Kinetics of Siderite Ore Roasting in the Shaft Furnace

Kinetics of the siderite ore roasting in the air, helium and hydrogen flows has been studied in a gasometrical unit with continuous mass variation logging. We have derived the expression for determination of an apparent degree of calcination and identified its dependence on the size of the prill, the heat treatment duration, and gas-phase composition. Using a generalized chemical kinetics equation, we have obtained a formula for calculation of the decomposition period for siderite ore samples. It has been found that calcination rate increases with the temperature rise, irrespective of the sample size and atmospheric composition. Calcination process has been studied at low temperatures. We have demonstrated that it is feasible to describe the process of siderite ore thermal dissociation by a first-order kinetics equation. We have obtained the expression to calculate the duration of this process depending on different parameters. Using a generalized chemical kinetics equation, we have obtained a formula for checking the expressions that describe the experimental data. We have studied kinetics of the reduction of roasted ore samples at various temperatures using different sizes of the samples. The obtained results have been applied for optimization of the design values and operating conditions of the siderite ore roasting in shaft furnaces. These will also be used for designing a shaft furnace consisting of a calcination zone, reduction zone (metallization zone) and metallized product cooling zone, which will increase iron content in the end-product to 65-70%.

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Study of the process of siderite ore thermal treatment in a shaft furnace

Ferrous Metallurgy Bulletin of Scientific Technical and Economic Information ◽

10.32339/0135-5910-2018-8-36-42 ◽

2018 ◽

pp. 36-42

Author(s):

B. P. Yur'ev ◽

V. A. Gol'tsev ◽

V. A. Dudko

Keyword(s):

Thermal Treatment ◽

Chemical Kinetics ◽

Shaft Furnace ◽

Cooling Zone ◽

Kinetics Equation ◽

Measuring Device ◽

Roasting Process ◽

Ore Roasting ◽

Siderite Ore ◽

Chemical Kinetics Equation

Results of a study of kinetics of siderite ore roasting process in flows of air, helium and hydrogen presented. The study was carried out at mass measuring device with continuous registration of mass changing. An expression received for determining of apparent decarburization degree and its dependence determined on a piece dimension, thermal treatment duration and gas phase content. Using a generalized chemical kinetics equation, a formula received for determining of decomposition time of siderite ore specimens. Increase of decarburization pace at temperature rise determined for specimens of all dimensions independent on the atmosphere content and mechanism of decarburization process at low temperatures considered. A possibility shown to describe the process of thermal dissociation of siderite ore by a kinetic equation of first order and an expression obtained for determining of this process duration depending on different parameters. By application of generalized chemical kinetics equation a formula obtained, which was used to check the expression, describing the test data. Kinetic of roasted ore specimens reduction studied at different temperatures and specimens dimensions.The results obtained in this work were used for optimization of structural and mode parameters of siderite ore roasting process in shaft furnaces. They will be applicable at designing of a shaft furnace, comprising decarburization zone, reduction zone (metallization zone) and cooling zone of the metalized product, that will enable to increase the iron content in the final product till 65–70%.

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Thermodynamic Analysis of Siderite Ore Carbonate Decomposition Process at Roasting

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.410.235 ◽

2021 ◽

Vol 410 ◽

pp. 235-240

Author(s):

Boris P. Yur'ev ◽

Vyacheslav A. Dudko

Keyword(s):

Thermodynamic Analysis ◽

Shaft Furnace ◽

Thermal Dissociation ◽

Decomposition Temperature ◽

Thermodynamic Activity ◽

Dissociation Rate ◽

Decomposition Process ◽

Process Time ◽

Carbonate Decomposition ◽

Siderite Ore

Carbonate decomposition with significant heat energy absorption takes place at siderite ore oxidizing roasting in a shaft furnace. Thermal dissociation of complex carbonates comprising the siderite ore was studied. Thermodynamic analysis was carried out for a sideroplesite decomposition process. Formulas allowing determination of the carbonate dissociation and exchange energy rates were obtained using the regular ion solution theory. The ion composition and thermodynamic activity simulation results were described for sideroplesites as well as iron and magnesium cation shares. The work output is of certain interest as knowing the initial sideroplesite decomposition temperature and the carbonate dissociation rate the optimal dimensions of various zones throughout the shaft furnace height may be defined, the roasting process time may be calculated and the optimal heat treatment conditions as well as the firing rate may be established.

