Iron ore deposits

There is a continuous debate over the impact of mining operations especially in northern parts of the USA near Boundary Water Canoe Area in Minnesota on the environment as well as the Nation's waters and, the positive impacts on the regions economy and jobs. This paper examines the use of emerging technologies to address wastewater treatment issue associated with these operation so that these enterprises can continue operating and creating economical benefits and jobs without negative impact on the environment. Removel of sulfates were particulary emphasized.

APRESENTAÇÃO: Fruto de um extenuante trabalho de pesquisa para um doutoramento em geografia na Faculdade de Filosofia, Letras e Ciências Humanas da Universidade de São Paulo, este Livro é uma baliza de referência para aqueles que se preocupam em entender a industrialização brasileira baseada na substituição de importações. Visto que, debate com rigor científico a mineração do ferro no contorno da reprodução ampliada do capital ao desvendar o processo de implantação, o caráter territorial do beneficiamento, a dinâmica da circulação, as teias de ligações com o Estado e as suas conexões históricas. Envereda pelo caminho do aprofundamento teórico da mineração de ferro e derivados, inserida em uma economia globalizada, plenamente associada aos ciclos longos com fases de expansão e depressão, em que, neste contexto, o tema central (mineração) encaixa-se com iminente exatidão. (Tito Carlos Machado Oliveira)

Iron ore deposits of Franche-Comté (France)
"Iron ores are so common in the province, we can consider its territory as entirely ferruginous. It would be easier to count the places where there is no iron ore than those where we find it ." This observation extracted from 'A look at the province of Franche-Comté presented to Mr. de La Chaise by "his humble servant, Father TIBURCE ", written in 1775, reflects substantially the reality that results of research done in the field or in the bibliography regarding iron ores. Such is the geographical distribution of iron deposits that at every point of the province, ironmasters disposed of ore resources close to  their blast furnace.
Except a few veins and stockworks associated with paleozoic basement of the southern Vosges, most of Franche-Comté iron ores are either marine jurassic and cretaceous deposits (domerian, toarcian, aalenian, callovian, oxfordian and valanginian oolitic iron deposits) or deposits formed by weathering, intact or reworked, (eocene and plio-pleistocene pisolitic iron deposits and ferricrusts).

A B S T R A C T The Meishan iron deposit contains 338 Mt of iron-ore reserves at 39% Fe and represents the largest magneti-te–apatite deposit in the Ningwu Basin of eastern China. Controversy has long existed about whether this deposit had a hydrothermal or iron-oxide melt origin. Iron mineralization is genetically related to plutons that are composed of gabbro-diorite, which were emplaced at 130 ± 1 Ma. These rocks have SiO 2 contents of 51.72–54.60 wt%, Na 2 O contents of 3.47–4.04 wt%, K 2 O contents of 2.02–2.69 wt%, and K 2 O/Na 2 O ratios of 0.51–0.73. These rocks are enriched in LILEs and LREEs and depleted in Nb, Ta, and Ti, which indicates that the magma originated through partial melting of an enriched lithospheric mantle source in a subduction environment. A pattern of decreasing initial Sr isotopic ratios and increasing εNd(t) values with time in Early Cretaceous magmatic rocks of the Ningwu Basin may indicate incorporation of increasing proportions of asthenospheric mantle material into the source magma, which is consistent with the processes of lithospheric thinning and asthenospheric upwelling in eastern China related to Mesozoic subduction of the Paleo-Pacific Plate. Two stages of magnetite are found in the gabbro-diorite: (1) early-crystallized magnetite as euhedral–subhedral crystals in larger clinopyroxene crystals, and (2) later-crystallized magnetite and accompanying ilmenite grains in the voids between plagioclase and clinopyroxene crystals. The formation of magnetite before clinopyroxene, combined with the results of Fe–Ti oxide geothermometry and analysis of magnetite V content, indicates that the oxygen fugacity of the source magma was greater than ΔFMQ +2.2 at an early stage (> 640 °C) but decreased to ΔFMQ −2.66 as abundant magnetite crystallized at a later stage (∼489 °C). The early crystallization of magnetite at a high oxygen fugacity does not support a Fenner evolution trend for the primitive magma and diminishes the likelihood of liquid immiscibility, which could have generated an iron-rich melt, and is thus inconsistent with an iron-oxide melt origin for the Meishan iron deposit. The δ 34 S values of pyrite (6.6–15.1‰) and anhydrite (15.6–16.9‰) in the deposit and the occurrence of evaporites under the volcanic rocks likely indicate that the iron ores and alteration rocks of the Meishan deposit were formed by the circulation of fluids of evaporitic origin driven by heat from the hypabyssal gabbro-diorite intrusives. In the late magmatic stage, oxygen fugacity decreased to a reducing range, triggering the reduction of sulfate to reduced sulfur and leading to local gold and pyrite mineralization.

