Spatial variations in leaching of a low-grade, low-porosity chalcopyrite ore identified using X-ray μCT

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).

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Bioleaching of copper from a low-grade chalcopyrite ore

Journal of Chemical Technology & Biotechnology ◽

10.1002/jctb.280310149 ◽

1981 ◽

Vol 31 (1) ◽

pp. 358-362 ◽

Cited By ~ 2

Author(s):

Desh Deepak ◽

Kumudeswar Das

Keyword(s):

Low Grade ◽

Chalcopyrite Ore

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X-Ray Luminescence Separation of Khibiny Low-Grade Apatite Ore

Физико-технические проблемы разработки полезных ископаемых ◽

10.15372/ftprpi20190115 ◽

2019 ◽

Keyword(s):

Low Grade ◽

X Ray

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Combined Influence of Low-Grade Metakaolins and Natural Zeolite on Compressive Strength and Heavy Metal Adsorption of Geopolymers

Minerals ◽

10.3390/min11050486 ◽

2021 ◽

Vol 11 (5) ◽

pp. 486

Author(s):

Alcina Johnson Sudagar ◽

Slávka Andrejkovičová ◽

Fernando Rocha ◽

Carla Patinha ◽

Maria R. Soares ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Compressive Strength ◽

Natural Zeolite ◽

Metal Adsorption ◽

Low Grade ◽

Heavy Metal Adsorption ◽

Adsorption Model ◽

X Ray ◽

Adsorption Capacities

Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce MK utilization’s environmental footprint. Geopolymers were synthesized with the replacement of MK by zeolite up to 75 wt.% (A25, B25—25% MK 75% zeolite; A50, B50—50% MK 50% zeolite; A75, B75—75% MK 25% zeolite; A100, B100—100% MK). The molar ratios of SiO2/Al2O3 and Na2O/Al2O3 were kept at 1 to reduce the sodium silicate and sodium hydroxide environmental impact. Geopolymers’ crystallography was identified using X-ray diffraction analysis. The surface morphology was observed by scanning electron microscopy to understand the effect of zeolite incorporation. Chemical analysis using X-ray fluorescence spectroscopy and energy dispersive X-ray spectroscopy yielded information about the geopolymers’ Si/Al ratio. Compressive strength values of geopolymers obtained after 1, 14, and 28 days of curing indicate high strengths of geopolymers with 100% MK (A100—15.4 MPa; B100—32.46 MPa). Therefore, zeolite did not aid in the improvement of the compressive strength of both MK-based geopolymers. The heavy metal (Cd2+, Cr3+, Cu2+, Pb2+, and Zn2+) adsorption tests exhibit relatively higher adsorption capacities of Barqueiros MK-based geopolymers for all the heavy metals except Cd2+. Moreover, zeolite positively influenced divalent cations’ adsorption on the geopolymers produced from Barqueiros MK as B75 exhibits the highest adsorption capacities, but such an influence is not observed for Alvarães MK-based geopolymers. The general trend of adsorption of the heavy metals of both MK-based geopolymers is Pb2+ > Cd2+ > Cu2+ > Zn2+ > Cr3+ when fitted by the Langmuir isotherm adsorption model. The MK and zeolite characteristics influence geopolymers’ structure, strength, and adsorption capacities.

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Extraction of Boron from Ludwigite Ore: Mechanism of Soda-Ash Roasting of Lizardite and Szaibelyite

Minerals ◽

10.3390/min9090533 ◽

2019 ◽

Vol 9 (9) ◽

pp. 533 ◽

Cited By ~ 4

Author(s):

Xin Zhang ◽

Guanghui Li ◽

Jinxiang You ◽

Jian Wang ◽

Jun Luo ◽

...

Keyword(s):

Sodium Carbonate ◽

Energy Dispersive Spectrometer ◽

Low Grade ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Selective Activation ◽

X Ray ◽

Shed Light ◽

Soda Ash ◽

Scanning Electron

Ludwigite ore is a typical low-grade boron ore accounting for 58.5% boron resource of China, which is mainly composed of magnetite, lizardite and szaibelyite. During soda-ash roasting of ludwigite ore, the presence of lizardite hinders the selective activation of boron. In this work, lizardite and szaibelyite were prepared and their soda-ash roasting behaviors were investigated using thermogravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscope and energy dispersive spectrometer (SEM-EDS) analyses, in order to shed light on the soda-ash activation of boron within ludwigite ore. Thermodynamics of Na2CO3-MgSiO3-Mg2SiO4-Mg2B2O5 via FactSage show that the formation of Na2MgSiO4 was preferential for the reaction between Na2CO3 and MgSiO3/Mg2SiO4. While, regarding the reaction between Na2CO3 and Mg2B2O5, the formation of NaBO2 was foremost. Raising temperature was beneficial for the soda-ash roasting of lizardite and szaibelyite. At a temperature lower than the melting of sodium carbonate (851 °C), the soda-ash roasting of szaibelyite was faster than that of lizardite. Moreover, the melting of sodium carbonate accelerated the reaction between lizardite with sodium carbonate.

