A High-Temperature Viscometer for Molten Materials

An oscillating-cup viscometer for the measurement of the viscosity of molten materials from room temperature to 1400 K was developed. The instrument is described in detail and the working equations are presented. The operational behavior was tested with water at room temperature. Preliminary measurements show that the new viscometer is capable of measuring the viscosity of water at room temperature to within 0.2%. As the primary objective of this work is the establishment of standard reference data for high-temperature viscosity measurements in molten salts, molten metals, and molten semiconductors, references of earlier viscosity measurements of molten KNO₃ are given.     

室温熔盐的研究进展

室温熔盐，又称离子液体，它在很大的室温范围内都是液态，具有宽的电化学窗口、高而稳定的电导率、挥发程度低、质量轻、热稳定、不燃烧等一系列有机溶剂所不具备的优点。在二次电池、电化学电容器、电镀等领域展现出良好的应用前景。本文介绍了室温熔盐（RTMS）的制备方法，着重阐述了氯化铝型RTMS的一些性质和研究现状，对新型RTMS的研究进展也作了详细的介绍。     

Characteristics and Nature of Metal Fog in Molten Salts

In this paper are reported the characteristicsand nature of metal fog in molten cryolite-aluminamixtures on the basis of laboratory experiments andquantum chemistry studies.The metal fog is thefinely divided metal particles in the molten salts,and it dissolves partly in the molten cryolite to formatomic clusters,such as(Al_nNa_m)~(x+) type.     

A rough hard-sphere model for the thermal conductivity of molten salts

A new model based on the rough hard-sphere theory is proposed for the correlation and prediction of the thermal conductivity of molten salts. The model is capable of predicting the thermal conductivity of all the members of a family of molten salts characterized by a common anion if the behavior of any single member of the family of salts is known. Only the molar volumes of the molten salt and the solid salt at the melting temperature are required in the calculations. In addition, the model is easily extended to mixtures with a simple mixing rule.     

A New Model for the Thermal Conductivity of Molten Salts

A new model based on rough hard-sphere theory is proposed for the thermal conductivity of molten salts. The model incorporates a smooth hard-sphere contribution using the properties of argon, as well as characteristic parameters based on the melting point of the molten salt. It is demonstrated that it is possible to correlate the thermal conductivity of monovalent and multivalent molten salts within experimental error using this approach. Furthermore, in salts with a common anion, the single adjustable parameter in the model exhibits regular behavior with the molecular weight of the salt. It is also shown that the thermal conductivity of several molten-salt mixtures can be predicted without any mixture parameters.     

Estimation of differential heat of dilution for aqueous lithium (bromide,iodide, nitrate,chloride) solution and aqueous (lithium,potassium, sodium) nitrate solution used in absorption cooling systems

The differential heat of dilution data are estimated theoretically using Duhring's diagrams for water/LiBr, water/(LiBr + LiI + LiNO₃ + LiCl) with mass compositions in salts of 60.16%, 9.55%, 18.54% and 11.75%, respectively, and water/(LiNO₃ + KNO₃ + NaNO₃) with mass compositions in salts of 53%, 28% and 19%, respectively, as these can be potentially utilized as working fluids in absorption cooling systems. The differential heat of dilution data obtained were correlated with simple polynomial equations for the three working fluids as a function of the solution concentration and temperature. The results showed that the differential heat of dilution of the non-conventional working fluid mixtures is lower than that of water/LiBr at typical operating temperature and concentration of interest in absorption cooling cycles employing these working fluid mixtures. The correlations developed could be useful in predicting the differential heat of dilution value while performing heat and mass transfer analyses of these potential non-conventional working fluid mixtures in absorption cooling systems.     

Surface modification of aluminum alloys in molten salts containing CeCl3

A process for surface modification of A16061-T6 has been carried out in molten salts containing Ce such as a NaCl---SnCl₂---CeCl₃ melt at 200 °C. Samples treated in molten salts for 2 h were subsequently exposed to a NaCl solution for 30 days to evaluate resistance against pitting corrosion. The coating mechanism in molten salts and the pitting corrosion behavior of the coated material have been studied by electrochemical impedance spectroscopy. The results show that this coating technique enhances the pitting corrosion resistance of aluminum alloys in contact with sea water.     

