scholarly journals GPR Survey on an Iron Mining Area after the Collapse of the Tailings Dam I at the Córrego do Feijão Mine in Brumadinho-MG, Brazil

2019 ◽  
Vol 11 (7) ◽  
pp. 860 ◽  
Author(s):  
Jorge Luís Porsani ◽  
Felipe Augusto Nascimento de Jesus ◽  
Marcelo Cesar Stangari
Keyword(s):  
Electromagnetic Waves ◽  
Iron Ore ◽  
Mining Area ◽  
Tailings Dam ◽  
Geophysical Investigation ◽  
Minas Gerais State ◽  
Underground Equipment ◽  
Pioneer Effort ◽  
Ground Penetrating ◽  
Humanitarian Work

This article shows the interesting results of a pioneer effort by IAG/USP researchers to use ground-penetrating radar (GPR) for humanitarian purposes, guiding the rescue of victims in the tragedy of Brumadinho. The tailings Dam I at the Córrego do Feijão iron ore mine, located in the Brumadinho complex, Minas Gerais State, Brazil, collapsed on 25 January 2019. About 11.7 million m3 of mining mud was spilled from the dam, burying bodies, equipment, structural buildings, buses, and cars along a length of 8.5 km up to the Paraopeba River. Additionally, the contaminated mud traveled more than 300 km along the bed of the Paraopeba River toward the São Francisco River. This work shows the results of a geophysical investigation using the GPR method 17 days after the event. To carry out the geophysical survey, an excavator was used for soil compaction. The data acquisition was performed on the tracks left by the excavator chain using SIR-4000 equipment and antennas of 200 and 270 MHz (GSSI). The GPR studies aimed to map bodies, structural buildings, and equipment buried in the mud. The location of the profiles followed preferably the edge of the slope due to the higher probability of finding buried bodies and objects. The GPR results allowed the detection of subsoil structures, such as concentrations of iron ore and accumulations of sand from the dam filter. The GPR was effective because the iron ore sludge in the mixing process became porous and the pores were filled with air, which provided penetration and reflection of the GPR electromagnetic waves up to a depth of 3.5 m. The results were surprising. Although no bodies or underground equipment were found, the results of this research served to eliminate the studied areas from future excavations, thus redirecting the rescue teams and optimizing the search process. These important results can serve as an additional motivation for the use of GPR in future humanitarian work in areas of tragedies.

Brazil’s dam disaster alters iron ore market dynamics

2019 ◽  
Keyword(s):  
United States ◽  
Iron Ore ◽  
The United States ◽  
High Grade ◽  
Tailings Dam ◽  
Northern Australia ◽  
Content Type ◽  
Steel Mills ◽  
Metallurgical Coal ◽  
Minas Gerais State

Subject Iron ore market. Significance China, which represents 70% of seaborne iron ore demand, has seen its port inventories fall after the tailings dam burst at Vale’s Brumadinho mine in Brazil’s Minas Gerais state in January. The 1.5-billion-tonne market is tightening as the particularly heavy cyclone season has also idled infrastructure in northern Australia. Steel mills are responding by restocking and prices are rallying above 100 dollars per tonne, up more than 50% year-on-year. Impacts China’s Chinalco leaving talks to buy Rio Tinto’s stake in Guinea's Simandou project clouds the future of West Africa’s largest deposit. Singapore Exchange's launch of a high-grade 65% iron ore derivative contract is a new step to financialise this market; more will come. The penalties imposed on alumina impurities in iron ore will increase if prices of metallurgical coal remain strong. If the United States decides to expand its tariffs on steel imports, iron ore would be one of the casualties. After seven years’ absence, magnetite is in demand to fill a gap in iron ore quality, with China already buying 4 million tonnes.

REFLECTION COEFFICIENT OF AN ELECTROMAGNETIC WAVE IN CONDUCTIVE MEDIA

2018 ◽  
pp. 100-106
Author(s):  
M. S. Sudakova ◽  
M. L. Vladov ◽  
M. R. Sadurtdinov
Keyword(s):  
Reflection Coefficient ◽  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Water Contamination ◽  
Survey Design ◽  
Direct And Inverse Problems ◽  
The Difference ◽  
Ground Penetrating ◽  
Ideal Dielectric

Within the ground penetrating radar bandwidth the medium is considered to be an ideal dielectric, which is not always true. Electromagnetic waves reflection coefficient conductivity dependence showed a significant role of the difference in conductivity in reflection strength. It was confirmed by physical modeling. Conductivity of geological media should be taken into account when solving direct and inverse problems, survey design planning, etc. Ground penetrating radar can be used to solve the problem of mapping of halocline or determine water contamination.

