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71.
72.
XIAO Yongli LIU Yin LI Yongqian Ironmaking Resources & Environment Division Research Institute Baosteel Iron & Steel Co. Ltd. Shanghai China 《Baosteel Technical Research》2011,5(2):3-8
This study describes the characteristics of mineral wool and its applications,and also introduces the traditional process of mineral wool made from molten blast furnace(BF) slag.Compared with high energy consumption of the traditional process,the production of mineral wool by using molten BF slag will be able to take full advantage of the sensible heat of molten slag,and also reduce production costs.However,there are also further issues to resolve such as how to obtain the required amount of molten BF slag and how to make it homogeneous.Based on the physical and chemical properties of the molten BF slag,the investigation into the relationship between temperature and viscosity under different acidity coefficients of the slag and silicon mixture was conducted.Combined with the crystallization and phase diagram of slag wool,its heat resistance,water resistance,durability and corrosion resistance were analyzed.Finally,trends of the technology development are proposed. 相似文献
73.
熔盐电解法制备高钛铁合金 总被引:6,自引:0,他引:6
采用电化学还原法,温度为900℃,在CaCl2熔盐中以烧结的TiO2与钛铁矿混合物(Ti:Fe=1:1原子比)为阴极,石墨棒为阳极,制备出了高钛铁合金.探讨了混合物烧结后的相组成变化及高钛铁合金的合金化历程.实验结果表明,混合物烧结后,TiO2由锐钛矿结构转变为金红石结构,钛铁矿转化为热力学稳定的Fe2TiO5.钛铁矿的晶体结构由烧结前的三方晶系经950℃以上烧结后,转变为斜方晶系的Fe2TiO5.制备出的高钛铁中铁钛含量分别为:77.19%和9.68%(质量分数).其合金化历程为:TiO2先生成CaTiO3,然后继续脱氧还原为金属钛;钛铁矿优先还原出金属铁,然后与生成的金属钛发生合金化反应生成钛铁合金.表明熔盐电解nO2与钛铁矿的混合物是一条制备高钛铁合金的新途径.优化电解条件提高电流效率可进一步提高电解速度,得到质量更高的高钛铁合金. 相似文献
74.
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76.
发动机气门积碳的熔盐清洗工艺 总被引:3,自引:0,他引:3
为了研究再制造过程中发动机气门积碳的熔盐清洗工艺,采用MiniLab软件进行方案设计,建立了回归方程和响应面模型,研究了配方和温度对熔盐清洗能力的影响,使用清洁度检验设备检验了熔盐清洗积碳效果。结果表明,配方中NaNO2质量分数增加,NO-2可以同时与多种有机物发生反应,相对于NO-3离子与C反应,OH-、NO-2与有机物的反应效率要高得多。而温度不仅影响热冲击、润湿等作用,还会影响化学反应的速率。因此随着清洗温度和NaNO2质量分数的升高,清洗积碳的能力增强。熔盐清洗积碳的最佳工艺参数为:温度在330~360℃,NaOH质量分数控制在30%,NaNO2质量分数在40%以上。熔盐清洗技术可以作为一种高效、洁净的清洗方法在再制造生产中广泛使用。 相似文献
77.
This study aims to determine the principal electrochemical characteristics of the electrodeposition of cerium metal from molten fluoride systems.The cathodic process of Ce3+ ions in LiF-NaF and LiF-NaF-CaF2 molten salts was studied using electrochemical techniques as steady state and cyclic voltammetry methods.The decomposition potential(Ed) and the overvoltage(η) were determined for NaCeF4 using current-potential curves under galvanostatic conditions.The Ed was found to be 2.025 V in LiF-NaF and 2.045 V in... 相似文献
78.
79.
L Karlsson 《Welding International》2013,27(1):5-11
In the pulsed MAG welding with highly precise periodic drop transfer, welding current was analysed by fast Fourier transform (FFT). By this analysis, peculiar frequency of the molten pool was detected by resonance phenomena with the base plate vibration and it was confirmed that peculiar frequency falls according to growth of the molten pool. Furthermore, natural frequency was detected at the natural welding state that is without vibration of the base plate and confirmed by the resonance method with the base plate vibration. To amplify natural vibration of the molten pool, drop transfer pulse was modulated consisting of regular pulse peak current and higher pulse peak current. The higher pulse peak current makes a change in the arc pressure and the molten pool is pushed down in the period of higher pulse. Because short circuit is apt to occur at the time that the molten pool is at the top of the front side, so it is effective for amplifying the molten pool oscillation that higher pulse phase begins at this time instantaneously or somewhat later. According to this, higher peak was gained at peculiar frequency by FFT analysis. It means that amplifying of the molten pool oscillation was successful. Appropriate period of higher pulse for maintaining stable oscillation is from about 1/4 to 1/2 of the oscillation cycle. 相似文献
80.
Tcherkasskaya Olga; Ptitsyn Oleg B. 《Protein engineering, design & selection : PEDS》1999,12(6):485-490
The direct energy transfer technique was modified and appliedto probe the relative localization of apomyoglobin A-, G- andH-helixes, which are partly protected from deuterium exchangein the equilibrium molten globule state and in the molten globule-likekinetic intermediate. The non-radiative transfer of tryptophanelectronic energy to 3-nitrotyrosine was studied in differentconformational states of apomyoglobin (native, molten globule,unfolded) and interpreted in terms of average distances betweengroups of the protein chain. The experimental data show thatthe distance between the middle of A-helix and the N-terminusof G-helix as well as the distance between the middle of theA-helix and the C-terminus of the H-helix in the molten globulestate are close to those in the native state. This is a strongargument in favor of similarity of the overall architectureof the molten globule and native states. 相似文献