Thermoluminiscence analysis of raw and ceramic materials

A method for analysis of silicate materials based on excitation of the materials with x-ray radiation and subsequent recording of thermally stimulated luminescence is considered. The possibility of analyzing the structure of raw materials and ceramics using the method proposed is displayed.     

Polymer-assistant ceramic nanocomposite materials for advanced fuel cell technologies

In this study,nanocomposites of LaCePr-oxide (LCP) and Ni_0.8Co_0.15Al_0.05LiO_2-δ (NCAL) with different contents of polyvinylidene fluoride (PVDF) were prepared and applied to solid oxide fuel cells. The composite materials were characterized by X-ray diffraction analysis (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and electrochemical impedance spectrum (EIS). The effect of PVDF concentration on the conductivity and performance of the fuel cells was investigated. It was found that PVDF plays a template role of pore forming in the nanocomposites, and the changed microstructure by as-formed pores greatly influences the electrochemical property of the nanocomposites. The cell with 3 wt% PVDF heat-treated at 210 °C achieved the highest power density of 982 mW cm⁻² at 520 °C, which enhanced performance by more than 57% than when no heat-treatment was implemented. It is 66% higher than the cell with no PVDF and no heat-treatment. Pores formed by PVDF after heat-treatment enlarged the triple phase boundary (TPB), which results in improved fuel cell performance.     

Use of nonconventional raw materials in ceramic production

This paper reports possibilities for use of nonconventional natural and synthetic raw materials in ceramic bodies and glazes.

Reactivity during the process of heating can be considered as a modern criterion for ceramic raw materials. A review of several types of alkali-containing rocks is made, which are more fusible than the common fluxes. The greater fluxing power of these raw materials compared to the traditional types provides for a higher rate of body sintering. As a result of this intensified process, a higher structural density and better mechanical strength of the bodies are achieved with shortened firing cycles. The introduction of more active fluxes reduces firing costs and allows economy of high quality traditional fluxing raw materials in the production of some tablewares, sanitary wares and faience tiles.

In combination with more reactive silicon-containing raw materials, the influence of the fluxes on sintering increases. This combined beneficial effect is experimentally confirmed in glaze frit melting and in the firing of glaze coatings. Investigations on these processes are discussed.

As a nonconventional raw material in the modern ceramic production, wollastonite can be considered. Since natural deposits of this valuable material are rarely found the use of synthetic wollastine is discussed. Obtaining an anorthite reaction phase in the ceramic bodies provides the formation of a compact and stable structure that permits firing in short and single cycle.     

Processing of some non-conventional ceramic raw materials and by-products

Technological procedures of processing selected industrial wastes into ceramic wares are described. They utilize the binding of raw materials grains by new compounds crystallizing from water solution (hydraulic binding) of from melts (eutectic binding) and hot consolidation.     

电感耦合等离子体发射光谱法测定陶瓷原料的化学成分

应用电感耦合等离子体发射光谱仪(ICP-OES)对陶瓷原料的化学组成中常量及微量元素Si、Al、Ca、Mg、K、Na、Fe、Ti、B、Zn、Zr、Sr、S、P、Mn、Pb、Ge等进行检测。     

Fabrication and characterization of anorthite-based ceramic using mineral raw materials

The purpose of this study is to design a novel single crystalline phase ceramic based on anorthite whose properties fulfill the tableware market requirements such as high appearance quality, strength and thermal shock resistance. To obtain the single phase anorthite ceramic, ball clay, quartz, calcite, feldspar and alumina were used as raw materials. The single phase anorthite ceramic was fabricated by slip casting and sintering at 1230 °C for 1 h. It has a high flexural strength of 103 MPa, which is higher than that of the conventional porcelain. The single phase anorthite ceramic had relatively low (4.9 × 10^?6 K^?1) thermal expansion coefficient which can be matched with applicable glaze easily. Furthermore, the single phase anorthite ceramic had high degree of whiteness (L* = 94) and excellent translucency behavior which could achieve a high-quality decorative effect.     