Iron ore mining promotes iron enrichment in sediments of the Gualaxo do Norte River basin, Minas Gerais State, Brazil

2013 ◽  
Vol 71 (9) ◽  
pp. 4177-4186 ◽  
Author(s):  
Aline Sueli de Lima Rodrigues ◽  
Guilherme Malafaia ◽  
Adivane Terezinha Costa ◽  
Hermínio Arias Nalini Júnior
Keyword(s):  
River Basin ◽  
Iron Ore ◽  
Minas Gerais ◽  
Iron Enrichment ◽  
Minas Gerais State

scholarly journals The Forecasting of Groundwater Fluctuations using Time Series Analysis and Combination of Data-Driven Models

2021 ◽  
Author(s):  
Amirhossein Najafabadipour ◽  
Gholamreza Kamali ◽  
Hossein Nezamabadi-pour
Keyword(s):  
Iron Ore ◽  
Least Squares Method ◽  
Moving Average ◽  
Groundwater Resources ◽  
Mining Area ◽  
Data Driven ◽  
Short Term ◽  
Iron Ore Mine ◽  
Groundwater Fluctuations ◽  
Groundwater Drainage

The Forecasting of Groundwater Fluctuations is a useful tool for managing groundwater resources in the mining area. Water resources management requires identifying potential periods for groundwater drainage to prevent groundwater from entering the mine pit and imposing high costs. In this research, Auto-Regressive Integrated Moving Average (ARIMA) and Holt-Winters Exponential Smoothing (HWES) data-driven models were used for short-term modeling of the groundwater fluctuations in a piezometer around the Gohar Zamin Iron Ore Mine. For this purpose, 250 non-seasonal groundwater fluctuations data in the period 22-Nov-2018 to 29-Jul-2019, 200 data for modeling, and 50 data for prediction were used. To take advantage of all the features of the two developed models, the predictions are combined with different methods and specific weights. The results show better accuracy for the ARIMA method between the two short-term forecasts, while the HWES method requires less time for modeling. Also, among all the predictions made, the highest accuracy for the combined least-squares method is for forecasting the groundwater fluctuations in the short-term. All the forecasts show a decrease in the groundwater fluctuations, indicating pumping wells around the Gohar Zamin Iron Ore Mine area.

scholarly journals Study Effect of Objects Orientation in the Mediums On GPR Signal Reflections Using FDTD Simulation

2018 ◽  
Vol 3 (11) ◽  
pp. 73-77
Author(s):  
Aye Mint Mohamed Mostapha ◽  
Gamil Alsharahi ◽  
Abdellah Driouach
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Ground Penetrating Radar ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Ground Surface ◽  
Propagation Path ◽  
Fdtd Simulation ◽  
Ground Penetrating ◽  
Dielectric Objects

Ground penetrating radar (GPR) is a very effective tool for detecting and identifying objects below the ground surface.  based on  the propagation and reflection of high-frequency electromagnetic waves. The GPR reflection can be affected by many things like the type of objects orientation, their shapes ..ect. The purpose of this paper is to  study by simulation the effect of objects orientation in two different mediums (dry and wet sand) on the GPR signal reflection using Reflexw software which is based on a numerical method known as finite difference in time domain (FDTD).  The simulations that have been realized included a conductor  and dielectric objects. The results obtained have led us to find that the propagation path, the reflection strength and the signal form change with the change of object orientation and nature. To confirm the validity of the results, we compared them with experimental results previously published by researchers under the same conditions.

WISDOM Antenna Pattern in the presence of Rover and Soil

2021 ◽  
Author(s):  
Wolf-Stefan Benedix ◽  
Dirk Plettemeier ◽  
Christoph Statz ◽  
Yun Lu ◽  
Ronny Hahnel ◽  
...  
Keyword(s):  
Pattern Matching ◽  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Complete System ◽  
Near Field ◽  
System Model ◽  
Soil Types ◽  
Broadband Antenna ◽  
Shallow Subsurface ◽  
Ground Penetrating

<p>The WISDOM ground-penetrating radar aboard the 2022 ESA-Roscosmos Rosalind-Franklin ExoMars Rover will probe the shallow subsurface of Oxia Planum using electromagnetic waves. A dual-polarized broadband antenna assembly transmits the WISDOM signal into the Martian subsurface and receives the return signal. This antenna assembly has been extensively tested and characterized w.r.t. the most significant antenna parameters (gain, pattern, matching). However, during the design phase, these parameters were simulated or measured without the environment, i.e., in the absence of other objects like brackets, rover vehicle, or soil. Some measurements of the rover's influence on the WISDOM data were performed during the instrument's integration.</p><p>It was shown that the rover structure and close surroundings in the near-field region of the WISDOM antenna assembly have a significant impact on the WISDOM signal and sounding performance. Hence, it is essential to include the simulations' environment, especially with varying surface and underground.</p><p>With this contribution, we outline the influences of rover and ground on the antenna's pattern and particularly on the footprint. We employ a 3D field solver with a complete system model above different soil types, i.e., subsurface materials with various combinations of permittivity and conductivity.</p>