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A Biomass Combustion-Gasification Model: Validation and Sensitivity Analysis

Journal of Energy Resources Technology ◽

10.1115/1.2835431 ◽

1995 ◽

Vol 117 (4) ◽

pp. 329-336 ◽

Cited By ~ 13

Author(s):

N. Bettagli ◽

U. Desideri ◽

D. Fiaschi

Keyword(s):

Experimental Data ◽

Sensitivity Analysis ◽

Kinetic Parameters ◽

Chemical Kinetics ◽

Operating Conditions ◽

Waste Materials ◽

Biomass Combustion ◽

Gas Composition ◽

Combustion Processes ◽

Kinetics Of

The aim of the present paper is to study the gasification and combustion of biomass and waste materials. A model for the analysis of the chemical kinetics of gasification and combustion processes was developed with the main objective of calculating the gas composition at different operating conditions. The model was validated with experimental data for sawdust gasification. After having set the main kinetic parameters, the model was tested with other types of biomass, whose syngas composition is known. A sensitivity analysis was also performed to evaluate the influence of the main parameters, such as temperature, pressure, and air-fuel ratio on the composition of the exit gas. Both oxygen and air (i.e., a mixture of oxygen and nitrogen) gasification processes were simulated.

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Process Development for Solid Fuel Use at Siderite Ore Roasting in Shaft Furnace

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.299.606 ◽

2020 ◽

Vol 299 ◽

pp. 606-610

Author(s):

Boris Yur'ev ◽

Vyacheslav Dudko

Keyword(s):

Solid Fuel ◽

Iron Content ◽

Process Development ◽

Shaft Furnace ◽

Iron Oxidation ◽

Content Increase ◽

Reducing Atmosphere ◽

Roasting Process ◽

Ore Roasting ◽

Siderite Ore

Lean coal burning kinetics was studied and the main burning rate dependence on oxygen content in gas phase and heating rate was obtained. Preliminary dressed lump siderite ore from Bakal deposit with the fraction of 18-25 mm and average iron content of 35% was roasted in a pilot unit in neutral (low reducing) atmosphere, obtained by coal grate firing. It was established that such roasting allowed iron oxidation level reduction, as compared to roasting in oxidizing atmosphere and iron content increase in the roasted product. The evaluation results allowed development of a roasting process for siderite ore in neutral (low reducing) atmosphere and designing of a shaft furnace operating on solid fuel. Such roasting process is of a certain interest, as far as saving the insufficient fuel types, and predominantly natural gas, is concerned.

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Research on Siderite Ore Reducing Firing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.989.434 ◽

2020 ◽

Vol 989 ◽

pp. 434-439

Author(s):

Boris Yur'ev ◽

Vladimir A. Gol'tsev ◽

Vyacheslav Dudko

Keyword(s):

Blast Furnace ◽

Iron Content ◽

Process Development ◽

Shaft Furnace ◽

Current Method ◽

Hydrogen Atmosphere ◽

Cooling Zone ◽

Reduction Degree ◽

Blast Furnace Smelting ◽

Siderite Ore

It was determined that the current method of the Bakalsk mining department siderite ore preparation for blast-furnace smelting does not allow production of concentrate meeting the state-of-the-art metallurgy requirements. The most perspective method is reducing firing when a metallized product with higher iron content is obtained. It was demonstrated that implementation of this method requires the use of a three-zone shaft furnace having the oxidizing roasting zone, the reduction zone and the reduced product cooling zone. Experiments were carried out on the siderite ore reducing firing on laboratory units. The possibility in principle was demonstrated for production of the reduced product with iron content of 60 – 65% from the siderite ore. After the magnetic dressing the concentrate with iron content of 65 – 75% was obtained. It was determined that firing and reduction in hydrogen atmosphere result in the fired product reduction degree of 97 %. The possibility to produce a product suitable for blast-furnace conversion with the reduction degree of about 60% with the use of natural gas air conversion gas was demonstrated. The obtained results were used in the process development for the siderite ore reducing firing in a three-zone shaft furnace.

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