이만승 Man Seung Lee , 김상배 Sang Bae Kim , 채종귀 Jong Gwee Chae

DOI: Vol.23(No.3) 183-189, 2010

It is of importance to separate Ni(II) and Co(II) from Mg(II) in solution which was leached from nickel laterite ore. In order to investigate the possibility of separating Ni(II) and Co(II) from Mg(II), adsorption behavior of the three metals from individual and mixed sulfate solutions was investigated by using Diphonix resin. The concentration of each metal In solution was fixed at 100 ppm and the pH of the sulfuric acid solution was changed from 5 to 7. At ambient temperature, the adsorption behavior of the three metal ions followed Langmuir adsorption isotherm. The loading capacity of Diphonlx resin for the three metal ions was obtained from the Langmuir isotherm. Since adsorption behavior of the three metal ions from the mixed solution was similar to each other, it was found to be difficult to separate Ni(II) and Co(II) from Mg(II) by using Diphonix resin.

니켈, 코발트, 마그네슘, 황산, 분리, Diphonix, Ni(2), Co(2), Mg(2), H2SO4, separation

신기웅 Gi Wung Shin , 안종관 Jong Gwan Ahn , 김동진 Dong Jin Kim , 김상배 Sang Bae Kim , 안재우 Jae Woo Ahn

DOI: Vol.23(No.3) 191-197, 2010

Fine nickel metal powder of uniform morphology, narrow size distribution, and high purity was prepared from high purity metal solution. Slurry reduction method for the synthesis of metal powder was applied with a special interest in their fine and spherical shape. The products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Well dispersed ultrafine nickel powder with the particle size range of 100~200 nm was produced from Ni-hydrazine precursor using hydrazine as a reductant for 90 min reaction in 4.5 M NaOH solution.

니켈 분말, 슬러리환원법, 전구체, 하이드라진(N2H4), 형상, Nickel powder, slurry reduction, precursor, hydrazine, morphology

박종력 Chong Lyuck Park , 김병곤 Byoung Gon Kim , 전호석 Ho Seok Jeon , 김상배 Sang Bee Kim , 박석환 Suk Hwan Park , 이재령 Jae Ryeong Lee

DOI: Vol.23(No.3) 199-209, 2010

Coal gasification technology in the sector of domestic clean coal technologies is being into the limelight since recent dramatic rise of international oil price. In this study, we used a low rank coal from Inner Mongolia, China as a starting material for gasification. Various properties including optical, mineralogical, X-ray spectroscopic, X-ray diffraction, and drying property were measured and tested in order to estimate the suitability of the coal to gasification. The coal was identified as a brown coal of lignite group from the measurement of vitrinite reflectance. The coal has very low slagging and fouling potentials, and the ignition temperature is about 250℃. The major impurities consist of quartz, siderite, and clay minerals. Additionally, the coal had moisture content above 28%. Tests for finding effective drying method showed that the microwave drying is more effective than thermal drying.

저급석탄, 가스화, 건조, 마이크로웨이브, 불순물, Low rank coal, gasification, drying, microwave, impurity

정미희 Mi Hee Jeong , 조상호 Sang Ho Cho , 정수복 Soo Bok Jeong , 김영훈 Young Hun Kim , 박재구 Jai Koo Park , 금자승비고 Katsuhiko Kaneko

DOI: Vol.23(No.3) 211-217, 2010

A micro-focus X-ray computed tomography (CT) was employed to determine quantitative phase analysis of skarn Zn-Pb-Cu ore by nondestructive visualization of the internal mineral distribution of a skarn ore. The micro CT images of the ore were calibrated to remove beam hardening artifacts, and compared with its scanning electron microscope (SEM) images to set the threshold of CT number range covering sulfide ore minerals. The volume ratio of sulfide and gangue minerals was calculated 20.5% and 79.5%, respectively. The quantitative 3D X-ray CT could be applied to analyse the distribution of economic minerals and their recovery.

스카른 Zn-Pb-Cu 복합광석, 마이크로 포커스 X-ray 단층촬영, 정량분석, Skarn Zn-Pb-Cu ore, micro-focus X-ray computed tomography, quantitative analysis

최홍일 Hong Il Choe , 김병곤 Byung Gon Kim , 박종력 Chong Lyuck Park , 정수복 Soo Bok Jeong , 전호석 Ho Seok Jeon , 장희동 Hee Dong Jang

DOI: Vol.23(No.3) 219-225, 2010

Optimal grinding condition was examined by changing only the size of screen opening with fixing other factors to produce coal fines of particle sizes required for circulating fluidized bed gasifier. At least 85 wt% of the coal particles should fall into the size range of 0.045~1.0 mm for efficient gasification. In this study, hammer mill was used to grind Chinese low rank lignite coal following grinding condition designed by Taguchi method. The analysis of signal to noise ratio showed that optimum grinding condition for the gasifier was 3 mm in primary screen size and 1.3 mm in secondary screen size on the 95% level of significance.

해머밀, 다구치 설계, 저등급석탄, 가스화, 분쇄, Hammer mill, Taguchi design, Low rank coal, gasification, grinding

김완태 Wan Tae Kim , 최도영 Do Young Choi , 김상배 Sang Bae Kim

DOI: Vol.23(No.3) 227-234, 2010

We investigated the effect of dry grinding of laterite on the extraction of nickel and cobalt. The major chemical compositions of the sample for this work were SiO2, Fe2O3 and MgO. The sample contained 0.81% Ni and 0.02% Co. The major minerals of the sample were lizardite and quartz with minor amounts of forsterite and enstatite. The mean particle size, specific surface area and density of the ground sample decreased with increasing grinding time, while the amorphization of lizardite increased as identified by XRD analysis. The grinding enabled the extraction ratio of Ni and Co to increase by the breakdown of Mg-OH bonding in the lizardite structure. However, physical properties of quartz were not changed by grinding. The extraction ratio of Ni and Co increased with increasing grinding time. Approximately 80% of Ni and Co were extracted regardless of the kind of acid solutions when the sample was ground for 60 minutes.

