Iron Ore Sintering Bed Research Articles

De novo formation characteristics of dioxins in the dry zone of an iron ore sintering bed

The objectives of this work are to understand the details of the mechanism of dioxin formation in the part of a sintering bed termed the dry zone, and to obtain ideas on how to prevent their formation. Sinter mixtures of various composition types were heated in a packed bed reactor, and dioxins in the outlet gas and in the sinter mixture residue were measured. The dioxin formation potential of a simple sinter mixture composed of iron ore, coke and limestone was markedly lower than that of fly ash from a municipal solid waste incinerator (MSWI). In consideration of this result, a series of experiments were conducted using a sinter mixture impregnated with CuCl 2. Experimental results showed that dioxin formation was temperature-dependent in the range of 300–550 °C, with the maximum observed at around 300 °C, which was quite similar to that of fly ash from the MSWI. The homologue distribution of PCDD/Fs in gas and solid reflected the possible difference in carbonaceous materials in coke and activated coke. Gaseous hydrogen chloride acted as a chlorinating reagent for dioxin formation.

Results from preliminary investigation of particulate emission during sintering of iron ore

Regulations on the emission of particulates from sinter plant stacks are becoming increasingly stringent and reducing these emissions by improving gas cleaning systems is a significant cost to the sinter plants. This paper describes an investigation into the emission of particulate matter from an iron ore sinter bed during the sintering of a Japanese Steel Mill (JSM) style ore blend in a 300 mm diameter pot grate test facility.Several techniques were trialled to determine a reliable method to sample the quantity of dust emitted and determine the mechanism of dust emission from the sinter bed. The nature of the dust was also examined using chemical and size analysis as well as optical and scanning electron microscopy. The paper discusses the techniques used to carry out the programme as well as results on dust loading measured during sintering and the nature of the dust captured.

Characterizing the contribution of the high-temperature zone to iron ore sinter bed permeability

In iron ore sintering the resistance of the bed to air flow is important because it influences machine productivity. It is clear from theory that the high-temperature zone of a sintering bed is the major resistance to air flow and, therefore, the major contributor to the pressure drop across the bed. Hitherto, however, no technique for measuring this resistance has been available so that the factors that control it can be studied. An experimental technique based on the Ergun equation is proposed to measure this resistance, which is expressed as the reduction in air flow after ignition of the bed. Seven ore blends were studied and the results showed that the resistance to air flow is dependent on ore blend composition and the pre-ignition air flow through the bed. The melting zone of a sintering bed is considered to have a controlling influence on its resistance. In this zone it is concluded that the inertial force, which is a function of gas flow rate, has the ability to dilate gas channels and decrease resistance to air flow. More study is required for understanding of the effect of melt property on the size of gas channels. Use of the technique as an aid to comparison of the 'sinterability' of sinter mixes is also discussed.

Numerical Simulation Model of the Iron Ore Sintering Process Directly Describing the Agglomeration Phenomenon of Granules in the Packed Bed.

Comprehensive numerical simulation model was developed to describe the structural changes in the iron ore sintering bed by using the discrete element method (DEM). The heat wave propagation through the sintering bed was incorporated by combining the solutions of the various reaction rates and gas-granule heat transfer with the calculation of the granule movement by DEM. Simulations were conducted under different conditions, i.e., different carbon content and melting temperature of the granules. Results show that both carbon content and melting temperature of the granule influence the final structure of the sintering bed. The obtained structural change of the sintering bed show that the proposed model is a potential tool to analyse the agglomeration phenomena occurring in the iron ore sintering process under various conditions.

Effect of Raw Materials Bed Segregation on the Structural Change of Iron Ore Sintering Bed.

Effect of Raw Materials Bed Segregation on the Structural Change of Iron Ore Sintering Bed.

コークスの燃焼により発生するNOガスの鉄鉱石焼結ベッド内除去反応

コークスの燃焼により発生するNOガスの鉄鉱石焼結ベッド内除去反応

An Analytical Study of Processes Occurring in an Iron Ore Sinter Bed

Fundamental heat and mass balance equations for an iron ore sintering process are presented and the method used in simulating the model is discussed. The model is validated by comparing the results of a digital computer simulation with those obtained from tests on pilot plant. The effects on heat wave propagation of varying ignition time, ignition temperature, size of mix, coke content, ore density, voidage and gas velocity are investigated.It is shown that burnthrough time is mainly dependent on gas velocity and that ignition time and temperature are not critical, provided that they exceed the values required for ignition.