scholarly journals Mineralogical characterization and evaluation of chromite ore in Grevena and Kozani Vourinos massif, Western Macedonia, Greece

2021 ◽  
Vol 15 (1) ◽  
pp. 11-18
Author(s):  
Apostolos Baklavaridis ◽  
Konstantinos Vatalis ◽  
Vayos Karayannis ◽  
Ploutarchos-Nikolaos Benetis ◽  
Georgios Charalampides
Keyword(s):  
Mineralogical Characterization ◽  
Mine Area ◽  
Chromite Ore ◽  
Weight Losses ◽  
Eds Analysis ◽  
Mineral Phases ◽  
Magnesian Olivine ◽  
Practical Implications ◽  
Ophiolitic Complex ◽  
Differential Thermogravimetry

Purpose. Chromite samples from Aetoraches mine area in the southern part of the Vourinos complex in Western Macedonia, Greece were examined from mineralogical-geochemical perspective. Methods. Χ-ray Diffraction (XRD) mineral phase analysis, elemental Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (SEM-EDS) analysis and Thermogravimetry/Differential Thermogravimetry (TG/DTG) were carried out. Findings. The XRD results showed that all the samples contain mainly magnesium- and aluminum-chromite (“aluminum-picrochromite”) phases, along with forsterite (magnesian olivine), serpentine and chlorite occurrences. Based on the SEM-EDS results, the computed average chemical formula indicative of this specific chromite type is: (Fe0.4 Mg0.6) (Cr1.6 Al0.4/)O4. The TG-DTG weight losses found to be in the range of 4.4-14.36%, at temperatures between 600 and 750°C, indicated the presence of the hydroxyl-rich silicate minerals, serpentinite and chlorite, in agreement to the Loss of Ignition (LOI) results. The mineral phases detected in the present analyses appear in the dunite/diorite/harzburgite/peridotite main rocks of the ophiolitic complex that hosts the chromite ore. Originality.In the current research, an original characterization, via thorough elemental, phase and thermal analysis, is carried out aiming to enlighten the geochemistry aspects of the Vourinos chromite complex, Region of Western Macedonia, Greece, particularly of easily accessible and exploitable chromite deposits of the Aetoraches mine area. Practical implications. The chromite mineral, and especially the metallurgical type, is of substantial importance in metal industry. In that sense, the findings of the present investigation of chromite purity and mineral structure is a prerequisite for future exploitation of the Aetoraches chromite deposits in particular and broadly for the ongoing exploitation of chromite ore in the Vourinos complex, situated in Region of Western Macedonia, Greece, an area with high unemployment and rather slow economic growth. Keywords: chromite ore, Vourinos massif, Aetoraches mine area, mineralogical characterization, geochemistry, XRD, SEM-EDS, TG/DTG

Developing Alternative Building Materials from Mining Waste

2014 ◽  
Vol 976 ◽  
pp. 202-206 ◽  
Author(s):  
Javier Flores Badillo ◽  
Juan Hernández Ávila ◽  
Francisco Patiño Cardona ◽  
Norma Yacelit Trápala Pineda ◽  
José Abacú Ostos Santos
Keyword(s):  
Compressive Strength ◽  
Building Materials ◽  
Subsequent Treatment ◽  
Mining Waste ◽  
Mineralogical Characterization ◽  
Green Strength ◽  
Mineral Phases ◽  
Heavy Clay ◽  
Industrial Materials ◽  
Strength And Plasticity

