Solid State Reduction of Haematite by Mechanical Alloying Process

The mechanochemical reaction of hematite with graphite by mechanical alloying (MA) has been investigated at room temperature. The solid state reduction of hematite to Fe3O4 and FeO has been observed after 120 hours of MA by a planetary ball mill. Saturation magnetization is gradually increased with milling time up to 80 h, and then deceased after 120 h of MA, indicating the transformation of Fe3O4 into nonmagnetic FeO through further reduction. Neither the solid state reduction of Fe2O3 by graphite nor a sizable grain refinement is observed in the MA process using a horizontal ball mill.

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Nanocrystalline Formation and Magnetic Properties in Fe2O3–C System by Mechanical Alloying

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2021.19228 ◽

2021 ◽

Vol 21 (7) ◽

pp. 3791-3794

Author(s):

Chung-Hyo Lee

Keyword(s):

Heat Treatment ◽

Solid State ◽

Mechanical Alloying ◽

Saturation Magnetization ◽

Two Phase ◽

Reaction Heat ◽

State Reduction ◽

Heat Treated ◽

Average Grain Size ◽

Solid State Reduction

The effect of mechanical alloying (MA) on the solid state reaction of hematite and graphite system with a positive reaction heat was investigated using a mixture of elemental Fe2O3–C powders. The solid state reduction of hematite to Fe3O4 has been obviously observed after 3 hours of MA by a vibrating ball mill. A two-phase mixture of Fe3O4 and remaining Fe2O3 is obtained after 5 hours of MA. Saturation magnetization gradually increases with MA time due to the formation of Fe3O4 and then reaches 23 emu/g after 5 hours of MA. In addition, a Fe3O4 single phase is obtained by MA after 3 hours and subsequently heat treated up to 700°C. X-ray diffraction result shows that the average grain size of Fe3O4 prepared by MA for 5 hours and heat treatment to be in the range of 92 nm. The saturation magnetization of Fe3O4 prepared by MA and heat treatment reaches a maximum value of 56 emu/g for 5 hours MA sample. It is also observed that the coercivity of 5 hours MA sample annealed at 700 °C is still high value of 113 Oe, suggesting that the grain growth of magnetite phase during annealing process tends to be suppressed.

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Nanocomposite Formation in the Fe2O3-M (M=Al, Ti, Zn, Cu) Systems by Mechanical Alloying

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.253 ◽

2004 ◽

Vol 449-452 ◽

pp. 253-256 ◽

Cited By ~ 3

Author(s):

Chung Hyo Lee ◽

S.H. Lee ◽

S.Y. Chun ◽

Sang Jin Lee ◽

Young Soon Kwon

Keyword(s):

Solid State ◽

Mechanical Alloying ◽

Saturation Magnetization ◽

Room Temperature ◽

Oxide Systems ◽

State Reduction ◽

Metal Metal ◽

Pure Metals ◽

Solid State Reduction ◽

Nanocomposite Powders

Nanocomposite formation of metal-metal oxide systems by mechanical alloying (MA) has been investigated at room temperature. The systems we chose are the Fe2O3-M(M=Al,Ti,Zn,Cu), where pure metals are used as reducing agent. It is found that nanocomposite powders in which Al2O3and TiO2are dispersed in Fe matrix with nano-sized grains are obtained by mechanical alloying Fe2O3with Al and Ti, respectively. However, the reduction of Fe2O3with Cu by MA is not occurred. And the system of Fe2O3-Zn results in the formation of FeO plus ZnO after 120 h of milling. It is also shown that the magnetic evidence for the solid state reduction by mechanical alloying through changes in saturation magnetization and coercivity.

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Solid-State Reduction of Oxide Nanoparticles – A New Front of Mechanochemical Technology for Advanced Materials

Chemistry for Sustainable Development ◽

10.15372/csd20180501 ◽

2018 ◽

Keyword(s):

Solid State ◽

Advanced Materials ◽

Oxide Nanoparticles ◽

State Reduction ◽

Solid State Reduction

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Feasibility of nickel extraction from Indian chromite overburden by solid state reduction and smelting route

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb190908007g ◽

2020 ◽

Vol 56 (2) ◽

pp. 229-235

Author(s):

P. Ganesh ◽

Dishwar Kumar ◽

S. Agrawal ◽

Mandal Kumar ◽

N. Sahu ◽

...

Keyword(s):

Solid State ◽

Horizontal Tube ◽

Low Grade ◽

State Reduction ◽

Nickel Extraction ◽

Reducing Atmosphere ◽

Chromite Overburden ◽

Solid State Reduction ◽

Horizontal Tube Furnace ◽

Direct Smelting

The present work demonstrates the extraction of nickel from low-grade chromite overburden by using solid state reduction and direct smelting route. Goethite & Quartz are present as major phases whereas chromite, hematite were identified as minor phases in the mineral. Solid state reduction of pellets were carried out inside a horizontal tube furnace at 1000?C, 1200?C, 1400?C for 30, 60, 90 and 120 minutes respectively with creating reducing atmosphere. Pellets of varying basicity (i.e. 0.5, 0.6, 0.7, 0.8 and 0.9) were used directly in the EAF for smelting studies. Highest percent of nickel (2%) having ~ 91% recovery were obtained in solid state reduction route for pellets which was reduced at 1400?C for 120 minute. Similar recovery (~90%) of nickel was obtained inside the ingot (0.67% Ni ) by using pellets of 0.9 basicity through smelting route. From the present investigation, it could be concluded that the solid state reduction as well as smelting routes are feasible for the recovery of nickel from low grade chromite overburden. The production of nickel pig (low grade ferronickel) could also be feasible by smelting route.

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