Titanomagnetite

Titanomagnetite

 

a mineral of the complex oxide class; an intermediate member of the isomorphous series of solid solutions of magnetite (FeFe2O4), ulvospinel (Fe2TiO4), and magnesian ulvospinel (Mg2TiO4). Titanomagnetite is also the name for magnetite with inclusions of the decay products of solid solutions (ulvospinel, ilmenite) and of the substituents of the decay products (rutile, brookite, perovskite).

In nature, there is an extremely wide distribution of magnetites having a high content (up to 37 percent) of the ilmenite component that retain their cubic structure despite vacancies in the tetrahedral and octahedral sublattices. These magnetites are referred to as titanomaghemites. The crystal structure is of the inverted spinel type. The parameter of the unit cell increases in the magnetite-ulvospinel series from 8.39 to 8.53 angstroms. Titanomagnetite contains admixtures of Al3+, V4+, Gr3+, and Mn2+. It occurs as octahedral crystals and, more frequently, granular aggregates and black masses. Hardness on Mohs’ scale is 5.0–5.5, and the density is 4,800–5,300 kg/m3. Titanomagnetites are decidedly ferrimagnetic, although ulvospinel is strictly paramagnetic. The two ranges of Curie points characteristic of titanomagnetite are 0°–100°C (for ulvospinel with an FeFe2O4 content up to 20 percent) and 500°–570°C (for magnetite with an Fe2TiO4 content up to 10 percent). Partial decomposition of the solid solution gives rise to autoreversal of thermoremanent magnetization in titanomagnetite, a phenomenon used in paleomagnetic studies.

Titanomagnetite deposits (basically magmatic) occur in association with ultrabasic, basic, and alkalic rocks; they also occur in placers. Titanomagnetite is used in producing iron, titanium, and vanadium.

G. P. KUDRIAVTSEVA

References in periodicals archive ?
The drill program targets the Company's flagship Lac Dore Vanadium Project where historical drilling and mechanical trenching and channel sampling conducted between 1958 and 2013 have revealed the presence within property limits of a 2 km-long by 200 m wide and minimum 200 m deep zone of banded vanadiferous titanomagnetite (VTM) mineralization.
Xie, "Development of intensified technologies of vanadium-bearing titanomagnetite smelting," Journal of Iron and Steel Research, International, vol.
The ore microscope observation shows that the matrix mineral components in the bauxite ores are cryptocrystalline diaspore, hematite, ferrohydrite, kaolinite, anatase, vanadium titanomagnetite and chamosite (Figs.
Titanium oxide (TiO2): TiO2 in the soils is normally contributed from the accessory minerals (such as rutile, sphenes, titanomagnetite etc.) of all the major rock types.
Coal addition rates, temperatures and reduction times were established to simulate those used by current pig iron producers utilising titanomagnetite feedstock.
According to the recalculation method suggested by Stormer (1983), titanomagnetite and ilmenite compositions have the range %[mol.sub.usp] = 13-19 and %[mol.sub.lim] = 67-89, respectively (Table 7 in Appendix A Supplementary Material).
The rock comprises plagioclase, clinopyroxene, and titanomagnetite with a seriate intergranular texture.
For example, titanomagnetite being the main carriers of magnetic properties of natural materials can be exposed to decay [3] or oxidation [4,5] processes.
Even though the samples do not contain the rutile phase, the Ti activity of 0.8 is suggested on the basis of the minor presence of apatite and titanomagnetite (as Ti-bearing phases) in the studied samples.
The mine has successfully completed the test period and is scheduled to produce 130 kt of titanomagnetite and 3 kt of ilmenite concentrate this year.
The titanomagnetite iron sands span the entire coastline, terminating near bordering El Salvador and continue westward into Mexico.