Corrigendum to: Pandora is on Earth: new species of Eukoenenia (Palpigradi) emerging at risk of extinction

2020 ◽  
Author(s):  
Maysa F. V. R. Souza ◽  
Rodrigo L. Ferreira
Keyword(s):  
New Species ◽  
Iron Ore ◽  
Mining Activities ◽  
Economic Interest ◽  
Brazilian Legislation ◽  
Iron Quadrangle ◽  
Minas Gerais State ◽  
Risk Of Extinction ◽  
Qualitative Characters

In 2008 the change to the Brazilian legislation regarding the use of natural caves has caused an increase in the number of studies on environmental impacts involving caves. The legislation requires the classification of such environments according to their importance, and caves that are not classified highly may be irreversibly impacted. Thus, caves in rocks of high economic interest have been intensively sampled, which has resulted in the collection of several specimens of Palpigradi in them. The Iron Quadrangle (in Minas Gerais state) stands out among these areas as one the most important sources of iron ore in Brazil. Several palpigrades from this region are housed in collections: most of them belong to the edaphic species Eukoenenia ferratilis, and a small portion belong to new species that are morphologically quite distinct from E. ferratilis, with longer bodies and more elongated appendages, indicating the presence of troglomorphisms. Therefore, the present study aimed to describe three new troglobitic species of Eukoenenia, which can be distinguished morphometrically and by means of some qualitative characters. These descriptions are important for the preservation of the caves where they occur, since the presence of troglobitic species increases the relevance of the caves, which have been severely threatened by mining activities.

scholarly journals THE RIO DOCE MINING DISASTER IN BRAZIL: BETWEEN POLICIES OF REPARATION AND THE POLITICS OF AFFECTATIONS

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Andréa Zhouri ◽  
Raquel Oliveira ◽  
Marcos Zucarelli ◽  
Max Vasconcelos
Keyword(s):  
Iron Ore ◽  
The Political ◽  
Corporate Management ◽  
Tailings Dam ◽  
Way Of Life ◽  
Anthropological Perspective ◽  
Political Processes ◽  
Iron Ore Tailings ◽  
Affected Person ◽  
Doce River

Abstract This article analyses the policies of affectations in the context of the disaster which occurred in late 2015, when an iron ore tailings dam ruptured, affecting thousands of families in the Rio Doce River Valley, in the southeast of Brazil. The paper discusses the challenges faced by victims of the disaster, given that the ‘affected person’ as a social subject goes through a dramatic process of forced sociability, forged in political processes and bureaucratic demands which are alien to her/his world. As a consequence, the claims of victims are transmuted by the rationalities and techniques of corporate management, therefore disabled and re-codified by taxonomies which define forms of damage reparations, as well as modes of reconstruction of their way of life. From an anthropological perspective, we examine the struggle between the objectification imposed by the policy of affectation and the political subjectivation of actors compulsorily brought to contentious settings over the control of their own destiny.

Ground‐penetrating radar velocity tomography in heterogeneous and anisotropic media

Geophysics ◽  
1997 ◽  
Vol 62 (6) ◽  
pp. 1758-1773 ◽  
Author(s):  
Don W. Vasco ◽  
John E. Peterson ◽  
Ki Ha Lee
Keyword(s):  
Ground Penetrating Radar ◽  
Electromagnetic Waves ◽  
Numerical Technique ◽  
Anisotropic Media ◽  
Perturbation Approach ◽  
Low Velocity ◽  
Weak Anisotropy ◽  
Geological Features ◽  
Velocity Anomalies ◽  
Ground Penetrating

A ray series solution for Maxwell's equations provides an efficient numerical technique for calculating wavefronts and raypaths associated with electromagnetic waves in anisotropic media. Using this methodology and assuming weak anisotropy, we show that a perturbation of the anisotropic structure may be related linearly to a variation in the traveltime of an electromagnetic wave. Thus, it is possible to infer lateral variations in the dielectric permittivity and magnetic permeability matrices. The perturbation approach is used to analyze a series of crosswell ground‐penetrating radar surveys conducted at the Idaho National Engineering Laboratory. Several important geological features are imaged, including a rubble zone at the interface between two basalt flows. Linear low‐velocity anomalies are imaged clearly and are continuous across well pairs.

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