Synthesis of Spinel Color Pigments from Aluminum Dross Waste

2018 ◽  
Vol 766 ◽  
pp. 282-287 ◽  
Author(s):  
Niti Yongvanich ◽  
Bovornrat Emtip ◽  
Boonyarit Hengprayoon ◽  
Ekkapot Jankat
Keyword(s):  
Spinel Phase ◽  
Ceramic Pigments ◽  
Blue Color ◽  
Spinel Crystal ◽  
Cobalt Ions ◽  
Aluminum Dross ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Ceramic Color ◽  
State Processing ◽  
Spinel Ceramic

Spinel-based ceramic color pigments were successfully synthesized from utilization of aluminum dross waste and relevant oxide precursors by solid-state processing. Cobalt ions were selected as a chromophore to produce blue pigments. The conventional oxide route was also carried out for comparison purposes. The spinel phase readily formed when fired at 1100 °C; longer duration yielded a higher degree of purity. No preferential orientation of XRD reflection was observed, indicating random crystallographic arrangement. Phase formation was also confirmed by Fourier Transformed Infrared Spectroscopy (FTIR) which displayed both Co-O tetrahedral and Al-O octahedral which are the main framework for a spinel crystal. Slightly sharper FTIR peaks for the dross route compared to those from the oxide route suggest a difference in crystallinity between the two with different precursors. The particle size distribution was relatively wide (5 – 30 micron), possibly due to a crude nature of the dross precursor. The UV-vis spectra showed absorption in the range of 450-550 nm which is associated with the blue color caused by a shift of the 3d7 electrons of Co2+. The obtained dross-route pigments possessed both a and b color parameters (a = -2.3 to-2.6; b = -3.4 to-4.0) in the negative territory, implying greenness and blueness respectively. The L values were in the 20-30 range. When incorporating into practical glazes, the b parameters unexpectedly became more negative, indicating an even deeper blue tone. This result suggested a high potential for utilization of this dross waste as an alternative precursor source for sustainable production of spinel ceramic pigments.

scholarly journals Ga-Substituted Cobalt-Chromium Spinels as Ceramic Pigments Produced by Sol–Gel Synthesis

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1078
Author(s):  
Egle Grazenaite ◽  
Edita Garskaite ◽  
Zivile Stankeviciute ◽  
Eva Raudonyte-Svirbutaviciene ◽  
Aleksej Zarkov ◽  
...  
Keyword(s):  
Phase Composition ◽  
Crystallite Size ◽  
Single Phase ◽  
Sol Gel ◽  
Ceramic Pigments ◽  
Blue Color ◽  
Cobalt Chromium ◽  
Light Blue ◽  
Sol Gel Synthesis ◽  
First Time

For the first time to the best of our knowledge, cobalt-chromium spinels CoCr2−xGaxO4 with different amounts of gallium (x = 0–2 with a step of 0.5) were synthesized via the aqueous sol–gel route as ceramic pigments. The phase composition, crystallite size, morphological features, and color parameters of new compositions and their corresponding ceramic glazes were investigated using XRD, CIELab, SEM, and optical microscopy. It was demonstrated that the formation of single-phase CoCr2−xGaxO4 samples was problematic. Full substitution of Cr3+ by Ga3+ ion in the spinel resulted in the formation of light blue powders, which yielded violetish blue color for the corresponding ceramic glaze.

Spectrally selective Cu1.5Mn1.5O4 spinel ceramic pigments for solar thermal applications

RSC Advances ◽  
2016 ◽  
Vol 6 (39) ◽  
pp. 32947-32955 ◽  
Author(s):  
Pengjun Ma ◽  
Qingfen Geng ◽  
Xianghu Gao ◽  
Shengrong Yang ◽  
Gang Liu
Keyword(s):  
Sol Gel ◽  
Cost Effective ◽  
Combustion Method ◽  
Solar Thermal ◽  
Ceramic Pigments ◽  
Spectrally Selective ◽  
Solar Thermal Applications ◽  
Spinel Ceramic

In this work, Cu1.5Mn1.5O4 spinel ceramic pigments have been successfully prepared by a facile and cost-effective sol–gel self-combustion method and annealed at a temperature ranging from 500 °C to 900 °C for 1 h.

Synthesis and characteristics of aluminate spinel ceramic pigments based on spent aluminium-cobalt-molybdenum catalyst

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Аleksandr Viktorovich Zaichuk ◽  
Аleksandra Andreevna Amelina ◽  
Yurii Sergeevich Hordieiev ◽  
Liliya Frolova ◽  
Viktoriia Dmitrievna Ivchenko
Keyword(s):  
Mineral Composition ◽  
Firing Temperature ◽  
Active Form ◽  
Spinel Solid Solution ◽  
Ceramic Pigments ◽  
Blue Colour ◽  
Content Type ◽  
Spinel Pigments ◽  
Colour Indices ◽  
Spinel Ceramic