On the determination of free silica in ceramic raw materials

The accurate quantitative determination of free quartz contained in local feldspars and clays was achieved through special methods of differential thermal analysis, and chemical analysis. and chemical analysis. Aswan feldspar and Aswan clays were found to contain varying free quartz contents and were therefore considered as suitable sources of raw materials for the preparation of clay-feldspar-quartz ceramic body mixes. Accordingly, no quartz addition was necessary for the production of pottery and porcelain ceramic bodies.     

铜川市建筑陶瓷原料分析与评价

通过对所取铜川建筑陶瓷原料的各项性能分析，对陶瓷原料做出恰当的使用评价。     

Firing behavior of argillites from northern Tunisia as raw materials for ceramic applications

This study reports the firing properties of clayey materials from northern Tunisia to evaluate their possible use as raw material in ceramic. Physical, chemical, and mineralogical characterization and thermal behavior were carried out by inductively coupled plasma atomic emission, X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis, particle size distribution, and Atterberg limits tests. Firing properties were evaluated by color, firing shrinkage, water absorption, bulk density, apparent porosity, and flexural strength. Studied clayey materials are made up mainly by kaolinite and illite and are rich in iron. The main transformations after thermal analysis were identified from 500°C to 1000°C subsequent to the dehydroxylation of clay minerals, calcite decomposition, and the recrystallization process. Fired samples up to 1100°C showed better physical and mechanical properties related with a great densification resulting in a significant increase in linear shrinkage, bulk density, and flexural strength and a decrease in apparent porosity and water absorption up to 1100°C. This behavior is due to a crystalline and liquid phases formed at low firing temperature associated with a high content of fluxing agents. The fired ceramic materials exhibited low water absorption up to 2.26% and high flexural strength up to 32.6 MPa, which makes their potential use for some earthenware and stoneware products.     

Synthesis of manganese ferrite from non-standard raw materials using ceramic technique

Manganese ferrite spinel has been synthesized by using mill scale and fines of manganese ore sinter as sources of iron oxide and manganese oxide, respectively. The magnetic and physico-mechanical properties of the produced sample are largely dependent not only on the sintering condition but also on the Mn:Fe mole ratio. The effect of silica (which is one of the constituents of the fines of manganese ore sinter) on the properties of the sintered samples is investigated. The results show that a single phase of manganese ferrite spinel with weak magnetic properties is obtained in a sample containing a Mn:Fe mole ratio of 1.4:2 and sintered at 1300 °C for 2 h. On the other hand, a maximum saturation magnetization (62 emu/g) with reasonable physico-mechanical properties is obtained for a sample containing a Mn:Fe mole ratio of 1.3:2 and sintered at the same sintering conditions.     

Fluorphlopgopite ceramic via sintering of glass using inexpensive natural raw materials

Fluorphlopgopite ceramic was prepared from kaolin, feldspar and steatite with the addition of pure chemicals Na₂CO₃, AlOOH·H₂O and MgF₂. Glass-ceramics containing the crystal phase fluorphlogopite were prepared using two different routes. The first route was to melt a glass and to crystallize fluorphlogopite by subsequent annealing at temperatures in the range from 900 to 1050 °C kept for 2 h. Here, fluorphlogopite and cordierite were formed. In the other route a sintering procedure was applied using the pre-mentioned materials and sintering temperatures in the range from 900 to 1200 °C kept for 2 h. Here, fluorphlogopite [(Na,K)Mg₃(AlSi₃O₁₀)F₂], spinel and norbergite were precipitated. The unit cell parameters of the formed fluorphlogopite phase are larger than those according to JCPDS data. This is caused by a partial replacement of Mg by Ca or Ba from the raw materials. The microstructure of sintered samples show interlocked fluorphlogopite rods and small spinel crystals. The samples prepared by thermal annealing of the glass showed curved fluorphlogopite and additionally tiny cordierite crystals.     

用安徽当地原料研制抛光砖

我们受安徽省淮北市当地企业委托，在立足于淮北市及周边地区的陶瓷矿产资源的前提下，根据企业现有的生产设备条件，进行抛光砖试制研究。经过系统的研究，试制出采用当地原料70％，周边地区原料20％的抛光砖配方及试验样品，基本满足企业的生产需要。现就研制情况作以总结，以供同行参考。