scholarly journals Studying the pelletization of rosseta ilmenite concentrate with coke breeze using molasses and reduction kinetics of produced pellets at 800-1150ºC

2012 ◽  
Vol 44 (1) ◽  
pp. 113-126 ◽  
Author(s):  
N.A. El-Hussiny ◽  
M.E.H. Shalabi
Keyword(s):  
Optimum Condition ◽  
Reaction Rate ◽  
Nitrogen Atmosphere ◽  
Coke Breeze ◽  
Reduction Kinetics ◽  
Solid Reaction ◽  
Ilmenite Concentrate ◽  
Controlling Mechanism ◽  
Mechanism Of Reaction ◽  
Kinetics Of

Ilmenite ore fine and coke breeze as reduced material which were pelletized with different amounts of molasses were studied in this investigation. The produced pellets at optimum condition were reduced in nitrogen atmosphere at temperature range 800-1150?C to determine the controlling mechanism. The reduction indicated that the reduction rates increased as the temperature increased and the controlling mechanism of reaction rate is solid-solid reaction.

scholarly journals Mechanism of reaction of silica and carbon for producing silicon carbide

2019 ◽  
Vol 45 ◽  
pp. 146867831989141
Author(s):  
Bahador Abolpour ◽  
Rahim Shamsoddini
Keyword(s):  
Experimental Data ◽  
Silicon Carbide ◽  
Reaction Kinetics ◽  
Direct Effect ◽  
Solid Reaction ◽  
Carbon Reduction ◽  
Temperature Range ◽  
Carbon Particles ◽  
Mechanism Of Reaction ◽  
Kinetics Of

The reaction kinetics of carbon reduction of silica were investigated using thermodynamic concepts and by fitting to relevant models the experimental data obtained for this reduction using a thermogravimetric unit in the temperature range of 1566 to 1933 K. The results show that the only way to produce SiC in this reduction is the reaction of Si, SiO, or SiO2 at the surface or by diffusion of SiO inside the carbon particles while CO and CO2 have no direct effect on the process. The controlling step of this reduction at temperatures lower than 1750 K is the chemical gas–solid or solid–solid reaction at the surface of the carbon particles, while at higher temperatures, the rate of SiO diffusing inside the carbon particles controls the rate of this reduction.

Experimental Investigation on Reduction Kinetics of Stainless Steel-Making Slag in Iron Bath Smelting Reduction

2013 ◽  
Vol 721 ◽  
pp. 164-168
Author(s):  
Bo Zhang ◽  
Shuai Niu ◽  
Wen Bin Chen ◽  
Wen Cai Li ◽  
Fa Tao Chen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Reaction Rate ◽  
Steel Slag ◽  
Interface Reaction ◽  
Reduction Kinetics ◽  
Smelting Reduction ◽  
Stainless Steel Slag ◽  
Bath Smelting ◽  
Iron Bath ◽  
Kinetics Of

Reduction kinetics of stainless steel slag in iron bath smelting reduction was studied at the temperature of 1500°C ~ 1650°C. It was concluded that the reduction process consisted of two parts. That is to say smelting reduction was controlled by stainless steel slag melting initially and by interface reaction later. In order to increase smelting reaction rate, the melting point of slag should be decreased at the first stage and adjust the liquidity of slag at later stage. Smelting reaction rate will be accelerated by means of optimize the slag content. The optimal reduction result that all most all of the chromium in slag been recovered was obtained in temperature was 1500°C, basicity of slag was 1.0~1.2, the value of Al2O3+MgO was 25%.

Reduction Kinetics of Chromite Pellets

2013 ◽  
Vol 760 ◽  
pp. 85-94
Author(s):  
D.M.A. Khan
Keyword(s):  
Chemical Reaction ◽  
Rate Control ◽  
Reaction Rate ◽  
Forward Direction ◽  
Reduction Kinetics ◽  
Muffle Furnace ◽  
First Order ◽  
Composite Pellets ◽  
Chemical Reaction Rate ◽  
Kinetics Of

Plain Chromite and Ore- Coal/charcoal Compositepellets were Reduced in the CO Atmosphere between 1350°C and 1600°C in a Superkenthal Muffle Furnace. the Reaction Followed the Path of First Order Reductionkinetics and the Reduction was under Chemical Reaction Rate Control. Theactivation Energy was Calculated in the Range from 225KJ/mole to 342KJ/mole.The Insitu Carbon Present in the Composite Pellets Motivated the Gasificationreaction of Carbon and the Reduced Fe and Cr Act as the Catalysts to Propagatethe Reduction in the Forward Direction.

scholarly journals Reducibility study of Rossetta ilmenite ore briquettes and powder with coke breeze at 800-1100°C

2013 ◽  
Vol 45 (1) ◽  
pp. 79-88 ◽  
Author(s):  
el Abd ◽  
N.A. El-Hussiny ◽  
Marguerite Wassef ◽  
M.G. Khalifa ◽  
Aly Soliman ◽  
...  
Keyword(s):  
Organic Materials ◽  
Nitrogen Atmosphere ◽  
Coke Breeze ◽  
Reasonable Condition ◽  
Temperature Range ◽  
Controlling Mechanism

Ilmenite ore fine and coke breeze as reduced material were briquetted with different amounts of organic materials such as molasses or pitch were studied in this investigation. The produced briquettes at reasonable condition were reduced in nitrogen atmosphere at temperature range 800 - 1100oC to determine the factors controlling the reduction and to determine the controlling mechanism. Also ilmenite ore fine with coke breeze were reduced at the same temperature range in nitrogen atmosphere without briquetting process, for the sake of comparison.

