Synthesis of Spinel Ceramic Pigments and Glazes Based on Them

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.

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

Pigment & Resin Technology ◽

10.1108/prt-08-2020-0081 ◽

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.

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Synthesis of Spinel Color Pigments from Aluminum Dross Waste

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.766.282 ◽

2018 ◽

Vol 766 ◽

pp. 282-287 ◽

Cited By ~ 2

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.

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