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A basic study was conducted to effectively recover nitric acid from a waste solder stripper by diffusion dialysis using anion exchange membranes. The effects of flow rate, flux ratio, nitrate concentration, and metallic ion types and concentration on the recovery percentage of nitric acid were investigated. The recovery percentage of nitric acid was decreased with the increase of flow velocity. But the recovery percentage of nitric acid was increased as the increase of flux ratio(W/F) and showing a recovery percentage of nitric acid of about 99% at a flux ratio of 1.5 or more. As the increase of nitric acid concentration in feed solution, the recovery percentage of nitric acid was increased up to 3.0M, but in case of greater than 3.0M, the recovery percentage gradually was decreased. Leakage percentage of metallic ions through the membrane were in the order of Pb, Na and Cu but Fe and Sn did not leakaged. As a result of diffusion dialysis using real waste solder stripper at a flow rate of , W/F = 1.3, a recovery percentage of nitric acid of approximately 94% was gained.

In order to recover tin from the waste tin plating solution, we used the ion exchange method using three types of ion exchangeresins. The ion exchange resin with tertiary functional group(Lewatit TP 272) has not adsorption ratio of tin. The ion exchangeresin with iminodiacetic functional group(Lewatit TP 207) has high adsorption ratio of tin, but impurity content in the recoveredtin solution was relatively high. Whereas, in case of the ion exchange resin with functional group of ethylhexyl-phos-phate(Lewatit VP OC 1026), adsorption ratio of tin was less than that of Lewatit TP 207. However, it was possible to removeimpurities in the recovered tin solution by controlling the pH of the solution. High purity tin solution can be recovered by remov-ing the organic materials with water washing process. Key words : Ion exchange resin, tin, recovery, waste plating solution 1. 서론 주석은 LED TV, 합금재료, 도금재료, 전기 및 전자제품의 필수 소재로 사용되는 금속으로 차세대 핵심소재로 부각되면서 수요도 꾸준히 증가하고 있다. 그러나주석 자원의 경우 동남아 등 일부 국가에만 편중되어

A study has been made on the recovery & separation of cobalt and copper from organic acid leaching solution by solventextraction. The experimental parameters such as the equilibrium pH, concentration of extractant and phase ratio were observed.Copper was extracted using LIX 84 and Cobalt was extracted using cyanex 272 and versatic acid 10. Experimental resultsshowed that extraction percent of copper was 99% at above eq. pH 2.0 and then more than 90% of cobalt were extracted bycyanex 272 in eq. pH 6.0 and versatic acid 10 in eq. pH 7.5. Stripping of copper and cobalt from the loaded organic phases canbe accomplished by sulfuric acid as a stripping reagent and 120 ~ 150 g/L of H 2 SO 4 was effective for the stripping of copperand cobalt respectively. Finially, the basic optimal process for recovery of copper and cobalt from the bio-leaching solution wasproposed. Key words : Solvent extraction, Copper, Cobalt, Separation, Organic acid · Received : December 26, 2014 · Revised : February 28, 2015 · Accepted : March 23, 2015Corresponding Author : Jae Woo Ahn (E-mail : jwahn@daejin.ac.kr)Advanced Materials Science & Engineering, Daejin University, Hoguk-ro 1007, Pocheon-si, Gyeonggi-do, 487-711, Korea ⓒThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the termsof the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permitsunrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.

The high pure tin production was conducted from crude-tin containing waste solder by electro-refining process. The electro-refining process maintained at 0.2V produced tin with purity of 99.98%, whereas a little increase of voltage to 0.3 V resulted tin purity of 99.92%. The high pure tin of 3N in the present process was produced by fixing the voltage at 0.3V. Considering the high pure tin production, the current density was maintained within with current efficiency of 94%. Addition of sulfuric acid of 20 ~ 25 g/L to the electrolyte solution was performed in order to keep Pb (lead) concentration below 100 mg/L in the final tin product. The anode slime generated during electro refining process was analyzed by X-ray diffraction (XRD) study to understand the phases of impurities in it. It detected the presence of Cu and Ag in the slime as in the form of , , whereas Pb occurred as compound.