This study utilizes the trace and rare earth element geochemistry of bulk ores and in situ LA-ICP-MS analyses of mineral grains to clarify the controversy in the origin of the Bahariya sedimentary iron ores, Egypt. Different types of iron ores were identified in the Bahariya Oasis including high grade, high-Mn, high-Ba, oolitic, and ochreous iron ores. Hematite and goethite are the main constituents of the studied ores with some manganese oxide and hydroxide minerals (pyrolusite, bixbyite, cryptomelane, aurorite, romanechite, manjiroite, and pyrochroite). Barite is common in the high-Ba ore, while some quartz, calcite, and halite are detected in the oolitic iron ore. High-Mn iron ores are characterized by higher contents of SiO 2 , Al 2 O 3 , MgO, CaO, Na 2 O, and K 2 O, while high-Ba iron ore has higher TiO 2 contents. Analyses of bulk ores and in situ mineral grains are characterized by substantially high contents of Ba (average of 9497 ppm); also Zn and Sr occur in considerably high concentrations (averages of 4263 and 429 ppm, respectively). Mn-rich ores and Mn-bearing minerals show relative enrichments of trace metals compared to the Mn-poor ores probably due to the ability of Mn-bearing minerals to fix such trace metals by adsorption, absorption, and/or replacement. The ΣREE ranges between 2.6 and 80 ppm with an average of 23 ppm. High-Mn ores show higher ΣREE (average of 61 ppm) compared with the low Mn ore (average of 13 ppm). The oolitic iron ore shows very low ΣREE content (7 ppm). Red and yellow ochers from El Gedida mine have similar ΣREE values (38 and 39 ppm, respectively), while red ocher from the Ghorabi area has relatively higher ΣREE (57 ppm). Chondrite-normalized REE patterns of all types of iron ores, whether in the form of bulk ores or Fe-and Mn-bearing grains, have LREE enrichment relative to HREE as shown by (La/Yb) N ratios that vary from 1.7 to 29.4. Majority of the bulk samples and mineral grains have negative Eu anomalies with Eu N /Eu* ranges from 0.68 to 0.8. However, bulk samples of one high grade and high-Ba ores as well as some of the Mn-bearing grains from El Gedida ores show positive Eu anomalies with Eu/Eu* ranges from 1.1 to 17.7. With few exceptions , all bulk ores and mineral grains show negative Ce anomalies with Ce/Ce* range from 0.28 to 0.96. A seawater precipitation (hydrogenous to hydrothermal exhalite) is proposed for the Bahariya iron ores. The hy-drogenous origin is suggested based on the occurrence of high-Mn iron ores in the base of the iron ore succession, oolitic texture of some of these ores, Si–Al plot, low La/Ce ratios, high Y/Ho ratios, and LREE-enriched patterns with negative Eu anomalies of most of the bulk ores and mineral grains. The hydrothermal contribution to the source of these iron ores can be evident from the high contents of some trace elements such as Ba, Zn, and Mo, and plots the analyzed samples in the hydrothermal fields of the Fe–M–(Ni + Co + Cu) * 10 ternary diagram, (Co + Ni)–(As + Cu + Mo + Pb + V + Zn) and (Co + Ni + Cu–Co/Zn) binary plot, low ΣREE concentrations and positive Eu anomalies and high La/Ce ratios in some of the analyzed samples. The hydrothermal contribution looks for local effect and is restricted to El Gedida area.

