Hu X.,Chongqing University |
Hu X.,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization |
Chen N.,Chongqing University |
Li W.,Chongqing University
Journal of Molecular Modeling | Year: 2016
Safety prediction is crucial to the molecular design or the material design of explosives, and the predictions based on any single factor alone will cause much inaccuracy, leading to a desire for a method on multi-bases. The presented proposes an improved method for fast screening explosive safety by combining a crystal packing factor and a molecular one, that is, steric hindrance against shear slide in crystal and molecular stability, denoted by intermolecular friction symbol (IFS) and bond dissociation energy (BDE) of trigger linkage respectively. Employing this BDE-IFS combined method, we understand the impact sensitivities of 24 existing explosives, and predict those of two energetic-energetic cocrystals of the observed CL-20/BTF and the supposed HMX/TATB. As a result, a better understanding is implemented by the combined method relative to molecular stability alone, verifying its improvement of more accurate predictions and the feasibility of IFS to graphically reflect molecular stacking in crystals. Also, this work verifies that the explosive safety is strongly related with its crystal stacking, which determines steric hindrance and influences shear slide. © 2016, Springer-Verlag Berlin Heidelberg.
Jiang C.,Chongqing University |
Jiang C.,Key Laboratory of Low Grade Energy Utilization Technologies & Systems of the Ministry of Education |
Jiang C.,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization |
Zhang M.,Key Laboratory of Low Grade Energy Utilization Technologies & Systems of the Ministry of Education |
And 4 more authors.
Huagong Xuebao/CIESC Journal | Year: 2014
The solubility of Na2CrO4, NaAlO2 and Na2SiO3 in the multicomponent systems related to the manufacture of chromium compounds by liquid-phase oxidation of chromite was measured by using the equilibrium analysis method at the atmospheric pressure and temperature ranging from 353.15 K to 403.15 K, which include ternary systems NaOH-H2O-Na2CrO4, NaOH-H2O-NaAlO2 and NaOH-Na2SiO3-H2O, quaternary systems NaOH-H2O- Na2CrO4-Na2SiO3, NaOH-H2O-Na2CrO4-NaAlO2 and NaOH-NaAlO2-Na2SiO3-H2O, and quinary systems NaOH-H2O-Na2CrO4-Na2SiO3-NaAlO2. Except the Na2CrO4 solubility in ternary system NaOH-H2O-Na2CrO4, in which NaOH concentration varied from 100 g·L-1 to 800 g·L-1, the NaOH concentration was constant at 500 g·L-1. The experimental data were correlated by the Antonie equation, λ-h equation, and Apelblat equation, demonstrating that the Apelblat equation can well predict the solubility of the systems. The results show that the presence of NaAlO2 and Na2SiO3 decreases Na2CrO4 solubility, while the coexistence of NaAlO2 and Na2SiO3 has less effect than the presence of single NaAlO2 and Na2SiO3. ©All Rights Reserved
Liu Z.,Chongqing University |
Liu Z.,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization |
Zheng X.,Chongqing University |
Zheng X.,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization |
And 6 more authors.
Chemical Engineering and Processing: Process Intensification | Year: 2014
Mixing is crucial in the dispersion of two immiscible fluids. The rational design of an impeller is necessary to form suitable flow conditions and improve fluid mixing efficiency. A double rigid-flexible combination impeller was designed by connecting the upper and lower rigid impeller blades with flexible pieces. Experimental measurements were performed in a laboratory-scale mixer-settler under different impeller types. The largest Lyapunov exponent (LLE) and multi-scale entropy (MSE) were investigated using Matlab. Results showed that the double rigid-flexible combination impeller enhanced liquid-liquid mixing in the mixer-settler through the multiple-body motion behavior triggered by the swings of flexible pieces. At the optimum mixing point of each impeller, the LLEs of the double impeller, double rigid combination impeller, and double rigid-flexible combination impeller were 0.018, 0.055, and 0.057, respectively. At 75. rpm, the MSE of the combination impellers was obviously greater than that of the double impeller, and the rigid-flexible combination impeller had larger MSE than the double rigid combination impeller. The mixing efficiency of the rigid-flexible combination impeller increased with increasing width and quantity of the flexible piece. The quantity of rigid blade slice also influenced the enhancement of mixing ability. The double rigid-flexible combination impeller intensified the chaotic mixing of the two-phase fluid by changing the flow field structure and energy dissipation mode, ultimately achieving an efficient-mixing operation. © 2014 Elsevier B.V.
Shu J.,Chongqing University |
Shu J.,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization |
Liu R.,Chongqing University |
Liu R.,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization |
And 6 more authors.
Environmental Science and Pollution Research | Year: 2015
Electrolytic manganese residue (EMR) is a solid waste found in filters after sulphuric acid leaching of manganese carbonate ore, which mainly contains manganese and ammonia nitrogen and seriously damages the ecological environment. This work demonstrated the use of electrokinetic (EK) remediation to remove ammonia nitrogen and manganese from EMR. The transport behavior of manganese and ammonia nitrogen from EMR during electrokinetics, Mn fractionation before and after EK treatment, the relationship between Mn fractionation and transport behavior, as well as the effects of electrolyte and pretreatment solutions on removal efficiency and energy consumption were investigated. The results indicated that the use of H2SO4 and Na2SO4 as electrolytes and pretreatment of EMR with citric acid and KCl can reduce energy consumption, and the removal efficiencies of manganese and ammonia nitrogen were 27.5 and 94.1 %, respectively. In these systems, electromigration and electroosmosis were the main mechanisms of manganese and ammonia nitrogen transport. Moreover, ammonia nitrogen in EMR reached the regulated level, and the concentration of manganese in EMR could be reduced from 455 to 37 mg/L. In general, the electrokinetic remediation of EMR is a promising technology in the future. © 2015 Springer-Verlag Berlin Heidelberg
Zhang X.-R.,Chongqing University |
Zhang X.-R.,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization |
Liu Z.-H.,Chongqing University |
Liu Z.-H.,Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization |
And 6 more authors.
International Journal of Minerals, Metallurgy and Materials | Year: 2015
In the present study, a response surface methodology was used to optimize the electroleaching of Mn from low-grade pyrolusite. Ferrous sulfate heptahydrate was used in this reaction as a reducing agent in sulfuric acid solutions. The effect of six process variables, including the mass ratio of ferrous sulfate heptahydrate to pyrolusite, mass ratio of sulfuric acid to pyrolusite, liquid-to-solid ratio, current density, leaching temperature, and leaching time, as well as their binary interactions, were modeled. The results revealed that the order of these factors with respect to their effects on the leaching efficiency were mass ratio of ferrous sulfate heptahydrate to pyrolusite > leaching time > mass ratio of sulfuric acid to pyrolusite > liquid-to-solid ratio > leaching temperature > current density. The optimum conditions were as follows: 1.10:1 mass ratio of ferrous sulfate heptahydrate to pyrolusite, 0.9:1 mass ratio of sulfuric acid to pyrolusite, liquid-to-solid ratio of 0.7:1, current density of 947 A/m2, leaching time of 180 min, and leaching temperature of 73°C. Under these conditions, the predicted leaching efficiency for Mn was 94.1%; the obtained experimental result was 95.7%, which confirmed the validity of the model. © 2015, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.