In this paper we present the production of alternative industrial materials from the mining waste in the form of tailings, this study was made with the tailings of Dos Carlos, establishing 4 sampling zones, dividing them into three strata in the bottom, middle and top. The sampling method used is quartering, to homogenize the material and anticipate the possible use of it as a building material, having for this purpose 12 ceramic mixtures for subsequent treatment. Chemical composition was determined as 70.43% SiO2, 7.032% Al2O3, 2.69% Fe2O3, 0.46% MnO2, 3.98% K2O, 3.34% CaO, 2.50% Na2O, 56 grams per tonne of Ag y 0.6 grams per tonne of Au. In the mineralogical characterization the tailings presents silica, albite, berlinite, orthoclase and potassium jarosite as the main mineral phases, among other mineral phases in lesser concentration such as gypsum, calcite, anorthoclase, pyrite, sphalerite and galena. The determinations of the tailing material granulometry in the range of 60% in a size less than 270 mesh (53 μm). Afterwards, the alternative industrial materials were produced by using the tailings and heavy clay in order to give the composite a good green strength and plasticity during development, but above all to give it a compressive strength similar or higher than that of products derived from conventional processes. Keywords: Tailings, green strength, compressive strength, plasticity, heavy clays, alternative industrial materials.

Chemical and mineralogical characterization of chromite ore processing residue from two recent Indian disposal sites

Chemosphere ◽  
2016 ◽  
Vol 155 ◽  
pp. 188-195 ◽  
Author(s):  
Katrin Matern ◽  
Holger Kletti ◽  
Tim Mansfeldt
Keyword(s):  
Chromite Ore Processing Residue ◽  
Mineralogical Characterization ◽  
Chromite Ore ◽  
Ore Processing

scholarly journals Chemical and mineralogical characterization of portuguese ceramic tiles in the historic center of São Luís do Maranhão (Brazil): an approximation of the mineralogy and firing temperature of the raw materials

2013 ◽  
Vol 66 (1) ◽  
pp. 91-98 ◽  
Author(s):  
José Manuel Rivas Mercury ◽  
Domingos de Jesus Costa Pereira ◽  
Nazaré do Socorro Lemos Silva Vasconcelos ◽  
Aluísio Alves Cabral Jr. ◽  
Romulo Simões Angélica
Keyword(s):  
Firing Temperature ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Ceramic Tiles ◽  
Mineralogical Characterization ◽  
Calcium Carbonates ◽  
Historic Center ◽  
Mineral Phases ◽  
Materials Used

This work involved the first-ever characterization of antique Portuguese ceramic wall tiles in the Historic Center of São Luis do Maranhão, Brazil. The tiles were characterized by optical microscopy, X-ray diffraction (XRD) and chemical analysis to identify the possible raw materials used in the fabrication process, as well as the firing temperature of these materials. The results indicate that the microstructure of these materials consists of pores of varying sizes with calcite incrustations and quartz grain sizes smaller than 500 µm distributed in a pinkish yellow matrix, which were identified by XRD as calcite, gehlenite, wollastonite, quartz, and amorphous mineral phases. Based on this information, it can be inferred that the original raw materials probably consisted of a mixture of kaolinitic clays (Al2O3·2SiO2·2H2O) rich in calcium carbonates and quartz, or mixtures of kaolinitic clays, quartz and calcite, which did not reach the pre-firing temperature of 950ºC.

The Mineral Composition and Microstructure of MAC Cementing Material Prepared Using Hydrated Lime

2013 ◽  
Vol 575-576 ◽  
pp. 527-530
Author(s):  
Yong Jie Liu ◽  
Lin Chen ◽  
Shi Quan Liu ◽  
Rui Xia Shi
Keyword(s):  
Ternary Phase ◽  
Ternary Phase Diagram ◽  
Raw Materials ◽  
Hydrated Lime ◽  
X Ray Diffraction ◽  
Eds Analysis ◽  
Mineral Phases ◽  
Diffraction Peaks ◽  
Cementing Material

MAC cementing material was in-situ synthesized with different ratios of raw materials and sintering temperatures. The raw materials include hydrated lime, magnesite and alumina. X-ray diffraction analysis indicates that the major mineral phases in the MAC are monocalcium aluminate (CA), magnesium aluminate spinel (MA) and calcium aluminate (C7A12). The relative contents of the mineral and amorphous phase were simply calculated based on the relative diffraction peaks and MgO-Al2O3-CaO ternary phase diagram. SEM and EDS analysis indicate that the MAC cementing material includes layered structured CA, long strip C7A12 and octahedral MA.

