금도금의 전류효율에 미치는 과황산칼륨 첨가의 영향

손인준 ( In Joon Son ),손호상 ( Ho-sang Sohn ),김경태 ( Kyung Tae Kim ) 대한금속재료학회(구 대한금속학회) 2016 대한금속·재료학회지 Vol.54 No.9

In this study, the effect of potassium persulfate on current efficiency for gold plating was investigated using electrochemical techniques. The current efficiency in the low-current-density range greatly decreased when potassium persulfate was added to the gold plating solution. However, the current efficiency in the high-current-density range did not change with the addition of potassium persulfate. The measured contact resistances of the resulting gold-plated layers showed almost similar values, regardless of the addition of potassium persulfate, suggesting that potassium persulfate does not affect the property of the gold layers. Linear sweep voltammetry and partial polarization curves showed that the persulfate ion was reduced when the noble potential was more than that of the gold ion. Therefore, the current efficiency for gold plating decreased when potassium persulfate was added in the low-current-density range because at such a current-density the reduction of persulfate preferentially occurs. (Received November 18, 2015; Accepted April 5, 2016)

백금족 금속의 제련과 폐촉매의 리사이클링

손인준,손호상,Son, Injoon,Sohn, Ho-Sang 한국자원리싸이클링학회 2021 資源 리싸이클링 Vol.30 No.3

백금족 금속(Platinum Group Metals, PGMs)은 화학적 저항성은 물론 전기·열전도성이 뛰어나 촉매, 전자기기, 전극, 전기기기, 연료전지, 고온 소재 등 광범위한 응용 분야에 사용된다. 일반적으로 백금족 금속은 구리와 니켈의 황화광과 관련되어 있으므로 백금족 금속의 상대적인 농도에 따라 주산물로 생산되거나 니켈과 구리의 부산물로 생산된다. 특히 이러한 자원들은 남아프리카와 러시아 같은 나라들에 편재되어 있으며, 백금족 금속의 연간 공급량은 500톤 미만이다. 이와 같은 백금족 금속의 한정된 공급량을 고려하면 향후에 백금족 금속의 공급 리스크가 증가할 것이다. 따라서 폐촉매와 같은 2차 자원으로부터 백금족 금속을 회수하는 것이 매우 중요하다. 본 논문에서는 백금족 금속의 제련 기술과 리사이클링 기술에 대하여 고찰하였다.

일메나이트 광의 Fe 선택염화 거동에 미치는 환원제의 영향에 관한 연구

손용익,손호상,정재영,Son, Yongik,Sohn, Ho-Sang,Jung, Jae-Young 한국자원리싸이클링학회 2018 資源 리싸이클링 Vol.27 No.3

In this study, the behaviors of Fe selective chlorination in ilmenite ore by using PVC or $CO-Cl_2$ gas mixture as reducing agents under the condition of 1173 K, for 60 minutes were investigated. The weight loss ratio was 28% when PVC was applied as the reducing agent. The condensate formed at the outlet of reaction tube was identified as $FeCl_2$ by X-ray diffraction analysis. From these results, it was observed that iron in ilmenite ore reacted with HCl gas and Fe was selectively removed in the form $FeCl_2$. However, when $CO-Cl_2$ gas mixture was used as a reducing agent, the weight reduction ratio was 54%, and the condensate formed at the outlet of reaction tube after the experiment was estimated to be $FeCl_3$. It was observed that the ilmenite ore reacted with the $CO-Cl_2$ gas mixture and was simultaneously removed in the form of $FeCl_3$ and $TiCl_4$. However, the results of X-ray diffraction of ilmenite ore after the reaction showed that Fe was almost removed.

