Typical Iron Ore Research Articles

Development of a Match Factor and Comparison of Its Applicability with Ant-Colony Algorithm in a Heterogeneous Transportation Fleet in an Open-Pit Mine

In a transportation fleet in open-pit mines, the match factor is defined between loading and dumping vehicles. This factor helps in indicating the number of vehicles that depend on each other. In this study, a new parameter termed the “detailed match factor” is developed to improve the transportation fleet and relationships are deduced to control the production and grade. A transportation fleet model was simulated for a typical iron ore mine and was solved using both the detailed match factor and ant-colony algorithm methods. The detailed match factor helped in increasing the production by 10.6%.

Dephosphorization of unroasted oolitic ores through alkaline leaching at low temperature

Roasting followed by acid leaching has long been an established dephosphorization technique for processing the goethite iron ore in the past. However, given the high-energy requirement in the process, there still exists further room for improvement. The present study of phosphorus removal from an unroasted iron ore via alkaline leaching method examined the possibility of dephosphorization from goethite ore at low temperature. The iron ore concentrate used in this study is an oolitic type of iron ore consisting primarily of goethite, in which phosphorus does not form a discrete mineral phase, but instead is diffused throughout the entire volume of the ore. This study reveals that the reduction of particle size, the increase in both temperature and hydroxyl ion [OH¯] concentration all promote phosphorus removal. About 50% of the phosphorus can be removed in relatively low [OH¯] concentration (1.25 M), about 80% phosphorous removal was attained after further increasing the [OH¯] concentration to 15 M resulting in 0.1% phosphorus in final solids with no iron losses, which was comparable to roasting followed by acid-leaching route. The optimum conditions was identified as temperature of 85 °C, [OH¯] concentration of 15 M, 0.025–0.038 mm particle size, and 10 min of leaching time with S/L ratio of 0.25 g/ml, in which P level can be reduced from 0.73 to about 0.1 wt%P. Additionally, leaching solution was demonstrated to be readily regenerated using hydrated-lime with comparable leaching ability in terms of phosphorus removal compared to fresh solution. No significant mineralogical change observed other than the uniform removal of phosphorus during the process.

Establishment and industrial practice of high-temperature process evaluation system in sintering

The behaviors of typical iron ores at high temperature were observed by confocal scanning laser microscopy. Four critical temperature points and liquid flow velocity at high temperatures of iron ores were obtained and the temperature points contain temperature at which sample starts to shrink, temperature at which the initial liquid phase forms, temperature at which a lot of liquid forms and temperature at which liquid consolidation ends. Under the same CaO to Fe2O3 ratio, the liquid phase fluidity of iron ore fines of Carajas (IOC) is good. However, under the same basicity, as the content of SiO2 in IOC is low, the liquid phase fluidity of IOC is much smaller than that of Yandi fine. After analysis of the initial formation and development of the liquid phase and the final consolidation process, the high-temperature process evaluation system (HTPES for short) of iron ore was established. The idea of “dense ore matching fusible ore” instead of “relatively fusible ore” was proposed based on the results of HTPES and applied in ore matching of a sinter plant from Shougang Jingtang. The use of IOC (13–18%) instead of standard sintering fines (SSF) improved liquid phase fluidity and ensured the sinter quality. Furthermore, the use of IOC fine (18–23%) with Hainan fine (0–2%) instead of SSF, a mixture of hematite and Marra Mamba ore and concentrates guaranteed the quality of sinter ore through improving fluidity, in the meantime reducing ore matching costs. With the establishment and application of HTPES, the sinter plant has achieved good economic benefits under the premise of ensuring the quality of sinter ore.

