• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.431-445
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• 2022

A quantitative phase analysis method of X-ray powder diffraction was studied to determine the mineral content of clay-rich rocks practically as well as effectively. For quantitative X-ray powder diffraction analysis of the clay-rich rocks, it is necessary to prepare whole-rock powder samples with a random orientation by side mounting method. In addition, for the identification of the clay minerals in the rock, it is required to prepare an oriented mount specimen with a clay particle size of 2 ㎛ or less, ethylene glycol treatment, and heat treatment. RIR (reference intensity ratio) and Rietveld method were used for the quantitative analysis of the clay-rich rocks. It was possible to obtain the total clay and the non-clay minerals contents from the whole-rock X-ray diffraction profiles using the RIR values. In addition, it was possible to calculate the relative content of each clay mineral from the oriented X-ray diffraction profiles of the clay particle size and assign it to the total clay. In the Rietveld method of whole-rock X-ray diffraction, effective quantitative values were obtained from the Rietveld diffraction patterns excluded the region of less than 10 degrees (2θ). Similar quantitative values were shown in not only the RIR but the Rietveld methods. Therefore, the analysis results indicate a possibility of a routine quantitative analysis of clay-rich rocks in the laboratory. However, quantitative analysis of clay minerals is still a challenge because there are numerous varieties of clay minerals with different chemical and structural characteristics.

• Journal of the Mineralogical Society of Korea
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• v.22 no.2
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• pp.115-127
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• 2009

Mineral quantification was performed on sediments of the Ulleung basin by X-ray powder diffraction and the computer software based on Rietveld quantification method. The sediments are dominated by amorphous opal-A with quartz, feldspars, micas, clays, calcite, and pyrite. The opal-A shows iterative variation in abundance with increasing burial depth. In addition, the relative abundance of opal-A is coincident with abundance of organic carbon contents, indicating that the Ulleung sediment consists mostly of amorphous silica derived from organism in the pelagic environment. Upward increase in the abundance of opal-A is markedly shown in the cores located in the slope region. On the other hand, there is a distinct tendency that the abundance of calcite is inversely proportional to that of opal-A. This indicates that the abundance of opal-A increases during the rise of sea level. Also, the fall of sea level lowers the abundance of opal-A.

• Journal of the Mineralogical Society of Korea
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• v.26 no.1
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• pp.27-34
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• 2013

X-ray powder diffraction is one of the most powerful techniques for qualitative and quantitative analysis of crystalline compounds. Thus, there exist a number of different methods for quantifying mineral mixtures using X-ray diffraction pattern. We present here the use of Rietveld and PONKCS (partial or no known crystal structure) methods for quantification of amorphous and crystallized mineral phases in synthetic mixtures of standard minerals (amorphous silica, quartz, mullite and corundum). Pawley phase model of amorphous silica was successfully built from the pattern of 100 wt% amorphous silica and internal standard-spiked samples by PONKCS approach. The average of absolute bias for quantities of amorphous silica was 1.85 wt%. The larger bias observed for lower quantities of amorphous silica is probably explained by low intensities of diffraction pattern. Averages of absolute bias for minerals were 0.53 wt% for quartz, 0.87 wt% for mullite and 0.57 wt% for corundum, respectively. The PONKCS approach achieved improved quantitative results compared with classical Rietveld method by using an internal standard.

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.363-381
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• 2006

Mineral compositions of granitic rocks from Geochang, Pocheon, Iksan, and China were obtained by the modal analysis, CIPW norm calculations, and Rietveld quantitative analysis for stone specification of the Geochang granitic rocks. The Geochang granitic rocks show grey to dark in color and medium grained porphyritic texture. They mainly consist of quartz, plagioclase, alkali feldspar, and biotite. Among three different method for determining the mineral compositions of granitic rocks, normative compositions using X-ray fluorescence data are not appropriate for representing real mineral composition. Rietveld quantitative analysis using X-ray powder diffraction data is proved better method to determine exact mineral compositions than modal analysis using microscopic observation. Q-A-P diagram shows that the Geochang granitic rocks are typical granodiorite, whereas the granitic rocks of Pocheon, Iksan, and China are monzogranite, monzogranite to granodiorite, and granodiorite, respectively. Compared to China ones, the Geochang granitic rocks are nearly close to each other in mineral composition.

• Journal of Conservation Science
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• v.32 no.3
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• pp.403-416
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• 2016

Mineral composition and content of 22 Korean Dancheong pigment products were obtained by Rietveld quantitative analysis. Jubosa, Hwang, Seokrok, Seokcheong and Hobun consist of pure cinnabar, orpiment, malachite, azurite and calcite (or aragonite), respectively. Whereas Seokganju, Hwangto, Noerok, Lapis lazuli, Baekto and Cockie hobun mainly consist of hematite, goethite, celadonite, lazurite, kaolin mineral and portlandite, respectively. And they all consist of soil minerals (quartz, feldspar, sericite and vermiculite) and filler minerals in the industry field (calcite, gypsum and anhydrite) at a different content. Quantitative XRD proved more useful method to determined exact mineral composition and content than chemical or microscopical data. If this method utilize for specification of natural pigment product, it is considered to be applicable in restoration technology and conservation science field.