Corrosion Characteristics of Silicon Carbide and Silicon Nitride

The present work is a review of the substantial effort that has been made to measure and understand the effects of corrosion with respect to the properties, performance, and durability of various forms of silicon carbide and silicon nitride. The review encompasses corrosion in diverse environments, usually at temperatures of 1000 °C or higher. The environments include dry and moist oxygen, mixtures of hot gaseous vapors, molten salts, molten metals, and complex environments pertaining to coal ashes and slags.     

聚合物动态成型技术的研究及进展

阐述了聚合物动态成型技术以及在聚合物体系中叠加振动的两类基本方式,即机械振动和超声振动体系,并着重综述了熔融聚物合物在振动作用下的流变行为与挤出特性,以及借助于流变仪,振动机头和塑料电磁动塑化挤出进行的的动态成型技术的研究及进展。     

Preparation and characteristics of Ni-ferrite powders obtained in the presence of fused salts

This paper describes Ni-ferrite formation in the presence of Li₂SO₄-Na₂SO₄ molten salts, and in particular the effects of the raw materials, amount of salts, heating temperature and time on the size and shape of the ferrite powders, as well as on the rate of ferrite formation. The molten salts accelerate ferrite formation and complete ferrite formation is attained at lower temperatures than in solid state reactions. Ferrite powders with two types of shapes are obtained from NiO with different particle sizes and aggregation states; one is similar to the starting Fe₂O₃ particles and the other has an octahedral crystal habit. The difference follows from the different dissolution rates of Fe₂O₃ and NiO. Growing particles in molten salts have a crystal habit, but the most stable particle shape is rounded.     

熔盐法合成大径厚比氧化铝的研究

以硫酸铝为原料,调控pH=10-11制备氢氧化铝溶液为前驱体,硫酸钠和氟化钠作为反应熔盐,MoO3为晶体生长诱导剂,与氢氧化铝前驱体充分混匀后,在1100℃条件下反应4h,水洗脱盐得到直径大约20-35μm、厚度为0.4-0.6μm的大径厚比片状氧化铝。     

Japanese research on thermophysical properties of fluids

Japanese research activities on thermophysical properties of gases and liquids, as well as some historical background, are outlined. The current situation is explained for industrially important substances, such as water and steam, high pressure gases and liquids, refrigerants, molten salts, and other fluids. Related activities are also briefly introduced. Although some of the Japanese studies can be traced back to more than 50 years ago, a systematic effort has been visible only in the last 20 years. However, quite recently, thermophysical properties research has begun to attract attention of more people in science and industry in Japan, probably as the natural sequence to the progress of technology.Presented at the Japan-United States Joint Seminar on Thermophysical Properties, October 24–26, 1983, Tokyo, Japan.     

A long-term ultraviolet aging procedure on foamed WMA mixtures

Long-term thermal and ultraviolet (UV) aging procedures of asphalt mixtures are complicated, but can be simulated in the laboratory. The objective of this study was to investigate the influence of long-term thermal and UV aging on foamed warm-mix asphalt (WMA) mixtures. Rut resistance, indirect tensile strength (ITS), deformation, dissipated elastic energy, and fracture energy were measured for all mixtures. The experimental design included two aggregate sources; three aging states (unaged, thermal and UV aging); one water-bearing WMA additive and water foaming technology; two PG 64-22 binders, and three air void contents (2, 4, and 7 %). A total of 24 mixtures were evaluated and 144 specimens were made and tested in this study. The test results indicated that thermal and UV aging procedures had limited contribution in improving the rut resistance of a mixture as air void content was low. Unaged samples had the highest ITS values amongst three aging states while UV aged samples had the lowest. In addition, UV aged mixtures generally had greater dissipated energy than thermal aged mixtures regardless of foaming technology, aggregate source, and air void. Moreover, the foaming technology might reduce the stored elastic energy of the mixture due to additional water or released water from water-bearing additive. Furthermore, UV aging generally reduces the fracture resistance of an asphalt mixture than standard thermal aging. In addition, when using WMA foaming technology, aggregate source affects the fracture resistance of the asphalt mixture.     

