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Jiang Y.,Northeastern University China | Xu Z.,Northeastern University China | Li Y.,Hebei University of Engineering | Li Q.,Yunnan Metallurgical Group Co.
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology) | Year: 2014

Considering that the chemical reaction, solute diffusion and pore structure evolution in porous geological material proceed simultaneously on micro-scale and meso-scale, and has interaction obviously, the three processes in the presence of inert solid and reactive solid coexistence were researched. In addition, considering that there are some one-one correspondences between microscopic reaction-diffusion and macroscopic buoyed weight, the relationship between reaction-diffusion and the buoyed weight was studied. A pellet kinetic model, which takes into consideration the resistances including the interface chemical reaction and the diffusion in boundary layer, was developed and then extended to representative element volume of porous media, solved by volume control method finally. By cases computation, some conclusions are as follows: The chemical reaction, solute diffusion and pore structure evolution in porous geological material are coupled and have interactions; Although the chemical reaction and solute diffusion in porous media take place slowly, the pore structure evolution due to them is obvious and can not be ignored; The change of porosity is more notable for chemical effect than single mechanical behavior; there are some one-one correspondences between microscopic reaction-diffusion and macroscopic buoyed weight. This model can be used to research the reaction-diffusion process in reactive porous media and has some reference value for further study in physicochemical hydrodynamics in porous media. ©, 2014, Central South University of Technology. All right reserved.

Xu F.-S.,Yunnan Metallurgical Group Co. | Xu F.-S.,Central South University | Zhang J.,Central South University | Deng Y.-L.,Central South University | Zhang X.-M.,Central South University
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2014

The precipitation behaviors of 2124 aluminum alloy under the conditions of artificial aging (AA), creep aging (CA) and creep aging with pre-deformation (PCA) were investigated by means of mechanical property and microstructure. The results show that the mechanical properties of CA treated sample decrease significantly compared with AA treated sample. The yield strength of the CA treated sample falls by 14%, the tensile strength falls by 6.2%, and the elongation falls by 21%. Nevertheless, the mechanical properties of PCA sample are improved obviously, close to the AA treated sample. Moreover, the generation and control mechanisms of the precipitation orientation effect in 2124 aluminum alloy were studied. It is deduced that the key mechanism lies in the effect of dislocation. © 2014 The Nonferrous Metals Society of China.

Tao J.,Wuhan Iron And Steel Company | Chen J.-X.,Yunnan Metallurgical Group Co.
Yejin Fenxi/Metallurgical Analysis | Year: 2014

A simple method was proposed for the determination of free calcium oxide(f-CaO) in steel slag. At room temperature, the sample was leached in 200 g/L sucrose solution for 30 min to liberate f-CaO from the sample and separate it from other elements and other forms of calcium. The solution then was filtered. The spectrum line with the wavelength of 393.366 nm was selected as the analytical line. Calcium amount in the filtrate was determined by inductively coupled plasma atomic emission spectrometry under proper working conditions, and thus the f-CaO content in the sample was obtained. The matrix had little interference in the determination of f-CaO and the coexisting elements had almost no interference. The method was applied to the determination of the f-CaO content in steel slag samples, the measured values were consistent with those obtained by the titrimetric method, with the relative standard deviation in the range of 0.78%-1.1%.

Tian L.,Kunming University of Science and Technology | Tian L.,Yunnan Metallurgical Group Co. | Zhou Y.M.,Kunming University of Science and Technology | Xie G.,Kunming University of Science and Technology | And 2 more authors.
Industrial and Engineering Chemistry Research | Year: 2012

Cold ramming paste was synthesized with electro-calcined anthracite (ECA) and artificial graphite as an aggregate and furan resin as a binder. Properties of synthesized paste were investigated by Universal Testing Machine, thermogravimetry (TG) and gas chromatography (GC) mass spectrometry (MS). The results show that the synthesized paste is an ecofriendly material and that it has some superior physical properties such as low electrical resistivity, high compressive strength, appropriate sodium penetration, and thermal expansion, all of which can meet industry requirements. The TG curve of the paste can be divided into three stages and the lower heating rate should be used in the second stage. Moreover, the resin functional groups disappear more completely at higher carbonized temperature based on infrared (IR) spectrum analysis. © 2012 American Chemical Society.

Jia F.,Kunming University of Science and Technology | Yan Y.,Kunming University of Science and Technology | Wu W.,Yunnan Metallurgical Group Co. | Liu X.,Yunnan Land Resources Planning and Design Institute
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2016

Laojunshan tin poly-metallic metallogenic region is an important resource base of tin, tungsten and other metals in the Southwest of China. S, Pb, H, and O isotopes of the typical deposits are tested, and geological interpretation is discussed. The results show that the sulfur isotope δ34S ranges from -1.50‰ to 8. 61‰, with an average 2.06‰, a mantle-crustal mixed source. The early crystallized minerals are characterized by mantle-source sulfur; while the late crystallized ones are tend to be with crustal source sulfur. The sulfur in stratiform skarn related ores is mantle source; while in granite and porphyry related ores the sulfur is crustal source. Quartz vein type ores could be divided into two kinds according to the sulfur source of mantle or crust. Pb isotopic characteristics indicate a mixed source of mantle and crust with the major from the crust. The oxygen and hydrogen isotopic compositions indicate that the ore forming fluids were composed of magmatic fluids in the early stage and of meteoric water in the late stage. The formation of Laojunshan tin poly-metallic metallogenic region might have been resulted from the combination of the volcanic exhalation sedimentary of Early Caledonian, the regional metamorphism of Indo-chinese, and the granitic superimposition of Late Yanshanian. © 2016, Jilin University Press. All right reserved.

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