Iron Magnetic Susceptibility Research Articles

RELATING MAGNETIC PROPERTIES OF MUNICIPAL SOLID WASTE CONSTITUENTS TO IRON CONTENT – IMPLICATIONS FOR ENHANCED LANDFILL MINING

Ferrous metals are a main recyclable waste fraction in Enhanced Landfill Mining (ELFM) projects. However, prior to mining, the metal content of municipal solid waste (MSW) landfills is unknown. We investigate if the metal content of MSW landfills can be estimated by inverse modeling of geophysical measurements as the magnetic properties of the subsurface are particularly sensitive to ferromagnetic metal enrichments. We conducted magnetic total-field measurements on a MSW landfill in Austria and estimated the bulk magnetic susceptibility (MS) of the subsurface by inverse modelling. For validation of the subsurface MS values, 32 drill-core samples from multiple locations and depths within the landfill were obtained and manually sorted into 12 waste fractions including ferrous metals (2.3 +/- 1.4 wt.%, 1 sigma). To investigate if bulk MS could be accurately predicted from inverse modeling when the exact composition of the waste is known, the MS of iron and other expected waste fractions were investigated in laboratory analysis using reference samples from waste treatment plants and another ELFM project. Laboratory analyses partly yielded significantly larger MS values for waste materials than those given for virgin materials in literature. The bulk MS for each sample from the ELFM project was computed using a weighted mean with respect to the waste composition derived from manual sorting. The bulk MS derived from inverse modelling of the field data (0.06 to 0.11 SI) exceeded the bulk MS derived from the material composition of waste samples and the MS values of reference samples (0.01 to 0.05 SI).

Recovery of Gold and Iron from the Cyanide Tailings by Magnetic Roasting

Abstract The pretreatment of the cyanide tailing by roasting and its effect on the followed comprehensive recovery of valuable metals were investigated. The results indicate that the leaching rate of gold reaches 46.14%, the magnetic susceptibility of iron is up to 86.27% when the roasting temperature is 750 °C, the roasting time is 1.25 h, and the dosage of reductant is 6%. Combined with mineral structure and principle of magnetic roasting, the promoting mechanism of gold leaching by roasting was explored. The gold exposed through the magnetic roasting is the foremost improvement for high leaching rate of gold.

Magnetic susceptibility of iron in malaria-infected red blood cells

During intra-erythrocytic maturation, malaria parasites catabolize up to 80% of cellular haemoglobin. Haem is liberated inside the parasite and converted to haemozoin, preventing haem iron from participating in cell-damaging reactions. Several experimental techniques exploit the relatively large paramagnetic susceptibility of malaria-infected cells as a means of sorting cells or investigating haemoglobin degradation, but the source of the dramatic increase in cellular magnetic susceptibility during parasite growth has not been unequivocally determined. Plasmodium falciparum cultures were enriched using high-gradient magnetic fractionation columns and the magnetic susceptibility of cell contents was directly measured. The forms of haem iron in the erythrocytes were quantified spectroscopically. In the 3D7 laboratory strain, the parasites converted approximately 60% of host cell haemoglobin to haemozoin and this product was the primary source of the increase in cell magnetic susceptibility. Haemozoin iron was found to have a magnetic susceptibility of (11.0 ± 0.9) × 10 − 3 mL mol − 1 . The calculated volumetric magnetic susceptibility (SI units) of the magnetically enriched cells was (1.88 ± 0.60) × 10 − 6 relative to water while that of uninfected cells was not significantly different from water. Magnetic enrichment of parasitised cells can therefore be considered dependent primarily on the magnetic susceptibility of the parasitised cells.

The effect of cold plastic deformation and subsequent annealing on the magnetic properties of metals with different initial structures

The effect of the degree of cold plastic deformation (CPD) and the temperature of subsequent annealing on the coercive force, relaxation magnetization, and relaxation magnetic susceptibility of iron and nickel is studied. The effect of the degree of CPD on steels with different initial structures in the annealed state (such as ferrite (Э10 steel), pearlite (ШX15 steel), and ferrite-pearlite (50Γ steel) structure), as well as on 50Γsteel with different initial structures obtained after quenching and tempering at different temperatures, is also studied. The dependences obtained are analyzed based on modern theories of magnetic hysteresis for magnetically soft materials. Recommendations for the use of nondestructive testing of the degree of CPD of articles (semifinished items) made from steels with different initial structures are given.