Semi-empirical Density Estimations for Binary,Ternary and Multicomponent Alkali Nitrate–Nitrite Molten Salt Mixtures

For sensible thermal energy storage in Concentrating Solar Power (CSP) plants, a molten salt mixture of 60 wt% sodium nitrate (NaNO₃) and 40 wt% potassium nitrate (KNO₃), known as Solar Salt, is commonly utilized. The paper presents semi-empirical estimation results of the density of Solar Salt and alternative molten salt mixtures with low melting temperatures in a range from 70 °C to 140 °C. These mixtures are Hitec, HitecXL, LiNO₃–KNO₃–NaNO₃ and a multicomponent mixture. The paper shows that density values of mixtures can be closely predicted from single salt densities. The paper examines different estimation rules for mixtures. The quasilinear volumetric additivity rule (QVAR) is known for ternary reciprocal systems. For the first time, the presented work extends the QVAR to multicomponent mixtures. Temperature-dependent densities of selected salt mixtures of the system Ca,Li,K,Na//NO₂,NO₃ were estimated. Estimations are motivated by a fast and reliable method compared to time-consuming and error-prone measurements of several mixtures.     

纳米材料改善硝酸熔盐传蓄热性能的研究进展EI北大核心CSCD

聚光式太阳能热发电是解决能源和环境矛盾的理想途径,传热蓄热技术是光热发电的重要环节,在此需要解决的关键问题是传热蓄热介质。熔盐作为储蓄热介质具有明显优势。国内外运行的光热电站中大多使用二元硝酸熔盐(Solar salt)与三元硝酸熔盐(Hitec),但二者传蓄热性能均欠佳,影响了太阳能的利用效率。纳米材料的独特空间结构,使其具有优异的导热性能、良好的稳定性等,将其作为添加剂引入到硝酸熔盐体系中,有望改善材料的传热蓄热等热物性能,进而提高太阳能光热利用的效率,降低发电成本。本文综述了纳米金属粒子、纳米金属氧化物、纳米碳材料和其他无机纳米材料作为添加剂掺杂到硝酸熔盐体系中的相关研究,论述了改性后熔盐热物性的变化并探讨了作用机理,以期为制备优异热性能的储能熔盐提供参考。未来的研究可重点关注热物性测试、传热机理、构效关系和工业化中试,将具有优异的传蓄热性能的硝酸熔盐应用在太阳能光热发电领域,在清洁能源开发利用方面发挥更重要的作用。     

Measurement of thermophysical properties of molten salts: Mixtures of alkaline carbonate salts

The purpose of this study is to develop measuring methods for the thermal diffusivity, the specific heat capacity, and the density of molten salts, as well as to measure these properties of mixtures of alkaline carbonate salts. The thermal diffusivity is measured by the stepwise heating method. The sample salt is poured into a thin container, and as a result, a three-layered cell is formed. The thermal diffusivity is obtained from the ratio of temperature rises at different times measured at the rear surface of the cell when the front surface is heated by the stepwise energy from an iodine lamp. The specific heat capacity is measured using an adiabatic scanning calorimeter. The density is measured by Archimedes' principle. Thermal conductivity is determined from the above properties. Measured samples are Li₂CO₃-K₂CO₃ (42.7–57.3, 50.0-50.0, and 62.0-38.0 mol%).Invited paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

不同煅烧介质中纳米氧化镁的合成技术研究

以化学沉淀法首先制备了氢氧化镁(Mg(OH)2)纳米材料,并且进一步在LiNO3和NaCl 2种盐介质中分别进行液相和固相辅助煅烧使其转变成纳米氧化镁.研究表明,液相LiNO3熔盐介质比固相NaCl熔盐介质更有利于纳米MgO的生成,并且纳米MgO产率也更高.简要分析了2种熔盐辅助煅烧的不同机理.     

