Phase equilibria analysis of hematite pellets during induration

The raw materials used in this study are the five main oxide components contained in pellets, namely Fe 2 O 3, SiO 2, CaO, MgO and Al 2 O 3. Typical composition of hematite pellet is used to analyze phase equilibria during induration. The prediction components are used to verify the accuracy of the phase quantification of the hardened …

Preheating and roasting characteristics of hematite–magnetite …

Abstract Regressive orthogonal design experiments have been carried out based on the analysis of the oxidation and induration behaviours of individual magnetite and hematite pellets. The research shows that the optimal pellet preheating time and temperature, and roasting time and temperature change with hematite/magnetite (H/M) …

Induration Process of Pellets Prepared from Mixed Magnetite …

The induration process for green pellets involv es 4 main. stages: (1) drying, (2) preheating, (3) heating and (4) coo l-. ing. In the drying stage ( 105–260 °C), water is removed from. the ...

Induration mechanisms of oxidised pellets prepared from mixed magnetite

The crystallisation behaviour of Fe2O3 during preheating and roasting of pellets made from mixed magnetite–haematite (M–H) concentrates has been studied. The results indicate that the strength of pellets is mainly provided by the crystalline connections between Fe2O3 particles during preheating. This occurs because the activity of Fe2O3 …

Influence of the olivine additive fineness on the oxidation …

The analysis of the thermogravimetric curves to be presented later suggests that the magnetite phase forms at 1 120 and 1 160°C for the pellets processed at 5 and 50°C/min, respectively, which ...

Mineral magnetic properties of artificial samples …

For every defined magnetite/haematite ratio, three pellets were analysed to monitor for sample inhomogeneity. For comparison, four larger samples were prepared by mixing either haematite or magnetite, together with small quantities of Al 2 O 3 powder and glue in 6 cm 3 plastic boxes. The remaining volume was filled with non-magnetic plastic …

hardness of magnetite mpared to haematite

T01:11:23+00:00; Hardness Of Magnetite Compared To Haematite. Hardness Of Magnetite Compared To Haematite Pdf Magnetic Susceptibility And Remanent Coercive Force Veitch and Schmid 1983 produced their magnetite by reducing dispersed haematite particles in an H2H20 atmosphere at 400 CThe magnetic …

Preheating and roasting characteristics of hematite–magnetite …

Under the conditions of preheating temperature 900°C, preheating time 10 min, roasting temperature 1275°C and roasting time 15 min, the compression strength of preheated and roasted pellets is found to be respectively more than 444 N/pellet (N/P) and 3993 N/P when the magnetite content in the pellets exceeds 20%.

Induration Process of Pellets Prepared from Mixed Magnetite…

The induration process for green pellets involves 4 main stages: (1) drying, (2) preheating, (3) heating and (4) cooling. In the drying stage (105–260°C), water is removed from the pellet in a controlled process to avoid cracking. During preheating (260–845°C), oxidation of the magnetite and decomposition of carbonates occur.

Kinetics of Carbon Oxidation During Induration of Hematite Ore Pellet

Hematite ore pellets require a much higher induration temperature than magnetite ore pellets because no exothermic heat is generated due to oxidation inside during induration-like magnetite pellets. Carbon is used as in situ heat source in hematite ore pellets which can reduce temperature requirement in the induration strand and …

Effect of Using Cornflour on Pellet Strength in Cold Hardening Pellet

The pellets were prepared by mixing 5%, 10% and 15% of cornflour with magnetite concentrate and dried at 100, 150, 200 and 250 oC for 30, 60, 90, 120 minutes and their strength values were ...

Modelling and numerical simulation of isothermal oxidation …

A mathematical model based on the computational fluid dynamics method, heat and mass transfer in porous media and the unreacted shrinking core model for the oxidation reaction of an individual magnetite pellet during preheating was established. The commercial software COMSOL Multiphysics was used to simulate the change in the …

Insight into the Consolidation Mechanism of Oxidized Pellets …

As with the fired pellet made from the magnetite or hematite concentrates, its hardening is mostly attributed to the recrystallization and the growth of the hematite crystals, while some slag phases are of minor importance to the hardening.[3–6] This kind of hardening is generally identified as a solid-state consolidation process in which ...