Purpose The purpose of this paper is to conduct the directed synthesis of blue-colour aluminate spinel pigments based on spent aluminium–cobalt–molybdenum (ACM) catalyst and to study peculiar features of mineral formation processes and changes in their colour indices depending on composition and firing temperature. Design/methodology/approach Aluminate spinel ceramic pigments with specified colour indices were synthesised by directed formation of their mineral composition and identification of the most rational technological parameters of production. Mineral composition of synthesised pigments was evaluated by X-ray phase analysis. The colour indices of pigments and pigment-containing glaze coatings were studied on the comparator colour. The chemical resistance of pigments was determined by loss of their weight loss after boiling in 1 N hydrochloric acid solution and 1 N sodium hydroxide solution. Findings Peculiar features of formation of the mineral composition of aluminate spinel pigments based on the ACM catalyst were studied. The expediency of using magnesium and zinc oxides in their composition has been proved. It is found that for the formation of stable pigments of intense blue colour, a concentration of cobalt (II) oxide in the amount of 0.5 mol is sufficient, which is 23.1 Wt.%. The colour of such pigments is determined by the ratios of cobalt, magnesium and zinc aluminates, which form a spinel solid solution. Practical implications The use of developed aluminate spinel pigments provides obtaining of high-quality glass coatings of blue colour, in particular, for ceramics. Originality/value Aluminium oxide in the spent ACM catalyst is predominantly in the active form (of amorphous aluminium hydroxide and y-Al2O3). This is a prerequisite for the use of this waste material as a complete substitute for chemically pure Al2O3 in the technology of aluminate spinel pigments and reduction of their firing temperature. Besides, spent ACM catalyst already contains 5 Wt.% of expensive cobalt (II) oxide in the form of stable colour-bearing phase CoAl2O4.

Synthesis of Spinel Ceramic Pigments and Glazes Based on Them

2014 ◽  
Vol 70 (9-10) ◽  
pp. 327-330
Author(s):  
N. F. Shcherbina ◽  
T. V. Kochetkova ◽  
N. N. Grishin
Keyword(s):  
Ceramic Pigments ◽  
Spinel Ceramic

Structural, morphological and magnetic properties of divalent copper-substituted Co–Zn Nanoferrites

2018 ◽  
Vol 32 (14) ◽  
pp. 1850172 ◽  
Author(s):  
B. B. V. S. Vara Prasad ◽  
K. V. Ramesh ◽  
Adiraj Srinivas
Keyword(s):  
Magnetic Properties ◽  
Magnetocrystalline Anisotropy ◽  
Copper Ions ◽  
Spinel Phase ◽  
Structural Parameters ◽  
Spherical Particles ◽  
Divalent Copper ◽  
Absorption Bands ◽  
Cobalt Ions ◽  
Morphological Studies

Nanocrystalline Co[Formula: see text]Zn[Formula: see text]Cu[Formula: see text]Fe2O4 spinel ferrites were prepared by autocombustion method with citric acid as fuel. Paramagnetic divalent copper ions substituted in place of ferromagnetic cobalt ions resulted in the modifications of structural and magnetic properties of the system. All samples were characterized with X-ray diffraction technique for structure determination. Crystallite sizes were calculated using Williamson–Hall plot and size–strain plots. Cation distribution and all other structural parameters were presented. Transmission electron microscopy measurements were done for x = 0 and x = 0.15 and they showed well-developed spherical particles with average sizes of 35 nm and 48 nm. Morphological studies were performed and grain growth was observed to be increased with copper concentration. EDAX measurements revealed the stoichiometric proportions of the samples as per the chemical composition. Mid-IR spectroscopy was used to characterize the spinel phase and displayed two characteristic absorption bands in all samples with a slight shift. M–H loops were recorded using vibrating sample magnetometer at room-temperature and highest saturation magnetization was observed to be 50.2 emu/g for the base (x = 0) sample. Magnetocrystalline anisotropy was discussed with the help of magnetocrystalline anisotropy constant K1.

scholarly journals Absorption spectra and crystal chemistry of quartz implanted with cobalt ions

2021 ◽  
Vol 63 (5) ◽  
pp. 57-66
Author(s):  
A. I. Bakhtin ◽  
A. V. Mukhametshin ◽  
O. N. Lopatin ◽  
V. F. Valeev ◽  
V. I. Nuzhdin ◽  
...  
Keyword(s):  
Raw Materials ◽  
Spinel Phase ◽  
Ion Beam ◽  
South Urals ◽  
High Dose ◽  
Rock Crystal ◽  
Absorption Bands ◽  
Cobalt Ions ◽  
Cobalt Spinel ◽  
Wide Range

