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Maghemite (Fe 2 O 3, γ-Fe 2 O 3) is a member of the family of iron oxides. It has the same formula as hematite , but the same spinel ferrite structure as magnetite ( Fe 3 O 4 ) and is also ferrimagnetic .
Magnetic roasting technology refers to the process of heating materials or ores under specific atmospheric conditions to induce chemical reactions. [1] This process selectively converts weakly magnetic iron minerals such as hematite (Fe 2 O 3 ), siderite (FeCO 3 ), and limonite (Fe 2 O 3 ·nH 2 O) into strongly magnetic magnetite (Fe 3 O 4 ) or ...
In the second type, the following chemical reaction occurs: 2 Fe 3+ + Fe 2+ + 8 OH − → Fe 3 O 4 ↓ + 4 H 2 O. Optimum conditions for this reaction are pH between 8 and 14, Fe 3+ / Fe 2+ ratio of 2:1 and a non-oxidizing environment. Being highly susceptibile to oxidation, magnetite (Fe 3 O 4) is transformed to maghemite (γ Fe 2 O 3) in the ...
Iron(III) oxide was the most common magnetic particle used in all types of magnetic storage and recording media, including magnetic disks (for data storage) and magnetic tape (used in audio and video recording as well as data storage). Its use in computer disks was superseded by cobalt alloy, enabling thinner magnetic films with higher storage ...
Iron(II,III) oxide, or black iron oxide, is the chemical compound with formula Fe 3 O 4.It occurs in nature as the mineral magnetite.It is one of a number of iron oxides, the others being iron(II) oxide (FeO), which is rare, and iron(III) oxide (Fe 2 O 3) which also occurs naturally as the mineral hematite.
Maghemite is a polymorph of hematite (γ-Fe 2 O 3) with the same chemical formula, but with a spinel structure like magnetite. Large deposits of hematite are found in banded iron formations. Gray hematite is typically found in places that have still, standing water, or mineral hot springs, such as those in Yellowstone National Park in North ...
The Schikorr reaction can occur in the process of anaerobic corrosion of iron and carbon steel in various conditions. Anaerobic corrosion of metallic iron to give iron(II) hydroxide and hydrogen: 3 (Fe + 2 H 2 O → Fe(OH) 2 + H 2) followed by the Schikorr reaction: 3 Fe(OH) 2 → Fe 3 O 4 + 2 H 2 O + H 2. give the following global reaction:
Natural remanent magnetization is the permanent magnetism of a rock or sediment.This preserves a record of the Earth's magnetic field at the time the mineral was laid down as sediment or crystallized in magma and also the tectonic movement of the rock over millions of years from its original position.