Thermodynamic Modeling of the Solid State Carbothermic Reduction of Chromite Ore

2018 ◽  
pp. 921-938
Author(s):  
Omid Marzoughi ◽  
Christopher A. Pickles
Keyword(s):  
Solid State ◽  
Thermodynamic Modeling ◽  
Carbothermic Reduction ◽  
Chromite Ore

Removal of anionic azo dye from water with activated graphene oxide: kinetic, equilibrium and thermodynamic modeling

RSC Advances ◽  
2016 ◽  
Vol 6 (46) ◽  
pp. 39762-39773 ◽  
Author(s):  
Yongfu Guo ◽  
Juan Deng ◽  
Junyan Zhu ◽  
Chao Zhou ◽  
Caiyun Zhou ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
High Temperature ◽  
Solid State ◽  
Adsorption Capacity ◽  
Thermodynamic Modeling ◽  
Azo Dye ◽  
Anionic Dye ◽  
Kinetic Equilibrium

In order to improve the BET value and adsorption capacity of graphene oxide (GO), activated GO (GOKOH) was successfully prepared by high temperature solid state activation with KOH, and was used to remove the anionic dye orange IV from water.

scholarly journals Kinetics of the Volume Shrinkage of a Magnetite/Carbon Composite Pellet during Solid-State Carbothermic Reduction

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1050 ◽  
Author(s):  
Guang Wang ◽  
Jingsong Wang ◽  
Qingguo Xue
Keyword(s):  
Activation Energy ◽  
Solid State ◽  
Apparent Activation Energy ◽  
Carbothermic Reduction ◽  
Iron Ore ◽  
Carbon Composite ◽  
Volume Shrinkage ◽  
Reduction Temperature ◽  
Iron Particles ◽  
Composite Pellet

The volume shrinkage evolution of a magnetite iron ore/carbon composite pellet during solid-state isothermal reduction was investigated. For the shrinkage, the apparent activation energy and mechanism were obtained based on the experimental results. It was found that the volume shrinkage highly depended on the reduction temperature and on dwell time. The volume shrinkage of the pellet increased with the increasing reduction temperature, and the rate of increment was fast during the first 20 min of reduction. The shrinkage of the composite pellet was mainly due to the weight loss of carbon and oxygen, the sintering growth of gangue oxides and metallic iron particles, and the partial melting of the gangue phase at high temperature. The shrinkage apparent activation energy was different depending on the time range. During the first 20 min, the shrinkage apparent activation energy was 51,313 J/mol. After the first 20 min, the apparent activation energy for the volume shrinkage was only 19,697 J/mol. The change of the reduction rate-controlling step and the automatic sintering and reconstruction of the metallic iron particles and gangue oxides in the later reduction stage were the main reasons for the aforementioned time-dependent phenomena. The present work could provide a unique scientific index for the illustration of iron ore/carbon composite pellet behavior during solid-state carbothermic reduction.

Thermogravimetric study on carbothermic reduction of chromite ore under non-isothermal conditions

2014 ◽  
Vol 42 (6) ◽  
pp. 409-416 ◽  
Author(s):  
X. Hu ◽  
L. Sundqvist. Ökvist ◽  
Q. Yang ◽  
B. Björkman
Keyword(s):  
Carbothermic Reduction ◽  
Chromite Ore ◽  
Isothermal Conditions ◽  
Thermogravimetric Study

Carbon in Solidphase Reduction of Oxides

2016 ◽  
Vol 870 ◽  
pp. 578-583
Author(s):  
A.V. Senin
Keyword(s):  
Active Carbon ◽  
Carbothermic Reduction ◽  
Reducing Agent ◽  
Experimental Results ◽  
Surface Porosity ◽  
Reduction Model ◽  
Chromite Ore ◽  
Reducing Conditions ◽  
Grain Surface ◽  
Reduction Of Oxides

The gasphase-solidphase model is used to explain the results of solid chromite ore carbothermic reduction. The reducing agent is carbon atoms. Carbon is brought to the surface of chromite grains by gaseous carbon-containing molecules and radicals, such as C3O2, CH4, CH3, CH2, CH, C2H2 and other carbon containing particles. Gas particles penetrate a piece of ore through the pores and cracks. Active carbon atoms C are formed by the dissociation of gaseous particles. Reduction by carbon is carried out on the chromite grain surface due to the cations and anions diffusion in the oxide lattice towards the grain surface. Porosity of chromite ores is experimentally defined under reducing conditions; it is estimated at up to 20 – 25 vol.%. Up to 1/4 of porosity is accounted for macropores and macrocracks that have the radius of over 50 microns, the remaining porosity share is accounted for the pore dimensions that are estimated at 0.5 – 50 microns in radius. The carbon presence in the pores of partially reduced ores is deduced based on experiment. There is also carbon in the reduced metal that is situated deep in the lump ore. The experimental results agree with the gasphase-solidphase reduction model.

Thermal Analysis Study on the Carbothermic Reduction of Chromite Ore with the Addition of Mill Scale

2015 ◽  
Vol 87 (5) ◽  
pp. 562-570 ◽  
Author(s):  
Xianfeng Hu ◽  
Qixing Yang ◽  
Lena Sundqvist Ökvist ◽  
Bo Björkman
Keyword(s):  
Thermal Analysis ◽  
Carbothermic Reduction ◽  
Analysis Study ◽  
Mill Scale ◽  
Chromite Ore ◽  
Thermal Analysis Study

Carbothermic Reduction of Chromite Ore Under Different Flow Rates of Inert Gas

2009 ◽  
Vol 41 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Dolly Chakraborty ◽  
S. Ranganathan ◽  
S.N. Sinha
Keyword(s):  
Carbothermic Reduction ◽  
Inert Gas ◽  
Flow Rates ◽  
Chromite Ore
Sign in / Sign up

Export Citation Format

Share Document