• Korean Journal of Materials Research
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• v.6 no.5
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• pp.504-514
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• 1996

고상반응법과 sol-gel법으로 제조된 NASICON의 상온과 25$0^{\circ}C$에서의 X선 회절 데이터를 리트벨트 분석을 행하였다. monoclinic에서 rhombohedral로 상전이가 일어나도 원자들의 변위는 매우 작았다. 이들 상간의 ZrO6 팔면체와 Si(P)O4 사면체고 구성된 골격은 다소 다르게 나타남으로 인하여 Na 이온의 자리도 변하였다. 이들 방법으로 제조된 NASICON은 Zr이 부족한 비화학양론 화학식, Na 1+x+4yZr2-xSixP3-xO12으로 표현될 수 있었다. 제조법에 따라 Na 이온들의 자리 점유율이 변화하였다. 상온에서는 Na(1)과 Na(3)자리의 자리 점유율의 합이 거의 1에 가까웠으나, 25$0^{\circ}C$에서는 Na(1)과 mid Na 자리를 단위 화학식 당 한 개를 약간 상회하는 Na 이온이 점유하였다. 상온과 25$0^{\circ}C$에서의 Na 이온의 이동 경로가 다름을 알 수 있었다. 또한 25$0^{\circ}C$에서는 Na(1)자리와 Na(2)자리 사이에 mid Na가 존재하며, 이 자리가 Na 이온의 이동에 중요한 역할을 함을 알 수 있었다.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.294-301
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• 2020

This study evaluated the burnability and hydration reaction of clinker burned with high Al₂O₃ content OPC to apply large amounts of industrial by-products in the cement manufacturing process. Specifically, after preparing a clinker with a high C₃A content by burning the OPC raw material with a high content of Al₂O₃ in a laboratory electric furnace, the burnability of the clinker was evaluated through XRD Rietveld analysis and polarization microscopy, and clinker hydration reactivity was reviewed through the Isothermal conduction calorimetry analysis and the cement compressive strength. As a result, the kiln burning temperature for the production of high Al₂O₃ content clinker lower, and the compressive strength was equal to or higher than OPC. Therefore it was confirmed the possibility to manufacturing energy-saving high Al₂O₃ content clinker using a large amount of industrial by-products.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.259-259
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• 2007

층상구조의 전이금속 산화물($LiMO_2$, M=Co, Ni, Mn)은 리튬이차전지용 양극재료로 활발한 연구가 진행되고 있다. 차세대 리튬이차전지 시스템의 개발 및 고성능화를 위해서는 전지의 용량을 결정하는 핵심 부품인 양극재료의 고용량화 및 고안정화는 필수 불가결하다. 따라서 본 연구에서는 상업적으로 큰 장점이 있는 고상반응 공정을 이용하여 리튬이차전지용 양극소재를 제조하고, 소재의 전기화학적, 구조적인 특성을 평가하였으며, 다음과 같은 주제를 가지고 연구를 진행하였다. $LiCoO_2$ 양극재료는 리튬이온전지로 널리 사용되고 있다. 높은 에너지 밀도의 리튬이온전지를 얻기 위해서는 $LiCoO_2$ 양극재료가 고용량화 및 고밀도화를 가져야 한다. 여기서 $LiCoO_2$ 분말이 irregular particle morphology를 가지면 tap density가 $2.2-2.4gcm^{-3}$로 에너지 밀도가 낮으나, 구형 $LiCoO_2$의 정극재료는 tap density가 $2.6-2.8gcm^{-3}$로 상대적으로 energy density가 높아지는 효과가 있다. 구형 $LiCoO_2$ 양극재료를 합성하기 위해서는 chelating agent를 이용한 "controlled crystallization" 침전법을 사용하여 합성한 구형 코발트 수화물을 사용하고 있다. "controlled crystallization" 침전법에서 사용되는 chelating agent로는 주로 ammonia가 이용되고 있다. 본 연구에서는 chelating agent로 ethylene diamine을 사용하여 sodium hydroxides를 precipitation으로 침전 반응하여 구형 코발트 수화물을 합성하였다. 상기 방법으로 합성된 코발트 수화물과 리튬 수화물($LiOH{\cdot}H_2O$-고순도화학(高殉道化學))을 사용하여 고상법을 통하여 $LiCoO_2$를 합성하였다. 제조된 분말의 결정구조와 전기화학적 특성분석은 X-선 회절분석 및 리트벨트 구조정산, 그리고 충/방전 싸이클링을 수행하였으며, 분말의 미세구조 변화를 SEM을 이용하여 분석하였다.