The giant polymetallic Bayan Obo REE-Nb-Fe ore deposit is the largest REE deposit in the world. Despite the fact that a great number of works have been done on the deposit, its origin remains controversial. Various genetic models have been proposed, including sedimentary origin, magmatic origin, hydrothermal origin or origin with multiple processes. Here the Fe isotope compositions of different types of rocks from the deposit and related geological formations, such as carbonatites, mafic dykes, and Mesoproterozoic sedimentary iron formation and carbonates, are systematically investigated. For the ore deposit, the average ı 56 Fe values are −0.03 ± 0.16‰ (2SD, n = 14), 0.01‰ ± 0.24‰ (2SD, n = 6), −0.07 ± 0.24‰ (2SD, n = 19) for bulk samples of fine-grained iron ores, gangue rocks and ore-hosting dolomite marble, respectively; and 0.01 ± 0.14 (2SD, n = 14), 0.08 ± 0.18 (2SD, n = 3), −0.21 for the magnetite, hematite and dolomite, the main Fe oxide and carbonate minerals in the deposit. The narrow range of the near-zero ı 56 Fe values of fine-grained iron ores and Fe oxide minerals are consistent with those of magmatic products such as igneous rocks and magmatic iron ores, but different from those of sedimentary or hydrothermal products like Precambrian sedimentary iron formations and hydrothermal iron ores reported previously. The slightly negative Fe isotope values of the orehosting dolomite marble are consistent with those of the carbonatite dykes in Bayan Obo area and the typical carbonatites worldwide, but different from those of Mesoproterozoic sedimentary carbonates. The small Fe isotope fractionations between magnetite and dolomite ( 56 Fe magnetite-dolomite ≈ 0.23‰), and between hematite and magnetite ( 56 Fe hematite-magnetite ≈ 0.07‰), indicate that the ore deposit experienced a very high temperature. Overall, the Fe isotope compositions are inconsistent with either sedimentary or hydrothermal origin, but support a magmatic origin for the Bayan Obo deposit.

The modern mining industry employs plenty of exploration data digitization and utilizes computational resources for future forecasting and production scheduling. In that regard, geostatistics and mine planning as disciplines are critical parts of the mining business. However, traditional mine planning does not allow the risk management associated with geological uncertainty due to using a single mineral resource model as an input. Integration of stochastic geostatistical realizations into mine planning can help to minimize the risk of not meeting the production targets. Nevertheless, there are still many limitations in commercially used stochastic geostatistical algorithms, particularly multivariate methods. For example, it is common to deal with challenging datasets containing bivariate complexities among variables, such as inequality constraints. The poor reproduction of this feature can lead to an overestimation of the secondary variable, affecting the processing cost. Therefore, this work's motivation is to propose a way to model datasets containing inequality constraints between variables and generate production schedules considering geological uncertainty. 
This study proposes an algorithm based on a hierarchical cosimulation framework integrated with inverse transform sampling, which is designed to model variables within thresholds derived from a linear inequation. The proposed algorithm is applied to a real case study from an Iron deposit with a sharp inequality constraint between Iron and Silica. Results are assessed based on validation of marginal distribution, spatial correlation and bivariate relationship. Overall, the proposed algorithm demonstrates simulations of similar quality as the conventional approach, which can be observed through histogram and variogram validations. Unlike conventional cosimulation, the integration of inverse transform sampling helps to reproduce an inequality constraint in the bivariate relationship and increases the correlation coefficient.
Next, a two-stage stochastic production scheduling approach is used as a replacement for deterministic mine planning. In the first stage, extraction periods are obtained using an e-type model and remain fixed for all realizations. The second stage decisions re-evaluate block destinations based on a set of realization. This approach minimizes the risk of sending an extracted material to the wrong destinations while producing optimal production schedules. Its NPV is only 17% lower than the best possible NPV for each scenario and 59% higher than the deterministic plan. Moreover, the proposed cosimulation algorithm increases the NPV by 0.76% due to the reproduction of an inequality constraint.