Kinetics of hematite to magnetite transformation by …

Gaviría et al. (2007) determined that the formation of magnetite by isothermal heating of hematite in the flow of a H 2 –Ar mixture begins at a temperature of 320 ... Redution kinetics of hematite to magnetite pellets containing coal char. Trans. Iron Steel Inst. Japan, 23 (1983), pp. 490-496, 10.2355/isijinternational1966.23.490.

Mineral magnetic properties of artificial samples …

wt-% haematite. Variations in haematite content can be ignored when interpreting most rock magnetic parameters, especially grain size indicative parameters for samples where haematite contents range from 0 to 98 wt-%. The S-ratio is still the most sensitive parameter for esti-mating the relative amount of haematite in magnetite/haematite …

The Study of Pelletizing of Mixed Hematite and …

For in-situ heat generation in hematite pellets, several investigators (Jiang et al. 2008; Kumar et al. 2019; Ooi et al. 2014) have mixed magnetite ore in pellet and found it to reduce energy ...

Insight into the Consolidation Mechanism of Oxidized …

pellets may help gain a better understanding of inter-particle reactions and has a potential to improve the efficiency of the pelletization processes. As with the fired pellet made from the magnetite or hematite concen-trates, its hardening is mostly attributed to the recrys-tallization and the growth of the hematite crystals, while

Heat Hardening Magnetite Vs Hematite Pellets

Heat Hardening Magnetite Vs Hematite Pellets. Heat hardening magnetite vs hematite pelletsOur company is one hightech enterprise, which involves rd, production, sales and serv as wellIn the past 30 years, we devote to producing mining equipments, sand making machines and industrial grinding mills, offering expressway, rail way and water …

Mechanism of magnetite iron ore concentrate morphology …

The pellets prepared from the synthesized magnetite attain the threshold Cold Crushing Strength (CCS) of 50 kg/pellet at a lower temperature of 1050 °C in comparison to hematite pellets (1100 °C).

Thermal treatment of magnetite nanoparticles

This paper presents the results of a thermal treatment process for magnetite nanoparticles in the temperature range of 50–500 °C. The tested magnetite nanoparticles were synthesized using three different methods that resulted in nanoparticles with different surface characteristics and crystallinity, which in turn, was reflected in their thermal …

Reduction roasting of hematite to magnetite using …

The main phase of the synthetic sample measured by XRD-data was hematite (Fig. 1 a), and the initial natural sample contain hematite and quartz traces with the characteristic peak (d-spacing) of 3.344 Å (Fig. 1 b).The characteristic peaks (d-spacing) of synthetic and natural hematite, and their comparison with the standard d-spacing of …

Pelletization of hematite and synthesized magnetite …

Furthermore, the conversion of magnetite to hematite is an exothermic reaction which indeed causes in-situ heat generation in synthesized magnetite pellets, consequently preventing the formation of micro-cracks and minimising the energy …

Mathematical modeling of thermal behavior of single iron ore pellet …

Magnetite ((hbox {Fe}_3hbox {O}_4)) had a great share in feedstock supplement for steel industry through the last 50 years and will continue to have from now on [].The oxidation of magnetite, which follows Eq. 1, being highly exothermic, provides a notable part of the energy required for heat hardening (induration) of iron ore pellets during …

The Study of Pelletizing of Mixed Hematite and …

The results showed that the use of hematite together with magnetite is possible to produce pellets with sufficiently good quality in terms of wet, dry and fired mechanical strengths. The...

