Mineralogy and chemistry of a new halloysite deposit from the Rio de Janeiro pegmatite province, south-eastern Brazil

Abstract Halloysite is a 1:1 dioctahedral clay mineral that has been studied widely for applications in nanotechnology and as a mineral exploration guide for recognizing regolith-hosted heavy rare earth element (HREE) deposits. In Brazil, pegmatites from the state of Rio de Janeiro have been catalogued, but their potential to host halloysite deposits has never been studied. After a mineral exploration programme, one pegmatite with considerable halloysite contents and economic potential was discovered. This study reports the mineralogical and chemical characterization of the halloysite of this pegmatite and evaluates the possibility of clay-adsorbed HREE deposits, like that in the Zudong (China) regolith-hosted HREE deposit. Seven samples were collected in horizontal channels. Bulk samples and clay fractions (<2 μm) were analysed by quantitative mineral analysis (X-ray diffraction/Rietveld method), chemical analysis (major elements by X-ray fluorescence and Y, U, Th and rare earth elements by inductively coupled plasma mass spectrometry), scanning electron microscopy, Fourier-transform infrared spectroscopy, particle-size analysis, nitrogen physisorption and cation-exchange capacity. Mixed polygonal/cylindrical halloysite-7Å in concentrations between 6.3 and 35.4 wt.% in bulk samples and between 58.0 and 89.8 wt.% in the clay fractions were identified in the pegmatite. The clay fractions presented an average chemical composition of 45.46 wt.% SiO2, 36.10 wt.% Al2O3, 14.62 wt.% loss on ignition and 1.04 wt.% Fe2O3, as well as technological properties close to those observed in world-class halloysite deposits such as Dragon Mine (USA) and Matauri Bay (New Zealand). The clay minerals did not present significant HREE contents.

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Characterization of Natural Slip Materials Geologically Found in the North of the State of Rio de Janeiro, Brazil

Materials Science Forum ◽

10.4028/www.scientific.net/msf.798-799.33 ◽

2014 ◽

Vol 798-799 ◽

pp. 33-38

Author(s):

Zélia Maria Peixoto Chrispim ◽

Maria da Gloria Alves ◽

Luciana Lezira Pereira de Almeida ◽

Jonas Alexandre ◽

Afonso Rangel Garcez de Azevedo ◽

...

Keyword(s):

Thermal Analysis ◽

Rio De Janeiro ◽

Ceramic Industry ◽

Particle Size Analysis ◽

The State ◽

Size Analysis ◽

X Ray ◽

Geological Materials ◽

The North

Slip is a semifluid clayey type of material used in the ceramic industry for coating earthware products, such as bricks and tiles, thus providing distinct surface colors or patterns. In the present work a characterization was conducted to identify the mineralogical as well the chemical and physical properties of geological materials existing in the slip used by industries in the north region of the state of Rio de Janeiro, Brazil. The basic natural materials composing a slip, namely clay and kaolin, are responsible for changes not only the slip plasticity but also in its viscosity and adhesion to the surface of the ceramic piece. The slip characterization was performed in terms of particle size analysis, Atterberg limits and actual grain density. The chemical composition was obtained by X-ray fluorescence and the thermal properties by differential thermal analysis. The results indicated that marked differences exist between slip from distinct origins. A few slip samples failed to present the required properties.

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Preparation and Performance of Vanadium Tailings-Reservoir Sediment-Phosphogypsum-Based Foamed Concrete

Mathematical Problems in Engineering ◽

10.1155/2021/8468063 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Xiaowei Cui ◽

