dehydroxylation of iron ore

Reduction roasting of limonite ores: effect of

2006-9-1  Dehydroxylation is the structural transformation leading to the destruction of the structural OH– groups or loss of mineral crystalline bound water. This is a step which naturally occurs in the reduction process as a result of heating. This is followed by rebuilding of the crystalline structure.

Quantification of Moisture Contents in Iron and

The dehydroxylation occurs in a broad range of temperatures due to the existence of a particle-size distribution, surface hydroxyls and formation of a hematite coating. The determination of all adsorbed water is best performed by adding the powdered sample into the Karl-

Spectroscopic characterization of iron ores formed in ...

2015-2-5  Thermoanalyses indicated that the dehydroxylation endothermic (DTA) peak of goethite of type 1 occurs between 329 and 345 °C, while goethite of type 3 iron ore occurs at lower temperatures between 284 and 330 °C. This could be interpreted as a result of the nanocrystalline nature of the pedogenic goethite.

Mineral transformations and textural evolution during ...

2015-7-15  In the case of bog iron ore, dehydroxylation starts below 200 °C, which is evidenced by the disappearance of goethite XRD peaks and infrared absorption bands. Hence, the coalescence of micropores and shrinkage of nanocrystalline aggregates produce meso- and macroporosity.

(PDF) Chemical and mineral transformation of a low

The low grade of the iron ore, where the Fe grade is less than 60% could be upgraded possibly by crushing, grinding, washing, classifying jiggling and de-sliming ( Pal et al., 2010 ).

Dehydroxylation - an overview ScienceDirect Topics

Dehydroxylation involves the heating process through which the hydroxyl group (OH) is released by forming a water molecule (Frost Vassallo, 1996). The generally accepted mechanism of dehydroxylation of kaolinite is the interaction between two liberated hydroxyl as below: (13.2) OH − ↔ H + + O 2 − H + + OH − ↔ H 2 O.

(PDF) Iron Ore Characterisation during High

It was found that these iron ores exhibit three endothermic reactions, which are dehydration below 447 K with mass loss of 0.13 wt% to 1.7 wt%, dehydroxylation at 525–609 K with mass loss of 1 ...

Reduction roasting of limonite ores: effect of

It continuously occurred to lizardite at around 600ºCand finally Fe and Fe-Ni formation at 900ºC.The occurred decomposition leads thetransformation, both phase and morphology. Phase transformation...

Quantification of Moisture Contents in Iron and

Thus, some iron ores that are currently mined worldwide might contain a large amount of goethite, which means a higher amount of “combined water”. 4) From the minerals that are the constituents of iron ores, goethite is exactly the one that has the highest surface area and thus can contain the highest amount of adsorbed water. 5) In addition, goethite contains structural hydroxyls that are converted in water upon

Rapid dehydroxylation of nickeliferous goethite in ...

2009-12-1  Acicular, nano-sized goethite was the main constituent of the samples with minor to trace amounts of quartz, talc, kaolinite, chromite, maghemite, and Mn oxides. Goethite was partially dehydroxylated to OH-hematite at 340–400°C and had completely altered to

Quantification of Moisture Contents in Iron and

The dehydroxylation occurs in a broad range of temperatures due to the existence of a particle-size distribution, surface hydroxyls and formation of a hematite coating. ... The world production of usable iron ore in 2010 reached the astonishing amount of 2.59 × 109 metric tons.1) The standard method to determine the total iron content

Open Access proceedings Journal of Physics: Conference

The higher iron contain on the ore tend to produce the fayalite mixture and slightly forsterite, while at low iron content will form a forsterite. Forsterite tends to inhibit reduction of nickel. ... The endothermic reaction at 638°C is a dehydroxylation reaction of hydroxy

Thermogravimetric Analysis of the Reduction of Iron

Iron ore with high hydroxyl content such as goethit is widely spread in Indonesia. Such iron ore is not used as feed in ironmaking industry. However due to limitation of primary iron ore reserve such material is an option to substitute the conventional iron ore. Unfortunately the characteristic of iron ore with high hydroxyl content is totally different to conventional iron ore.

Minerals Free Full-Text Dehydroxylation and

As a high-temperature sorbent, kaolinite undergoes the flash calcination process in the furnace resulting in the dehydroxylation and structural distortion, which are closely related to its heavy metal/alkali metal adsorption characteristics. We investigated the flash calcination of kaolinite by the experiments using a drop tube furnace and by the characterization of flash-calcined products ...

Mineral transformations and textural evolution during ...

In the case of bog iron ore, dehydroxylation starts below 200 C, which is evidenced by the disappearance of goethite XRD peaks and infrared absorption bands. Hence, the coalescence of micropores and shrinkage of nanocrystalline aggregates produce meso- and macroporosity. Also, the stress associated with water expulsion may cause the development ...