Iron ore deposits associated with Hormuz evaporitic series in Hormuz and Pohl salt diapirs, Hormuzgan province, southern Iran

Three types of iron ore, including banded ore, hydrothermal-metasomatic ore and earthy hematite ochre occur in Hormuz and Pohl salt diapirs. Primary banded ores of upper Neoproterozoic age contain alternating iron-rich and silica-rich bands, which characterized by the presence of folded hematite-rich bands and glacial diamictite fragments of quartz, dropstone and other clastics. Hematite as specularite and oligist is the major mineral in the iron-rich bands with minor goethite, pyrite, magnetite and rare siderite. Textural relationships between the ore and gangue minerals indicate that these ores are Rapitan-type sedimentary banded iron deposits. This is supported by the geochemical data of iron ores, such as low concentration of Al2O3, TiO2, Ba, V, Cr, Co, Ni, Cu and other trace elements, plus high value of MnO, Fe/V and Fe/Ti ratios, and REE patterns. Subsequent to the formation of iron ore deposits, an immense thickness of evaporitic rocks was formed in the oceanic marginal basins. Negative δ13C and δ18O values of the cap carbonates and strong positive δ34S values of the underlying sulfates are similar to the isotopic patterns of Ediacaran Rapitan-type iron deposits. Due to salt diapirism in the upper Mesozoic and Cenozoic eras, secondary iron deposits were formed by the activation of hot hydrothermal fluids during salt rising. High contents of some indicative elements such as Sr, Zr, U, Th, Pb, Zn, Sn, W and Mo in the metasomatic iron ores showed that they are the products of iron ore remobilization–redeposition in a hydrothermal system. The nearness of these ores to the fault zones is consistent with the scheme of migration and redeposition of iron compounds as metasomatic deposits under oxidizing conditions. Finally, earthy ochre was formed following the weathering and erosion of pre-existent iron ores.

Iron Smelting in Sudan: Experimental Archaeology at The Royal City of Meroe

ABSTRACTThe Royal City of Meroe, ca. 200 km north of Khartoum in the modern-day Republic of the Sudan, was an ancient capital of the Kingdom of Kush. From the 3rd century b.c. to the 4th century a.d., Kushite rulers controlled significant territory from the banks of the Nile at Meroe, in part through their ability to ensure the production of significant quantities of iron. The extensive archaeological remains of Meroitic iron production have been investigated over decades, and recently a series of experimental iron smelts in a replica Meroitic furnace has shed new light on the archaeometallurgical evidence. The data generated during the smelting campaigns has provided an understanding of the type of iron ore used, the construction and operating parameters of the furnace, and the workshop space created by the ancient iron smelters during the later and post-Meroitic times.

Effect of iron ore type on the thermal behaviour and kinetics of coal-iron ore briquettes during coking

Effect of three iron ore types (limonite, hematite and oolitic hematite) on the thermal behaviour and reaction kinetics of coal-iron ore briquettes during coking was investigated using the thermal analysis method. The carbonized briquettes were characterized using the XRD and SEM. The results showed that all three iron ores were completely reduced to Fe at the final coking stage. The addition of iron ore to the coal briquette had little influence on the gas yield, but could significantly affect the reaction rate. A synergistic effect of iron ore and coal occurred in the later reaction stage, and the initial temperature of the synergistic effect varied with the type of iron ore in coal-iron ore briquettes. The type of iron ore hardly affected the devolatilization rate of coal-iron ore briquettes, but could greatly influence the reduction rate of iron ore, subsequently the gasification rate of coal char. In addition, the better reduction ability of iron ore could more easily lead to the cracking of coke. When the iron ore was blended into the coal briquette, the reaction kinetics at the first and third reaction stage changed. The three coal-iron ore briquettes had similar weighted average apparent activation energies of 30.67–35.52 kJ/mol.