Pakistan has been blessed with a large number of natural resources beneath its soil. Most of them are exploiting and playing their part in the country's economic growth but many need detailed exploration to bring into production. In this report, five metals of Balochistan are described with their localities and reserve potential. These are Iron, Copper, Chromite, Lead, Zinc.

— Nigde Massif is the southest part of the CACC (Central Anatolian Crystalline Complex) which is composed of magmatic and metamorphic rocks. Niğde Massif consist of Gümüşler, Kaleboynu and Aşıgediği formations. Üçkapılı granitoid cuts all these units. The iron mineralization is observed in all the units forming an irregular distribution in the Niğde massif. Field studies and the results of mineralogical research on polished sections indicates that the origin of the mineralization is hydrothermal. The iron ore deposits in the study area have a paragenesis composed of magnetite, hematite and limonite. The mineralization paragenesis is accompanied by chalcopyrite, malachite, covellite, chalcocite, native Cu and native Au.

Economic Geography of the Australian Mining Industry.  Tijdschrift Voor Economische En Sociale Geografie.  2016.  ISSN: 1467-9663. 
http://onlinelibrary.wiley.com/doi/10.1111/tesg.12185/abstract

This paper is a discussion of the economic geography of Australia. It provides a history of foreign investment in mining, and discusses several resources booms that shaped the landscape of the continent and the role of governments (state, federal and territory governments) in this process. The paper presents a chronological account of the development of the Australian mining industry, the primary activities of which are the extraction, and export of unprocessed coal, iron, minerals and increasingly natural gas. The paper analyzes the industry’s interaction with foreign investment and government assistance (that is government spending in relation to the industry such as subsidies, loans and infrastructure construction etc). Australia’s trade and foreign investment environment have long been deregulated. The Australian mining industry has benefited from this deregulation. But its most spectacular period has been the “commodities super-cycle” of the 2000s-2010s. Overall, its contribution to exports has long typified the mining industry. The discussion herein draws attention to the applicability of the ‘eclectic theory’ in reference to foreign investment in mining. That is, investing mining MNEs (multinational enterprises) have three main types of ‘locational advantages’ in Australia, 1) volume of the availability of resources, 2) foreign investment regulatory environment and 3) government assistance that benefits the mining industry’s expansion.
Keywords: Australia, economic geography, mining, FDI, government, neoliberalism

Die Erforschung der Eisenerze im Raum Oberpullendorf bzw. in der Landseer Bucht nahm eigentlich durch Archäologen und "Heimatforscher" ihren Ausgang. In den Wäldern des mittleren Burgenlandes um Oberpullendorf -Unterpullendorf -Großmutschen (römische Bernsteinstrasse) sowie Langental -Großwarasdorf -Nebersdorf erregten hunderte trichterförmige Vertiefungen erste Aufmerksamkeit (SCHMID, , 1977, die sich in weiterer Folge als Pingen von mehreren, lange zurückliegenden Bergbauen erwiesen. Ab der zweiten Hälfte der Sechzigerjahre wurden gezielt auf breiter wissenschaftlicher Basis Forschungen durchgeführt. Durch die detaillierte Bestandsaufnahme und Vermessung der Pingenfelder im Bezirk Oberpullendorf konnte MEYER (1977) in diesem Gebiet allein 22 Pingenfelder ausweisen (siehe Abb. am Ende dieses Beitrages). In der geologischen Karte 107/108 Mattersburg/Deutschkreutz (KÜMEL, 1957 b) wird darauf kein Bezug genommen, sehr wohl aber in der geologischen Karte 138 Rechnitz . Die zeitliche Stellung der burgenländischen Eisenerzgewinnung und -verhüttung wird von KAUS (1977) von der späten Hallstattkultur bis in die Römerzeit sowie im Frühund Hochmittelalter angegeben. Es ist naheliegend, dass die Limonite auch für die Herstellung von Mineralpigmenten von ocker über rotbraun bis dunkelbraun bereits seit der Jungsteinzeit zumindest lokale Bedeutung hatten. Über die mittelburgenländischen Eisenschlackenplätze und das Eisenhüttenwesen berichtet BIELENIN (1977). Eine eingehende Diskussion über die Lagerstätten und Verhüttung des berühmten "Ferrum Noricum" stammt von KAUS (1981). In der Stadtgemeinde Oberpullendorf ist ein Schauraum über die ur-und frühgeschichtliche Eisenindustrie eingerichtet. Die mineralogische Untersuchung erfolgte durch KURZWEIL (1971KURZWEIL ( , 1977. In der Österreich weiten Darstellung über Minerallagerstätten werden diese Vorkommen im "Eisenerzbezirk Landseer Bucht" (WEBER et al., 1997 b) zusammengefasst.