PVC에 의한 일메나이트 광석 중 선택염화에 의한 Fe의 제거

손용익,링리에,손호상,Son, Yongik,Ring, Rie,Sohn, Ho-Sang 한국자원리싸이클링학회 2016 資源 리싸이클링 Vol.25 No.3

Study on chlorination of ilmenite ore were carried out by using PVC(polyvinyl chloride) as the chlorinating agent in a static bed reactor for selective removal of iron. The effect of amount of PVC and reaction temperature were investigated. It was found that the removal ratio of iron increased with amount of PVC and temperature. After reaction with HCl gas generated from PVC, porous surface of the specimens were observed. As a result, HCl gas could react with iron in the central portion of ilmenite particle through these pores. Examination of data using kinetic model suggest that the selective chlorination rate is controlled by chemical reaction at the interface of particles. The activation energy for the selective chlorination of ilmenite using PVC was calculated as 20.47 kJ/mol. 고정층 반응기에서 PVC를 염화제로 사용하여 일메나이트 광석 중 철을 선택적으로 제거하기 위한 염화반응에 대하여 조사하였다. 철의 제거율에 미치는 PVC첨가량과 반응온도의 영향에 대하여 조사하였다. 철의 제거율은 PVC 첨가량과 온도가 증가할수록 상승하였다. PVC에서 생성된 HCl가스와 반응한 후의 시편 표면에는 많은 기공이 관찰되었다. 이러한 기공에 의해서 일메나이트 입자의 중앙부분에 있는 철과 반응할 수 있었던 것으로 생각된다. 선택적 염화반응을 속도론적 모델에 의해 조사한 결과 입자 계면에서의 화학반응에 의해서 율속되는 것으로 생각된다. PVC를 사용한 일메나이트의 선택적 염화반응에서 활성화 에너지는 20.47 kJ/mol로 계산되었다.

일방향 응고에 의한 금속급 실리콘 중 Fe 제거

사공성대,손인준,손호상,Sakong, Seong-Dae,Son, Injoon,Sohn, Ho-Sang 한국자원리싸이클링학회 2021 資源 리싸이클링 Vol.30 No.4

Solar grade silicon (SoG-Si) has been commercially supplied mainly from off-grade high-purity silicon manufactured for electronic-grade Si (EG-Si). Therefore, for wider application of solar cells, the development of a refining process at a considerably lower cost is required. The most cost-effective and direct approach for producing SoG-Si is to purify and upgrade metallurgical-grade Si (MG-Si). In this study, directional solidification of molten MG-Si was conducted in a high-frequency induction furnace to remove iron from molten Si. The experimental conditions and results were also discussed with respect to the effective segregation coefficient, Scheil equation, and Peclet number. The study showed that when the descent velocity of the specimen decreased, the macro segregations of impurities and ingot purities increased. These results were derived from the decrease in the effective segregation coefficient with the decrease in the rate of descent of the specimen.

용융(熔融) Bi-Pb-Sb계(系) 합급(合金)의 산화(酸化)에 의한 Sb과 Pb 제거(除去)

김세종,손인준,손호상,Kim, Se-Jong,Son, In-Joon,Sohn, Ho-Sang 한국자원리싸이클링학회 2012 資源 리싸이클링 Vol.21 No.4

본 연구에서는 비철제련의 공정 부산물에서 얻어진 Bi-Pb-Sb 3원계 합금 용탕의 산화반응에 따른 Sb과 Pb의 제거거동에 대하여 조사하였다. $N_2+O_2$ 가스를 침지 노즐을 통해 1173 K의 합금 용탕 중에 취입하여 Sb을 산화물과 금속상의 혼합물로 분리 회수할 수 있었다. 그리고 923 K의 Bi-Pb 2원계 용탕에 $N_2+O_2$ 가스를 취입하면 Pb가 산화되어 슬래그상으로 제거될 수 있으나, Bi도 동시에 산화되어 Bi를 정제할 수 없었다. In this study, behaviors of removing Sb and Pb by oxidation of molten Bi-Pb-Sb alloy which is a by-product of non-ferrous smelting process was investigated. The molten alloy was oxidized at 1173 K by bubbling $N_2+O_2$ gas through a submerged nozzle. The Sb was removed and recovered as mixed phase of $Sb_2O_3$ and metal Sb. In the case of bubbling $N_2+O_2$ gas into molten Bi-Pb alloy at 923 K, Pb was oxidized and removed to slag. But Bi could not be refined due to simultaneous oxidization of Bi with Pb.

