in the higher values. But the recovery of copper from the fresh copper solution and $\alpha$-Etchent solution reached 90% and 60%, respectively. And in all tests the copper recovery from pure copper solution is higher by 30~40% than that from $\alpha$Etchent solution. 2) The recovery of copper was increased up to 30 minute of reaction time, and after then it became constant. The copper particles prepared in the initial 30 min have the needle-like shapes and in the longer reaction time than 30 min the shape was changed into noudle-like form. The average particle size was about $2~3\mu\textrm{m}$.

• Resources Recycling
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• v.31 no.4
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• pp.56-65
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• 2022

Copper is one of the non-ferrous metals used in the electrical/electronic manufacturing industries due to its superior properties particularly the high conductivity and less resistivity. The effluent generated from the surface finishing process of these industries contains higher copper content which gets discharged in to water bodies directly or indirectly. This causes severe environmental pollution and also results in loss of an important valuable metal. To overcome this issue, continuous R & D activities are going on across the globe in adsorption area with the purpose of finding an efficient, low cost and ecofriendly adsorbent. In view of the above, present investigation was made to compare the performance of a plant root (Datura root powder) as a bio-adsorbent to that of the synthetic one (Tulsion T-42) for copper adsorption from such effluent. Experiments were carried out in batch studies to optimize parameters such as adsorbent dose, contact time, pH, feed concentration, etc. Results of the batch experiments indicate that 0.2 g of Datura root powder and 0.1 g of Tulsion T-42 showed 95% copper adsorption from an initial feed/solution of 100 ppm Cu at pH 4 in contact time of 15 and 30 min, respectively. Adsorption data for both the adsorbents were fitted well to the Freundlich isotherm. Experimental results were also validated with the kinetic model, which showed that the adsorption of copper followed pseudo-second order rate expression for the both adsorbents. Overall result demonstrates that the bio-adsorbent tested has a potential applicability for metal recovery from the waste solutions/effluents of metal finishing units. In view of the requirements of commercial viability and minimal environmental damage there from, Datura root powder being an effective material for metal uptake, may prove to be a feasible adsorbent for copper recovery after the necessary scale-up studies.

• Resources Recycling
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• v.15 no.2 s.70
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• pp.45-49
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• 2006

The removal of copper ion from aqueous solution by adsorption with bone char that made from spent pig bone has been studied. This paper was studied the effects of bone char dosage and pH. The optimal results show that bone char adsorbs about 96.5 percent of copper ion in aqueous solution containing 50 mg/L as initial concentration at pH 5.0 when the bone char of 5g/L is used for 30 hours. Increase in the initial pH of the copper solution resulted in an increase in the copper ion uptake per weight of the sorbent Freundlich isotherm model was found to be applicable for the experimental data of $Cu^{2+}$.

• Resources Recycling
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• v.9 no.1
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• pp.70-75
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• 2000

The sand particle was coated with $Fe_3O_4$ and then $Fe_2O_3$ that adsorption capacity was more excellent than $Fe_3O_4$ was mostly found in 2nd step for preparation of iron-oxide-coated sand (IOCS). The copper removal rate was 74.9 percent by adding 30 gram per liter iron-oxide-coated sand from the solution with 5 mg/l Cu in 20 minute. Breakthrough time occurred in 23 hours and adsorption capacity 0.87$\cdot$Cu/g$\cdot$IOCS in case of breakthrough copper concentration was 1.0 mg/l in the continuous test.

• Resources Recycling
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• v.17 no.6
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• pp.24-33
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• 2008

The leaching of Cu from waste PCBs was investigated with electro-generated chlorine as an oxidant. The leaching experiments were carried out according to the design of experiments to analyze quantitatively the effect of parameters on copper leaching. From the analysis of variance (ANOVA) it was suggested that the effective parameters were current density, temperature, concentration of HCl, and the interaction between the concentration of HCl and temperature. Especially, the effect of current density was analyzed to contribute to the interpretation of result for copper leaching up to 95.7%. A multiple regression model obtained from the analysis of effective parameters explained 99% of leaching results. From the model equation, it was found that the effect of HCl concentration on copper leaching increased with temperature.

• Resources Recycling
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• v.2 no.4
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• pp.33-41
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• 1993

In recovering copper from the copper converter slag, various separation methods, such as flotation, sieving and magnetic separation had been tried. The copper converter slag used in this study was prepared in two ways, i.e. 2 hour cooled and 10 hour cooled. From the flotation of copper slag, 45% Cu concentrate is obtained and the amount of copper recovery is about 93%. Before the flotation, copper in the slag could be also pre-recovered using sieving and separation. It is also found that as the content of copper in the concentrate increa-ses, that of arsenic increase, while zinc and iron contents decrease.