Ao João Batista, meu pai, e à minha vó Gilda com os quais não posso mais compartilhar a felicidade dessa conquista; À minha mãe, Cleusa, ao vô Pedro e à Liraine, porque há um pouco deles em tudo que faço; Ao Luís António Boareto Silva, pela companhia durante esses anos do Doutorado e pelo que ainda viveremos juntos.

Abstract The Meishan iron deposit contains 338 Mt of iron-ore reserves at 39% Fe and represents the largest magnetite–apatite deposit in the Ningwu Basin of eastern China. Controversy has long existed about whether this deposit had a hydrothermal or iron-oxide melt origin. Iron mineralization is genetically related to plutons that are composed of gabbro-diorite, which were emplaced at 130 ± 1 Ma. These rocks have SiO2 contents of 51.72–54.60 wt%, Na2O contents of 3.47–4.04 wt%, K2O contents of 2.02–2.69 wt%, and K2O/Na2O ratios of 0.51–0.73. These rocks are enriched in LILEs and LREEs and depleted in Nb, Ta, and Ti, which indicates that the magma originated through partial melting of an enriched lithospheric mantle source in a subduction environment. A pattern of decreasing initial Sr isotopic ratios and increasing eNd(t) values with time in Early Cretaceous magmatic rocks of the Ningwu Basin may indicate incorporation of increasing proportions of asthenospheric mantle material into the source magma, which is consistent with the processes of lithospheric thinning and asthenospheric upwelling in eastern China related to Mesozoic subduction of the Paleo-Pacific Plate. Two stages of magnetite are found in the gabbro-diorite: (1) early-crystallized magnetite as euhedral–subhedral crystals in larger clinopyroxene crystals, and (2) later-crystallized magnetite and accompanying ilmenite grains in the voids between plagioclase and clinopyroxene crystals. The formation of magnetite before clinopyroxene, combined with the results of Fe–Ti oxide geothermometry and analysis of magnetite V content, indicates that the oxygen fugacity of the source magma was greater than ΔFMQ +2.2 at an early stage (>640 °C) but decreased to ΔFMQ −2.66 as abundant magnetite crystallized at a later stage (∼489 °C). The early crystallization of magnetite at a high oxygen fugacity does not support a Fenner evolution trend for the primitive magma and diminishes the likelihood of liquid immiscibility, which could have generated an iron-rich melt, and is thus inconsistent with an iron-oxide melt origin for the Meishan iron deposit. The δ34S values of pyrite (6.6–15.1‰) and anhydrite (15.6–16.9‰) in the deposit and the occurrence of evaporites under the volcanic rocks likely indicate that the iron ores and alteration rocks of the Meishan deposit were formed by the circulation of fluids of evaporitic origin driven by heat from the hypabyssal gabbro-diorite intrusives. In the late magmatic stage, oxygen fugacity decreased to a reducing range, triggering the reduction of sulfate to reduced sulfur and leading to local gold and pyrite mineralization.

