Iron Ore Extraction and Environmental Problems

The gradual increase in the exploitation of iron ore leads to a need for the disposal of tailings from its processing. One of the key features of a granular system stacked is its moisture content. This work aimed at evaluating the use of microwave oven to determine the moisture content (following the ASTM D4643-17 standard) of iron ore dewatered tailings, for fast assessment of the geotechnical condition of every stacked layer on disposal areas. The preconized method has showed good agreement with the conventional oven method (standard assay), resulting in linear equation with coefficient of determination of 0.9953. However, the recommended method has shown less accuracy in the range of low moisture values (below 5 %), which does not represent a critical disadvantage from the point of view of geotechnical safety. The economic impact of the method advocated here will be great, since the movement of large volumes of tailings in limited areas leads to customary downtime, often resulting from waiting for confirmatory analytical results to practice within the safety limits.

The use of conventional bentonite binder is favorable in terms of mechanical and metallurgical pellet properties, however, because of its acid constituents bentonite is considered as impurity especially for iron ores with high acidic content. Therefore, alternative binders to bentonite have been tested. Organic binders are the most studied binders and they yield pellets with good wet strength; they fail in terms of preheated and fired pellet strengths. This study was conducted to investigate how insufficient pellet strengths can be improved when organic binders are used as binder. The addition of a low-melting temperature and slag bonding/strength increasing constituent (free in acidic contents) into pellet feed was proposed. Addition of boron compounds such as colemanite, tincal, borax pentahydrate, boric acid together with organic binders such as CMC, starch, dextrin and some organic based binders, into iron oxide pellet was tested. Wet and thermally treated pellet physical-mechanical qualities (balling - moisture content - size - shape - drop number - compressive strengths - porosity - dustiness) were determined. The results showed that good quality wet, dry, preheated and fired pellets can be produced with combined binders (an organic binder plus a boron compound) when compared with bentonite-bonded pellets. While organic binders provided sufficient wet and dry pellet strengths, the boron compounds provided the required preheated and fired pellet strengths at even lower firing temperature. Especially, the contribution of boron compound addition is most pronounced for hematite pellets which do not have strengthening mechanism through oxidation like magnetite pellets during firing. Therefore, addition of boron compound is beneficial to recover the low physical-mechanical qualities of pellets produced with organic binders through slag bonding mechanism. Furthermore, lowering the firing temperature thanks to low-melting boron compounds will be cost-effective for firing part of the pelletizing plants.

Mining activities are important in the economic development of any country endowed with mineral resources. This is due to the economic benefits made available to countries involved in the extraction of mineral resources, internal and external. Internally, employment and revenue generation; externally, a substantial foreign exchange is available to such countries. This research work examined the ore extraction and mining operations of the three (3) largest Mining companies in Palawan, Philippines, and their effect on the environment and the people. This research work undertook a thorough and broader outlook into the environmental implications of Mining on the island of Palawan, both negative and positive. The study utilized the descriptive-evaluative research design while using a combination of quantitative and qualitative methodology. A total of one hundred eighty-eight respondents from four different communities in four municipalities in the Southern part of Palawan were contacted for relevant information through questionnaire administration and interviews. A researcher-made questionnaire was formulated to gather data on mining and ore extraction methods employed by different mining firms in the Province of Palawan, their effect on the environment and people. The study is well-aimed to find out whether the mining companies are compliant with the different government regulations. Findings show that the community members were aware that mining companies employed surface mining as their method of mineral extraction, as revealed by a weighted mean of 2.66. Surface mining causes air/noise pollution, water pollution, and siltation of rivers, and land degradation. Mining companies have attempted re-afforestation of the minedout areas (2.57), resettle affected communities and other measures (2.28), provided livelihoods (3.14) and satisfactory crop compensations (2.85), employment, and other benefits (3.22). They also provided development projects, school buildings as well as healthcare facilities. Mining companies are compliant with all the mining regulations set by the government. It has been recommended stringent and rigorous efforts at re-afforestation, resettlement of affected communities, and other measures aimed at restoring back degraded lands to their proximate state after mining activities should be intensified by the mining companies and additional health facilities be built which will particularly be made accessible to non-workers and other neighboring municipalities at very affordable charges.

At present, Western Sahara is politically one of the most sensitive areas of the World. Its economic development could be achieved through the exploitation of mineral resources that can be found in the almost unexplored area administrated by the Saharawi Arab Democratic Republic. In this paper, we describe applications of known and cost-effective remote sensing techniques to detect and map areas containing mineral deposits, through the enhancement of Landsat ETM+ imageries. Several image processing techniques (false color composite, band ratioing, and principal component analysis) were used to highlight the presence of iron deposits. Two test areas were selected, one in Western Sahara and another one in Algeria. The occurrence of iron deposits in these test areas was assured using literature data for the Algerian test site and through a field campaign for the Western Sahara. There is good agreement between the ground truth data and the results obtained by the enhancements of the satellite images. Landsat images can be downloaded free of charge and their enhancements does not need expensive hardware or software tools. Therefore this technology could be transferred to the Saharawi technicians, enabling them to explore and manage the mineral resources of their own country independently.

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The study area is located in the northeast half of Nairiz in Fars province. Geologically the units of study area are located in Sanandaj - Sirjan zone and with northwest - southeast general trend. Most of these units are calcareous units, schistite-chlorite units and amphibolite units. In this study, ASTER ester images and terrestrial magnetometry data were used to potential and identify promising alteration and analytical regions of the iron ore mineralization system in the study area. In addition, false color combination, band ratio and principal component analysis methods were used on ASTER data and the zones with ferrous mineralization and related alterations were identified and quantified and processed. Qualitative terrestrial magnetometry data Magnetic residual maps, pole inversion map, ultrasound continuum, first order vertical derivative, tilt angle (Tilt map), analytical signal were prepared in the study area, which

On November 5th, 2015, , the Fundão dam rupture released N50 million m 3 of ore tailings into the Doce River, Minas Gerais State, Brazil. The huge volume of mud spread along the river and reached the sea, 17 days after the disaster, in Regência, Espírito Santo State (ES). In 2018, after three years of the disaster, the impacts of the ore tailings in the marine environment are still unclear. This study aims to investigate possible short-term impacts in marine biodiversity caused by the ore tailings' mud over the reef ecosystems that are closest to the disaster area: i.e. recently discovered reefs in the southern Abrolhos Bank. A remote sensing surveillance including winds, sea surface temperature, total suspended material and watercolor (MODIS Aqua data) indicated that the iron tailings plume reached the southern portion of Abrolhos Bank on June 16th, 2016. Subsequently, to obtain further evidence of the presence of the tailings in the coral reefs, water samples were collected in a gradient spanning from the river estuary to the reefs in southern Abrolhos Bank, we also analyzed the isotopic and microbial composition of the samples, as well as the reef benthic composition. Despite no clues of negative impact on benthic (coral) communities, isotopic analysis con fi rmed the presence of the plume over the reefs area. This study serves as a baseline for future long-term impact assessments of the health of coral reefs in the Abrolhos Bank.