라테라이트, 니켈, 코발트, 분쇄, 침출, Laterite, nickel, cobalt grinding, extraction

박철현 Chul Hyun Park , 전호석 Ho Seok Jeon , 한오형 Oh Hyung Han , 김병곤 Byoung Gon Kim , 백상호 Sang Ho Baek , 김학순 Hak Sun Kim

DOI: Vol.23(No.3) 235-242, 2010

Froth flotation using the residual water in the end of flotation process has been per-formed through controlling of pH. IEP (isoelectric point) of molybdenite and quartz in distilled water was below pH 3 and pH 2.7, respectively and the stabilized range was pH 5~10. In case of a suspension in reusing water, zeta potential of molybdenite decreased to below -10 mV or less at over pH 4 due to residual flocculants. As result of pH control, flotation efficiency in the alkaline conditions was deteriorated by flocculation, resulting from expanded polymer chain, ion bridge of the divalent metal cations (Ca2+), and hydrophobic interactions between the nonpolar site of polymer/the hydrophobic areas of the particle surfaces. However, the weak acid conditions (pH 5.5~6) improved the efficiency of flotation as hydrogen ions neutralize polymer chains and then weakened its function. In cleans after rougher flotation, the Mo grade of 52.7% and recovery of 90.1 % could be successfully obtained under the conditions of 20 g/t kerosene, 50 g/t AF65 , 300 g/t Na2SiO3, pH 5.5 and 2 cleaning times. Hence, we developed a technique which can continuously supply waste water filtered from tailings into (`he grinding-rougher-cleaning processes.

휘수연석, 부유선별, 순환수, 여과, 광미, pH, Molybdenite, flotation, recycling water, filtering, tailing

김학순 Hak Soon Kim , 전호석 Ho Seok Jeon , 김병곤 Byoung Gon Kim , 백상호 Sang Ho Baek

DOI: Vol.23(No.3) 243-250, 2010

Froth flotation of complex copper ore from Indonesia Jambi mine has been carried out to produce high-grade Cu concentrate. Since the ore contained minor Cu sulfides in addition to major Cu carbonate (malachite), copper concentrate was recovered by two-stage process of flotation, which consisted of copper sulfide flotation using xanthate followed by copper oxide flotation using oleic acid. The copper sulfide concentrate of 57.5% Cu grade with 9.5% recovery was obtained by copper sulfide flotation under conditions of 300 g/t collector (1:1 mixture of xanthate series Aero Promoter 211 and Aero Promoter 242) and pH 6.0 pulp. In subsequent copper oxide flotation on sink products, the concentrate of 30.8% Cu grade with 92.1% recovery was obtained under the conditions of oleic acid 300 g/t, AF65 50 g/t, pH 8.0 and 2 times cleaning. The flotation techniques which can achieve a Cu grade of 36.1% and a recovery of 92.1% have been developed from the two-stage process of flotation.

황화동, 산화동, 동, 부유선별, 올레인산, 잔세이트, Copper sulfide, copper oxide, Cu, froth flotation, xanthate, oleic acid

박천영 Cheon Young Park , 조강희 Kang Hee Cho

DOI: Vol.23(No.3) 251-265, 2010

A column bioleaching experiment at room temperature with no addition of sulfuric acid was effectively carried out to leach the valuable elements from pyrite, which is common mine waste. The Fe concentration of pyrite leachate from bioleaching column was 14 times higher than that of the control leachate, and secondary minerals were not formed. The SO4(2-) concentration of the pyrite leachate was 2.99 times higher. The XRD intensity of the (111), (200), (220), (31]), (222), (230) and (321) planes of pyrite decreased, whereas the intensity of (210) and (211) increased after column bioleaching.

칼럼미생물용출, 토착호산성박테리아, 황철석, 광산폐석, Column bioleaching, indigenous acidophilic bacteria, pyrite, mine waste

황길찬 Gil Chan Hwang , 김영호 Young Ho Kim

DOI: Vol.23(No.3) 267-272, 2010

High pressure x-ray diffraction patterns of α-cristobalite gallium phosphate (GaPO4) were acquired up to 8.9 GPa at room temperature using Mao-Bell type diamond anvil cell with high flux synchrotron radiation. Starting orthorhombic phase (phase-I) shows the splitting of peak which is possibly resulted from the pressure induced orientation disorder of the framework structure of tetrahedra. This is designated as phase-I`. This phase transforms to the orthorhombic high pressure phase-III between 2 and 3 GPa. Present phase transition sequence is not in accord with the recent high pressure X-ray diffraction results performed on the same starting sample (Ming et αl., 2007). X-ray pattern of the unloaded sample to ambient pressure shows that the structure retains that of the high pressure phase prior to decompression.

α-크리스토발라이트, GaPO4, 분리, 망상구조, 고압상, α-cristobalite, gallium phosphate, splitting, framework, high pressure phase

허철호 Chul Ho Heo , 김의준 Eui Jun Kim

DOI: Vol.23(No.3) 273-280, 2010