This work addresses the problem of the cosimulation of cross-correlated variables with inequality constraints. A hierarchical sequential Gaussian cosimulation algorithm is proposed to address this problem, based on establishing a multicollocated cokriging paradigm; the integration of this algorithm with the acceptance-rejection sampling technique entails that the simulated values first reproduce the bivariate inequality constraint between the variables and then reproduce the original statistical parameters, such as the global distribution and variogram. In addition, a robust regression analysis is developed to derive the coefficients of the linear function that introduces the desired inequality constraint. The proposed algorithm is applied to cosimulate Silica and Iron in an Iron deposit, where the two variables exhibit different marginal distributions and a sharp inequality constraint in the bivariate relation. To investigate the benefits of the proposed approach, the Silica and Iron are cosimulated by other cosimulation algorithms, and the results are compared. It is shown that conventional cosimulation approaches are not able to take into account and reproduce the linearity constraint characteristics, which are part of the nature of the dataset. In contrast, the proposed hierarchical cosimulation algorithm perfectly reproduces these complex characteristics and is more suited to the actual dataset.

Felieton przywołuje mało znaną informację, że Polska ma bogate złoża rudy żelaza (w okolicy Suwałk), których się jednak nie eksploatuje ze względu na konieczność zachowania naturalnego środowiska w tym przyrodniczo ciekawym rejonie. Zabawną cechą tych polskich, nie eksploatowanych złóż jest fakt, że ruda żelaza jest w nich połączona z pierwiastkami, które zwykle trzeba dodawać do rudy w procesie wytwarzanie stali, żeby uzyskać jej szczególne właściwości. W szczególności polska ruda zawiera spory dodatek manganu, którego obecność w stali powoduje, że wyrobów nie da się przeciąć metodą piłowania. Jest to więc idealny materiał na wszelkiego typu kraty.

Рассмотрены события 2.7-2.2 млрд лет. Возможное геотектоническое районирование Украинского щита в это время, образование шовных зон, включающих железистую формацию (BIF), особенности состава метаморфических пород блоков щита.  Проанализированы отличия в составе метаморфической толщи и железистых формаций неоархея -палеопротерозоя от палеоархейских. По составу магматических и метаморфических комплексов в первом приближении установлено расположение границы астеносфера-литосфера на каждом этапе процесса (в каждом единичном плюмовом событии). Показано, что около 2.7 млрд лет назад происходит изменение состава глубинных флюидов.

Abstract The El Laco iron deposits in northern Chile consist of magnetite (or martite) and minor hematite, pyroxene, and apatite. The orebodies are situated on a volcanic complex and resemble lavas and pyro-clastic deposits, but a magmatic origin is rejected by some geologists who regard the ores as products of hydrothermal replacement of volcanic rocks. This study describes spherules of magnetite in the ore at Laco Sur and outlines a previously unrecognized crystallization process for the formation of spherical magnetite crystal aggregates during volcanic eruption. Mining at Laco Sur, the second largest deposit at El Laco, shows that most of the ore is friable and resembles pyroclastic material; hard ore with vesicle-like cavities occurs subordinately. The friable ore is a porous aggregate of 0.01–0.2 mm magnetite octahedra with only a local stratification defined by millimeter-thin strata of apatite. Films of iron phosphate are common on magnetite crystals, and vertical pipes called gas escape tubes are abundant in the ore. A SEM study reveals that magnetite spherules in the range 0.05–0.2 mm occur in most samples of friable ore from the central-lower part of the deposit. The proportion of spherules in a sample varies from high to nil, but overall the spher-ule content is low in the ore. The spherules are aggregates of octahedral crystals, or single octahedra, that have been rounded by stepwise, subparallel growth of magnetite with a systematic slight shift in orientation of successive steps. The shape of the spherules demonstrates that they formed unattached to any surface. Growth from hot magmatic gas saturated in iron in a volcanic plume and deposition as ash fall can account for the features of the spherule-bearing friable ore.