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Study of Low-Grade Nickel Laterite Processing Using Palm Shell Charcoal as Reductant

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1000.436 ◽

2020 ◽

Vol 1000 ◽

pp. 436-446

Author(s):

Bambang Suharno ◽

Nolzha Primadha Ilman ◽

Achmad Shofi ◽

Deni Ferdian ◽

Fajar Nurjaman

Keyword(s):

Sodium Sulfate ◽

Selective Reduction ◽

Reduction Process ◽

Low Grade ◽

X Ray Diffraction ◽

X Ray ◽

Palm Shell ◽

Higher Temperature ◽

Nickel Grade

This study was conducted to investigate the effect of palm shell charcoal reductant in the selective reduction of nickel ore with the addition of additive at various temperatures and times. In this present work, 10 wt. % of sodium sulfate as additive and 5, 10, 15 wt. % of palm shell charcoal as reductants were used. The reduction of nickel ore was performed at 950oC, 1050oC, and 1150oC for 60, 90, and 120 minutes. A wet magnetic separation method was then carried out to separate the concentrates and tailings. Characterization of reduced ore was performed by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), while the composition of ferronickel in concentrate was identified by X-Ray Fluorescence (XRF). The result showed that the higher temperature reduction, the higher of nickel grade, and its recovery at the concentrate. Nevertheless, the longer reduction time and the more reductant in nickel ore lowering the nickel grade and its recovery in the concentrate. The optimum condition in this selective reduction process was obtained with the addition of 5 wt. % of reductant and 10 wt. % of sodium sulfate in nickel ore, which was reduced at 1150oC for 60 minutes. It resulted in 4.60% and 73.23% for nickel grade and its recovery, respectively.

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Research on Properties of Low Grade Cement-Based Composite Materials Modified by Silica Fume

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.174-177.751 ◽

2012 ◽

Vol 174-177 ◽

pp. 751-756

Author(s):

Zi Fang Xu ◽

Ming Xu Zhang ◽

Jin Hua Li

Keyword(s):

Silica Fume ◽

Mechanical Performance ◽

Raw Materials ◽

Cement Matrix ◽

Hardened Cement ◽

Low Grade ◽

X Ray ◽

Matrix Microstructure ◽

Nano Powder ◽

Strength And Durability

In order to notably improve the mechanical properties and durability of low-grade cement-based material, superfine silica fume was used to modify the cement-based composite based on special perfomance and effects of nano powder. The mechanical performance and durability were investigated.Then the phase compositions,microstructure and morphologies of as-received cement-based composite were studied by X-ray Diffractometer、TGA-DTA and SEM. The results show that： the best formula of raw materials is 1:1:0.025:0.015, and hydration can be accelerated and increasing of hydration products is observed after modification. In the hardened cement matrix, microstructure is very compacted and C-S-H gel forms densed structure, so the structure defect is notably reduced. This means that both strength and durability of cement-based composite are notably improved by the addition of superfine silica fume.

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Online X-Ray Fluorescence Monitoring of Coarse Ore for Silver at the Process Conveyors at Kazakhmys Corporation LLC

Inżynieria Mineralna ◽

10.29227/im-2020-01-56 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Aydar NIGMATULIN ◽

Zaure ABDRAKHMANOVA ◽

Andrey KAN ◽

Sergey EFIMENKO ◽

Dmitry MAKAROV

Keyword(s):

Online Monitoring ◽

Copper Smelter ◽

Size Class ◽

Low Grade ◽

Reliable Measurement ◽

X Ray ◽

Copper Zinc ◽

Methodological Aspects ◽

Iron Grade ◽

Cadmium Zinc

This paper examines the process and methodological aspects of implementing online X-ray fluorescence monitoring of ore in terms ofits silver, cadmium, zinc, lead, molybdenum, and iron grade at the process conveyors at Balkhash and Karagaily Concentrators andthe main conveyor of the Nurkazgan underground mine operated by Kazakhmys Corporation LLC. The research was complicated bythe need to: a) ensure reliable measurement of silver and cadmium in the range of 1+ ppm, molybdenum in the range of 10+ ppm, aswell as copper, zinc, lead, and iron in the ore size class –300 mm; b) implement monitoring of the grade of these elements (except molybdenum) at Balkhash Concentrator in the waste slag of Balkhash Copper Smelter, characterized by a very complex elemental matrix.A modification of the ore monitoring station RLP-21T (by Aspap Geo LLC, Alma-Ata) was developed, implemented, and thoroughlytested for online monitoring of low-grade silver ore flows. Energy dispersive X-ray fluorescence method was adopted for ore assays.Instrument spectra were measured every second. Silver, cadmium, and molybdenum grade was calculated based on 40 measurements,copper, zinc, lead, and iron grade – based on 20 measurements.

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