Yanqing Di ◽

Changlong Wang ◽

Yongbo Wang ◽

Suhua Zhang ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Raw Materials ◽

Particle Size Analysis ◽

Size Analysis ◽

Reservoir Sediment ◽

X Ray ◽

Inductively Coupled ◽

Mineral Phases ◽

Foamed Concrete ◽

And Performance

Foamed concrete (FC) was prepared from raw materials of vanadium tailings (VTs), reservoir sediment (RS), and phosphogypsum (PG). The physicochemical properties of the raw materials were studied by using X-ray diffraction (XRD), X-ray fluorescence (XRF) analysis, and inductively coupled plasma emission spectrometer (ICP-OES). The preparation and properties of FC were investigated by particle size analysis and strength test. The hydration products and microstructure of FC were analyzed by XRD and field emission scanning electron microscopy (FE-SEM). The results show that when the specific surface area (SSA) of VTs is 768 m2·kg−1 and the content is 40%, the products with a compressive strength of 3.56 MPa and density of 619.1 kg·m−3 meet the requirements of JG/T 266-2011 standard on FC of grades A06 and C3.0; the main mineral phases in the products are calcium silicate hydrate (C-S-H) gel, ettringite (AFt), and calcite, as well as the residual mineral phases after the system reaction include quartz, orthoclase, mullite, pyrite, and PG.

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Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽

10.3390/min11030232 ◽

2021 ◽

Vol 11 (3) ◽

pp. 232

Author(s):

Pedro J. Sánchez-Soto ◽

Eduardo Garzón ◽

Luis Pérez-Villarejo ◽

George N. Angelopoulos ◽

Dolores Eliche-Quesada

Keyword(s):

Particle Size ◽

Raw Materials ◽

Phase Evolution ◽

Particle Size Analysis ◽

Size Analysis ◽

Mining Wastes ◽

X Ray Diffraction ◽

X Ray ◽

Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

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Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

Water Science & Technology ◽

10.2166/wst.2010.013 ◽

2010 ◽

Vol 61 (5) ◽

pp. 1235-1243 ◽

Cited By ~ 4

Author(s):

Y. F. He ◽

F. R. Li ◽

R. M. Wang ◽

F. Y. Li ◽

Y. Wang ◽

...

Keyword(s):

Adsorption Mechanism ◽

Removal Rate ◽

Freundlich Isotherm ◽

Particle Size Analysis ◽

Lead Ions ◽

Size Analysis ◽

Optimum Conditions ◽

X Ray Diffraction ◽

X Ray ◽

Ft Ir

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb2 + ] = 500 mg L−1, [XBent] = 2 g L−1, pH = 5.0; oscillating 60 min under 200 rpm at 25°C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions—XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

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Recycling of Waste Solution after Hydrothermal Conversion of Fly Ash on a Semi-Technical Scale for Zeolite Synthesis

Materials ◽

10.3390/ma14061413 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1413

Author(s):

Rafał Panek ◽

Jarosław Madej ◽

Lidia Bandura ◽

Grzegorz Słowik

Keyword(s):

Fly Ash ◽

Nitrogen Adsorption ◽

Particle Size Analysis ◽

Al2o3 Content ◽

Size Analysis ◽

Zeolite Synthesis ◽

Hydrothermal Conversion ◽

Waste Solution ◽

X Ray ◽

X Zeolites

Nowadays, using fly ash for zeolites production has become a well-known strategy aimed on sustainable development. During zeolite synthesis in a hydrothermal conversion large amount of post-reaction solution is generated. In this work, the solution was used as a substrate for Na-A and Na-X zeolites synthesis at laboratory and technical scale. Obtained materials were characterized using particle size analysis, X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), transmission electron microscopy (TEM), Fourier transformed infrared spectroscopy (FTIR), and nitrogen adsorption/desorption isotherm. Produced zeolites revealed high purity (>98%) and monomineral zeolitic phase composition. The SiO2 content was in the range 39–42% and 40–38%, whereas Al2O3 content was 23–22% and 25–26% for Na-X and Na-A, respectively. TEM and BET analyses revealed Na-X zeolite pores were almost identical to commercial 13X with SBET in the range 671–734 m2/g. FTIR indicated slight differences between materials obtained at laboratory and technical scale in Si-O-(Si/Al) bridges of the zeolitic skeleton. The results showed good replicability of the laboratory process in the larger scale. The proposed method allows for waste solution reusability with a view to highly pure zeolites production in line with circular economy assumptions.

