Synthesis Of Ceramic Pigments Research Articles

Synthesis of Ceramic Pigments with Willemite Structure and Their Use for Blue Glazes

Synthesis of Ceramic Pigments with Willemite Structure and Their Use for Blue Glazes

Synthesis of Ceramic Pigments with Chromium Content from Leather Waste

Two different coloured ceramic pigments, blue-green and black, were prepared by using solid phase reaction method from calcined leather waste and industrial grade metal oxides. Chemical compositions of leather waste were characterized by X-ray fluorescence (XRF) in order to determine their chemical compositions, which indicated that the calcined leather waste could be used as a chromium precursor system to prepare ceramic pigments. Crystal structure, microstructure, absorption spectra and colorimetric coordinates of ceramic pigments were characterized by XRD, SEM, UV- vis spectrophotometer and fully automatic colorimeter, respectively. Glaze experiments proved that the as-prepared pigments had good stability and excellent colour development performance. In addition, it was found that the best black colour rendering effect (L*=9.95) occured when the content of calcined leather was 45 wt%, however, the colour rendering performance of blue-green pigments was related to the amount of Al2O3 added. The process scheme is green and environmentally friendly, which is of great significance to resource recycling, sustainable economy and social development.

Patterns in the synthesis processes and the characteristics of silicate-spinal ceramic pigments when introducing mineralizers

The synthesis of ceramic pigments is conventionally carried out at a high temperature (not less than 1,200 °C). Its reduction implies using mineralizing additives, which have a different mechanism of action on the starting components of pigment charges. The effectiveness of the mineralizers is determined by their nature, content, degree of dispersion in the activated reagent. Thus, searching for the most effective mineralizers in the synthesis, in particular, of silicate-spinel ceramic pigments is an important scientific and practical task.We have investigated the effect of various mineralizing additives (B2O3, Na2B4O7, Na2O, NaF) on the processes of forming the crystal-phase composition of slag-containing ceramic pigments and the change in their color indicators. A direct dependence has been established between the melting point of the mineralizers and the efficiency of their influence on the formation of spinel phases, which are color carriers in such pigments. The tangible effect of the introduction of sodium fluoride, which has the highest melting point among the examined additives, is achieved as a result of the firing of pigments at a temperature not lower than 1,150 °C. The effect of sodium oxide is effective starting at a temperature of 1,100 °C. The most expedient to apply are the boron-containing compounds. Their introduction makes it possible to lower the firing temperature of slag-containing pigments to 1,050 °C while completely binding the starting components in the spinel solid solutions. The ceramic pigments that are thus synthesized enable the formation of glazed coatings, which, in terms of qualitative indicators, are not inferior to coatings obtained with the addition of high-temperature pigments (a firing temperature of 1,200–1,250 °С). The formation of silicate phases (diopside and wollastonite), which are not color carriers in the examined pigments, undergoes effective mineralized action from the supplements of NaF and B2O3

Synthesis of ceramic pigments from industrial wastes: Red mud and electroplating sludge

The perception of industrial waste has changed, in the last decades, from an economic and environmental problem to a potential raw material. In this work, the synthesis of a stable pigment was prepared by combining two hazardous and unexplored wastes: red mud (RM, rich in Fe) and electroplating sludge (ES, rich in Ni/Cr). The wastes were mixed in different proportions and calcined at 1200 °C. Black and brown pigments were obtained from the mixture of RM/ES in 1:3 and 1:1 wt proportions, respectively. The color was given by the chrome-iron-nickel spinels, based on Ni2+ 3T1g(3F) transitions (≈13,000 cm−1), Cr3+ 4A2g → 4T1g(4F) transitions (≈24,400 cm−1) and Fe3+ (≈15,000–≈22,500 cm−1). The achieved coloring strength and thermal stability on various ceramic glazes render excellent prospects for the industrial application of such waste-based pigments.

Rice Husk Ash as a Raw Material to Produce Willemite Pigments

This study focuses in the synthesis of ceramic pigments based on the crystal structure of willemite (Zn2SiO4). The willemite obtained from the combination of commercial zinc oxide and rice husk ash is produced in a conventional ceramic process without the use of mineralizer agent and with the addition of cobalt oxide or nickel oxide as the source of chromophore ions. The synthesis temperature used was 1200°C. The characterization of pigments involves the use of X-ray diffraction and scanning electron microscopy. The pigments applied in matte enamel and sintered at 1100°C or 1200°C developed color between blue and beige. The construction of absorbance curves showed the color development behavior of each pigment. The results showed the possibility of obtaining willemite, from rice husk ash and the color development efficiency of the material, besides showing the interference of chromophore ion (Ni and Co) in color development.

