Top submerged lance 로의 스파이스산물 중 구리의 황산 침출에 대한 납과 안티몬의 영향

채수진,유경근,Richard Diaz Alorro,Manis Kumar Jha 대한금속·재료학회 2021 대한금속·재료학회지 Vol.59 No.1

Cu-Pb and Cu-Sb alloys were prepared at various ratios, from 10:90 to 90:10, and leaching tests with sulfuric acid were conducted to investigate the effect of Pb and Sb on the leaching of Cu from speiss, which is obtained from the top submerged lance furnace process. The Cu leaching efficiency increased as the amount of Cu increased in both alloys, but the leaching efficiencies were lower in the Cu-Sb alloy than in the Cu-Pb alloy. For example, in alloys with 70% Pb and Sb ratio, the leaching efficiency of Cu from the Cu-Pb alloy increased to 95%. The leaching efficiency of the Cu-Sb alloy was 67% in 2 mol/L sulfuric acid solution with 1% pulp density and 1000cc/min O2 at 90 °C, 400 rpm, and 6 hours. When the leaching residues were examined with SEM (scanning electron microscopy)-EDS (Energy-dispersive X-ray spectroscopy), it was found that in all Cu-Pb alloys, Cu and Pb exist as independent metal phases, while, in Cu-Sb alloys, Cu formed intermetallic compounds with Sb such as Cu2Sb, because the Cu-Sb alloy has a lower melting point than the Cu-Pb alloy. These results suggest that Sb may retard the leaching rate of Cu from the alloy. When the leaching residue of speiss obtained from a top submerged lance furnace, intermetallic alloys of Cu-Sb were also observed, having a net structure. The net structure contains Cu metal in the center of the speiss particle, while the intermetallic alloys of Cu-Sb were present in the outer layer of the particle, in good agreement with the results using the alloys in this study. This suggests the intermetallic alloys of Cu-Sb can prevent copper from leaching.

Regeneration of Sn4+ from Sn2+ solution during electrowinning process using anion exchange membrane

정문철,유경근,Richard Diaz Alorro 한국자원공학회 2019 Geosystem engineering Vol.22 No.1

Electrowinning process to regenerate Sn4+ from Sn2+ in HCl solution using an electrowinning cell with anion exchange membrane was proposed to suggest a novel recycling process to recover Sn. During the tests, the effects of initial Sn2+ concentration on the regeneration of Sn4+ were investigated under the following condition; 7,000 mg/L, 10,000 mg/L, and 13,000 mg/L of Sn2+, 1 M HCl, 250 A/m2 of current density, graphite anode, titanium cathode, room temperature, and 2 h. Electro-deposited Sn on the cathode showed dendritic structure regardless of the Sn2+ concentration and no change of Sn concentration was observed in the anolyte. Leaching tests were performed using the anolyte, obtained from the electrowinning tests, to examine the amount of regenerated Sn4+ concentration during electrowinning process. Based on the results of Sn leaching tests, it was found that 84.44%, 81.03%, and 79.43% of Sn4+ were regenerated from 7,000 mg/L, 10,000 mg/L, 13,000 mg/L initial concentration of Sn2+ solution, respectively. Consequently, it was found that the regeneration of Sn4+ can occur during the electrowinning process at the same time with Sn recovery and Sn4+ can be reused as an oxidant to leach Sn successfully.

Lithium Extraction from Spent Lithium-Ion Batteries (LIBs) Using Mechanochemical Process: A Comprehensive Review

Yuik Eom,Richard Diaz Alorro,Jonah Gamutan,Aleksandar N. Nikoloski 한국자원리싸이클링학회 2023 資源 리싸이클링 Vol.32 No.5

The rapidly rising demand for lithium has made the recycling of spent lithium-ion battery highly attractive. However, the conventional process has faced environmental problems due to gas and wastewater generation, high-energy consumption, and the use of strong acids/alkalis for an extended period of time. An innovative recycling technology exploiting the mechanochemical process is proposed to overcome the drawbacks of the conventional process and improve the metal recovery from spent batteries. In general, the unique mechanism by mechanochemical reaction enables metal extraction with non-hazardous materials and minimal use of solvents at ambient temperature. This emerging technique can be combined with hydrometallurgical processes and offers potential for reagent regeneration. This article reviews different recycling technologies for spent lithium-ion battery cathode materials, particularly the mechanochemical process, to achieve circular economy in spent battery recycling and enhance lithium recovery.

