[en] This work is about the study project in the ferriferrous Valentines area. The aim is to determine the existence of iron ore deposits.

[en] The precambrian itabirites and hematite ores of the Morro Agudo iron ore mine on the NE border of the Quadrilatero Ferrifero in Minas Gerais/Brazil contain uranium-bearing minerals and rare-earth elements. In association with phosphates they occupy planes of joints, fractures and cleavage in the area of amphibolitic schist which is intercalated in the s¹-planes of the itabirites and hematite ores. Preliminary analyses of the uranium-bearing minerals were made by energy dispersive X-ray spectrometry and electron microscopy. The results are presented in connection with the lithologic and tectonic features of the Morro Agudo mine. (orig.)

[en] Uranium-series nuclides are responsible for the γ-ray anomalies associated with iron veins in Israel; Th and K contributions are negligible. The U content in hand samples is as high as 2000 ppm. Uranium, like a variety of other trace metals encountered, is disseminated within the Fe phases and does not form independent minerals even at high concentrations. The richest U content is found in hematite. Goethite, derived from the alteration of hematite, contains less U, but still considerably more than the U-poor marine carbonate host rocks, generally of Cretaceous age. Uranium, unlike the other associated trace metals, is geographically confined to those iron veins found within the phosphorite province of the Negev, whereas Fe and other trace metals, which are believed to be derived from hydrothermal solutions rising from depth, are also found along fault zones elsewhere. Uranium is believed to be scavenged from Cenomanian aquifer groundwaters enriched in U which were leached through weathering of Senonian phosphorites. The iron veins enriched in U and other trace metals are located along structural elements which were activated after the Miocene, developing up to subrecent times. 19 refs.; 7 figs.; 2 tabs

[en] This work is about the summary activities of the research work carried out in the Valentines ferriferrous zones . In the graphics are located the different deposit areas.

[en] Some U occurrences from western Mali are studied in relation to the local geomorphological evolution. They occur either as blocks immediately below an Fe-rich crust corresponding to a Lower Pleistocene surface or, lower in the landscape, as boulders found in a crust corresponding to an Upper Pleistocene surface. Even for the high-grade boulders (up to 1000 μg g^-1) U is extremely diffused; it would be localized in aluminous goethites and, in a lesser extent, in an Al-phosphate. A direct experiment of uranyl fixation onto natural species confirms the significant role of sorption onto Fe-hydroxides at neutral or weakly acid pH. According to the evolving surficial conditions (evolution of the Fe-oxyhydroxides from amorphous state to well-crystallized goethite and evolution of pH toward acidic conditions), the primary U content is redistributed but here without any significant chemical migration. 16 refs.; 4 figs.; 1 table

[en] Analyses of iron ores, sinters, blast furnace slags and cast abrasives by Mossbauer spectroscopy are discussed

[en] Preliminary results of the application of the spectrometric neutron gamma-logging for studying iron ores in Kuzbas wells are presented. It is shown that it is possible to identify iron-bearing rocks and ores in wells, to determine the depth and the thickness of the deposition and to estimate quantitatively the content of iron in enriched ores by the spectrometric neutron gamma-logging

[en] The mechanical and physical phenomena observed in cracking of iron ore submitted to forces of compression and graphite submitted to bending have been studied by acoustic emission. The relation between acoustic and mechanical parameters has been established

No abstract available

[en] The presence of iron ores in Uruguay has been carried out in this report the following: a mapping scale 1: 20 000,as well the realization of 1900 meters. of drilling and trenches and the analysis of 120 samples .