• Resources Recycling
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• v.22 no.1
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• pp.48-54
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• 2013

A laboratory study was carried out to recover KI crystals with high purity by using fractional crystallization method from a waste solution generated from the production of polarizing film for LCD industry. The waste solution contains 1.3% KI, and other impurities such as B, Na, and PVA etc. With purity higher than 99.5% KI crystals were produced through refining process such as vacuum evaporation, fractional crystallization, filtering, and 24hr aging. Also the concentrated impurities were eliminated about 70% by recrystallization.

• Clean Technology
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• v.28 no.2
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• pp.103-109
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• 2022

Nd-Fe-B waste permanent magnet contains about 20~30% rare earth elements and about 60~70% iron elements, and the rare earth and iron components were recovered through sulfuric acid leaching and fractional crystallization. Oxidation roasting was not performed for separation and recover of the rare earth and iron elements. The leaching characteristics were confirmed by using as variables the sulfuric acid concentration and the mineral solution concentration ratio. Sulfuric acid leaching was carried out for 3 hours for each sulfuric acid concentration. The leached solid phase was characterized for its crystalline phase, composition, and quantitative components by XRD and XRF analysis, and the filtrate was analyzed for components by ICP analysis. With sulfuric acid leaching at 3M sulfuric acid concentration, neodymium compounds were formed, the iron content was the least, and the recovery rate was high. After the filtrate remaining after sulfuric acid leaching was subjected to fractional crystallization through evaporation and concentration, the neodymium component was found to be concentrated 7.0 times and the iron component 2.8 times. In this study, the recovery rate of waste permanent magnets through sulfuric acid leaching and a fractional crystallization method without an oxidation and roasting process was confirmed to be about 99.4%.

• Journal of the Korean earth science society
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• v.36 no.5
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• pp.447-459
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• 2015

Dok island comprises Pliocene volcanic products such as a series of volcanoclastic rocks and lavas ranging in composition from alkali basalts, and trachyandesites to trachytes. Compositional variation of the basaltic rocks can be attributed to fractional crystallization of olivine, clinopyroxene, plagioclase, and magnetite. Chemical variations among the trachyandesites are caused by fractionation of clinopyroxene, plagioclase, and magnetite with minor amphibole, while trachytes are controlled mainly by feldspar fractionation. Incompatible element abundance ratios and chondrite normalized LREE/HREE ratios (e.g., (La/Yb)c: 24.8 to 32.8 for basalts, 15.6 to 31.2 for trachyandesites) suggest that the origins of the basalts and trachyandesites involve both different degrees of partial melting and subsequent fractional crystallization processes. Trace element ratios of the basalts from Dok island are characterized by high Ba/Nb, La/Nb, Ba/Th and Th/U and isotopic ratios (Tasumoto and Nakamura, 1991) that are similar to the EM 1 type of oceanic island basalts such as Gough and Tristan da Cunha basalts.

• Economic and Environmental Geology
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• v.29 no.2
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• pp.171-182
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• 1996

Quaternary Jungok basalts are distributed along the old Hantan river in Mid-Korean Peninsula. They were flowed out from Mt. Ori and Upland (680 m), and they formed narrow and long basalt plateau showing the layers of 10 to 20 meters in thickness and about 95 km in length. Fifty seven samples were collected from the study area, and sixteen rock samples were selected and analysed for major and trace elements. The analyzed samples have alkalic composition and show a relatively restricted variation in major element chemistry (except MgO), as comparing to the that of trace element. Based on major element chemistry, a quantitative modelling of fractional crystallization by multiple linear regression method suggests that the chemical evolution of the evolved rocks can be generated by fractionation of olivine, plagioc1ase, clinopyroxene, and magnetite in proportion of 56 : 25 : 17 : 2, respectively. The calculated trace element abundances by mineral proportions estimated from major element modelling, however, underestimate the incompatible element concentrations in the evolved rocks. According to the incompatible element abundances, simple fractional crystallization process has difficulty to explain the chemical variation of the evolved rocks. It seems that the other processes, which enrichment of incompatible elements can occure without concomitant changes in major element compositions, are needed in order to explain the chemical variation of the Jungok basalts. Thus, the major elements and compatible trace elements variations of the Jungok basalts are due to fractional crystallization, but the incompatible elements variation is due to fractional crystallization superimposed on already varying concentrations caused by slightly different degrees of melting of the same source, and/or due to periodic replenishment, tapping and fractionation(RTF) processes.

• Proceedings of the Petrological Society of Korea Conference
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• 2006.05a
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• pp.61-62
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• 2006

• Economic and Environmental Geology
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• v.27 no.5
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• pp.459-467
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• 1994

The Gadaeri granite near Ulsan mine is an oval-shape isolated granitic body, and is genetically related to the iron-tungsten mineralization. The Gadaeri granite exhibits calc-alkaline and I-type characteristics, and generally shows the micrographic texture which indicates the shallow depth of emplacement. Consideration of the stratigraphic thickness of Ulsan formation and minimum-melt compositions suggests that the bulk magma crystallized at pressure of 0.5~2.0 kbar under water saturated condition. The evolutionary trend observed in the studied rocks represents that feldspar fractional crystallization has been a major magmatic process at the Gadaeri granite pluton. Different chemical characteristics between the Gadaeri and the Masan-Kimhae granites cannot be explained by fractional crystallization or different degrees of partial melting, and it reflects that the magma source for Gadaeri granite was different from that of the Masan and Kimhae granites.

• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.121-138
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• 2018

We have examined the petrotectonic setting and magmatic evolution from petrochemical characteristics of major and trace elements for the Cretaceous volcanic rocks in and around the Mireukdo Island. The volcanic rocks, can be devided into Jusasan, Unmunsa, Yokji and Saryang subgroups on the ascending order, are classified as basalt, basaltic andesite, andesite, dacite and rhyolite on TAS diagram. Petrochemical data show that the rocks are calc-alkaline series, and suggest that erupted earlier medium-K series and later high-K series. The volcanic rocks provide a case in which the calc-alkaline magma are formed, not only from separate protoliths, but following separate paths from source to surface. Earlier and later subgroups take different paths to the surface respectively, and are emplaced in the shallow crust as a series of discrete magma chambers through the volcanic processes. After emplacement, each chamber evolves indepently through fractional crystallization with a little assimilation of wall rock. The volcanic rocks have close petrotectonic affinities with orogenic suite and subduction-related volcanic arc. The rhyolitic magma can be derived from calc-alkaline andesitic magma by fractional crystallization with crustal assimilation, which may be derived from a partial melt of peridotite in the upper mantle.

• The Journal of the Petrological Society of Korea
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• v.18 no.1
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• pp.1-17
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• 2009

This article carried studies of the petrographical and petrochemical characteristics on the Cretaceous volcanic rocks in the area of Janggun peak and Gyemyeong peak which is located at the northeastern area of Mt. Geumjeong, Busan. The areas are composed of andesitic rock, sedimentary rock, rhyolitic rock, and intrusive hornblende, biotite granites, in ascending order. According to petrochemistry, the major elements show the calc-alkaline rock series ranged medium-K to high-K. With increasing $SiO_2$, $Al_{2}O_{3}$, $Fe_{2}O_{3}$, $TiO_2$ CaO, MgO MnO and $P_{2}O_{5}$ are decreased and $K_{2}O$ and $Na_{2}O$ are increased in the volcanic rocks. The trace element compositions show high LILE/HFSE ratios and negative anomaly of Nb, and REE patterns show enrichments in LREE and (-) anomaly values increase of Eu from the basaltic andesite to andesite facies, therefore the volcanic rocks have typical characteristics of continental margin arc calc-alkaline volcanic rocks, produced in the subduction environment. The volcanic rock show nearly the same patterns in spider and REE diagram. Fractional crystallization of the basaltic magma would have produced the calc-alkaline andesitic magma. And the rhyolitic magma seems to have been evolved from the basaltic andesitic magma with fractional crystallization of plagioclase, pyroxene, hornblende, biotite.

• The Journal of the Petrological Society of Korea
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• v.17 no.2
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• pp.57-82
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• 2008

The volcanic sequence of the late Cretaceous Moonyu volcanic mass which distributed in the southwestern part of Ryeongnam massif, can be divided into felsic pyroclastic rocks, andesite and andesitic pyroclastic rocks, rhyolite in ascending order. The earliest volcanic activity might commence with intermittent eruptions of felsic magma during deposition of volcaniclastic sediments. Explosive eruptions of felsic pyroclastic rocks began with ash-falls, to progressed through pumice-falls and transmitted with dacitic to rhyolitic ash-flows. Subsequent andesite and andesitic pyroclastic rocks were erupted and finally rhyolite was intruded as lava domes along the fractures near the center of volcanic mass. Petrochemical data show that these rocks are calc-alkaline series and have close petrotectonic affinities with subduction-related continental margin arc volcanic province. Major element compositions range from medium-K to high-K. Petrochemical variation within the volcanic sequence can be largely accounted for tractional crystallization processes with subordinate mixing. The most mafic rocks are basaltic andesite, but low MgO and Ni contents indicate they are fractionated by fractional crystallization from earlier primary mafic magma, which derived from less than 20% partial melting of ultramafic rocks in upper mantle wedge. Based on the stratigraphy, the early volcanic rocks are zoned from lower felsic to upper andesitic in composition. The compositional zonation of magma chamber from upper felsic to lower andesitic, is interpreted to have resulted from fractionation within the chamber and replenishment by an influx of new mafic magma from depth. Replenishment and mixing is based on observations of disequilibrium phenocrysts in volcanic rocks. REE patterns show slight enrichment of LREE with differentiation from andesite to rhyolite. Rhyolite in the final stage can be derived from calc-alkaline andesite magma by fractional crystallization, but it might have underwent crustal contamination during the fractional crystallization.

• Journal of the Korean Chemical Society
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• v.19 no.6
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• pp.434-437
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• 1975

By fractional crystallization D-mandelic acid salt of diethyl-dl-1-aminobenzylphosphonate prepared from benzaldehyde, diethylphosphite and ammonia at the atmospheric pressure, gave diethyl(-)-1-aminobenzylphosphonate. (+)-1-Aminobenzylphosphonic acid was obtained by acidic hydrolysis of diethyl(-)-1-aminobenzylphosphonate hydrochloride.