Effect of sintering temperature on the microstructure and properties of foamed glass-ceramics prepared from high-titanium blast furnace slag and waste glass

Foamed glass-ceramics were prepared via a single-step sintering method using high-titanium blast furnace slag and waste glass as the main raw materials The influence of sintering temperature(900–1060℃) on the microstructure and properties of foamed glass-ceramics was studied. The results show that the crystal shape changed from grainy to rod-shaped and finally turned to multiple shapes as the sintering temperature was increased from 900 to 1060℃. With increasing sintering temperature, the average pore size of the foamed glass-ceramics increased and subsequently decreased. By contrast, the compressive strength and the bulk density decreased and subsequently increased. An excessively high temperature, however, induced the coalescence of pores and decreased the compressive strength. The optimal properties, including the highest compressive strength(16.64 MPa) among the investigated samples and a relatively low bulk density(0.83 g/cm^3), were attained in the case of the foamed glass-ceramics sintered at 1000℃.

Effect of Fe_2O_3 on the crystallization behavior of glass-ceramics produced from naturally cooled yellow phosphorus furnace slag

CaO–Al2O3–SiO2(CAS) glass-ceramics were prepared via a melting method using naturally cooled yellow phosphorus furnace slag as the main raw material. The effects of the addition of Fe2O3on the crystallization behavior and properties of the prepared glass-ceramics were studied by differential thermal analysis, X-ray diffraction, and scanning electron microscopy. The crystallization activation energy was calculated using the modified Johnson–Mehl–Avrami equation. The results show that the intrinsic nucleating agent in the yellow phosphorus furnace slag could effectively promote the crystallization of CAS. The crystallization activation energy first increased and then decreased with increasing amount of added Fe2O3. At 4wt% of added Fe2O3, the crystallization activation energy reached a maximum of 676.374 kJ·mol−1. The type of the main crystalline phase did not change with the amount of added Fe2O3. The primary and secondary crystalline phases were identified as wollastonite (CaSiO3) and hedenbergite (CaFe(Si2O6)), respectively. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

Influence of aluminium nitride as a foaming agent on the preparation of foam glass-ceramics from high-titanium blast furnace slag

To effectively reuse high-titanium blast furnace slag （TS）, foam glass-ceramics were successfully prepared by powder sintering at 1000℃. TS and waste glass were used as the main raw materials, aluminium nitride （AIN） as the foaming agent, and borax as the fluxing agent. The influence of the amount of A1N added （lwt%-5wt%） on the crystalline phases, microstructure, and properties of the produced foam glass-ceramics was studied. The results showed that the main crystal phases were perovskite, diopside, and augite. With increasing A1N content, a transformation from diopside to augite occurred and the crystallinity of the pyroxene phases slightly decreased. Initially, the aver- age pore size and porosity of the foam glass-ceramics increased and subsequently decreased; similarly, their bulk density and compressive strength decreased and subsequently increased. The optimal properties were obtained when the foam glass-ceramics were prepared by adding 4wt% AIN.

Influence of CeO_2 addition on the preparation of foamed glass-ceramics from high-titanium blast furnace slag

Foamed glass-ceramics doped with cerium oxide（CeO_2）were successfully prepared from high-titanium blast furnace slag by one-step sintering.The influence of CeO_2 addition（1.5wt%–3.5wt%）on the crystalline phases,microstructure,and properties of foamed glass-ceramics was studied.Results show that CeO_2 improves the stability of the glass phase and changes the two-dimensional crystallization mechanism into three-dimensional one.XRD analysis indicates the presence of Ca（Mg,Fe）Si_2O_6 and Ca（Ti,Mg,Al）（Si,Al）_2O_（6 ）in all sintered samples.Added with CeO_2,Ti CeO_4 precipitates,and crystallinity increases,leading to increased thickness of pore walls and uniform pores.The comprehensive properties of foamed glass-ceramics are better than that of samples without CeO_2.In particular,the sample added with a suitable amount of CeO_2（2.5wt%）exhibits bulk density that is similar to and compressive strength（14.9 MPa）that is more than twice of foamed glass-ceramics without CeO_2.

