Procedures for Stage Processing of Iron-Ore Wastes in Industrial Mining Areas

Novichikhin, A. V.; Shorokhova, A. V.

doi:10.17073/0368-0797-2017-7-565-572

Cited by 4 publications

(5 citation statements)

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“…It has been established that the pellets strength obtained at the optimum firing temperature depends on the characteristics of the initial finely dispersed iron ore raw material [22,23].…”

Section: Methodsmentioning

confidence: 99%

Analysis of the Granulometric Composition of the Feedstock Influence on Mechanical Properties of Iron Ore Pellets

Бобков

Morgunova

2022

MSF

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The paper investigates the effect of high-temperature roasting and cooling modes of roasted iron ore pellets on their strength and porosity. These characteristics depend on the initial iron ore raw materials properties, the parameters of the raw pellets, the firing temperature, the holding time at this temperature, the heating and cooling rate, and take into account the change in these indicators in connection with the chemical and mineralogical compositions of the pellets. It has been established that the strength of iron ore pellets obtained at the optimum firing temperature depends on the characteristics of the initial finely dispersed iron ore raw material. The relationship between the content of draw rock and the strength of calcined pellets has been revealed. A significant influence of the raw pellets porosity on the strength of the calcined pellets was found. It is shown that the crushing strength of pellets cooled in air is higher than the strength of pellets cooled with water, and a decrease in the final cooling temperature leads to an increase in the strength of the pellets. It is substantiated that the heating rate should not exceed the rate of gas diffusion, and with a decrease in the size of finely dispersed iron ore raw materials, the shrinkage of the pellet layer increases during heating. It is shown that shrinkage appears at temperatures lower than the optimal calcining temperature and insignificantly affects the strength of the pellets. The results obtained can be used to substantiate resource-and-energy efficient operating modes of horizontal-grate machines in ferrous metallurgy.

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“…It has been established that the pellets strength obtained at the optimum firing temperature depends on the characteristics of the initial finely dispersed iron ore raw material [22,23].…”

Section: Methodsmentioning

confidence: 99%

Analysis of the Granulometric Composition of the Feedstock Influence on Mechanical Properties of Iron Ore Pellets

Бобков

Morgunova

2022

MSF

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“…The roasting conveyor machines are used for roasting of iron ore raw materials [20]. Their operating experience during several years testifies on substantial disadvantages during chemical-metallurgical roasting process [21].…”

Section: Experimental Examination Of the Roasting Process Of Iron Ore...mentioning

confidence: 99%

“…To reveal the causes of insufficient power engineering efficiency of the chemical-metallurgical roasting process, the qualitative analysis of the thermal conditions in roasted layer of iron ore raw material is required. Conduction of such analysis is impossible on the base of the data of technological control which is provided for a roasting conveyor machine [26]. Additional data on distribution of heating gas temperature in different areas of dynamically dense layer and on a fire grate in different sections of a roasting machine are required.…”

Section: Experimental Examination Of the Roasting Process Of Iron Ore...mentioning

confidence: 99%

Experimental examination of the chemical-metallurgical roasting process for iron ore raw materials on the fire grate of a roasting conveyor machine

Bobkov,

Dli,

Kulyasov

2023

cisisr

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The results of experimental power engineering examination of operating roasting conveyor machines are presented. These machines are used for complicated energy-intensive chemical-metallurgical process of roasting of iron ore raw materials in moving dense layer with cross feed of heat-carrying gas. The studies were conducted within the temperature ranges of thermal and aerodynamic operating conditions of the existing roasting conveyor machines. The causes of insufficient power engineering efficiency of the chemical-metallurgical roasting process were revealed, qualitative analysis of thermal conditions of roasting dense layer of iron ore raw materials was carried out. The data on temperature distribution of heating gas and iron ore material in different areas of a dynamic dense layer and on a fire grate in different sections of the roasting machine were obtained. The experimental data from technological control of the roasting conveyor machine were presented, as well as the results of chemical and granulometric analyses of roasting iron ore raw materials. Essential deviations in the thermal conditions of operating roasting machine in comparison with designed parameters were found out. The data on roasting conditions of iron ore raw materials in the experimental unit -the sintering pan, which provides simulation of the roasting conditions close to designed ones, are displayed. Insufficient heating in the lower layer levels at the operating roasting machines (in comparison with the designed parameters), stipulated by low speed of heat-carrying gas sweeping in the roasting area was revealed. Temperature heterogeneity along the width of a fire grate, caused by heterogeneity of heat-carrying gas sweeping due to segregation of iron ore material by its size during its loading to the roasting conveyor machine was substantiated scientifically.

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“…Research of mutual determining features of heat exchange and kinetics of heterogeneous transformation in iron ore raw materials was examined during high-temperature roasting via building of a mathematical model, which takes into account the most essential appearances, as well as analysis of taken solutions [15,16].…”

Section: Mathematical Model Of the Process Of Thermal Dissociation Of...mentioning

confidence: 99%

Influence of the conditions of internal heat exchange on the process of thermal decomposition of carbonates in iron ore raw materials

Bobkov¹,

Dli²,

Rubin³

2022

cisisr

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This work considers influence of heating rate of iron ore raw materials on chemical and metallurgical processes of thermal dissociation of carbonates, which occur during its high-temperature roasting. The research was conducted for the temperature ranges of the existing roasting and sintering machines, taking into account macro-kinetics of calcination processes. Substantial influence of heating rate of iron ore samples on kinetics of thermal decomposition of carbonates was revealed. The cause of the effect of internal heat exchange conditions in reacting iron ore sample on macro-kinetics of dissociation reaction for carbonates was substantiated scientifically. Influence of nonisothermal properties on precision of thermal analytical investigations, which were conducted using the methods of non-isothermal kinetics with different heating rates of iron ore samples, was studied. The authors suggested the mathematical model, which allows to take into account wide range of variations of the parameters in kinetic equations and volumetric thermal and chemical-metallurgical dissociation processes for carbonates. A series of calculating experiments, aimed on reveal of the relationship between heating rate of iron ore samples and evolution of concentration fields, transformation rates and temperature gradients, was carried out using the suggested model. The obtained results can be used for development of the optimal operating conditions for sintering and roasting machines, which propose optimization of heat treatment processes for iron ore preparation, owing to intensification of heat and mass exchange processes during high-temperature roasting. These conditions are considered as optimal from the point of view of power-and resource efficiency. Forming of the above-mentioned conditions allows to decrease fuel and power expenses for thermal preparation of raw materials at metallurgical production facilities, as well as to lower total economical production charges due to use of thermal decomposition of carbonates.

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Procedures for Stage Processing of Iron-Ore Wastes in Industrial Mining Areas

Cited by 4 publications

References 0 publications

Analysis of the Granulometric Composition of the Feedstock Influence on Mechanical Properties of Iron Ore Pellets

Analysis of the Granulometric Composition of the Feedstock Influence on Mechanical Properties of Iron Ore Pellets

Experimental examination of the chemical-metallurgical roasting process for iron ore raw materials on the fire grate of a roasting conveyor machine

Influence of the conditions of internal heat exchange on the process of thermal decomposition of carbonates in iron ore raw materials

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