Kinetics of the Dehydroxylation of Serpentine Energy

2011-12-20  We examined the dehydroxylation of natural serpentine ore, considered to be a candidate for mineralization of CO 2. In this study, serpentine and dehydroxylated serpentine have been characterized using different techniques and the dehydroxylation kinetics of serpentine has been investigated by non-isothermal thermogravimetry.

Thermal characteristics and phase transformation of

Iron ore, with high combined water such as goethite, is widely spread in Indonesia. This is not commonly used as the main raw material in iron and steel making pr0Cess. However, as iron ore resources are getting limited and decreasing in number, iron making industries have to seek other iron ore sources, such as low-grade iron ore goethite ore. The purpose of this research is to investigate ...

RAPID DEHYDROXYLATION OF NICKELIFEROUS

2009-12-1  A method for extracting Ni and other metals from lateritic ores by means of shock heating has been investigated. Shock heating releases some of the metal from its goethitic host.

Quantification of Moisture Contents in Iron and

The world production of usable iron ore in 2010 reached the astonishing amount of 2.59 × 10 9 metric tons. 1). The standard method to determine the total iron content in ores is the ISO 2597-2:2008, which makes use of a titrimetic method with potassium dichromate as the titrant.

Reduction of lateritic iron ore briquette using coal bed ...

In this study, isothermal-temperature gradient method was used to separate iron and alumina in lateritic iron ore as an alternative technique. The lateritic iron ore was ground to obtain grain size of less than 200 mesh and agglomerated in the form of cylindrical briquette using a press machine. The iron oxide in the briquette was reduced by addition of coal so that all surface of the ...

Open Access proceedings Journal of Physics: Conference

The higher iron contain on the ore tend to produce the fayalite mixture and slightly forsterite, while at low iron content will form a forsterite. Forsterite tends to inhibit reduction of nickel. ... The endothermic reaction at 638°C is a dehydroxylation reaction of hydroxy

Minerals Free Full-Text Dehydroxylation and

As a high-temperature sorbent, kaolinite undergoes the flash calcination process in the furnace resulting in the dehydroxylation and structural distortion, which are closely related to its heavy metal/alkali metal adsorption characteristics. We investigated the flash calcination of kaolinite by the experiments using a drop tube furnace and by the characterization of flash-calcined products ...

Thermogravimetric Analysis of the Reduction of Iron

Iron ore with high hydroxyl content such as goethit is widely spread in Indonesia. Such iron ore is not used as feed in ironmaking industry. However due to limitation of primary iron ore reserve such material is an option to substitute the conventional iron ore. Unfortunately the characteristic of iron ore with high hydroxyl content is totally different to conventional iron ore.

Reduction of Goethitic Iron Ore Using Thermogravimetric ...

iron ore-coal is shown in Figure 5. It shows that weight loss occurs continuously from low to high temperatures. Significant slope occurs at around 285 °C shows that the composite pellet loses weight significantly in a short time. It indicates that the dehydroxylation of lateritic iron ore oc-curred. There are at least 3 other slopes that

Minerals Free Full-Text Factors Affecting the ...

If all of the iron in the ore were present as goethite, then the mass loss due to dehydroxylation would be about 9.5%. Up to 600 °C, the mass loss was much higher at about 15%, and this additional 5.5% mass loss could mainly be attributed to the evaporation of the majority of the sulphur and some reduction.

Investigation into coal-based magnetizing roasting of

Investigation into coal-based magnetizing roasting of an iron-rich rare earth ore and the associated mineralogical transformations. Nebeal Faris, James Tardio, Rahul Ram, Suresh Bhargava, ... Magnetite formation was found to proceed by the reduction of hematite formed from the dehydroxylation of goethite. X-ray diffraction showed that further ...

Thermal characteristics and phase transformation of

Iron ore, with high combined water such as goethite, is widely spread in Indonesia. This is not commonly used as the main raw material in iron and steel making pr0Cess. However, as iron ore resources are getting limited and decreasing in number, iron making industries have to seek other iron ore sources, such as low-grade iron ore goethite ore. The purpose of this research is to investigate ...

RAPID DEHYDROXYLATION OF NICKELIFEROUS

2009-12-1  A method for extracting Ni and other metals from lateritic ores by means of shock heating has been investigated. Shock heating releases some of the metal from its goethitic host.

(PDF) The Influence of Coal and Reduction Process ...

Other iron phases present such as Fe3O4 and FeO. The ore size do not affect clearly to phase change for pellet having 1:1 of ore: coal ratio at 1100°C for 60 minutes. All iron phase present at all ore size after roasting. The weak of FeNi peak even at high temperature is due to reduction process that do not immediately follow dehydroxylation ...

CiteSeerX — Properties of iron oxides in two Finnish

CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Abstract--Fifteen iron oxide accumulations from the bottoms of two Finnish lakes ("lake ores") were found to contain as much as 50 % Fe. Differential X-ray powder diffraction and selective dissolution by oxalate showed that the samples consisted of poorly crystallized goethite and ferrihydrite.

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