scholarly journals Oxidative conditions can lead to exceptional preservation through phosphatization

Geology ◽  
2020 ◽  
Vol 48 (12) ◽  
pp. 1164-1168 ◽  
Author(s):  
Pierre Gueriau ◽  
Sylvain Bernard ◽  
François Farges ◽  
Cristian Mocuta ◽  
Didier B. Dutheil ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Fine Scale ◽  
Teleost Fishes ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Exceptional Preservation ◽  
Mineral Phases

Abstract Exceptional preservation through phosphatization is primarily controlled by a reduction in pH, favoring the precipitation of apatite over that of calcite. Laboratory experiments have suggested that phosphatization results from anoxic decay. Here we report results of the fine-scale mineralogical characterization of Cretaceous phosphatized fossils of teleost fishes and crustaceans from the Jebel oum Tkout Lagerstätte (Morocco). Data collected using complementary laboratory and synchrotron-based X-ray techniques reveal that oxidative conditions were established at a certain step of decay. Supporting these conclusions are the presence, covering and embedded in the phosphatized tissues, of Fe(III)-rich mineral phases, the precipitation of which was likely biologically induced during decay. The present study highlights that the establishment of oxidative conditions during decay can be compatible with exceptional preservation of fossils through phosphatization.

scholarly journals Behaviors of Perfluorocarbon Emulsion during Dissolution of Oxide Layers

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1329
Author(s):  
Naon Chang ◽  
Huijun Won ◽  
Chonghun Jung ◽  
Seonbyeong Kim ◽  
Heechul Eun ◽  
...  
Keyword(s):  
Anionic Surfactant ◽  
Hydroxyl Group ◽  
Dissolution Behavior ◽  
Dissolution Test ◽  
Perfluorocarbon Emulsion ◽  
Oxide Layers ◽  
X Ray ◽  
Weight Losses ◽  
Eds Analysis ◽  
Cr2o3 Layer

This study investigates the dissolution behavior of oxide layers containing radionuclides using perfluorocarbon (PFC) emulsion as a reusable medium. Chemicals such as PFC, anionic surfactant, and H2SO4 are used for preparing the PFC emulsion, and emulsified using an ultrasonication process. The FTIR results show O–H stretching that is formed by the interaction of the carboxyl group of the anionic surfactant with the hydroxyl group of water containing H2SO4, and find that the H2SO4 can be homogeneously dispersed in the PFC–anionic surfactant–H2SO4 emulsion. The dissolution test of the simulated Cr2O3 specimen is conducted using PFC emulsion containing KMnO4. Through the weight losses of specimens and Scanning Electron Microscope-Energy Dispersive X-ray Spectrometer (SEM-EDS) analysis, it is confirmed that the Cr2O3 layer on the SUS304 specimen is easily dissolved using PFC emulsion. During the dissolution of the Cr2O3, it is observed that the dispersed H2SO4–KMnO4 became unstable and separated from PFC emulsion. Based on these results, the behavior of the PFC emulsion during the dissolution of the oxide layer is explained.

Visual and microscopic examination of the rocket engine combustion chamber

2019 ◽  
Vol 92 (3) ◽  
pp. 368-375
Author(s):  
Adam Wisniewski ◽  
Maciej Malicki ◽  
Wojciech Manaj
Keyword(s):  
Fracture Surface ◽  
Combustion Chamber ◽  
Cross Sections ◽  
Rocket Engine ◽  
Content Type ◽  
Eds Analysis ◽  
Engine Combustion ◽  
Microscopic Inspection ◽  
Practical Implications ◽  
Selection Of

