• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.53.2-53.2
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• 2009

몰리브덴(Mo)은 우수한 전기전도도와 고온 안정성으로 인해 전자부품의 전극으로 널리 사용되고, 미래 에너지인 태양전지 분야에서 CIS계 화합물박막태양전지의 후면전극으로 이용되고 있는 재료로서 현재 증착 방법으로는 D.C. sputtering이 가장 널리 이용되고 있다. 또한 $MoO_3$ 분말이 Mo 분말로 수소 환원되는 과정은 $MoO_3+H_2{\rightarrow}MoO_2+H_2O$ 와 $MoO_2+2H_2{\rightarrow}Mo+2H_2O$의 2단계를 통해서 수행되며 이중 첫 번째 단계에서 $MoO_3(OH)_2$라는 기상을 통해 지배적으로 일어난다고 알려져 있고 이를 화학증기수송(Chemical vapor transport : CVT)이라고 한다. 본 연구에서는 $MoO_3$분말의 수소 환원 과정 중에 발생하는 기상인 $MoO_3(OH)_2$을 이용하여 몰리브덴 옥사이드 박막을 증착하고 이를 다시 수소분위기에서 수소 환원하는 증착 방법을 통해 균일하고 부착성이 우수한 Mo 박막을 제조하고자 하였다. 기판으로 사용된 Glass를 $MoO_3$ 분말 위에 홀더를 이용하여 $MoO_2$ 박막을 증착하고 이를 다시 수소분위기에서의 수소 환원을 통해 Mo 박막을 성공적으로 제조하였다. 제조된 Mo박막의 결정구조 및 미세조직을 XRD 와 SEM을 통해 분석하였다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.2
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• pp.155-161
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• 2015

Technetium-99m (^99mTc) is an important, short-lived decay product of molybdenum-99 (⁹⁹Mo), and it is considered the backbone of the modern nuclear diagnostic procedures. Since fission of ²³⁵U is the main source of production of ⁹⁹Mo, either highly-enriched uranium (HEU) targets or low-enriched uranium (LEU) targets are irradiated in the research reactors. The use of LEU targets is being promoted by the international community to avoid the proliferation issues linked with the use of HEU. In order to define the waste management strategy at the planning stage of establishment of an LEU based ⁹⁹Mo production facility, the impact of the use of LEU targets on the radioactive waste stream of the ⁹⁹Mo production facility was analyzed. Because the volume of uranium waste is estimated to increase six times, the use of high uranium density targets and the utilization of hot isostatic pressing were recommended to reduce the increased waste volume from the use of LEU based targets.

• Resources Recycling
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• v.25 no.1
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• pp.16-23
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• 2016

The separation behaviour of Mo and W from sulfuric acid solution by solvent extraction with Alamine 336 was investigated as a function of solution pH and extractant concentration. Selective extraction of Mo over W by Alamine 336 was obtained in the pH range of 3-5 with low amine concentration. The mixture of Alamine 336 and acidic extractants improved the separation factor between Mo and W and was in the following order: D2EPHA > PC88A > Decanol > Versatic acid. The stripping efficiency of Mo and W from the loaded mixture of Alamine 336 and D2EHPA was very poor, while complete stripping of Mo and W was possible from the mixture of Alamine 336 and Decanol by using a mixture of $NH_4OH$ and $NH_4Cl$.

• Resources Recycling
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• v.22 no.4
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• pp.3-11
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• 2013

The recovery of molybdenum and vanadium from acid leaching solutions of spent catalysts using solvent extraction has been investigated. Among various acid leaching solutions, sulfuric acid solution is found to be adequate for the recovery of these two metals. The extraction and stripping behavior of the two metals in the absence and presence of other impurity metals by various types of extractants such as cationic, solvating, amine and a mixture of cationic and solvating extractants was discussed. Each type of extractants has advantage and disadvantage in terms of the possibility of separation and of forming a third phase. Among the various types of extractants, a mixture of cationic and solvating extractants seems to be the most promising extractant system for the separation of Mo and V from the acid leaching solutions of spent catalysts.

• Journal of the Korean Chemical Society
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• v.29 no.5
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• pp.482-489
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• 1985

The substituted quinolinium salts of pentachlorooxomolybdate (V) have been synthesized and characterized by means of the investigation of elemental analysis, infrared spectra, electron spectra, electric conductivity. The results of elemental analysis were well coincided with the theoretical value and all prepared salts were mononuclear complexes. The complexes were binary univalent electrolytes and analyzed d-d transition and charge transfer transition.

• Journal of the Korean Chemical Society
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• v.25 no.4
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• pp.263-269
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• 1981

The substituted pyridinium salts of oxochloromolybdates(V) have been prepared characterized by visible and infrared spectra, and magnetic moments. The electrical conductance of aqueous solutions of substituted pyridinium salts have been measured over a range of concentrations. The results indicate that the complex anions are monomeric in the solid. The magnetic moments of the complexes are similar to the spin-only values. Substituted pyridines are present as pyridinium cation in solid state.

• Journal of the Korean Chemical Society
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• v.26 no.2
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• pp.73-80
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• 1982

The pyridine and 3,5-lutidine complexes of quinquevalent molybdenum have been prepared. The infrared, electronic and reflectance spectra and magnetic susceptibility data of the complexes are reported. It is found that the binuclear complexes contain the di-${\mu}$-oxo-dimolybdenum(V) group, $MoO_2Mo$, and the possible structures are proposed on the basis of elemental analysis and physical measurements.

• Resources Recycling
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• v.18 no.5
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• pp.19-25
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• 2009

Molybdenite concentrate ($MoS_2$) is the major mineral for the molybdenum industry, of which the industrial processing is first converted to technical grade molybdenum trioxide ($MoO_3$) by its oxidative roasting and purification, used as a raw material for manufacturing several molybdenum compounds. In the present work, detailed experimental results for the oxidative roasting of low grade Mongolian molybdenite concentrate are presented. The experiments were carried out in the temperature range of 793 to 823 K under an oxygen partial pressure range of 0.08 atm to 0.21 atm by using a thermogravimetric analysis technique. The molybdenite concentrate was an average particle size of $67\;{\mu}m$. In the oxidative roasting of low grade Mongolian molybdenite concentrate, more than 95% of molybdenite was converted to molybdenum trioxide in 60 min. at 828 K. The lander equation was found to be useful in describing the rates of the oxidative roasting and the reaction order with respect to oxygen concentration in a gaseous mixture with nitrogen was 0.11 order.

• Resources Recycling
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• v.33 no.3
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• pp.38-47
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• 2024

Molybdenite is the primary molybdenum resource and is extracted via flotation due to its unique hydrophobic surface. Meanwhile, the grade and crystal size of mined molybdenite are decreasing. As a result, the size of the molybdenum ore required for liberation is decreasing, and the flotation process's feed size input is also decreasing. Therefore, in order to secure molybdenum, it is necessary to perform research on the flotation for the fine molybdenite. In this study, we developed a method to enhance the flotation efficiency of fine molybdenite particles in the range of 5-30 ㎛. The methodology involved implementing bubble size reduction and particle aggregation. Through simulations of bubble-particle collision probability and flotation experiments, we were able to find the ranges of bubble size and particle aggregate size that make fine particles float more effectively. This range provided the conditions for effective flotation of fine molybdenite particles. Therefore, we will implement the flotation conditions established in this study for fine molybdenum ore to improve the flotation process in molybdenum mineral processing plants in the future.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.158-160
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• 2007

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