Optimization of Induration Cycle for Magnetite

Under optimum conditions, such as preheating temperature 1000–1150 °C, preheating time 10 min, roasting temperature 1250 °C and roasting time 7.5 min, the …

Sintering characteristics and kinetics of acidic haematite ore pellets …

(DOI: 10.1080/03019233.2016.1264153) Haematite ore pellets require very high induration temperature (>1573 K) while, magnetite ore pellets require much lower temperature due to the oxidation of magnetite during induration. Mixing of some magnetite in haematite ore can improve the sintering property of pellets during induration. Mill scale is a waste …

Mechanism of Reduction of Hematite-Magnetite Hollow Cylindrical Pellet

In this study, the mechanism of reduction of hematite-magnetite concentrate (HMC) by graphite-calcium carbonate reductant mixture at about 1000 °C was investigated. The initial and middle stages of the reduction process (up to 63 pct) were mainly affected by the heat transfer inside the crucible. It was concluded that in the …

heat hardening of magnetite and haematite pellets

Drying and mechanical performance of hematite pellet in … The tensile strength of the hot air pretreated hematite pellet is 7.5 MPa, while those for the microwave heating at 385, 539 and 700 W are 13.2, 13.2 and 14.0 MPa, respectively. …

Pelletization of hematite and synthesized magnetite …

Also, the threshold CCS of 250 kg/pellet is attained by synthesized magnetite pellets at a lower temperature of 1250 °C compared to hematite pellets …

Optimization of Induration Cycle for Magnetite Concentrate …

Under optimum conditions, such as preheating temperature 1000–1150 °C, preheating time 10 min, roasting temperature 1250 °C and roasting time 7.5 min, the …

Induration aspects of low-grade ilmenite pellets: …

The heat hardening by oxidation is a process commonly used in iron ore pelletization process. The green pellets are fired in induration machine using Corex gas at JSW Steel Limited Pellet Plant. ... Abstract The crystallisation behaviour of Fe2O3 during preheating and roasting of pellets made from mixed magnetite–haematite (M–H ...

Effect of additives concentration on pelletization of high …

The aim of the present work is to investigate the effect of additives (bentonite, limestone and anthracite coal) variation (0.2, 0.5, 0.7 and 1%) on the physical, chemical …

Effect of Heating Rates on the Sintering of Oxidized Magnetite Pellets

to the sintering temper ature of 1573 K at three. different heating rates, low (15 K/min), m edium (30. K/min) and high (45 K/m in), and hold at that. temperature for 20 m in. Thereafter, the pell ...

Optimization of Firing Temperature for Hematite Pellets

Moreover, studies that quantify magnetite formation in ore pellets in hardening furnaces at high temperatures, found that it reduces the produced pellets resistance, thus further undermining its ...

Oxidation induration process and kinetics of Hongge …

Abstract. The induration process and oxidation kinetics of Hongge vanadium titanium-bearing magnetite (HVTM) pellets have been investigated by employing X-ray diffraction, scanning electron microscope, energy-dispersive spectroscopy, thermogravimetric and differential thermal analysis and thermogravimetric and …

Induration mechanisms of oxidised pellets prepared from mixed magnetite

Abstract. The crystallisation behaviour of Fe 2 O 3 during preheating and roasting of pellets made from mixed magnetite–haematite (M–H) concentrates has been studied. The results indicate that the strength of pellets is mainly provided by the crystalline connections between Fe 2 O 3 particles during preheating. This occurs because the …

Sintering characteristics and kinetics of acidic haematite ore pellets …

In magnetite ore pellet, oxidation of Fe 3 O 4 happens with generation of some exothermic heat (490 kJ kg −1). 2 The oxidation of magnetite helps in diffusion and recrystallisation bonding. 3,4 In contrary haematite pellet has no such oxidation, therefore diffusion or recrystallisation bonding happens at very high temperature and it requires …

Production of pelletizing concentrates from Zandrivierspoort magnetite

Kumba Iron Ore's Zandrivierspoort (ZRP) magnetite-haematite project aims to mine and beneficiate a magnetite resource with low contaminant levels to produce from 1 Mt/a to 2.5 Mt/a product, which ...

Optimization of Firing Temperature for Hematite Pellets

As for the firing of hematite pellets, more heat need to be supplied from external sources due to the absence of the exothermic reaction like that of magnetite oxidation. So the …

Thermal Implications of Phase Transformations during …

To produce pellets, iron ore concentrate (either hematite-Fe2O 3, or magnetite-Fe3O 4) ground to a p80 of 30–70μm, along with additives such as limestone, dolomite and a …