江西新余式铁矿地质地球化学、Fe同位素特征及其地质意义

本文对江西新余地区“新余式”铁矿成矿的区域地质背景、矿化地质条件特征、矿石共生组合特征和矿石主微量元素含量以及铁同位素进行了分析。认为该区铁成矿以化学沉积建造为主，同时伴有诸多陆源碎屑物加入，显示成矿物质来源多样，成矿环境复杂。铁同位素分析结果显然新余铁矿富集铁的重同位素的矿物相。各区段同位素值的差异性显示该区不同的氧化还原状态的演化变化状态。重铁同位素富集和Ce异常缺失等特征指示成矿期为低氧逸度环境，新余式铁建造形成于地球冰盖开始融化初期，冰川溶化后大量悬浮细碎屑物质的淡水加入，出现大量氢氧化铁和胶体SiO2先后或同时沉积，形成含铁硅建造，后来再遭受区域变质、挤压变形等地质作用，使氢氧化铁脱水和重结晶变成磁铁矿，胶体SiO2变成石英，原来的隐晶质的铁质燧石岩变成磁铁石英岩，形成现在的新余铁矿BIF标志层。 In this paper, the regional geological background, mineralization geological characteristics, ore symbiotic combination characteristics and main and trace element content and iron isotope of Xinyu type iron ore mineralization in Xinyu area of Jiangxi Province were analyzed. It shows that the iron ore deposits mainly composed of chemical deposition, accompanied by a number of terrestrial debris to join, which show that the mineral resources are diverse and the mineralization environment is complicated. Iron isotope analysis results are clearly enrichment of iron heavy isotope mineral phase. The difference in the isotopic values of each segment shows the evolutionary state of the redox state of the region. Heavy iron isotope enrichment and Ce anomaly and other characteristics indicate that the ore-forming period is a low-oxygen fugacity environment. The iron is formed at the beginning of the melting of the Earth’s ice sheet. At the beginning of the melting of the glacier, with the lots of fine clastic and freshwater, there are lots of colloidal ferric hydroxide and SiO2 deposited in succession or simultaneously to form formation of iron-containing silicon construction. After this, the formation subjected to regional metamorphism, deformation and other geological effects, the dehydration and recrystallization make Fe(OH)3 into magnetite, and colloid SiO2 into quartzite. Ultimately, the original aphanitic iron flint Shiyan transforms magnetite quartzite, finally, form the current Xinyu iron ore BIF marker layer.

Geological Controls on High-Grade Iron Ores from Kiriburu-Meghahatuburu Iron Ore Deposit, Singhbhum-Orissa Craton, Eastern India

Numerous iron ore deposits are hosted within the Meso to Neo-Archean banded iron formations (BIFs) extending across the Singhbhum-Orissa Craton, eastern India. Despite the widespread distribution of BIFs, which forms part of the iron ore group (IOG), heterogeneity in their grade and mineral composition is occasionally observed even within a single ore deposit. Kiriburu-Meghahatuburu iron ore deposit (KMIOD), west Singhbhum district, Jharkhand, eastern India is characterized by a dominant hematite (often martitized) occurrence with a total resource of >150 million tonnes (MT) at 62.85 wt % Fe. Very high-grade blue dust ore (friable and powdery hematitewith~67% Fe), high-grade massive, hard laminated hematitic ores (~66% Fe) and medium to low grade goethitic/lateritic ores (50%–60% Fe) are the common iron-ore lithologies in KMIOD. These ores can be distinguished in the field from their physical appearance, meso-scale texture and spatial occurrences with the host rocks along with the variation in chemical composition. The high-grade ores are characterized by high Fe (>62 wt %), low Al2O3 (1.5–2.5 wt %), low SiO2 (2.0–4.5 wt %) and low P (<0.06 wt %). Detailed field studies and laboratory investigations on the ore mineral assemblages suggest that the mineralization of high-grade iron ores at KMIOD is controlled by three major parameters, i.e., lithological, paleoclimatic and structural controls. High-grade iron ores such as blue dust seem to be formed during leaching processes through inter-bedded ferruginous shale and banded hematite jasper (BHJ) occurring within BIFs. Structural elements such as folds, joint network, fracture arrays, local faults and steeply dipping bedding planes are surmised as strong controls for the evolution of different iron ore types from the BHJ. Most of the high-grade ores are concentrated at the hinge portions of second generation folds (F2) owing to the easy access for circulation of meteoric solution along the fractures developed due to release of stresses at the hinge portions aided by supergene ore enrichment processes. The BHJ and interbedded ferruginous shale seem to have been given a significant contribution for the formation of different grades of iron ores over the area. Lithologically, the BIFs are governed by rheological features providing channel ways in the ore enrichment process. The variation in the iron ore mineralogy is caused by the variation in depositional and paleoclimatic environment, structural setting and lithological attributes. Hence, these parameters could be used for future exploration and grade recovery of iron ore resources in the region and in the adjoining areas.