Energy Efficiency in the Microwave-Assisted Solid-State Synthesis of Cobalt Aluminate Pigment

Abstract: Due to their rapid, selective, and volumetric heating, microwaves have been widely used in the past to enhance solid-state reactions as well as the synthesis of ceramic pigments. The aim of this work is to present a case study involving the preparation of blue CoAl2O4 pigment using different microwave applicators and generator frequencies, showing the advantages which can derive from a properly designed microwave reactor for the solid-state synthesis of such pigment. The results show that, when using a properly designed microwave applicator, the specific energy consumption can be significantly lowered compared to conventional heating techniques. Consistently with the data on the dielectric properties of precursors found in literature, the microwave processing of cobalt oxide and aluminum hydroxide mixtures resulted more favorable at 2.45 GHz than at 5.8 GHz microwave frequency.

Synthesis of Ceramic Pigment Based on Crystal Structure of Wollastonite

In the ceramic industry, color is of great importance to product development. Parameters such as hue, brightness and color intensity influence the visual appearance of the ceramic surface and its market value. Research on the development of new pigments is ongoing, with focus on cost reduction, environmental suitability and color innovation. Different studies have shown the feasibility of using industrial by-products to obtain pigments. Many of these waste products have calcium carbonate and nickel oxides in their composition. This study investigates the synthesis of ceramic pigment with the structure of wollastonite - CaSiO3, with the use of nickel as chromophore ion. In order to evaluate the effect of adding nickel to the formation of crystalline phases X-ray diffraction was used. Particle size analysis was performed by Laser diffraction technique and a colorimetric study was conducted through the analysis of the pigment applied to a commercial enamel, by determining colorimetric parameters L*, a* and b*. The results showed that wollastonite combined with nickel acts as pigment and that its presence may interfere with the performance of new pigments depending on the nickel content and synthesis temperature.

Síntese de pigmento cerâmico verde com base na estrutura cristalina da wollastonita

RESUMO Na indústria cerâmica de revestimento a cor é um parâmetro de grande importância no desenvolvimento de produtos. O aspecto visual da peça cerâmica e seu valor de mercado são influenciados por parâmetros como tonalidade, brilho e intensidade de cor. Neste segmento, a busca de novos pigmentos é constante, com foco na redução de custos, na adequação ambiental de pigmentos e na necessidade de inovação em cores e processos. Estes pigmentos, quando dispersos em um sólido, devem ser capazes de desenvolver cor mantendo-se insolúveis e inertes nas elevadas temperaturas de processamento. O objetivo do presente trabalho foi a síntese de pigmento cerâmico com a estrutura de Wollastonita - CaSiO3, com a inclusão de cromo como íon cromóforo, em teores variados. A difratometria de raios-X foi utilizada para avaliar o efeito da adição do cromo na formação das fases cristalinas. A análise de distribuição de tamanho de partícula foi realizada pela técnica de difração a laser. A análise colorimétrica foi realizado pela incorporação do pigmento em esmalte comercial e a avaliação da cor desenvolvida, através da determinação dos parâmetros colorimétricos L*, a*, b*. Os resultados mostraram que o teor de cromo utilizado e a temperatura de síntese interferem no desenvolvimento dos silicatos e na performance dos pigmentos.

Synthesis of Spinel Ceramic Pigments and Glazes Based on Them

The results of research on the synthesis of ceramic pigments based on titanomagnetite with modifying additives zinc, magnesium, cobalt and manganese oxides are presented. X-ray phase analysis is used to determine the phase compositions of the pigments as a function of the composition and synthesis temperature. The optimal compositions and synthesis conditions of pigments are determined.

Synthesis of ceramic pigments with merwinite crystal structure

The results of a study of the possibility of synthesizing pigments based on merwinite are presented, methods for directed regulation of structure and phase formation processes for synthesis of pigments possessing high physical-chemical properties are developed and a relation is established between the temperature–time parameters of synthesis, the content of the added chromaphoric oxides with the type and amount of color-carrying phases giving saturated colors and a wide range of pigment colors.

Silica based pigments

Research on the synthesis of ceramic pigments using silica gel and quartz sand is presented. It has been determined that the temperature of synthesis and the composition are related with the properties of the pigments. It is shown that the pigments are best obtained using quartz sand. Awide palette of pigment colors was obtained by introducing transition-metal oxides (CoO, NiO, Fe2O3, Cr2O3), mineralizers (H3BO3, Na2CO3, NaF), and modifiers (ZnO, CaO, MgO).

Synthesis and characterization of hematite pigment obtained from a steel waste industry

Pigments that meet environmental and technology requirements are the focus of the research in the ceramic sector. This study focuses on the synthesis of ceramic pigment by encapsulation of hematite in crystalline and amorphous silica matrix. Iron oxide from a metal sheet rolling process was used as chromophore. A different content of hematite and silica was homogenized by conventional and high energy milling. The powders obtained after calcinations between 1050 and 1200 °C for 2 h were characterized by X-ray diffraction and SEM analysis. The pigments were applied to ceramic enamel and porcelain body. The effect of pigment was measured by comparing L* a* b* values of the heated samples. Results showed that the color developed is influenced by variables such as oxide content employed, conditions of milling and processing temperature. The results showed that the use of pigment developed does not interfere in microstructural characteristics of pigmented material. The best hue was obtained from samples with 15 wt% of chromophore, heated at 1200 °C in amorphous silica matrix.

