Magnetite deposition

KEYWORDS Ulsan carbonate rocks, Kyongsang Basin, magnetite deposit, melting/fluxing of crustal carbonate melt, Alkaline A-type granitic rocks... 

The Ulsan carbonates (Fig. 1) have long been interpreted as limestone of Paleozoic age or "age unknown" and as the host of a skarn-type iron (magnetite) deposit due to the intrusion of Cretaceous granitic rocks (Park Park 1980 Choi et al. 1999). However, a Paleozoic marine limestone hypothesis fails to explain the spatial association or the relationship between carbonate and ultramafic rocks in a concentric, ellipsoidal shape surrounded by Cretaceous sedimentary, volcanic, and granitic rocks. The sedimentary hypothesis also fails to explain the isolated exposure of a funnel-shaped Paleozoic marine limestone where no marine limestone has been previously observed within the Mesozoic Kyongsang Basin. 

The ilmenite-magnetite deposits usually contain ilmenite and magnetite as granular intergrowths, which can be separated readily to yield ilmenite and magnetite concentrates. 

RE minerals in Esfordi apatite- magnetite deposit, Central Iran Mohammad Boomeri Kazuo Nakashima David R. Lentz ... 

Jami, M., Dunlop, A.C., Cohen D.R. 2007. Fluid inclusion and stable isotope study of the Esfordi apatite-magnetite deposit. Central Iran. Economic Geology, 102, 1111-1128. 

Sillitoe, R.H. Burrows. D.R. 2002. New field evidence bearing on the origin of the EL Laco magnetite deposit, northern Chile. Economic Geology, 97, 1101-1109. 

Seredkin, M.V., Zotov, I.A., Karchevskii, P.I. 2004. Geological and genetic model for the formation of the Kovdor massif and the accompanying apatite-magnetite deposit. Petrology, 12, 519-539 (Transl. from Rus.)... 

Finely divided magnetite deposited on a support is liable to oxidation and hydrolysis, which leads to hydrated supported iron(III) oxide. To prevent oxidation and hydration, the loaded support has to be dried in an inert gas. After being dried the supported magnetite is fairly stable on exposure to atmospheric air, although reaction to y-Fe203 may proceed. 

Molybdenite samples from Cu-Au-Mo and magnetite deposits in the Yangtze River valley (China) have been examined by Re-Os age dating using ICP-MS and NTIMS. The results of the two mass spectrometric techniques are almost identical. The Re-Os ages of 16 molybdenite samples range from 134.7 2.3 to 143.7 1.6Ma. Emopium isotope variation in Allende CAIs with a deficit for Eu of up to %o have been detected by MC-ICP-MS. " The lack of Sm isotope fractionation in the same samples makes fractionation by kinetic processes an unlikely case of the Eu deficit. The authors interpreted that based on the low ionization potential of Eu, in which electromagnetic separation of ionized gas preferentially depletes the nebular gas in a heavy isotope. 

Lapteva (1958) experimentally determined the redox potential E ) in the neutralization of a mixture of Fe and Fe sulfates by an alkali—at a pH above 7 a black magnetite deposit was formed according to the reaction ... 

Magnetite deposition from flowing aqueous suspensions (Newson etal 1981]... 

FIGURE 7.8. Particulate magnetite deposition on the inside of aluminium tubes... 

Newson. I.H., Bott, T.R. and Hussain, C.I., 1981, Studies in magnetite deposition from a flowing suspension. 20th Nat. Heat. Trans. Conf Milwaukee, Fouling in Heat Exchange Equipment, ASM HTD, 17, 73 - 81. 

Very extensive, nonproducing, vanadium-bearing magnetite deposits exist in Australia, New Zealand, Canada and India similar to those now being worked. 

Forder et al. [70] have successfully prepared superparamagnetic conductive polyester textile composites (polypyrrole and magnetite on polyester textile fiber substrate) by a two-step deposition method, i.e., magnetite deposition and PPy deposition. 

Since much of the magnetite deposit is not in electrical contact with a reducible substrate, an external reducing agent usuaily is a part of the solvent mixture. Pitzer proposed a mixture of ammonium EDTA with 0.1-0.5 M of hydrazine, used at... 

Failures of the membrane wall were reported from the Puertollano plant. These were caused by magnetite depositions on the water side because of the feed water pH values fluctuating. Now that the pH value is monitored, no such problems have occurred since [27]. 

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