• Resources Recycling
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• v.25 no.4
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• pp.42-48
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• 2016

A research for the recovery of the metal with high purity from the waste tin plating solution was carried out. First, tin plating waste solution was tested to remove the organic substances and metallic impurities such as Fe, Zn, Na etc. using ion exchange resin having iminodiacetic functional groups (Lewatit TP 207). Second, the tin solution was purified to obtain the high purity tin solution using ion exchange resin having ethylhexyl-phosphate functional groups (Lewatit VPOC 1026). Finally, 99.98% of the high purity of tin metal can be recovered from the purified solution by cyclone type electrowinning method.

• Resources Recycling
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• v.16 no.3 s.77
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• pp.27-33
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• 2007

It is very important in the view point of resource recycling to recover valuable metals such as copper and tin from waste electric and electronic scrap. The waste electric and electronic scrap contains significant amounts of copper, tin, and so on. In this study, a new process for extracting copper and tin contained in the waste electric and electronic scrap using waste copper slag which is generated from the melting furnace of copper smelter was presented. Advantage of the proposed process is to reuse waste copper slag instead of new fluxes as slag formatives. In each experiment, the waste electric and electronic scrap and waste copper slag were melted inputting suitable amount of CaO as an additional flux. Up to 95% of copper and 85% of tin in the raw material were extracted in a Cu-Fe-Sn alloy phase.

• Resources Recycling
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• v.24 no.3
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• pp.51-58
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• 2015

In order to recover tin from the waste tin plating solution, we used the ion exchange method using three types of ion exchange resins. The ion exchange resin with tertiary functional group(Lewatit TP 272) has not adsorption ratio of tin. The ion exchange resin with iminodiacetic functional group(Lewatit TP 207) has high adsorption ratio of tin, but impurity content in the recovered tin solution was relatively high. Whereas, in case of the ion exchange resin with functional group of ethylhexyl-phosphate(Lewatit VP OC 1026), adsorption ratio of tin was less than that of Lewatit TP 207. However, it was possible to remove impurities in the recovered tin solution by controlling the pH of the solution. High purity tin solution can be recovered by removing the organic materials with water washing process.

• Resources Recycling
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• v.23 no.3
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• pp.37-43
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• 2014

A study has been made on the recovery of tin and copper from waste solder stripper by oxalate precipitation. With the increasing of the oxalic acid addition, tin was precipitated effectively and removed above 99.5% of tin when the oxalic acid, in an amount 1.0-1.5 times the stoichometric requirement, was added. But, in this case, only 2.0% of copper was precipitated and lead, iron were not precipitated. So, tin was selectively removed from the waste solution. With the increasing of the reaction temperature, the removal percentage of tin was increased and maximum value at arounf $60^{\circ}C$ and decreased with increase in the temperature any more. After filtering the precipitate and drying in oven, $SnO_2$ was obtained from the precipitate. After removal of tin in stripping solution, above 91% of copper was selectively removed by Cu-oxalate by addition of oxalic acid.

• Resources Recycling
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• v.27 no.6
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• pp.38-43
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• 2018

In this study, using electro-refining process and methane gas reduction, we performed studying the recovery of tin with high purity from waste tin oxide had used as a electrode rod of ceramic furnace which occurred during glass production process. We recovered the crude tin of 99% purity from a methane gas reduction process and controlled a little amount of impurities. When the electrolytic refining condition was a current density of $60A/dm^2$ and the sulfuric acid concentration of 0.75 mol, 96.8% of recovered tin (99.979% of purity) were recovered during the electrolytic refining. We confirmed that toxic impurities such as Pb, Sb included in electrode rod. could be controlled.

• Resources Recycling
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• v.31 no.6
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• pp.18-24
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• 2022

Dry reduction using natural gas was proposed to recover tin from waste tin oxide generated in a tin bath that was used for controlling the smoothness of architectural glass during production, and the reduction behavior was investigated. The utilized vertical natural gas dry reduction system is capable to process 4 L or 20 kg depending on input raw materials. The system was established by applying the upper intake and lower discharge method. The recovery rate was 97.2% at 800 ℃ and 4 sccm flow rate and increased with the amount of input gas. Hydrogen accounted for 23% of the discharge gas, showing a 16.6% hydrogen conversion rate. The reaction behavior of tin recovered via natural gas reduction provides basic data on the new waste resource reduction/recovery technology.

• Journal of the Korean Ceramic Society
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• v.49 no.6
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• pp.505-510
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• 2012

A study of the recovery of tin and nickel from steel ball scraps for barrel plating was carried out through a physical treatment, a leaching treatment, hydrogen reduction and an electrolysis experiment. The recovery of the iron component was over 95% by the physical treatment. We obtained tin oxide in the form of metastannic acid ($SnO_2{\cdot}xH_2O$) with impurities of less than 5% from the leaching treatment. We also recovered the high-purity metallurgical tin at a rate that exceeded 99.9% by the electrolysis of crude tin obtained from the hydrogen reduction of metastannic acid.

• Resources Recycling
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• v.31 no.3
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• pp.61-72
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• 2022

We investigated the electrochemical behavior of Sn (93.0 %)-Ag (4.06 %)-Cu (0.89 %) during electrolysis of Pb-free solder waste to recover tin and silver. A thin strip of the solder waste produced by high-temperature melting and casting was used as a working electrode to perform electrochemical analysis. During anodic polarization, the current peak of an active region decreased with an increase in the concentration of sulfuric acid used as an electrolyte. This resulted in the electro-dissolution of the working electrode in the electrolyte (1.0 molL^-1 sulfuric acid) for a constant current study. The study revealed that the thickening of an anode slime layer at the working surface continuously increased the electrode potential of the working electrode. At 10 mAcm^-2, the dissolution reaction continued for 25 h. By contrast, at 50 mAcm^-2, a sharp increase in the electrode potential stopped the dissolution in 2.5 h. During dissolution, silver enrichment in the anode slime reached 94.3% in the 1 molL^-1 sulfuric acid electrolyte containing a 0.3 molL^-1 chlorine ion, which was 12.7% higher than that without chlorine addition. Moreover, the chlorine enhanced the stability of the dissolved tin ions in the electrolyte as well as the current efficiency of tin electro-deposition at the counter electrode.

• Resources Recycling
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• v.25 no.4
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• pp.49-53
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• 2016

The electro-refining process was performed to purify the casted tin crude metal from waste tin in methanesulfonic acid. The surface morphologies of electrodeposited tin on cathode were observed, the dendrite and delamination were inhibited by glycol group of organic additive. The impurity concentrations of tin crude metal and deposited metal were analyzed using ICP-OES. Quantitative analysis on casted tin crude metal showed that it consists of tin with 97.280 wt.% and several impurity metals of Ag, Cu, Pb, Ni, and etc. After tin electro-refining, the purity of tin increased up to 99.956 wt.%. Reduction current by cyclic voltammetry seems to be closely related to behavior of impurity in tin electro-refining.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.219-220
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• 2015

주석도금폐액으로부터 이온교환수지를 이용하여 주석을 회수하는 연구를 하였다. 주석 흡착이 가능한 3종류의 이온교환수지를 사용하여 기초 실험한 결과 tertiary기능기를 가진 이온교환수지는 주석을 흡착하지 못하였고, iminodiacetic 기능기를 가진 이온교환수지는 주석의 흡착률은 높으나, 불순물 함량이 높았으며, ethylhexyl-phosphar의 기능기를 가진 이온교환수지는 주석의 흡착률은 낮으나 pH 조절에 따라 불순물의 제어가 가능하였다.