Effect of mineralizers on the synthesis of ceramic pigments from talc

The mineralizing effect of sodium fluoride, boric acid, and a natural fluorine-bearing mineral (topaz concentrate) on the synthesis from talc of ceramic pigments with magnesium metasilicate, forsterite, and diopside structures is investigated. It is shown that NaF is the most active mineralizer. It is noted that NaF has a positive effect not only on the synthesis of crystalline structure but also on the chromaticity of the pigments. The pigment compositions developed can be widely used to tint ceramic pastes, glazes and glasses, in the manufacture of building materials, and to make paints.

Sol–gel combustion synthesis of chromium doped yttrium aluminum perovskites

A water-based sol–gel combustion synthesis was optimized in order to achieve pure yttrium aluminium perovskite (YAlO3, YAP). The method involved three main steps: xerogel formation, combustion treatment and calcination of the combusted precursors. TG DTA, FTIR and XRPD, used to investigate the precursor phase evolution, confirmed the strong influence of gel synthesis conditions, combustion temperature and calcination rate on YAP purity. Both stoichiometry and kinetics control during all the preparation steps are crucial in order to avoid the formation of undesired Y3Al5O12 (YAG) and Y4Al2O9 (YAM) stable phases. This method allowed to synthesize, for the first time from an aqueous sol–gel process, single phase samples of YAP. A series of samples with composition: YAl(1−x)Cr(x)O3 where x is 0, 0.035, 0.135, 0.250, 0.500, 0.750 was obtained. A consistent decrease of calcination temperature, with respect to conventional solid state synthesis, was achieved by sol–gel combustion, avoiding polyphase materials even without the use of mineralizers. This is an important result in several applications like the synthesis of ceramic pigments.

Synthesis of neodymium-containing pigments

Synthesis of ceramic pigments with equimolecular ratios of oxides (Nd2O3: P2O5, Nd2O3: ZrO2, Nd2O3: TiO2) was investigated. It was shown that these oxide ratios allow obtaining pigments of different palettes suitable for coloring glazes.

Obtaining of the Ceramics Pigments (Fe, Zn)Cr<sub>2</sub>O<sub>4</sub> Using Waste of Electroplating as Raw Material

The solid material from electroplating wastewater treatment was used as raw material in synthesis of ceramic pigments, once the formation of ZnCr2O4 and FeCr2O4 crystalline phases can be considered as a process of heavy metals inertization, such as chromium, zinc and iron. To reach the purpose of this paper, the techniques of elementary chemical analysis (Atomic Absorption Spectroscopy and X-Ray Fluorescence, thermal analysis (DTA/TGA) and X-Ray Diffraction were applied in samples of waste with the aim of physical and chemical characterization. After the characterization of residue were incorporate metallic oxides for correction of composition and obtaining of inorganic pigment. Pigment formation was followed through X-ray diffraction, where the formation of spinel phases containing the metals Fe, Cr and Zn were observed. The pigment was characterized through scanning electron microscopy, differential thermal analysis and thermogravimetry. The 8 hours cycle calcinated pigments formed crystalline spinel phases, where we can say that the present metals in the sludge became inert. It was possible to incorporate up to 20% of the galvanic waste in the production of Fe, Cr and Zn based inorganic pigments.

Use of the Precipitation Method in the Synthesis of Ceramic Pigments

The results of the synthesis of ceramic pigments using coprecipitation of hydroxides and difficultly soluble salts of multivalent metal ions are described. The specifics of the coprecipitation process and the effect of various factors on the production of the initial precipitates for subsequent synthesis of ceramic pigments are analyzed. The technology of pigment production is described.

Ceramic Pigments with the Mullite Structure Based on Topaz and Kaolinite

The possibility of obtaining ceramic pigments with the mullite structure based on natural minerals (kaolinite and topaz) is considered. It is established that these minerals are promising for the synthesis of ceramic pigments. The obtained pigments are resistant to high temperatures and have various tints.

Microwave Technology Applications in the Synthesis of Ceramic Pigments

Microwave Technology Applications in the Synthesis of Ceramic Pigments

Synthesis of pigments based on the CuO-Cr2O3-Al2O3 system using the precipitation method

Compositions of ceramic pigments for coloring glaze and flux coatings have been developed using the powder method and the coprecipitation method. Comparative parameters of chromophore properties of the obtained pigments are given. The expediency of using the coprecipitation method in the synthesis of ceramic pigments is demonstrated.