Background. High-dose implantation of cobalt ions into the crystal structure of natural colourless quartz was carried out. Samples of crystal plates of rock crystal from the Svetlinskoye deposit in the South Urals plane-parallel were studied. All samples were crystallographically oriented perpendicular to the symmetry axis of the third order. Cobalt implantation into quartz was carried out using an ILU-3 ion-beam accelerator along the С axis of symmetry.Aim. To determine the ranges of thermal annealing for a controlled change in the sample colour and to establish the crystal-chemical features of the changes occurring in quartz matrix due to ionbeam modification of mineral properties.Materials and methods. Implantation modes included: room temperature, residual vacuum 10–5 torr, radiation dose from 1.0×1017 to 1.5×1017 ion/cm2 at a constant ion current density of 10 μA/cm2. Post-implantation heat treatment was carried out in three stages. The control of crystallochemical changes was carried out using a highly sensitive spectrophotometer with a wide range of wavelengths.Results. It was found that the revealed absorption bands are associated with electronic transitions in cobalt ions (Со2+ and Со 3+) coordinated in the crystal matrix of implanted and heat-treated rock crystal. The formation of an independent ultradispersed spinel phase in the irradiated quartz matrix was confirmed. The newly formed phase belongs to a partially reversed cobalt spinel.Conclusions. Taking into account the quantum-optical properties of cobalt spinel (laser shutters), the method of ion-beam modification of mineral crystal structures, quartz in particular, is highly promising in terms of creating new composite materials based on natural and artificial mineral raw materials.

CuCr2O4 Spinel Ceramic Pigments Synthesized by Sol-Gel Self-Combustion Method for Solar Absorber Coatings

2016 ◽  
Vol 25 (7) ◽  
pp. 2814-2823 ◽  
Author(s):  
Pengjun Ma ◽  
Qingfen Geng ◽  
Xianghu Gao ◽  
Shengrong Yang ◽  
Gang Liu
Keyword(s):  
Sol Gel ◽  
Combustion Method ◽  
Ceramic Pigments ◽  
Solar Absorber ◽  
Spinel Ceramic

scholarly journals Effect of Basicity on Precipitation of Spinel Crystals in a CaO-SiO2-MgO-Cr2O3-FeO System

2019 ◽  
Vol 38 (2019) ◽  
pp. 867-872
Author(s):  
Jianli Li ◽  
Qiang Zeng ◽  
Qiqiang Mou ◽  
Yue Yu
Keyword(s):  
Crystal Size ◽  
Solid Phase ◽  
Spinel Phase ◽  
Steel Slag ◽  
Solid Particles ◽  
Particle Diffusion ◽  
Spinel Crystal ◽  
Stainless Steel Slag ◽  
Comprehensive Utilization ◽  
Key Factor

AbstractThe comprehensive utilization of stainless steel slag is one of major problems to be solved at “green steelworks”. Precipitation of spinel crystals can effectively detoxify residue. The effect of basicity defined by ω(CaO)/ ω(SiO2) ratio on precipitation of spinel crystals in a CaO-SiO2-MgO-Cr2O3-8 wt% FeO system has been determined with such tools as FactSage 7.1, SEM-EDS, IPP 6.0 and XRD. The FactSage 7.1 results showed that the rate of spinel phase enrichment with chromium was about 98% for the system basicity less than 1.4 and about 78% above this value. The precipitation of solid particles in solution appeared to be significantly influenced by basicity. With its increase the solid phase grew, the liquid one reduced, the particle diffusion was limited, and the growth of spinel crystals was inhibited. The spinel crystal size increased rapidly with decrease of basicity. When basicity increased from 0.6 up to 1.0, the crystal size decreased sharply from 12.30 μm down to 6.22 μm, and the reduction constituted as much as 49.43%. When basicity increased from 1.0 up to 2.2, the spinel crystal size moderately decreased from 6.22 μm down to 4.47 μm. Therefore, reduction of basicity is conducive to spinel crystal enrichment with chromium what appears to be a key factor to control basicity at detoxification of the chromium-containing steel slag.

Synthesis of Carbon Dots via Hydrothermal Reaction for Selective Detection of Serotonin

2020 ◽  
Vol 20 (9) ◽  
pp. 5365-5368
Author(s):  
Yeji Kim ◽  
Jongsung Kim
Keyword(s):  
Carbon Dots ◽  
Hydrothermal Reaction ◽  
Limit Of Detection ◽  
Uv Light ◽  
Aqueous Solubility ◽  
Excitation Wavelength ◽  
Blue Color ◽  
Cobalt Ions ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Serotonin (5-HT) is a significant neurotransmitter involved in the regulation of mood, social behavior, depression, and other neurological activities. In this work, we synthesized nitrogen-doped carbon dots using naturally occurring amino acids such as L-aspartic acid and L-cysteine by employing a one-step hydrothermal reaction. The amino acid-derived carbon dots (CDs) are called AACDs. The as-synthesized AACDs showed strong blue-color emission under UV light and photoluminescence (PL) emission maximum wavelength at 457 nm with an excitation wavelength of 344 nm. The AACDs had superior aqueous solubility due to the carboxyl (–COOH) and amine (–NH2) functional groups on their surface. 5-HT could be detected by adding cobalt ions (Co2+) to the AACDs. The Co2+ ions facilitate cross-linking between free amino and carboxylate groups. Fluorescence quenching by AACDs incorporating Co2+ ion was observed to be dependent on the concentration of serotonin. The limit of detection (LOD) of AACDs for 5-HT was 2.24 μM.

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