The mass absorption coefficients of tungsten and tantalum were measured with soft x-ray photons from 1450 eV to 2350 eV using an undulator source. This region includes the M3, M4, and M5 absorption edges. X-ray absorption fine structure was calculated within a real-space multiple scattering formalism; the predicted structure was observed for tungsten and to a lesser degree tantalum as well. Sep...

BACKGROUND AND PURPOSE We have noted that glue-Lipiodol mixtures harden prematurely in the catheter during embolization of brain arteriovenous malformations. However, we observed that hardening of this embolic material does not occur when tungsten powder is added to the glue mixture. In order to clarify the effect of tungsten powder on the glue mixture, we evaluated the reaction time and hardne...

In the 17century, German miners discovered a red coloured ore they believed to contain copper. They discovered upon analysis that there was no copper but that a useless, smelly material was actually present. Thinking the ore was evil they dubbed it "Kupfernickel" or Old Nick's Copper, which meant false or bad copper. Swedish scientist Baron Axel Frederich Cronstedt in 1751 finally isolated nick...

Resource gathering is depending on leaner crude ores. Iron ore mining typifies this trend. To make lean taconite iron ores useful required a technologic breakthrough-pelletization. The shift to iron ore pellets has the advantage that they require less energy and labor per ton of molten iron than high-grade naturally concentrated ores. Increased reliance on pellets causes a geographic shift of s...

Two new species of Leptokoenenia Condé 1965 (Eukoeneniidae: Palpigradi), Leptokoenenia pelada sp. nov. and Leptokoenenia thalassophobica sp. nov., are described based on both male and female specimens collected in iron ore caves from the Brazilian Amazon. This is the first record of the genus for the Americas. Furthermore, a new combination is stated for Eukoenenia gallii based on its morphology.

A fundamental study was carried out on the high-temperature zone flow resistance during iron ore sintering. In present work, firstly, quartz sand was used to replace iron ores to investigate the impact of temperature if bed structure has no change; then a three-layer bed structure was used to explore the primary factors controlling high-temperature zone structure for airflow. The zone where tem...

The collapse of the Fundão tailings dam at Mariana (State of Minas Gerais, Brazil) started a huge human tragedy and likely the most serious environmental disaster in recent Brazilian history. The dam had contained waste from processing iron ore from mines owned by Samarco, a joint venture company of the Brazilian Vale S.A. and the Anglo-Australian BHP Billiton Ltd. Following ineffective attempt...

The risks in the evaluation of mining projects are directly related to the probability of errors in the estimates, and, as the estimates are based on sampling results, this activity must be performed in a careful and planned way, to prevent surprises at the beginning of operation. To validate the representativeness of the borehole samples selected for the mineral processing studies, the geologi...

Abstract. In order to study the effect of carbon impurity in plasma on tungsten first wall, hydrogen-carbon mixed ion beam was irradiated to tungsten. It was found that very small amount of carbon (~0.3% or more) significantly enhanced blister formation. According to XPS analysis, all of tungsten atoms in a top surface were combined with carbon atoms to form tungsten carbide (WC) layer (~6 nm t...