Effect of refractory agent on ash fusibility temperatures of briquettet

To solve the problem of the low ash fusion point of briquette, this paper reported that the ash fusibility temperatures can be elevated by changing ash ingredients through blending refractory agents in briquette ash, which will create favorable conditions for moving bed continuous gasification of briquette with oxygen-rich air. The effects of A1203, SiO2, kaolin, dry powder and bentonite on ash fusibility temperatures were studied, based upon the relationship between briquette ash components and ash fusibility. The results show that the increasing of ash fusibility temperatures by adding the same amount （11%, w） of refractory agents follows the sequence of SiO2, bentonite, dry powder, kaolin, A1203, with the softening temperatures being elevated by 37.2, 57.6, 60.4, 82.6 and 104.4℃. With the same ratio of SIO2/A1203 in briquette, adding the A1203 component is more effective than SiO2 for raising ash fusibility temperatures. In this paper, inexpensive kaolin and bentonite rich in A1203 are found to be better refractory agents, and the suitable adding quantities are 9% and 11%, respectively.

Potential of Some Granites from Foumban (West Region of Cameroon) as Fluxing Materials for Ceramics

This study focuses on the mineralogical, geochemical and petrographic characterization of three granite rock samples (LTP, LTS and LTMB) from Foumban, West Region of Cameroon. Fusibility tests were carried out on the samples containing the highest amount of alkali to assess the potential of these materials as fluxing admixture for ceramics. The results show that the granite consists of alkaline feldspars, notably orthoclase and microcline of perthitic micro-texture, plagioclases (in particular albite) and also mafic minerals such as amphibole and pyroxene. The quantity of alkali in the samples is quite high (16.83% for LTS, 17.08% for LTMB and 18.87% for LTP) compared to standard data. Fusibility tests carried out on the samples having the highest alkali content (LTMB and LTP) showed that the vitreous phase appears between 1050°C and 1100°C in these samples when they were heated. The Fe2O3 and TiO2 content of LTMB (3.01% and 1.49% respectively) led to a brown colour of its fired product. Therefore, based on their composition, these materials can be used as feldspathic fluxes for the formulation of ceramic products.

The application of molecular simulation in ash chemistry of coal

One of the crucial issues in modern ash chemistry is the realization of efficient and clean coal conversion.Industrially,large-scale coal gasification technology is well known as the foundation to improve the atom economy.In practice,the coal ash fusibility is a critical factor to determine steady operation standards of the gasifier,which is also the significant criterion to coal species selection for gasification.Since coal behaviors are resultant from various evolutions in different scales,the multi-scale understanding of the ash chemistry is of significance to guide the fusibility adjustment for coal gasification.Considering important roles of molecular simulation in exploring ash chemistry,this paper reviews the recent studies and developments on modeling of molecular systems for fusibility related ash chemistry for the first time.The discussions are emphasized on those performed by quantum mechanics and molecular mechanics,the two major simulation methods for microscopic systems,which may provide various insights into fusibility mechanism.This review article is expected to present comprehensive information for recent molecular simulations of coal chemistry so that new clues to find strategies controlling the ash fusion behavior can be obtained.

Simulation of aerothermodynamics model on ballistic safety of fusible alloy fuze

In order to ensure the ballistic safety of fusible alloy fuze at reliable delay arming, melting point of fusible alloy needs to be calculated based on projectile velocity at safe time and distance. Taking shrapnel KZVD fuze of Switzerland oerlikon 2ZLa/353 35 mm double barrel self-propelled antiaircraft artillery as an example, based on the aerodynamics heating theory, the calculation of theory model and simulation of projectile head stagnation point temperature were done in initial stage of sim-plified exterior ballistic from engineering viewpoint when the initial projectile velocity was 1 175 m/s and the error was ±15 m/s. The melting point of fusible alloy in the safe distance was obtained by analyzing the temperature of projectile head stagnation point at corresponding projectile velocity. The simulated results indicate that the melting point of fusible alloy de-rived by theoretical calculation is identical with the result of simulation at the velocity range of 1 160 to 1 190 m/s. So the aero- thermodynamics model can be applied to design the fusible alloy fuze of corresponding melting point based on the requirement of safe distance. This method can be taken as the reference in studying the thermodynamic question of projectile flying at high speed.