Перетворення гематиту та гетиту на магнетит у водному середовищі за дії мікрохвильового випромінювання

There are three main types of industrial iron ores in Kryvyi Rih basin: rich ore that are directly used in metallurgy, magnetite ore and oxidized ferruginous quartzites that need enrichment. Deposits of rich ore are depleted. Nowadays, ferruginous quartzites are the main part of all deposits of Kryvyi Rih basin. Main commercial significance of ferruginous quartzites belongs to unoxidized magnetite and magnetite-hematite types but their reserves are nearly exhausted. But, there are large reserves of oxidized iron ore available in Kryvyi Rih basin that could be used as raw material for concentrates’ production. It is known that production of iron ore concentrates from poor oxidized iron ores related with various problems. Processes of transformation were studied for three types of iron ores: hematite ore, oxidized hematite ore (two samples) and hematite-goethite ore from deposits of Kryvyi Rih. Transformation of hematite and goethite, which are main mineral components of iron ore, to magnetite by heating to temperature of 98°С in aqueous Fe+2-containing medium under microwave radiation was investigated. Phase composition of initial samples was determined by X-ray diffraction (XRD). It was shown by XRD method that hematite ore consists of quartz and hematite, oxidized hematite ores consist of hematite and kaolinite and hematite-goethite ore consists of hematite, goethite and quartz. It was shown by XRD method that, after transformation in all obtained samples appears a phase of magnetite. Saturation magnetization of initial and obtained samples was investigated by magnetometry method. Saturation magnetization of initial samples was < 1 А∙m2/кg. Saturation magnetization of obtained samples was within the range 8-30 A·m2/kg. Possible mechanisms of hematite and goethite transformation to magnetite have been described. The results could be used for the development of effective techniques of iron ores enrichment for ore concentrates creation.

Oldest volcanic-hosted submarine iron ores in South China: Evidence from zircon U–Pb geochronology and geochemistry of the Paleoproterozoic Dahongshan iron deposit

The Dahongshan iron deposit is hosted in the Paleoproterozoic submarine metavolcanic rocks of the Dahongshan Group in the Yangtze Block, South China. LA-ICP-MS dating of hydrothermal zircon grains from the genetically associated albitite and dolomite albitite show ca. 2008Ma ages that are consistent with the zircon ages from the host metavolcanic rocks (ca. 2012Ma), and postdated the post-ore diabase dike (ca. 1724Ma), marking the Dahongshan iron deposit as the oldest submarine volcanic-hosted deposit so far as known. The ore-hosting metavolcanic rocks in the Dahongshan deposit have low Ni (9.1–77.4ppm), Cr (1.0–63.0ppm) and Co contents (5.6–62.9ppm), suggesting the fractionation of olivine, clinopyroxene and plagioclase within the magma chamber. The major and trace element features of the alkaline to tholeiitic metavolcanic rocks are consistent with high-degree partial melting of the mantle wedge metasomatized by melts enriched in high field strength elements (HFSEs), which were derived from the subducted slab in volcanic arc setting. Based on an evaluation of the morphology of orebody, ore fabrics, petrology and melt-fluid inclusions, as well as the geochemical characteristics of the major ore mineral (magnetite), we correlate the iron mineralization in the Dahongshan deposit with hydrothermal process induced by the high-temperature, high-salinity and Fe-rich brines derived through magmatic exsolution. The similar characteristic of Ce and Eu anomalies of the Dahongshan iron deposit and banded iron formations (BIFs) suggest that the Dahongshan deposit was formed in reducing environment, although the two types of iron ores were generated through distinct processes with hydrothermal processes dominating for the submarine volcanic-hosted iron deposits whereas the BIFs were formed through chemical precipitation.