CONTROLLING AND MONITORING THERMOTE NICAL PARAMETERS OF GLASS MELTING FURNACE

According to the characteristics of the ther-motechnical parameters such as temperature pressure and glass level for glass melting furnace, the design method for monitoring and controlling these parameters is introduced in this paper based on MACROMAX-2 concentrated and dis-tributedcontrol system. The configuration of management information and control loop is described, and research tests were performed to check the functions of system.

TWO-DIMENSIONAL MATHEMATICAL MODEL OF COMBUSTION SPACE IN GLASS MELTING FURNACES

Under some assumptions and dividing the combustion space into several isothermal zones and isothermal surface elements, a two-dimensional mathematical model for combustion space in cross-fired glass melting furnaces was constructed. The finite element method and the Gauss integration were used to calculate direct ex-change areas, and a inverse matrix was used to obtained the total ex-change areas. The temperature distributions were obtained by itera-tions. Some results were presented to show the effects of the fire tem-perature distribution, the convective -heat transfer coefficients and the heat losses through crown surfaces on the temperature distributions.

ENERGY ANALYSIS OF GLASS TANK FURNACE

The article puts forward a kind of reasonable scientific method of energy analysis - the energy method of analysis. Some accurate results of the energy analysis have been provided. The artical makes the energy balance to the glass tank furnace with the energy method. The auther makes a de- tailed study on the calculation way in which many items of the energy balance in glass tank furnace are concerned. The article gives an energy ana- lysis to end-port flame tank furnace and makes an energy balance. The energy method can show the quality use of energy which can not be shown in the heat method analysis. The energy method tells us that the most of energy loses in the irreversible process.

Innovation of Regenerator Checkerwork for Glass Melting Furnaces

Regenerator checkerwork for glass melting furnaces should have high resistance against thermal stress and chemical attack,high mechanical stability,high efficiency to recover the heat from waste gas and low tendency for clogging.This article reviews the innovation of the regenerator checkerwork from the past decades.The state of the art for optimised material choice and optimised checker shapes will be reported.

Fused Cast AZS Refractories for Glass Furnace

1 Scope This standard specifies technical requirements, testing method, testing rules, marking, packing, transports and storage of fused cast AZS refractories for glass furnace.

Magnesia Bricks for Glass Furnace(MgO Content≥95%)

1 Scope This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packing, transportation, and storage of magnesia bricks for glass furnace.

Sintered AZS Bricks for Glass Melting Furnace

1 Scope This standard specifies the brand, technical requirements, test methods, inspection rules, marking, packing, transportation, storage, and quality certificate of sintered AZS bricks for glass melting furnace. This standard is applicable to sintered AZS bricks for glass melting furnace.

Fireclay Refractory Bricks for Glass Melting Furnace

This standard is applicable to fireclay refractory bricks with unit weight ≥ 50 kg for glass melting furnaces.

Fused Cast Alumina Refractory Products for Glass Tank Furnace

1 Subject and Scope The standard specifies the requirement, testing method, inspection rule and requirements for the labeling, packing, shipping and storing of the fused cast alumina refractory products for glass tanks.

Fused Cast Alumina Refractory Products for Glass Melting Furnace

JC/T 494-92(96) 1 ScopeThis standard specifies the technical requirements, test methods, inspection rules, marking, packing, transportation, and storage of fused cast alumina refractory products for glass melting furnace. This standard is applicable to the fused cast alumina refractory products for glass melting furnace (called products for short).2 Normative ReferencesGB 2997 Test method for apparent porosity, water absorption, bulk density and true porosity of dense shaped refractory productsGB 5072 Test method for cold crushing strength of dense shaped refractory productsGB 5989 Test method for refractoriness under load of dense shaped refractory products (Differential, with rising temperature)GB 7320 Test method for thermal expansion of refractory productsGB 10204 Test method for corrosion resistance of refractories for glass melting furnace to molten glassGB 10325 Stacking, sampling, acceptance, storage and transportation of shaped refractory productsGB 10326 Inspections of dimension, appearance and section of refractory productsGB/T 14351 Chemical analysis method of fused cast alumina refractoriesYB 4015 Sample preparation for testing of refractory products for glass melting furnaceYB 4016 Sampling and inspection of refractory products for glass melting furnaceJC 493 Fused cast zirconia corundum refractory products for glass melting furnace