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Synthesis of Alpha-Tricalcium Phosphate by Wet Reaction and Evaluation of Mechanical Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1164 ◽

2012 ◽

Vol 727-728 ◽

pp. 1164-1169 ◽

Cited By ~ 3

Author(s):

Mônica Beatriz Thürmer ◽

Rafaela Silveira Vieira ◽

Juliana Machado Fernandes ◽

Wilbur Trajano Guerin Coelho ◽

Luis Alberto Santos

Keyword(s):

Mechanical Properties ◽

Calcium Phosphate ◽

Tricalcium Phosphate ◽

Calcium Nitrate ◽

Chemical Precipitation ◽

Particle Size Analysis ◽

Size Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Calcium Phosphate Cements

Calcium phosphate cements have bioactivity and osteoconductivity and can be molded and replace portions of bone tissue. The aim of this work was to study the obtainment of α-tricalcium phosphate, the main phase of calcium phosphate cement, by wet reaction from calcium nitrate and phosphoric acid. There are no reports about α-tricalcium phosphate obtained by this method. Two routes of chemical precipitation were evaluated and the use of two calcinations temperatures to obtain the phase of cement. The influence of calcination temperature on the mechanical properties of cement was evaluated. Cement samples were characterized by particle size analysis, X-ray diffraction, mechanical strength and scanning electron microscopy. The results demonstrate the strong influence of synthesis route on the crystalline phases of cement and the influence of concentration of reactants on the product of the reaction, as well as, on the mechanical properties of cement.

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Rare-earth crystal chemistry of thalénite-(Y) from different environments

Mineralogical Magazine ◽

10.1180/minmag.2017.081.044 ◽

2018 ◽

Vol 82 (2) ◽

pp. 313-327

Author(s):

Markus B. Raschke ◽

Evan J. D. Anderson ◽

Jason Van Fosson ◽

Julien M. Allaz ◽

Joseph R. Smyth ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

Spatial Scales ◽

Structure Refinement ◽

X Ray Diffraction ◽

Heavy Rare Earth ◽

Heavy Rare Earth Element ◽

X Ray ◽

Golden Horn

ABSTRACTThalénite-(Y), ideally Y3Si3O10F, is a heavy-rare-earth-rich silicate phase occurring in granite pegmatites that may help to illustrate rare-earth element (REE) chemistry and behaviour in natural systems. The crystal structure and mineral chemistry of thalénite-(Y) were analysed by electron microprobe analysis, X-ray diffraction and micro-Raman spectroscopy from a new locality in the peralkaline granite of the Golden Horn batholith, Okanogan County, Washington State, USA, in comparison with new analyses from the White Cloud pegmatite in the Pikes Peak batholith, Colorado, USA. The Golden Horn thalénite-(Y) occurs as late-stage sub-millimetre euhedral bladed transparent crystals in small miarolitic cavities in an arfvedsonite-bearing biotite granite. It exhibits growth zoning with distinct heavy-rare-earth element (HREE) vs. light-rare-earth element (LREE) enriched zones. The White Cloud thalénite-(Y) occurs in two distinct anhedral and botryoidal crystal habits of mostly homogenous composition. In addition, minor secondary thalénite-(Y) is recognized by its distinct Yb-rich composition (up to 0.8 atoms per formula unit (apfu) Yb). Single-crystal X-ray diffraction analysis and structure refinement reveals Y-site ordering with preferential HREE occupation of Y2 vs. Y1 and Y3 REE sites. Chondrite normalization shows continuous enrichment of HREE in White Cloud thalénite-(Y), in contrast to Golden Horn thalénite-(Y) with a slight depletion of the heaviest REE (Tm, Yb and Lu). The results suggest a hydrothermal origin of the Golden Horn miarolitic thalénite-(Y), compared to a combination of both primary magmatic followed by hydrothermal processes responsible for the multiple generations over a range of spatial scales in White Cloud thalénite-(Y).