ASD field hyperspectral measurements for discrimination of the ferruginous rocks and the iron ore types at El Gedida-Ghorabi area, Bahariya Oasis, Western Desert, Egypt

The ironstone succession at El Gedida-Ghorabi-Naser area of El Bahariya depression is subdivided into lagoonal manganiferous mud and fossiliferous ironstone consisting mainly of hematite and goethite-hydrogoethite. The application of the ASD field spectroradiometer measurements (spectral range) in the ASTER data led to the interpretation of the presence of ferruginous units as quartzitic sandstone, gluconitic sandy clay, and pink marly limestone. The existing iron ore minerals in the iron ore localities were also classified into high Mn hematite, low Mn hematite, goethite, hydrogoethite as well as low- and high-grade Hematite and Barite. Quartz, feldspars, rutile, and clay minerals (e.g., kaolinite and illite) are mainly associated with the iron ore. Accessory minerals of manganese, e.g., psilomelane and pyrolusite, were also present. The Barite mineral is recorded as a common mineral association with the iron ore deposits at El Gedida and Ghorabi localities. The stratigraphical units investigated in the study area include the oldest gravely clayey sandstones of the Bahariya Formation overlain by the fossiliferous and oolitic limestones of the El-Hamra, Qazzun, and Naqb Formations. Quartztic sandstones and clayey sandstones of the Radwan Formation and youngest Quaternary sediments of sandy-clayey materials were often found as intermittent cover and overburden in unconformity surfaces over the iron ore bands.

In-situ trace element and Fe-isotope studies on magnetite of the volcanic-hosted Zhibo and Chagangnuoer iron ore deposits in the Western Tianshan, NW China

The Carboniferous Zhibo and Chagangnuoer iron deposits are situated within a caldera centre and along the flank of the same volcanic edifice, respectively, in the Awulale Iron Metallogenic Belt of the Western Tianshan orogen. Several stratiform 10 to 100m large, tabular to lenticular shaped magnetite-dominated ore-bodies occur in (trachy-) andesitic to rhyolitic host rocks. The magnetite mineralization mainly occurs as massive iron ores, partly with columnar-network or flow textures, and as disseminated magnetite ores. Trace element and isotope investigations of the different ore types reveal two major groups of magnetite: Group I, represented by the massive, partly brecciated ores from both deposits, is enriched in Ti, V, Ni, and HFSE such as Y, with concentrations similar to Iron Oxide-Copper-Gold (IOCG) ores. The δ56Fe values (up to 0.4‰) support an ortho-magmatic origin corresponding with an isotopic source calculation at ~800°C. Positive correlations between Fetotal and δ56Fe (from +0.4‰ to −0.1‰) and incompatible trace element contents (e.g. Si, Al, Nb, Ti and Y) in Group I magnetite are interpreted to be the consequence of a Raleigh-type fractionation process. Decreasing V, Ni and Mn values indicate changing fO2 conditions at the time of ore genesis. Group II, which is represented by the disseminated ores from Chagangnuoer, is - compared to Group I - relatively depleted in elements like Ti, V, Ni and Y and further spans a dominant δ56Fe range from about 0‰ to −0.5‰. These textural and chemical characteristics and the garnet-actinolite-diopside-epidote-carbonate-K-feldspar paragenesis are in accordance with hydrothermal Fe-skarn ores.The similar multi-element patterns of magnetite from all investigated samples, the overlapping δ56Fe ratios of the same massive ore-type from Zhibo and Chagangnuoer and the close proximity of both deposits indicate a common source of Fe-enrichment for the different iron ore types. In contrast to the ortho-magmatic Group I magnetite, reverse trace element trends with decreasing δ56Fe ratios (from 0‰ to −0.5‰) among the disseminated ores cannot simply be explained by a straightforward Raleigh fractionation or alteration processes. Therefore, a bimodal formation model is suggested for the Group II magnetite formation, including a partial remobilization of iron from the proximal, ortho-magmatic ore bodies and a subsequent distal re-precipitation. These processes were driven by late-stage hydrothermal fluids, which originated from deeper- seated granitic/granodioritic intrusions in the immediate vicinity.