Purpose This paper aims to enhance the selection of the best material of the rocket engine combustion chamber. The chamber has been destroyed during dynamometer tests, and the goal of this inspection is to verify the nature of the damage in the context of checking the usefulness of this type of graphite for the combustion chamber construction. Design/methodology/approach This paper presents the results of visual and microscopic inspection of the rocket engine combustion chamber of Ø50 × 165 mm in dimension, which was made of R type graphite. Findings An analysis of the fracture surface shows that in the inspected combustion chamber voids and inclusions are present. EDS analysis of the fracture surface shows that in the inspected combustion chamber inclusions are present which have a relatively high amount of elements like: Ti, C, S, V, Si, O and a relatively small amount of Fe and Ni. Research limitations/implications Research limitations is concerned the failure analysis by a scanning electron microscope (SEM) Zeiss EVO 25 MA with EDS detector: Brüker X Flash Detector 5010 125 eV and Espirit 1.9.0.2176 EDS software. Practical implications Designing of the engine combustion chamber the researches can select the best of the rocket engine combustion chamber, made of R type graphite, with the minimum voids and inclusions to decrease the possibility of bursting of this chamber. Originality/value The most dangerous issues in the inspected combustion chamber during an outflow are hot gases as a result of high fuel combustion temperature, so it causes the nozzle heating and the engine stress increase of visible inclusions in cross-sections.

Automated mineral analysis in TASK8

1990 ◽  
Vol 48 (2) ◽  
pp. 212-213
Author(s):  
William F. Chambers ◽  
Arthur A. Chodos ◽  
Roland C. Hagan
Keyword(s):  
National Laboratory ◽  
Control Program ◽  
Mineral Analysis ◽  
Alamos National Laboratory ◽  
Mineral Phase ◽  
Los Alamos National Laboratory ◽  
California Institute Of Technology ◽  
Mineral Phases ◽  
Letter Code ◽  
Institute Of Technology

TASK8 was designed as an electron microprobe control program with maximum flexibility and versatility, lending itself to a wide variety of applications. While using TASKS in the microprobe laboratory of the Los Alamos National Laboratory, we decided to incorporate the capability of using subroutines which perform specific end-member calculations for nearly any type of mineral phase that might be analyzed in the laboratory. This procedure minimizes the need for post-processing of the data to perform such calculations as element ratios or end-member or formula proportions. It also allows real time assessment of each data point.The use of unique “mineral codes” to specify the list of elements to be measured and the type of calculation to perform on the results was first used in the microprobe laboratory at the California Institute of Technology to optimize the analysis of mineral phases. This approach was used to create a series of subroutines in TASK8 which are called by a three letter code.

A correlation of CL emissions from Penrith sandstone with elemental distributions obtained by simultaneous SEM-CL and EDS analysis

1995 ◽  
Vol 53 ◽  
pp. 392-393
Author(s):  
Paul J. Wright
Keyword(s):  
Optical Microscope ◽  
Electron Gun ◽  
High Electron ◽  
Collection System ◽  
Electron Hole ◽  
Depositional Processes ◽  
Eds Analysis ◽  
Distribution Mapping ◽  
Backscattered Electron ◽  
Electron Imaging

Most industrial and academic geologists are familiar with the beautiful red and orange cathodoluminescence colours produced by carbonate minerals in an optical microscope with a cold cathode electron gun attached. The cement stratigraphies interpreted from colour photographs have been widely used to determine the post depositional processes which have modified sedimentary rock textures.However to study quartzose materials high electron densities and kV's are necessary to stimulate sufficient emission. A scanning electron microscope with an optical collection system and monochromator provides an adequate tool and gives the advantage of providing secondary and backscattered electron imaging as well as elemental analysis and distribution mapping via standard EDS/WDS facilities.It has been known that the incorporation of many elements modify the characteristics of the CL emissions from geological materials. They do this by taking up positions between the valence and conduction band thus providing sites to assist in the recombination of electron hole pairs.

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