자철석을 이용한 침출모사액 중 금이온의 흡착 거동

오주미,유경근,배무기,김수경,Richard Diaz Alorro 한국자원공학회 2019 한국자원공학회지 Vol.56 No.1

본 연구에서는 자철석을 흡착재로 이용, 금침출모사액으로부터 금이온을 선택적으로 분리하는 연구실험을진행하였다. 그 결과, 액중 pH 중성영역대에서 교반속도, 온도, 자철석투입량이 증가할수록 금이온의 흡착효율이 증가하였다. 금이온 농도 100 mg/L 및 염화나트륨 농도 0.1 mol/L, 자철석 투입량 3.6 %, pH 6-8, 교반속도 150 rpm, 반응온도 90°C 조건에서 실험을 수행한 결과 6시간 이내에 금이 100% 흡착되었다. 또한, 금이온이 구리, 니켈 같은 불순물과 함께 존재할 경우 금이온 흡착제거율이 96%인 반면, 구리나 니켈이온은 거의 흡착되지 않아 자철석으로 금의 선택적인 분리가 가능함을 확인하였다. 자철석은 흡착 후 자력 분리가 가능하여 기존 흡착공정내 고액분리공정시 자주 발생하는 체막힘 문제를 피할 수 있어 공정 효율 향상이 기대된다. In the present study, the separation of gold ions from simulated gold leaching solution was performed by selective adsorption of gold ions onto the magnetite. The adsorption efficiency of gold ions increased in neutral pH with increasing agitation speed, temperature, and amount of magnetite added. All of the gold ions were completely adsorbed within 6 h under the following conditions: gold ion concentration 100 mg/L, NaCl concentration 0.1 mol/L, magnetite addition 3.6%, pH 6-8, agitation speed 150 rpm, and temperature 90°C. When gold ions exist with copper and nickel ions, 96% of gold ions are adsorbed onto magnetite particles while the low adsorption of copper and nickel ions was observed, which indicates that selective adsorption of gold ions could be achieved. The efficiency of the separation process would be enhanced by avoiding clogging of screen because the magnetite particles with gold ions on them could be separated by magnetic separation processes.

Dismantling of Electric and Electronic Components from Waste Printed Circuit Boards by Hydrochloric Acid Leaching with Stannic Ions

Jung, Moonchul,Yoo, Kyoungkeun,Alorro, Richard Diaz JAPAN INSTITUTE OF METALS 2017 MATERIALS TRANSACTIONS Vol.58 No.7

Hydrochloric acid leaching behavior of metals from non-magnetic fraction of Pb dross

Sanghyeon Choi,Kyoungkeun Yoo,Richard Diaz Alorro 한국자원공학회 2019 Geosystem engineering Vol.22 No.6

The leaching behaviors of tin (Sn), antimony (Sb), iron (Fe), and lead (Pb) from non-magnetic fraction of Pb dross, which was obtained from magnetic separation process to remove As components, were investigated using HCl solution. The leaching efficiencies of Sn, Fe, and Pb increased with increasing agitation speed, temperature, and HCl concentration and with decreasing pulp density, but Sb was dissolved only in the 3 and 5 M HCl solutions. The leaching efficiencies of metals increased to 100% in the 5 M HCl solution at 400 rpm and 70°C with 1% pulp density within 120 min. In the case of leaching test with 1 M HCl, Sb components could be recovered as leach residue. After leaching test, Pb could be recovered as PbCl2 from the solution by lowering temperature. Tin ions were extracted selectively by solvent extraction with tri-butyl phosphate, remaining Fe and Pb ions in the solution. The process consisting of HCl leaching, precipitation, and solvent extraction recovers successfully Sb, Pb, and Sn from non-magnetic fraction of Pb dross.

Investigation on effects of ion exchangers structure and functional groups on the Re(VII) ions adsorption behavior from aqueous solution

Mohammad Bagher Fathi,Farshad Nezhadshahmohammadi,Bahram Rezai,Richard Diaz Alorro 한국자원공학회 2019 Geosystem engineering Vol.22 No.3

Alteration adsorption properties of Re(VII) on two resins with different functional groups and structure, weak base/macroporous and strong base/gel type, Purolite A170 (A170) and Dowex 21K (21K) respectively, were investigated experimentally and interpreted by isotherm, kinetic and thermodynamic modeling. Following the comparison of coefficient of determination values, the Freundlich and D-R isotherm models were found to be more suitable for description of investigated systems (R2 > 0.99). The Langmuir isotherm capacities (qm) were indicated that the perrhenate ions (ReO4−) adsorption is higher for weak base/macroporous type resin rather than the other at pH 3 in the presence of 50–250 mg L−1 Re (166.67 and 142.86 mg g−1, respectively). Also, the results from EDX studies corroborated this phenomenon. The adsorption reaction on both adsorbents was found to be chemically with mean free energy, E, as 12.18 and 13.62 kJ mol−1 for A170 and 21K, respectively. Kinetics of adsorption was studied by fitting the data into different mechanisms, among which the pseudo-second order mechanism was found successful for both used resins, but in case of 21K, the rate of perrhenate ions uptake was more rapid than A170. That is possibly attributed to the presence of strong base (quaternary amine) in functional groups. ΔG values obtained were all negative for both resins indicating a spontaneous adsorption process. The positive values of both ΔH (3.34 kJ mol−1) and ΔS (27.31 J mol−1 K−1) obtained suggest an endothermic reaction and in increase in randomness at the solid–liquid interface during the adsorption onto the A170 resin while for 21K, the negative changes in enthalpy and entropy provide an indication that the process is endothermic as well as it follows associative mechanism.

