• Economic and Environmental Geology
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• v.44 no.1
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• pp.11-20
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• 2011

Geological survey on the occurrence of copper oxide in Suparaura area around Abancay in the south-central part of Peru had been carried out. Geology of the area is composed of granitoids such as granodiorite, tonalite and andesitic porphyry related to Tertiary igneous activity, Ferrobamba formation with Cretaceous limestone and sandstone in descending order. Red sandstone is widely distributed and emplaced with their attitude of $N70^{\circ}W$ strike and $60^{\circ}NE$ dip. Copper oxides were mineralized along the bedding plane of red sandstone with maximum width of 30 cm. Ore-body structure bounding red sandstone strata have different occurrence characteristics with generally known porphyry system in terms of alteration, mineral assemblage and occurrence mode. Therefore, it is thought to be stratiform sediment-hosted copper (SSC) deposits genetically corresponding to Mississippi-valley type from preliminary study.

• Journal of the Mineralogical Society of Korea
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• v.31 no.3
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• pp.183-191
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• 2018

It is reported that Li-bearing minerals regarding as a promising battery industrial commodity occur in the Mogok metamorphic belt, Myanmar. Preliminary considerations on the mineralization of pegmatite occurrences within Mogok metamorphic belt such as Singu, Mogok and Momeik are as follows. In Singu area, lepidolite and rubellite occur together (Letpanhla No. 2 & 7 pegmatite) while rubellite only occur (Letpanhla No. 4 pegmatite). In Mogok area, lepidolite and rubellite occur together (Sakangyi pegmatite). In Momeik area, lepidolite and rubellite occur together (Pheyeou pegmatite) while rubellite only occur (Khetchel Ywar Thit pegmatite). In the future, it is estimated that it is necessary to implement the detailed exploration for the resource evaluation of lithium-bearing mineral targeted for the pegmatite of Mogok metamorphic belt.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.06a
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• pp.260-265
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• 2004

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.525-528
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• 2004

The photoluminescence (PL) emission of Si nanocrystals synthesized by 400 keV Si ion implanted in $SiO_2$ is studied as a function of ion dose and annealing time. The formation of nanocrystals at around 600 nm from the surface was confirmed by RBS and HRTEM, and the Si nanocrystals showed a wide and very intense PL emission at 700-900 nm. The intensity of this emission showed a typical behaviour with a fast transitory increase to reach a saturation with the annealing time, however, the red shift increased continuously because of the Ostwald ripening. The oversaturation of dose derived a decrease of PL intensity because of the diminishment of quantum confinement. A strong enhancement of PL intensity by H passivation was confirmed also, and the possible mechanism is discussed.

• 한국문화재보존과학회:학술대회논문집
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• 2006.04a
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• pp.108-110
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• 2006

• The Journal of the Petrological Society of Korea
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• v.24 no.2
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• pp.65-75
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• 2015

Around Harar in the northeastern part of the Ethiopia, the Precambrian granitic gneiss and gabbro bodies are developed with several pegmatites. The rock bodies in this area have been deformed by ductile and brittle deformations developing fold and ductile shear structure, and thrust and fault.

• Economic and Environmental Geology
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• v.48 no.6
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• pp.525-536
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• 2015

Trapiche project corresponds to the advanced exploration stage which is thought to be a part of various porphyry copper deposits occurring in the margin of Andahuyalas-Yauri metallogenic belt. This deposit is genetically related to the monzonitic porphyry intrusion and Oligocene breccia pipe. Mineralization consists of primary sulfides such as pyrite, chalcopyrite, bornite, and molybdenite and secondary sulfides such as chalcocite, covellite and digenite. It occurs malachite, tenorite and cuprite as copper oxide. As a result of lixiviation or enrichment process, mineralization shows untypical zonation structure. Breccia and porphyry areas characterize the vertical zonation patterns. In the northern area, lixiviation zone, secondary enrichment zone, transitional zone and primary mineralized zone are distributed in northern area. In the western area of deposit, oxidation zone and mixed zones are narrowly occurred. Inferred resources of deposit is estimated to be 920 Mt @ 0.41% Cu with the cut-off grade of 0.15%.

• Resources Recycling
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• v.23 no.6
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• pp.12-21
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• 2014

Nickel oxide ores are composed of two kinds of minerals; one is saprolite that is processed by smelting to obtain nickel products, and the other is limonite that is used in hydrometallugical processes. It is not efficient economically to process the mixture of limonite and saprolite, so the processes to saparate the ore mixture should be developed. In the present study, the mixture was separated by dry-classification after liberationg using grindability difference between limonite and saprolite. Consequently, it is possible to obtain the limonite with less than 10% of Mg+Si contents, which could be treated by hydrometallurgical processes, when the limonite contain less than 30% of saprolite.

• Economic and Environmental Geology
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• v.47 no.2
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• pp.169-180
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• 2014

Surface geological and trench surveys and drilling exploration (total length, 1,100 m; 9 drill holes) were carried out to secure new Au ore bodies in the area($0.96km^2$) of Actosity gold field, where is located at the western Kuldjuktau mineralized district in the middle territory of Uzbekistan. Several Au ore bodies occurring as tabular or lens shapes with thickness of 0.5~35 m were newly discovered on the outcrops and extended to $N40{\sim}70^{\circ}\;W$ direction with dipping of $70{\sim}90^{\circ}$ SW or NE. Indicated ore resource of gold with Au grade of 0.25~3.52 mg/kg was newly estimated by 2,382 t(gold resource of 2.5 t) as a result of 9 drilling exploration in 2010~2012 from the Actosity gold field. Judging from the ore resources and Au grade of the Actosity gold field, economic potentiality of mining development seems to be low. Because of high possibility to secure new ore resources through more detailed exploration works from the Actosity area, the growth of econonic value will be expected by a mine of middle scale.

• Resources Recycling
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• v.30 no.6
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• pp.3-11
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• 2021

In this study, the effect of the solubility of ammonium metavanadate and the decomposition ratio of ammonium ions on a precipitation reaction-the precipitation of ammonium metavanadate by adding ammonium chloride to a sodium vanadate solution-was investigated. As the precipitation temperature and pH increased, the decomposition ratio of ammonium ions increased, and the decomposition ratio was greater than 81% at 45 ℃ and pH 9.3. This was approximately four times higher than that at pH 8. The result of the precipitation reaction, in view of these two factors that significantly influence the precipitation reaction, was that the precipitation yield increased as the temperature increased. However, the effect of temperature was not significant above 35 ℃. A kinetic study of the precipitation reaction revealed that the activation energy of the reaction was 42.3 kJ/mol. Therefore, considering the solubility of ammonium metavanadate, the lower the temperature, the better the vanadium recovery yield. Additionally, considering the decomposition of ammonium ions, the lower the pH of the aqueous solution, the more advantageous. However, at pH 8 or less, sodium polyvanadate is precipitated and the purity of vanadium oxide may reduce.