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X-ray fluorescence spectrometry for rapid screening of particle size in soils

10.5194/egusphere-egu21-5307 ◽

2021 ◽

Author(s):

Maame Croffie ◽

Paul N. Williams ◽

Owen Fenton ◽

Anna Fenelon ◽

Karen Daly

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Soil Texture ◽

Particle Size Analysis ◽

Parent Material ◽

Fluorescence Spectrometry ◽

Rapid Screening ◽

Size Analysis ◽

X Ray

Soil texture is an essential factor for effective land management in agricultural production. Knowledge of soil texture and particle size at field scale can aid with on-going soil management decisions. Standard soil physical and gravimetric methods for particle size analysis are time-consuming and X-ray fluorescence spectrometry (XRF) provides a rapid and cost-effective alternative. The objective of this study was to explore the use of XRF as a predictor for particle size. An extensive archive of Irish soils with particle size and soil texture data was used to select samples for XRF analysis. Regression and correlation analyses on XRF determined results showed that the relationship between Rb and % clay varied with soil type and was dependent on the parent material. There was a strong relationship (R > 0.62, R2>0.30, p<0.05) between Rb and clay for soils originating from bedrock such as limestones and slate. Contrastingly, no significant relationship (R<0.03, R2=0.00, p>0.05) exists between Rb and % clay for soils originating from granite and gneiss. Furthermore, there was a significant negative correlation (p<0.05) between Rb and % sand. The XRF is a useful technique for rough screening of particle size distribution in soils originating from certain parent materials. Thus, this may contribute to the rapid prediction of soil texture based on knowledge of the particle size distribution.&#160;

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Synthesis of SnO2 Nanoparticles by High Potential Electrolysis

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.12.2.773.281-286 ◽

2017 ◽

Vol 12 (2) ◽

pp. 281 ◽

Cited By ~ 4

Author(s):

Fredy Kurniawan ◽

Rahmi Rahmi

Keyword(s):

Particle Size ◽

Sno2 Nanoparticles ◽

Particle Size Analysis ◽

Reaction Engineering ◽

High Potential ◽

Size Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Nanoparticles Synthesis ◽

The Fourier Transform

SnO2 nanoparticles have been synthesized by high voltage electrolysis. Tin bare was used for anode and cathode. The effect of potentials and electrolyte were studied. The particles obtained after electrolysis was characterized using X-ray Diffraction (XRD). The diffractogram is in agreement with the standard diffraction pattern of SnO2 which is identified as tetragonal structure. The Fourier Transform Infrared (FTIR) spectrum indicates that there is a vibration of Sn–O asymmetric at 580 cm-1. The optimum potential for SnO2 nanoparticles synthesis is 60 V at 0.06 M HCl which shows the highest UV-Vis spectrum. The absorption peak of SnO2 nanoparticles by UV-Vis spectrophotometer appears at about 207 nm. The particle size analysis shows that the SnO2 nanoparticles obtained have the size distribution in a range of 25-150 nm with the highest volume at 83.11 nm. Copyright © 2017 BCREC Group. All rights reservedReceived: 15th November 2016; Revised: 26th February 2017; Accepted: 27th February 2017How to Cite: Rahmi, R., Kurniawan, F. (2017). Synthesis of SnO2 Nanoparticles by High Potential Electrolysis. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2): 281-286 (doi:10.9767/bcrec.12.2.773.281-286)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.773.281-286

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The Evaporative Decomposition of Solutions Method (Eds) for the Production of Ultrafine Y1Ba2Cu3O7 from Nitrate and Mixed Anion Precursor Solutions

MRS Proceedings ◽

10.1557/proc-169-385 ◽

1989 ◽

Vol 169 ◽

Cited By ~ 2

Author(s):

Rollin E. Lakis ◽

Sidney R. Butler

Keyword(s):

Electron Microscopy ◽

Particle Size ◽

Barium Carbonate ◽

Hollow Spheres ◽

Particle Size Analysis ◽

Size Analysis ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron

AbstractY1Ba2Cu3O7 has been prepared by the evaporative decomposition of solutions method. Nitrate and mixed anion solutions were atomized and decomposed at temperatures ranging from 300°C to 950°C. The resulting materials have been characterized using x-ray powder diffraction, Thermal Gravimetric Analysis (TGA), particle size analysis, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The powder consists of 0.3 micron agglomerated hollow spheres with a primary particle size of 0.06 micron. TGA and x-ray diffraction indicate the presence of barium nitrate and barium carbonate due to incomplete decomposition and/or product contamination by the process environment.

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