A study on the solvent extraction for the recovery of Li from lithium-containing waste solution was investigated usingD 2 EHPA as an extractant. The experimental parameters, such as the pH of the aqueous solution, concentration of extractant andphase ratio were observed. Experimental results showed that the extraction percentage of Li was increased with increasing theequilibrium pH. More than 50% of Li was extracted in eq. pH 6.0 by 20% D 2 EHPA. From the analysis of McCabe-Thiele dia-gram, 95% of Li was extracted by four extraction stage at phase ratio(O/A) of 3.0. Stripping of Li from the loaded organic phasescan be accomplished by sulfuric acid as a stripping reagent and 90 ~ 120 g/L of H 2 SO 4 was effective for the stripping of Li.Finially, Li was concentrated about 11.85 g/L by continuous stripping process, and then lithium carbonate was prepared by pre-cipitation method.Key words : Solvent extraction, D 2 EHPA, Lithium, Lithium carbonate · Received : July 10, 2014 · Revised : August 22, 2014 · Accepted : September 4, 2014Corresponding Author : Jae-woo Ahn (E-mail : jwahn@daejin.ac.kr)Advanced Materials Science & Engineering, Daejin University, Hoguk-ro 1007, Pocheon-si, Gyeonggi-do 487-711, KoreaTel : +82-31-539-1982 / Fax : +82-31-539-1980ⓒThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the termsof the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permitsunrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.

Tin has been widely used to solder, tin plated steel, bronze alloy, sputtering target for transparent electrode and chemical additives. It has been widely reported to the recycling technologies for tin scraps because of the scarcity and economic efficiency of the reserve. This study was analyzed by using open/registered patents KR, US, CN, JP and EP related to recycling technologies for processing scrap, sludges, waste fluid for plating process and spent alloy containing tin in between 1970 and 2013. Patents were collected using key-words searching and filtered by filtering criteria. The trends of the patents were analyzed by year, country, appliant and technology.

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 and decreased with increase in the temperature any more. After filtering the precipitate and drying in oven, 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.

In order to separate Indium and Tin from spent indium tin oxide (ITO) sludge, direct hydrochloric acid leaching and thermalreduction followed by HCl leaching were applied. In case of direct leaching of spent ITO, leaching rate of In and Sn was 18.5% and19.95%, respectively. Whereas, in case of thermal hydrogen treatment of ITO sludge at different temperatures such as 700 o C,800 o C, 900 o C and 1100C, followed by HCl leaching, we obtained the result of more than 97% leaching rate of Sn. Specially,thermal treatment at 800 o C showed the highest leaching rate of 98.2% of Sn. Precipitation method was used for separation andrecovery of Sn from leached mixed solution. If the solution pH were adjusted 2.0, 99.69% of Sn precipitated and 10.3% of Inwas precipitated. This confirmed the possibility of separation of Sn and In from leached solution by precipitation method. Key words : Hydrochloric acid leaching, Hydrogrn reduction, ITO sludge, Tin Recovery * Received : February 17, 2014 · Revised : March 17, 2014 · Accepted : April 1, 2014Corresponding Author : Jae woo Ahn (E-mail : jwahn@daejin.ac.kr)Advanced Materials Science & Engineering, Daejin University, Hoguk-ro 1007, Pocheon-si, Gyeonggi-do, 487-711, KoreaTel : +82-31-539-1982 / Fax : +82-31-539-1980ⓒThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the termsof the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permitsunrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.

In this study, a electrochemical-chemical combined dissolution technology was conducted by electro-generated chlorine toobtain ruthenium solution from ruthenium metal. To find out the optimum leaching conditions of ruthenium in chloride solution,this leaching process was carried out on the variation of pH, reaction time, temperature and applied voltage at the electro-gen-erated chlorine system in the reaction bath. Also, ozone generator was used to obtain ruthenium(III) chloride solution to increase * Received : October 21, 2013·Revised : November 15, 2013·Accepted : December 5, 2013Corresponding Author : Jong-Gwan Ahn (E-mail : dran@jwu.ac.kr)Department of Resources Recycling and Environmental Engineering, Jungwon University, 85, Munmu-ro, Goesan-eup, Goesan-gun, Chungbuk, 367-805, KoreaTel : +82-43-830-8627 / Fax : +82-43-830-8115 ⓒThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the termsof the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permitsunrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.