PVC에 의한 네오디뮴 자석 스크랩으로부터 희토류 회수

이소영,박성훈,손인준,손호상,Lee, So-Yeong,Park, Sung-Hun,Son, Injoon,Sohn, Ho-Sang 한국자원리싸이클링학회 2018 資源 리싸이클링 Vol.27 No.1

A large amount of Nd-Fe-B magnet scraps are generated during magnet manufacture process. In this study, selective chlorination of the rare earth elements by hydrogen chloride gas which obtained from the pyrolysis of polyvinyl chloride (PVC) was investigated. In thermogravimetric analysis, drastic weight loss was occurred at about 500 K and 710 K. At the isothermal experiments, the weight loss reaches about 30% above 673 K. XRD patterns characterized that after each experiments, ${\alpha}$-Fe, Nd oxychloride, Nd chloride, and Fe chlorides were formed, and the leaching residues remain only ${\alpha}$-Fe. The yields of Nd, Dy, and Fe for the isothermal experiment were increased with temperature and peaked at 873 K. As PVC ratio increased, the yields of Nd, Dy and Fe were also increased.

황산용액에 의한 전기로 제강분진으로부터 Zn의 침출

박수지 ( Su Ji Park ),손인준 ( In Joon Son ),손호상 ( Ho Sang Sohn ) 대한금속재료학회(구 대한금속학회) 2015 대한금속·재료학회지 Vol.53 No.11

The sulfuric acid leaching of electric arc furnace(EAF) dust was studied in an attempt to find a suitable hydrometallurgical method for the recovery of zinc. The effect of acid concentration, reaction temperature, stirring rate and solid-to-liquid ratio on Zn and Fe extraction from the solution was investigated. It was found that the leaching rate of Zn and Fe increased with increasing reaction temperature and sulfuric-acid concentration. Examination of data using a shrinking core model suggest that the leaching rate is controlled by mixture kinetics. The activation energy for the leaching reaction of Zn and Fe were calculated as 44.45 kJ/mol and 65.45 kJ/mol, respectively.

CaO-SiO2-Al2O3-MgO계 슬래그 중 Cu와 Ni의 용해도

한보람 ( Bo Ram Han ),손인준 ( In Joon Son ),손호상 ( Ho Sang Sohn ) 대한금속재료학회(구 대한금속학회) 2015 대한금속·재료학회지 Vol.53 No.11

In this study, the solubility of Cu and Ni, which are the main metal components of waste PCB in a CaO-SiO2-Al2O3-MgO slag system, was investigated by the chemical equilibration technique in the temperature range 1673-1823 K, under a CO-CO2 atmosphere. The concentrations of Cu and Ni in the slag increased with increasing oxygen partial pressure and MgO content in the slag. The concentrations of Cu and Ni in the slag decreased with increasing temperature. The concentration of Cu in the slag decreased with increasing activity of CaO, but that of Ni increased. The dissolution mechanisms of Cu and Ni in the CaO-SiO2-Al2O3-MgO slag could be described by the following equations from the effect of oxygen partial pressure and slag basicity on Cu and Ni dissolution behaviors: From the results obtained, the enthalpy changes from dissolution of Cu into the CaO-SiO2-Al2O3-MgO slag were calculated to be -59.17 kJ/mol, and that for Ni was calculated to be -78.89 kJ/mol.

가스취입에 의한 용융 동 합금 중 납의 증발속도

김항수,정성엽,정우광,윤의한,손호상,Kim, Hang-Su,Jeong, Seong-Yeop,Jeong, U-Gwang,Yun, Ui-Han,Son, Ho-Sang 한국재료학회 2002 한국재료학회지 Vol.12 No.1

The lead has to be removed for the recycling of copper alloy. The lead cannot be removed from the copper alloy by oxidation. It can be removed by the evaporation because of its high vapor pressure. However, rare information is found on removal of lead from copper alloy. The purpose of present work is to provide a fundamental knowledges on the removal of lead from the copper alloy by evaporation. Gas injection was made in molten copper alloy, and the evaporation rate of lead was measured. The influence of Ar gas flow rata(2~4 L/min), initial contents of lead(2~4wt%Pb), temperature(1200~140$0^{\circ}C$) was investigated based on the thermodynamic and the kinetics. The rate constant is increased with increasing flow rate of Ar and temperature. Though amount of lead removed is increased with higher initial lead concentration, the rate constant is not changed significantly. The activation energy is estimated from the temperature dependence of the rate constant. Also removal of lead from the copper by adding chloride was made for the comparison.