Sintering behaviours of iron ore with flue gas circulation

ABSTRACTFlue gas circulation is an important method for energy conservation and pollutant emission reduction in iron ore sintering. In this paper the effects of flue gas recirculation ratio on sintering of different iron ores including haematite, magnetite and limonite were studied by illustrating the variation of sinter bed temperature, atmosphere and mineralisation characteristics of different types of iron ores induced by the circulation. It shows that the proper flue gas circulation ratios for haematite, magnetite and limonite are 37, 30 and 25%, respectively. For magnetite ore, preheating and high consumption of oxygen in combustion zone caused more silicate minerals and less acicular calcium ferrite, thereby lowering sinter tumbler strength. As for haematite ore, the rapid change of temperatures of combustion, melting and solidification zones leads to elevated combustion efficiency and increased formation of acicular calcium ferrite, which enhances the sinter strength. When using limonite ore as the main raw material, high oxygen consumption, lower maximum temperature of sintering bed, higher cooling rate and larger porosity of sinter are observed.

Experimental research on the behavior of the pneumatic transport of fine-grained iron

Mixed injection of fine–grained iron ore and pulverized coal in the furnace, involves determining the behavior of these materials during pneumatic transport in a dense state through the pipe and setting possibilities for adjusting the flow rate of material transported with the corresponding values of the process. Parameters of the pneumatic transport were determined for the main types of iron ore and chalk used in Arcelor Mittal Galati. Outside the intended purpose of injecting iron ore and flux, it was considered also the experimental check of the possibility for injecting ilmenite in the furnace for crucible protection purpose. The possibility of injecting cinder mill into the furnace was also considered. Injecting cinder could be taken into account for the recycling of ferrous waste in the furnace, also as additive for intensifying the combustion process around the tuyeres.

A Dynamic Time Warping based covariance function for Gaussian Processes signature identification

Modelling stratiform deposits requires a detailed knowledge of the stratigraphic boundaries. In Banded Iron Formation (BIF) hosted ores of the Hamersley Group in Western Australia these boundaries are often identified using marker shales. Both Gaussian Processes (GP) and Dynamic Time Warping (DTW) have been previously proposed as methods to automatically identify marker shales in natural gamma logs. However, each method has different advantages and disadvantages. We propose a DTW based covariance function for the GP that combines the flexibility of the DTW with the probabilistic framework of the GP. The three methods are tested and compared on their ability to identify two natural gamma signatures from a Marra Mamba type iron ore deposit. These tests show that while all three methods can identify boundaries, the GP with the DTW covariance function combines and balances the strengths and weaknesses of the individual methods. This method identifies more positive signatures than the GP with the standard covariance function, and has a higher accuracy for identified signatures than the DTW. The combined method can handle larger variations in the signature without requiring multiple libraries, has a probabilistic output and does not require manual cut-off selections.

The Role of MgO Powder in Preventing Defluidization during Fluidized Bed Reduction of Fine Iron Ores with Different Iron Valences

The role of MgO powder in preventing defluidization during the fluidized bed reduction of fine iron ores with different iron valences is investigated. The inhibiting effect of MgO powder on different types of fine iron ores is the same at 973 K, whereas it is sequenced as FeO > Fe3O4 > Fe2O3 at 1073 and 1173 K. Specific diffusion couples are employed to clarify the valence-dependent inhibiting mechanism. Electron probe microanalysis, X-ray diffraction results, and the estimation of diffusion activation energy indicate that the inhibiting effect of MgO powder on defluidization is mainly caused by the physical barrier effect for all iron oxides below 1073 K, while the defluidization prevention of Fe3O4 and FeO at 1173 K is mainly attributed to the formation of Fe2MgO4 and MgO · FeO compounds on the surface, respectively. As a result, the required MgO content to prevent defluidization is sequenced as m(Fe2O3) > m(Fe3O4) > m(FeO) at 1173 K. Consequently, the MgO addition at the FeO stage will be more effective in preventing defluidization than the addition at Fe2O3 and Fe3O4 stages during multi-stage fluidized bed reduction of fine iron ores.