A comparative study has been carried out on the removal of impurities such As, Sb, Bi from the copper sulfate solution byion exchange resin containing aminophosphosphonic acid as functional group. The various parameters which affect the removalof impurities; such as the reaction temperature, the reaction time, the amount of ion-exchange resins, the concentration of sulfuricacid in electrolyte, were studied. The basic experimental results showed that about 88% of Sb & 94% of Bi can be adsorbedin these chelate resins and removed from the copper sulfate solutions but As was removed below 10% from the solutions. Andthe selective elution of Bi and Sb from the adsorbed ion exchange resin also can be achieved by H 2 SO 4 or HCl solutions. Theresults also showed that 98.1% of Sb and 96.6% of Bi can be adsorbed from the copper sulfate solutions after 2 Bed-volumeof continuous ion exchange column test. Key words : Copper sulfate, Ion exchange, Antimony, Bismuth, Purification * Received : July 4, 2012·Revised : July 30, 2012·Accepted : August 8, 2012Corresponding Author : Jae woo Ahn (E-mail: jwahn@daejin.ac.kr)Advanced Materials Science & Engineering, Daejin University, Hoguk-ro 1007, Pocheon-si, Gyeonggi-do, 487-711, KoreaTel :+82-31-539-1982 / Fax : +82-31-539-1980ⓒThe Korean Institute of Resources Recycling. All rights reserved. This is an open-access article distributed under the termsof the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permitsunrestricted non-commercial use, distribution and reproduction in any medium, provided the original work is properly cited.

Enviromental friendly leaching process for the recovery of cobalt and copper from the cobalt concentrate was investigated byorganic acids as a leaching reagent. The experimental parameters, such as organic acid type, concentrations of leachant, time andtemperature of the reaction as well as the solid to liquid ratio were tested to obtain the optinum conditions for the leaching ofcobalt and copper. The results showed that citric acid was the most effective leaching reagent among the organic acids used inthis experiment. About 99% of cobalt, 95% of copper and 70% of nickel was dissolved by 2.0 M of citric acid. Addition of3.0 vol.% of hydrogen perioxide was effective to enhance the leaching efficiency and the optinum temperature was found to beabout 70 o C.Key words : cobalt, copper, organic acid, leaching, citric acid 1. 서론 코발트 광석으로부터 코발트를 회수하는 방법으로는원료의 성질, 함유량 등에 따라 각종의 제련법이 택해지고 있으며 크게 건식법과 습식법으로 구분할 수 있다. 1) 그러나 건식법의 경우 CO 2 발생이나 연료비 등의 문제와 고품위 원료의 고갈로 인하여 최근에는 습식법에 관심이 많다. 습식법에 의한 코발트 회수 공정은 정광에서 먼저 황산, 염산 등의 무기산을 사용하여 금속성분들을 침출시킨 후 침전법 및 용매추출법 그리고 전해채취법 등의 단위공정을 거치게 된다. 그러나 이때 사용하는 무기산으로 인해 인체에 유해한 유독 가스 방출이나 수질오염의 우려 등 환경문제를 초래할 가능성이 크다. 따라서 보다 환경친화적인 금속제련기술의 개발이요구되고 있다. 최근 고품위광의 고갈과 공정 폐기물 등

Environmental friendly leaching process for the recovery of cobalt and lithium from the was investigated by organic acids as a leaching reagent. The experimental parameters, such as organic acid type, concentrations of leachant and hydrogen peroxide, reaction time and temperature as well as the pulp density were tested to obtain the most effective conditions for the leaching of cobalt and lithium. The results showed that the latic acid was the most effective leaching reagent for cobalt and lithium among the organic acids and was reached about 99.9% of leaching percentage respectively. With the increase of the concentration of citric acid, hydrogen peroxide and temperature, the leaching rate of cobalt and lithium increased. But the increase of pulp density decreased the leaching rate of cobalt and lithium.

Solvent extraction experiments were carried out to recover and separate Ru(III) from aqueous hydrochloric acid media using TBP and Cyanex923. The efficiency of the extraction was studied under various experimental conditions, such as concentration of HCl and NaCl, concentration of extractant in the organic phase and temperature. The extraction behavior of metal impurities, such as Pt, Bi, Sn, Fe, Pb and Cu in mixed solutions was examined. From the experimental studies, it was found that the Cyanex923 resulted in higher extraction percentage of Ru than TBP. However TBP was more effective for the separation of Ru and Pt, Bi, Sn in mixed solutions than Cyanex923.