Feasibility project for implementation of conveyor belts in an iron ore mine. Study case: Fabrica Mine in Minas Gerais State, Brazil

AbstractNative palladium is rare and occurs in oxidizing environments (hematite stability field) and consistently has very low contents of other metals. On the other hand, gold may contain significant amounts of alloyed palladium. A nugget of palladian gold, obtained from a specularite-rich auriferous vein (‘jacutinga’) of the Gongo Soco iron ore mine, Quadrilátero Ferrífero, Minas Gerais, allows the definition of a paragenetic sequence of native palladium formation. The cm-sized nugget is brecciated and consists of fragments of palladian gold [Au0.79Pd0.09Cu0.07Ag0.04Hg0.01] with inclusions of isomertieite [Pd11Sb2As2], cemented by kaolinite-hematite-palladian gold infill. The isomertieite inclusions are preferentially fractured and display various degrees of alteration to a Pd-O phase. Native palladium occurs as a crystallized component within the Pd-O phase, with microstructural and chemical features suggesting a desiccation process. It is proposed that native palladium forms by (1) oxidation of a pre-existent palladium mineral to a Pd-O phase, and (2) subsequent crystallization of native palladium from the Pd-O phase, by oxygen loss and dehydration. This process operates in a low-temperature hydrothermal or weathering environment and leads to strong fractionation of palladium and gold.

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Hydrosedimentologic disturbance index applied to watersheds of Minas Gerais state

Ciência e Agrotecnologia ◽

10.1590/s1413-70542014000100007 ◽

2014 ◽

Vol 38 (1) ◽

pp. 61-67 ◽

Cited By ~ 5

Author(s):

Matheus Fonseca Durães ◽

Carlos Rogério de Mello

Keyword(s):

Natural Resources ◽

Subsequent Development ◽

Minas Gerais ◽

Environmental Response ◽

Minas Gerais State ◽

Assessment And Monitoring ◽

Hydrological Stress ◽

Study Case ◽

The Relationship ◽

Potential Tool

Ecological indicators have become important tools for assessment and monitoring of natural resources, being the understanding of the relationship between antropic activities and the environmental response essential for their structuring. Although the development of potential indicators may prove sensitive to many variables, they must demonstrate their ability to take the surrounding conditions, from those relatively preserved to those highly disturbed. Based on this premise, the development of the Hydrossedimentological DisturbanceIndex (HSDI) for environmental assessment at watersheds in Minas Gerais state, emerges as a potential tool to support decisions which should be focused on the improvement of natural resources management. A HSDI proposal was developed from the hydrological, climate and water quality database available in Minas Gerais state, highlighting sediment transport (ST), hydrological stress (HS), groundwater recharge (Rec) and current soil erosion potential (SEP), working with a robust tool for determining the weights of factors with appropriate scientific background and subsequent development of map for analyzing its distribution, having Paraopeba river watershed as study case.

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