Characterization of Black Sand Mining Activities and Their Environmental Impacts in the Philippines Using Remote Sensing

Magnetite is a type of iron ore and a valuable commodity that occurs naturally in black sand beaches in the Philippines. However, black sand mining often takes place illegally and increases the likelihood and magnitude of geohazards, such as land subsidence, which augments the exposure of local communities to sea level rise and to typhoon-related threats. Detection of black sand mining activities traditionally relies on word of mouth, while measurement of their environmental effects requires on-the-ground geological surveys, which are precise, but costly and limited in scope. Here we show that systematic analysis of remote sensing data provides an objective, reliable, safe, and cost-effective way to monitor black sand mining activities and their impacts. First, we show that optical satellite data can be used to identify legal and illegal mining sites and characterize the direct effect of mining on the landscape. Second, we demonstrate that Interferometric Synthetic Aperture Radar (InSAR) can be used to evaluate the environmental impacts of black sand mining despite the small spatial extent of the activities. We detected a total of twenty black sand mining sites on Luzon Island and InSAR ALOS data reveal that out of the thirteen sites with coherence, nine experienced land subsidence at rates ranging from 1.5 to 5.7 cm/year during 2007–2011. The mean ground velocity map also highlights that the spatial extent of the subsiding areas is 10 to 100 times larger than the mining sites, likely associated with groundwater use or sediment redistribution. As a result of this subsidence, several coastal areas will be lowered to sea level elevation in a few decades and exposed to permanent flooding. This work demonstrates that remote sensing data are critical in monitoring the development of such activities and their environmental and societal impacts.

EVOLUTION OF SCHEMES OF HEAT EXCHANGE IN A BLAST FURNACE

The development of schemes of heat exchange in a blast furnace was considered with the improvement of the blast furnace smelting technology. It was noted that for the estimation of the thermal state of blast furnace as a control object it is expedient to divide it into two thermal zones, upper and bottom. The interface between them is in the top of the mixed recovery between the level of the beginning of the carbon gasifi cation of coke and the horizon, below which iron oxides are directly reduced. Upper slow heat exchange section in terms of heat exchange is reserve height providing better thermal and regenerative operation of the furnace. The bottom section of slow heat exchange should not be used as a reserve for improvement of thermal and reduction work of the blast furnace. It is shown that the presence of two zones of intense heat exchange in the present conditions of smelting of various types of iron ore using the combined blowing of high parameters is a prerequisite for the stability of the course of the blast furnace process and effi ciency of smelting.

Classification of iron ore based on acidity and alkalinity by laser induced breakdown spectroscopy coupled with N-nearest neighbours (N3)

LIBS technique coupled with N3 for classification and identification of four types of iron ore.

Application of Self-Organizing Map for Exploration of REEs’ Deposition

Varieties of approaches and algorithms have been presented to identify the distribution of elements. Previous researches based on the type of problem, categorized their data in proper clusters or classes. This means that the process of solution could be supervised or unsupervised. In cases, where there is no idea about dependency of samples to specific groups, clustering methods (unsupervised) are applied. About geochemistry data, since various elements are involved, in addition to the complex nature of geochemical data, clustering algorithms would be useful for recognition of elements distribution. In this paper, Self-Organizing Map (SOM) algorithm, as an unsupervised method, is applied for clustering samples based on REEs contents. For this reason the Choghart Fe-REE deposit (Bafq district, central Iran), was selected as study area and dataset was a collection of 112 lithology samples that were assayed with laboratory tests such as ICP-MS and XRF analysis. In this study, input vectors include 19 features which are coordinates x, y, z and concentrations of REEs as well as the concentration of Phosphate (P2O5) since the apatite is the main source of REEs in this particular research. Four clusters were determined as an optimal number of clusters using silhouette criterion as well as k-means clustering method and SOM. Therefore, using self-organizing map, study area was subdivided in four zones. These four zones can be described as phosphate type, albitofyre type, metasomatic and phosphorus iron ore, and Iron Ore type. Phosphate type is the most prone to rare earth elements. Eventually, results were validated with laboratory analysis.