The Study on the Structure of Pure Iron Under A High Pressure of 100GPa
Lei Feng,
Fei Wang,
Wufeng Jiang,
Chen Chen,
Yuzhu Zhang,
Jingbo Ren,
Zhenguo Wang
Issue:
Volume 6, Issue 2, April 2017
Pages:
7-10
Received:
8 March 2017
Accepted:
16 March 2017
Published:
2 April 2017
Abstract: Using a new crystal structure prediction software CALYPSO (Crystal Structure Analysis by Particle Swarm Optimization), a new phase F222 of pure iron was obtained in a high pressure of 100GPa, which is different to δ-Fe, γ-Fe, α-Fe, the structure is a orthogonal structure, with this structure, the element Fe has the lattice parameters a=1.8459, b=10.6604, c=3.7637, α=β=γ=90°. The electric structures of the element Fe with F222 structure have also been studied, and the results of density of states revealed that the element Fe is a non-magnet.
Abstract: Using a new crystal structure prediction software CALYPSO (Crystal Structure Analysis by Particle Swarm Optimization), a new phase F222 of pure iron was obtained in a high pressure of 100GPa, which is different to δ-Fe, γ-Fe, α-Fe, the structure is a orthogonal structure, with this structure, the element Fe has the lattice parameters a=1.8459, b=10...
Show More
Variation of Physico-Chemical and Textural Properties of Laboratory Prepared Red Mud Through Acid and Thermal Activations
Tsamo Cornelius,
Richard Kamga
Issue:
Volume 6, Issue 2, April 2017
Pages:
11-19
Received:
28 March 2017
Accepted:
18 April 2017
Published:
1 June 2017
Abstract: Red mud prepared in the laboratory was activated using hydrochloric acid with concentrations from 2-4 mol/L, heat at 900°C and combined acid and heat at 900°C, and the respective yields evaluated. The physico-chemical properties of these samples were determined using pH, EC, XRF, XRD, SEM, TGA-DTA analyses and textural properties (isotherm type, BET surface area, pore size distribution, total pore volume, average pore size, external surface area, micropore volume, micropore area) determined by nitrogen gas adsorption-desorption. Acid activation reduces red mud quantity than by thermal means. Raw red mud showed a pH of 11.0, EC of 2.50 x 109 μS/cm, BET surface area of 13 m2/g, total pore volume of 0.063 cm3/g with the major oxides being Fe2O3, Al2O3, TiO2 and SiO2. It contain mesopores > macropores > micropores. All these properties are improved variably by acid and thermal activation. Acid modification increase alumina content but decreases that of iron. Conversely, heat treatment increase iron content but reduces alumina content. Combined acid and heat treated red mud shows high thermal stability than untreated and acid treated red muds. These results show that possible different applications of red mud can be achieved depending on modification conditions.
Abstract: Red mud prepared in the laboratory was activated using hydrochloric acid with concentrations from 2-4 mol/L, heat at 900°C and combined acid and heat at 900°C, and the respective yields evaluated. The physico-chemical properties of these samples were determined using pH, EC, XRF, XRD, SEM, TGA-DTA analyses and textural properties (isotherm type, BE...
Show More