The Use of Methyl Ethyl Ketone in Nitric Acid Leaching Processes for Enhancement of Ag Recovery from Used X-ray Films

Jo, Hyeonji,Yoo, Kyoungkeun,Kim, Soo-kyung,Alorro, Richard Diaz JAPAN INSTITUTE OF METALS 2018 Materials transactions Vol.59 No.5

습식사이클론을 이용한 건축폐기물 슬러리의 정밀분급과 탈수

신희영,지상우,최상현,박일환,유경근,박제현,Richard Diaz Alorro 한국자원공학회 2015 한국자원공학회지 Vol.52 No.6

The classification and dewatering processes are required to use efficiently slurry generated from recycling processes of construction wastes. The classification tests with 2-inch hydrocyclone were performed using two samples; as-recived one and re-dispersed one in distilled water after filtration, and the effects of pressure and pulp density on the separation efficiency and dewatering were investigated. In the tests with as-recieved sample, the median diameter of underflow product decreased with increasing the pressure, and the diameter was 31.10 ㎛ at 0.3 MPa with 5% pulp density. The dewatering efficiency was higher in the tests with re-dispersed sample than with as-received one, which would be due to foam observed in the classification test. In the case of re-dispersed sample test, the dewatering efficiency increased with increasing pulp density, the water content of underflow product was 48.8% at 0.3 MPa with 8% pulp density. 건설폐기물 재활용 공정에서 발생하는 슬러리의 효율적인 이용을 위해 적절한 분급과 탈수공정이필요하다. 당 연구에서는 건축폐기물 재활용 공정 슬러리와 이를 탈수 후 증류수에 재분산한 시료를 대상으로2인치 습식사이클론 분급실험을 수행하였고, 주입압력(공급유량)과 광액농도가 분급 및 탈수에 미치는 영향을조사하였다. 원시료의 분급실험에서 주입압력을 증가시켰을 때, underflow 산물의 평균입도는 감소하여 광액농도 5%, 주입압력 0.3 MPa의 조건에서 31.10 ㎛이었다. 탈수효율은 원시료보다 증류수에 재분산한 경우가 높았는데, 이는 원시료의 분급실험 중 발생하는 기포가 분급효율을 저해하는 것으로 판단되었다. 재분산시료를 사용한 경우 광액농도가 증가할수록 탈수효과가 증가하여 8% 광액농도, 0.3 MPa 조건에서 분급을 실행한 결과underflow 산물의 함수율은 48.8%이었다.

Separation of Sn, Bi, Cu from Pb-free solder paste by ammonia leaching followed by hydrochloric acid leaching

Jeon, Sang-Hee,Yoo, Kyoungkeun,Alorro, Richard Diaz Elsevier 2017 Hydrometallurgy Vol.169 No.-

<P><B>Abstract</B></P> <P>A recycling process consisting of swelling, ammonia leaching and hydrochloric acid leaching was developed to recover Sn, Bi, Cu, and resin from Pb-free Sn-Bi-Cu solder paste. The resin was separated from metal powder by swelling the solder paste in methyl ethyl ketone at 30°C, 200rpm and 5% pulp density. The addition of distilled water precipitated the resin from methyl ethyl ketone. The recovered resin was confirmed to be epoxy resin by FT-IR analysis. Ammonia leaching followed by hydrochloric acid leaching was performed to separate Cu, Sn, Bi sequentially from metal powder. Copper was solubilized easily with leaching efficiency reaching 100% within 15min under the following conditions: 5M NH<SUB>3</SUB> solution, 1M (NH<SUB>4</SUB>)<SUB>2</SUB>CO<SUB>3</SUB>, 0.1M CuCO<SUB>3</SUB>, 50°C, and 1% pulp density. Tin and bismuth were recovered as leach residue in the ammonia leaching. Tin was selectively leached in 0.5M HCl solution with 10,000mg/L Sn<SUP>4+</SUP> and 1% pulp density at 50°C and 400rpm, while Bi was not detected in the leach solution. The recycling process has successfully separated Sn, Cu, Bi and resin.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A solder-paste recycling process was proposed to separate resin, Sn, Bi & Cu, respectively, by swelling & leaching processes </LI> <LI> Epoxy resin could be recovered by swelling with methyl ethyl ketone followed by distilled water addition </LI> <LI> Cu can be dissolved by ammonia leaching leaving Sn & Bi as leach residue from metal powder obtained from the swelling process </LI> <LI> Sn could be selectively leached from Sn and Bi powder using HCl solution with SnCl<SUB>4</SUB>. </LI> </UL> </P>