Deactivation Analysis of SCR Denitrification Catalyst in a Glass Furnace

The causes of deactivation of SCR denitrification catalyst used in a glass furnace were studied by means of low temperature nitrogen adsorption and desorption characterization,X-ray fluorescence spectrometry analysis,and thermogravimetric-mass spectrometry-infrared characterization.The results show that the main causes of sample A inactivation were serious alkali/alkaline earth metal poisoning and As poisoning;sample B was weakly affected by alkali/alkaline earth metal poisoning,mainly by As poisoning and P poisoning.Severe micropore and mesoporous blockage occurred in the inactivated samples A and B,mainly due to tar adsorption and the deposition of large amounts of ammonium bisulfate and metal sulfate in the carrier.The tar and ammonium sulfate adsorbed in the catalyst can be effectively removed before being heated to 550℃.

Silica Refractory Bricks for Glass Melting Furnace

1 Scope This standard specifies the classification, technical requirements, test method, inspection rules, marking, packing, transportation, storage and quality certification of silica refractory bricks for glass melting furRaces.

Low Porosity Fireclay Bricks for Glass Melting Furnace

This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packing, transportation, storage and quality certificate of low porosity fireclay bricks for glass melting furnace.

High Quality Silica Bricks for Glass Melting Furnace

This standard specifies the classification, technical requirements, test method, inspection rules, marking, packing, transportation, storage and quality certification of high quality silica bricks for glass melting furnace.

Volume and Surface Nucleation of Crystals in Glass Based on Blast-Furnace Slag

Using differential thermal analysis, X-ray phase analysis, electron microscopy, and optical microscopy, the nucleation of crystals in glass obtained by blending metallurgical slag with silicon dioxide has been studied. The type of crystallization (homogeneous or heterogeneous, volume or surface) is revealed for each of nine compositions of synthesized glass. It is shown that the first crystalline phase in a volume crystallizing glass is perovskite (CaO·TiO2);in this phase a nucleation of the main phase occurs: melilite (solid solution of gehlenite 2CaO·Al2O3·SiO2 in akermanite 2CaO·MgO·2SiO2). The fundamental characteristics of homogeneous (for a catalizing phase, perovskite) and heterogeneous (for a catalyzed phase, melilite) of crystallization are determined: the steady state nucleation rate Ist, time of unsteady state nucleation τ, crystal growth rate U, and activation energy of frictional flow. The temperature dependences of Ist, τ, and U are obtained. The kinetics of the crystallization of glass is studied and the rates of the surface crystal growth are determined in the glass of nine compositions. The influence of grinding the particles of the original glass on the sequence of deposition of the crystalline phases was studied. Practical recommendations are presented for the use of blast-furnace slag as a raw material for the synthesis of glass and their further utilization.

Recent Development in Improving Energy Efficiency of Glass Furnaces

The energy required for continuous glass melting usually accounts for about 30~75% of the total energy consumptions supplied to the glass industry, and the energy cost contributes to about 10~25% of total glass manufacturing cost depending upon the type of glass and manufacturing efficiency. Typically, energy efficiency of glass furnaces offers major opportunities for manufacturing cost reduction.Significant rising of energy cost, environmental requirements for clean air and pressure for reducing global warming and carbon dioxide emissions, as well as the cost of capitals are main drivers for the technology developments. In this paper, energy efficiency of glass furnaces is discussed. Technology developments in selective batching, oxy-fuel firing with preheating batch and cullet, non-conventional advanced melting systems, such as segmented glass melting and submerged combustion melting, as well as using math modeling to optimize fuel distribution for energy savings are presented.