Molten salts for rechargeable batteries

The growing demand of advanced electrochemical energy storage devices for various applications, including portable electronic products, electric vehicles, and large-scale energy storage grids, has triggered extensive research interests and efforts on various rechargeable batteries such as lithium/sodium-ion batteries (LIBs/NIBs), aluminium-ion batteries (AIBs), liquid metal batteries (LMBs), and molten-air batteries (MABs) in the past decades. A key issue to push forward the development of these batteries is the exploration of high-performance electrodes and electrolytes, which calls for efficient and versatile synthetic methods. Molten salts (MSs), liquid-phase ionic compounds or mixtures, provide an effective platform to widen the reaction temperatures and enrich the chemical environments for the synthesis of novel electrode materials and electrolytes. In this review, the general principles of molten salts and recent research progresses on molten salt-based battery materials are surveyed. Molten-salt synthesis of electrode materials, including sintering and electrolysis, are emerging as competitive substitutes for conventional synthesis techniques. These methods have shown their effectiveness and uniqueness in adjusting the crystal structure, morphology, and performance of electrode materials for LIBs/NIBs, as suggested by recent progresses and applications of diverse cathodes (layered oxides, spinel oxides, polyanions, etc.) and anodes (metal oxides, alloys, carbons, etc.). Furthermore, the applications of molten salts as effective electrolytes are demonstrated in representative new-type secondary batteries including AIBs, LMBs and MABs. Finally, the emerging opportunities, challenges, and interesting research trends are envisioned to promote the further development of molten-salt methodology for rechargeable batteries.     

Decomposition of hydroxylamine/water solution with added iron ion

Decomposition hazards of hydroxylamine (HA)/water solution with and without the addition of iron ion were studied in this paper. Tests were conducted to obtain information about decomposition hazards of HA/water solution following the United Nations recommendations on the transport of dangerous goods.When the heat accumulation storage test was conducted using HA50 wt.%/water solution without the addition of iron ion, the self-accelerating decomposition temperature (SADT) was 80 degrees C. Therefore, HA50 wt.%/water solution was not classified with self-reactive substances following the United Nations recommendations on the transport of dangerous goods. Decomposition hazards of HA50 wt.%/water solution with added iron ion were investigated. The concentration of iron ion in sample of HA50 wt.%/water solution without the addition of iron ion was below 1.0 ppm. The range of the concentration of iron ion in sample of HA50 wt.%/water solution with added iron ion was between 1.0 and 5.4 ppm. The thermal stability of HA50 wt.%/water solution decreased by the addition of iron ion in the heat accumulation storage test. HA50 wt.%/water solution with the addition of iron ion was classified with self-reactive substances following the United Nations recommendations on the transport of dangerous goods. The intensity of the thermal decomposition of HA50 wt.%/water solution increased by the addition of iron ion in the Koenen test.     

Formulating a programme of repairs to structural home injury hazards in New Zealand

Home injuries are a substantial health burden worldwide, with the home setting being at least as important as the road for injury. Focusing on common injury hazards presented by the home environment, we sought to examine the justification for significant expenditure on safety-related repairs to the housing stock. Trained inspectors assessed 961 New Zealand houses for injury hazards. Using administrative data from the Accident Compensation Corporation (the national injury insurance agency), 1328 home injuries were identified amongst the 1612 occupants of these houses over the 2006–2009 period. Telephone interviews gathered data on the location and nature of these injuries, and the attitudes of those injured to potential injury hazards in their homes. Commonly occurring injury hazards that could be repaired at modest cost were identified based on their prevalence estimated by the housing inspection, and their location with respect to the areas of the home where the injuries occurred (identified during the telephone interviews). About 38% of the home injuries studied were potentially related to a structural aspect of the home environment. Common safety hazards included the lack of working smoke detectors (65% of the sample), inadequately fenced driveways (55%), hot water temperatures measured at over 60° (49%) and poorly lit access to the house (34%). A protocol for identifying and repairing important common hazards was designed. The actual safety effects of this protocol are in the process of being examined in a randomised controlled trial.