SURFACE MAGNETIC ORDERING OF Fe-O and Ti-O GROUPS DISPOSED ON DIAMAGNETIC SUPPORT

Multiplex dependence of the magnetic susceptibility of iron and titanium-oxygen two-dimensional nanostructures on the amount of metal–oxygen groups deposited on a silica surface was found. The effect of two-dimensional ferrimagnetism was observed. Its appearance is explained by the existence of magnetization areas arising only for certain amounts of Fe–O groups in the surface layer of silica. In the case of samples containing surface Ti–O groups, the structure-induced magnetic effect was observed. Such an effect is caused by an increase of the diamagnetism polarizing component and by the ordering action of silica support on Ti–O bonds.

Coordination chemistry of microbial iron transport compounds. 15. Electrochemistry and magnetic susceptibility of iron(III)-hydroxamate and -thiohydroxamate complexes

Coordination chemistry of microbial iron transport compounds. 15. Electrochemistry and magnetic susceptibility of iron(III)-hydroxamate and -thiohydroxamate complexes

Molecular structure, quadrupole splitting, and magnetic susceptibility of iron in deoxygenated myoglobin and hemoglobin

For three stereo-structural models of deoxymyoglobin (Mb) and deoxyhemoglobin (Hb) we derive electronic configurations and their mutual spin-orbit coupling. From the temperature dependent molecular electric field gradient (EFG) tensor we calculate temperature dependent quadrupole splittings, ΔE q(T), asymmetry parameters, η(T), and orientations of the EFG component V zz(T) with respect to the heme group. Comparing theoretical and experimental data we find a molecular electronic structure, which then is used to compute temperature dependent magnetic susceptibilities, χ(T). Theoretical and experimental χ(T) data are in reasonable agreement. From the consistency of our model calculations with experimental results we conclude that iron in Mb and Hb probably is pentacoordinated and considerably out of the heme plane by 0.4–0.8 A.

Magnetic Susceptibility of Beef Tendon

That tendon fibers show marked mechanical and optical anisotropy has long been known. In addition to these properties, the magnetic anisotropy of tendon has been studied. Measuring the magnetic susceptibility of beef tendon parallel and perpendicular to the fiber axis, Wöhlisch concluded that the tendon shows positive paramagnetic properties, i.e., the susceptibility is greater parallel than perpendicular to the fiber axis. His method was only qualitative, consisting of the observation of the rotation of the fiber freely suspended between the poles of a magnet, hence no numerical value for the susceptibility could be given. While some degree of magnetic anisotropy is to be expected in such fibers it seems probable that, like most organic substances, they would be diamagnetic rather than paramagnetic. Gelatin, which is closely related to collagen, was found to be diamagnetic both in the dry form (Ambronn, quoted by Wöhlisch) and in approximately 1% solutions (Fallot). The susceptibilities obtained by the latter investigator ranged between −0.76 × 10−6 and −0.91 × 10−6 In Considering the cause of this apparent discrepancy it seemed possible that Wöhlisch' result may have been due to contamination of the material with traces of iron derived from the instruments with which the tendon was cut. The magnetic susceptibility of iron at low field strength is of the order of 103. One gram of diamagnetic substance of the susceptibility of 10−6 will appear to be paramagnetic, therefore, if the content of iron is higher than 10−9 g. If a sample consisting of such a mixture of a ferromagnetic and a (presumably) diamagnetic substance is brought into a nonhomogeneous magnetic field, two forces will act (Curve B). However, Curve B shows saturation with increased field strength. A mixture of a diamagnetic and a ferromagnetic substance is characterized by Curve C.

I. Experimental researches in magnetism

The paper describes in detail experiments of which preliminary notices have already been published in the “ Proceedings of the Royal Society,” vol. 34, p. 39, and in the “ Philosophical Magazine,” November, 1883. The experiments relate to— (1.) The magnetic susceptibility of iron and steel, the form of the magnetisation curve, and the changes of magnetism caused by cyclic changes of magnetising force.