TY - JOUR

T1 - Physicochemical and Mass Transfer Processes when Samples from Fluxed Magnetite Iron Ore Concentrates are Heated in a Thermal Plant

AU - Yuriev, B. P.

AU - Dudko, V. A.

PY - 2023/2/1

Y1 - 2023/2/1

N2 - It is established that firing samples (granules) in a layer of fluxed magnetite iron ore concentrates are accompanied by complex physicochemical processes related to the oxidation of magnetite and the decomposition of carbonates. When they are heated, along with heat exchange processes, mass transfer processes also occur. These processes are interrelated and affect each other, as well as the degree of completion of the processes of oxidation and decarbonization in the layer. The oxidation mechanism of the samples containing magnetite is considered. A model of the mass transfer process for the period of decomposition of carbonates is refined. An equation is proposed that describes the kinetics of magnetite oxidation in samples upon heating for a more general form of boundary conditions. An equation is presented that makes it possible to determine the rate constant of the oxidation process depending on the characteristics of the heat-carrier gas and the properties of the material. A calculation procedure is developed to determine the diffusion coefficient of oxygen in the combustion products of various fuels. Experiments are carried out to study the kinetics of oxidation and decarbonization processes in a layer of granules on an experimental setup, which make it possible to simulate these processes in relation to different periods of their heat treatment in thermal plants and determine the mass transfer coefficients. This will make it possible to determine the degree of completion of processes by the height of the layer at the given values of the temperature and duration of firing.

AB - It is established that firing samples (granules) in a layer of fluxed magnetite iron ore concentrates are accompanied by complex physicochemical processes related to the oxidation of magnetite and the decomposition of carbonates. When they are heated, along with heat exchange processes, mass transfer processes also occur. These processes are interrelated and affect each other, as well as the degree of completion of the processes of oxidation and decarbonization in the layer. The oxidation mechanism of the samples containing magnetite is considered. A model of the mass transfer process for the period of decomposition of carbonates is refined. An equation is proposed that describes the kinetics of magnetite oxidation in samples upon heating for a more general form of boundary conditions. An equation is presented that makes it possible to determine the rate constant of the oxidation process depending on the characteristics of the heat-carrier gas and the properties of the material. A calculation procedure is developed to determine the diffusion coefficient of oxygen in the combustion products of various fuels. Experiments are carried out to study the kinetics of oxidation and decarbonization processes in a layer of granules on an experimental setup, which make it possible to simulate these processes in relation to different periods of their heat treatment in thermal plants and determine the mass transfer coefficients. This will make it possible to determine the degree of completion of processes by the height of the layer at the given values of the temperature and duration of firing.

UR - http://www.scopus.com/inward/record.url?partnerID=8YFLogxK&scp=85152691679

UR - https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=tsmetrics&SrcApp=tsm_test&DestApp=WOS_CPL&DestLinkType=FullRecord&KeyUT=000963048000007

UR - https://elibrary.ru/item.asp?id=61105552

U2 - 10.1134/S199079312301030X

DO - 10.1134/S199079312301030X

M3 - Article

VL - 17

SP - 60

EP - 67

JO - Russian Journal of Physical Chemistry B

JF - Russian Journal of Physical Chemistry B

SN - 1990-7931

IS - 1

ER -