Production of Integrated Automotive Part in High Pressure Diecasting Process Using Salt Core

A new concept of salt core, a melting temperature of which is lower than the solidus temperature of cast alloy,was introduced to produce an integrated casting part having a complicated inner shape or requiring under-cut in high pressure die casting or squeeze casting process. A salt core, named a fusible core in this paper because the salt core can be easily extracted just as holding at a temperature under a solidus temperature of a casting alloy, was developed and applied to produce a fuel control part for automotive GDI engine in high pressure diecasting machine. A different salt material of a lower melting temperature than that of A1 alloy was mixed with a different ceramic particulate to improve a thermo-physical property of fusible core. The thermo-physical property of the fusible core was measured and a weight faction of the ceramic particulate was optimized. The selected core materials were poured in metallic mold by gravity to produce a fusible core for a fuel control part for automotive GDI engine. The fuel control part, which the fusible core was included inside, was successful to fabricate in a conventional diecasting machine with no melting of fusible core during casting.

Characteristics Study on Bi-Pb Based Alloys Quenched from Melt

Three different bismuth-lead systems namely, Wood＇s alloy （Bi50Pb25Sn12.5Cd12.5）, Newton＇s alloy （Bi50Pb31.2Sn18.8） and Rose＇s alloy （B50Pb28Sn22）, with one used as fusible alloys were quenched from melt by melt spinning technique. Thermal analysis, structure and mechanical properties of all alloys have been studied and analyzed. From X-ray diffraction analysis, an intermetallic compound phase, designated Pb7Bi3 is detected. The formation of an intermetallic compound phase causes a pronounced increase in the electrical resistivity. The Wood＇s alloy containing-cadmium exhibits mechanical properties superior to both the Newton＇s and Rose＇s alloys. The presence of cadmium in Wood＇s alloy decreases its melting point. Wood＇s alloy has better properties, which make it useful in various applications such as in protection shields for radiotherapy, locking of mechanical devices and welding at low temperature.

Seam Damage Control and Image Analysis for Cuprammonium Fabrics

Cuprammonium fabrics are susceptible to punctuation of the sewing needle during the manufacturing processes of a garment.This type of punctuation splits the yarns in the fabrics,creates ladder-like sewing defects,and seriously affects the aesthetics of the finished garment.To minimize this seam damage,a sandwiched structure of cuprammonium fabrics with a fusible interlining was proposed to enhance the friction between the yarns in the fabrics.A measurement system was set up to evaluate the seam damage,and the effects of stitch length and seam width on the seam damage were studied.The seam damage tended to become less severe as the stitch length increased.The addition of the fusible interlining between two pieces of the fabrics could effectively suppress the seam damage.The seam margin should be below or equal to 5 mm for the stitch length of 2.0 mm.An excessive seam margin might lead to a distorted seam.

新型发热材料在医疗辅助用品上的应用 安全型电热毯与电热敷

本文应用最新超安全型发热材料(电热PTC,NTC性能的多层加热线)于医疗辅助用品电热毯,电热敷,进一步提升了这一传统产品的安全系数和产品性能,并以此为基础跨入了超安全型电热毯,电热敷这一行业发展的方向性领域。

Experiments on the effect of the pressure on the mineral transformation of coal ash under the different reaction atmosphere

This paper investigated the effect of the pressures,reaction atmospheres and coal ash species on the ash fusibility with high-pressure thermogravimetric analysis(PTGA)apparatus and X-ray diffraction(XRD)analysis.Each specimen analyzed by XRD was observed for the mineral conversion and formation of new minerals with the pressures under different atmospheres.These results indicate that the pressure restrains the transformation and decomposition of minerals.Many low-temperature minerals are still present under the elevated pressure.The different reaction atmospheres have different effects on the formation of coal ash minerals.Under the N_(2)atmosphere,the present microcline may decrease the melting temperature of coal ash.And later,it transforms into sanidine at high pressure;thus,the melting temperature of coal ash may increase.Under the CO_(2)atmosphere,the minerals such as microcline,lomonitite,geothite and illite are still present with the increase in pressure;this may reduce the melting temperature.While under the H_(2)O atmosphere,there are magnetite and anorthoclase,which may produce the low-temperature eutectics decreasing the melting temperature.The coal ash abundance in basic oxides or higher SiO_(2),Fe_(2)O_(3),K_(2)O and Na_(2)O has lower melting temperature.While the ash sample with more SiO_(2)and Al_(2)O_(3)and less Fe_(2)O_(3)and basic oxides may lead to higher melting temperature.