Isothermal reduction kinetics of Panzhihua ilmenite concentrate under 30vol% CO–70vol% N2 atmosphere

2017 ◽  
Vol 24 (3) ◽  
pp. 240-248 ◽  
Author(s):  
Ying-yi Zhang ◽  
Wei Lü ◽  
Xue-wei Lü ◽  
Sheng-ping Li ◽  
Chen-guang Bai ◽  
...  
Keyword(s):  
Reduction Kinetics ◽  
Ilmenite Concentrate ◽  
Isothermal Reduction ◽  
N2 Atmosphere ◽  
Kinetics Of

scholarly journals The photosensitised decomposition of nitrogen trichloride. Part II.— The effects of surface and inert gases, and the mechanism of reaction

1932 ◽  
Vol 135 (826) ◽  
pp. 69-83 ◽  
Keyword(s):  
Gas Phase ◽  
Reaction Rate ◽  
Zero Order ◽  
Inert Gases ◽  
Chain Mechanism ◽  
Chain Reactions ◽  
Nitrogen Trichloride ◽  
Mechanism Of Reaction ◽  
A Chain ◽  
Kinetics Of

In Part I it has been established that nitrogen trichloride vapour is decomposed by the photosensitive action of chlorine.The reaction is strictly of zero order, and the high values to which the quantum efficiency rises at low total pressures indicate the existence of a chain mechanism. Further evidence is now presented which locates the decomposition in the homogeneous gas phase, and rules out the possibility of accounting for the zero order on the basis of a surface reaction. The kinetics of all chain reactions so far studied are in accord with the view that they are propagated in a homogeneous phase; this does not preclude a reaction involving a chain mechanism from occurring exclusively on a surface, but such a possibility is susceptible of a simple test by a variation of the total available surface. This criterion has been applied in the present instance, and neither alteration of the total illuminated surface nor of the total available surface has any other than a secondary effect upon the reaction rate. It is therefore concluded that the chain mechanism in the photosensitised decomposition of nitrogen trichloride is primarily confined to the gas phase, and other evidence will be referred to later which supports this conclusion.

scholarly journals Reduction Kinetics of Fine Hematite Ore Particles in Suspension

2021 ◽  
Author(s):  
Zhiyuan Chen ◽  
Christiaan Zeilstra ◽  
Jan van der Stel ◽  
Jilt Sietsma ◽  
Yongxiang Yang
Keyword(s):  
Particle Size ◽  
Rate Constant ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Reduction Kinetics ◽  
Rate Determining Step ◽  
Peak Function ◽  
Hematite Ore ◽  
Heating Up ◽  
Kinetics Of

AbstractSuspension reduction kinetics of hematite ore particles at 1710 K to 1785 K was described by the Johnson-Mehl-Avrami-Kolmogorov model with Avrami exponent of 1.405. The apparent activation energy is 105.5 kJ mol−1 with the rate determining step of nucleation and growth. The reduction degree of the hematite at the endpoint is a linear function of temperature and the logarithmic oxygen potential of the reacting gas. A peak function of reaction rate constant with particle size has been verified in this work, and the maximum value of the reaction rate is located at around 85 µm particle size. The influence of heat transfer on the reaction process has been evaluated. The results suggest that the heating-up process for large particles, 244 µm particles, for instance, cannot be ignored. It can retard the reaction rate compared to small particles. Normally, the reaction rate constant decreases linearly with the increase of ln[p(O2)] of the reacting gas mixture. However, 95 vol pct CO2 in the reacting gas can accelerate the reaction rate of thermal decomposition of hematite due to the emissivity of CO2 gas. It results in a higher reaction rate of 110 µm particles in 95 vol pct CO2-containing gas than that in other less CO2-containing gases.

STUDYING THE KINETIC CHARACTERISTICS OF THE EXTRACTION OF ANTHOCYANINS FROM THE SQUEEZE OF KRASNOSTOP ZOLOTOVSKY

2020 ◽  
Author(s):  
M.A. Egyan ◽  
Keyword(s):  
Reaction Rate ◽  
Sugar Content ◽  
Extraction Process ◽  
Efficiency Coefficient ◽  
Kinetic Characteristics ◽  
Reaction Rate Constants ◽  
Solids Content ◽  
Kinetics Of ◽  
Process Speed

The article shows studies characterizing the quality of the squeeze: the mechanical composition of the squeeze is determined, the structural moisture of each component is determined, the sugar content in the formed process of sedimentation of the juice and its acidity are determined refractometrically. The kinetics of anthocyanins extraction was determined in two ways, the solids content in the extract was calculated, and the reaction rate constants of the extraction process and the efficiency coefficient of ultrasonic amplification of the extraction process speed were calculated.

Thermal Decomposition Kinetics of Glyphosate (GP) and its Metabolite Aminomethylphosphonic Acid (AMPA)

2019 ◽  
Author(s):  
Milad Narimani ◽  
Gabriel da Silva
Keyword(s):  
Thermal Decomposition ◽  
Reaction Rate ◽  
Decomposition Kinetics ◽  
Rate Theory ◽  
Thermal Decomposition Mechanism ◽  
Treatment Processes ◽  
Aminomethylphosphonic Acid ◽  
Reaction Rate Theory ◽  
Decomposition Chemistry ◽  
Kinetics Of

Glyphosate (GP) is a widely used herbicide worldwide, yet accumulation of GP and its main byproduct, aminomethylphosphonic acid (AMPA), in soil and water has raised concerns about its potential effects to human health. Thermal treatment processes are one option for decontaminating material containing GP and AMPA, yet the thermal decomposition chemistry of these compounds remains poorly understood. Here, we have revealed the thermal decomposition mechanism of GP and AMPA by applying computational chemistry and reaction rate theory methods. <br>

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