Ore Distribution Research Articles

Magnesite and bauxite ores as petrophysical objects of spectral-grade estimation based on electrometry (from the archives of oxide-metric exploration in the Ural deposits)

Research subject. Distribution of magnesite and bauxite ores in mining blocks of deposits according to electrical conductivity in connection with signals of scattered phases of Ca, Mg and Al oxides. Petrophysical objects and differentiation of the properties of oxides detected in the boundary area and at the boundary with dielectrics, the semiconductor range in the geochemical environment of metamorphic formations from carbonate sediments.Materials and methods. An approach of searching for stationary features was applied. First, a study at the elemental level (review) was undertaken. Further, the authors’ electrometric measurements of the deposits were analyzed. Results. In the review part, the analysis of the metal constants – the relative electronegativity of the OEO (Luo and Benson scale), the electronic potentials E0, and the relationship of electrical resistance and pressure in pure elements was performed. The inversion of the properties of CaO ↔ MgO was revealed (for the first time in 2002–2004); Ca was identified as a reducing agent (CaO is a solid dielectric), which contradicts the current ideas about the comparative additivity of light Mg. It was established that MgO is a separate source of semiconductor carriers. Favourable conditions for studying the conductivity during the experimental part of the work were the absolute exchange increments of ore oxides at geological contacts. The properties of ores, rocks and oxides were measured and calculated. The relationships of the varietal growth of conductivity with compaction, increased basicity and magnetic susceptibility (magnetization) were predicted. This, in turn, provides a basis for studying cores, samples from debris, shredding and recycled geo-material, including concentrates, tailings and waste.Conclusions. The spectral properties of scattered oxides with atomic numbers ≤ 20 were identified. The activation effect of MgO and Al2O3 in the ionic medium (CaCO3 = CaO+CO2) was noted. In the phenomena of the semiconductor nature (n- and psources), a version of the donor-acceptor mechanism was proposed. The established properties are a factor in the implementation of measuring identification of oxides and ore grades in the conditions of deposits, both in the estimates of carbonate chemical types of terrigenous fossils, and plagioclase-pyroxene – in igneous ones. Varietal exploration and prototype electrometry were discussed from the standpoint of high-precision interpretation in the potential and replenishment combination of various petrophysical meters.

Роль окружающей среды в размещении апокарбонатного золотого оруденения Чакылкалянского мегаблока (Южный Узбекистан)

Analysis of the available information and the results of many years of research on gold deposits in Uzbekistan made it possible to identify the main unconventional types of deposits. Among them, the most interesting are apocarbonate, crustal, sulfide-carbonaceous and apovolcanogenic quartzite (Upper-Kattakashkasai ore occurrence). The apocarbonate type is widespread in Uzbekistan, has been studied in sufficient detail and information is provided on it in this article. The article examines the existence, distribution and genesis of ores of Karlin type gold deposits. The generalizing characteristics of the Karlin type gold mineralization are given. The issues of geochemical specialization of the Paleozoic strata of the Chakylkalyan megablock are considered, the most favorable stratolevel for the localization of mineralized zones is determined, and the features of carbonate rocks in the process of gold deposition during reactions with silicic solutions are characterized. Based on the materials of regional geochemical profiling, the behavior of the main ore-forming elements in the rocks of both carbonate and volcanogenic-terrigenous strata is analyzed. As a result of the analysis, subclarkic contents of the main ore-forming elements (As, Co, Ni, Pb, Cu, Ag, V, Cr, Sc) were revealed, which create increased concentrations in gold-bearing pyrites of both apocarbonate gold mineralization and related formations.

Platinum-group elements and gold distribution in ores of the Haftcheshmeh porphyry Cu-Mo-Au deposit, NW Iran

The Haftcheshmeh porphyry Cu-Mo-Au deposit is located in the Arasbaran metallogenic belt, northwest Iran, with mineralization occurring mainly in gabbro-diorite and granodiorite porphyry. Pyrite and chalcopyrite are the most abundant sulfides that occur as disseminated and veinlet type ores in the potassic alteration zone. Platinum-group elements (PGEs), Au, and Cu concentrations of selected pyrite- and chalcopyrite-bearing samples were analyzed using in situ LA-ICP-MS and bulk rock Lead Fire Assay. Relatively high contents of PGEs and other precious elements are present in sulfide minerals, especially in pyrite that is the principal carrier of these elements in the deposit. Palladium is the most abundant of the PGEs in the sulfides. The contents of Pd are systematically higher than Pt in this deposit, consistent with other porphyry deposits, although Os, Rh, and Ir abundances are in general equal to or below the limits of detection in pyrite and chalcopyrite. The most important factors related to potential PGEs and chalcophile elements enrichment in the Haftcheshmeh deposit is the oxidized mafic endmember components of source magmas, i.e., high ƒO2 conditions, possibly with a semi-metal collector melt involved, and the high saline magmatic hydrothermal fractionation process. All these mechanisms seem to have enhanced the concentration of PGEs, Au, and other chalcophile metals. PGEs and other chalcophile elements were transported by exsolved high-T, saline magmatic hydrothermal fluids and then low T reaction and reduction to enhance saturation of sulfide phases during mineralization associated with potassic alteration.

Extraction of large-scale geological anomalies and positioning regularities of rich deposits: A case study of the Minle sedimentary manganese deposit, Hunan, China

In the exploration of sedimentary manganese deposits, prospecting models with large-scale ore-generating geological anomalies are required to satisfy productive demands. This study presents a novel approach combining theories of sedimentary basin analysis with techniques of quantitative analysis of mineral resources for extracting large-scale geological anomalies based on variations of intra-manganese-basin tectonic and sedimentary environments. For this purpose, the Minle sedimentary manganese deposit in Hunan province, China, was taken as a case study. First, the stratigraphic and lithological characteristics were analyzed to divide the region on the scales of manganese basins and mining areas. Subsequently, suitable paleogeographic features were selected as ore-generating geological anomalies and analyzed for three-dimensional quantitative evaluation of mineral resources. Finally, the thicknesses and grades of ore bodies were quantitatively analyzed to summarize the positioning regularities of rich ores. Pre-mineralization tectonic and sedimentary environments were found to be closely related to the distribution of rich ores. Areas suitable for the formation of rich ores were found to be those that feature coarse clastic sedimentation at the edge of the barrier-tidal flat-lagoon system and experienced a shift in the stable transitional environment from the barrier-tidal flat-lagoon to the bay before mineralization. Large-scale sedimentary features, fault activities, structural styles, and evidence of multiple mineralization mechanisms should also be taken into account in the selection of ore-generating geological anomalies.

An improved Goldsmith-Cruz-Orive method for estimation of spherical size distribution from sectional size distribution, suitable for arbitrary size classes

Pore size distribution in ores and rocks is of considerable importance, because it affects features such as permeability. Along with the measurement of other features, pores are commonly observed by microscopy, using sectioned samples (hence, in two-dimensions (2D) though originally in three-dimensions (3D)). Therefore, estimation of 3D size distributions from the measurable 2D size distributions of sections is required. The Goldsmith-Cruz-Orive method (GCO) is an effective tool for this purpose, but the size class (bin) is fixed at 15, with equal division from zero to maximum size, and thus not suitable for the wide-ranging size distributions typically depicted in log-normal graphs. In this study, an improved GCO (ImpGCO) was developed, in which arbitrary bins were configurable. A simulator for spherical size distribution calculation in 3D and 2D was also developed, and 8000 size distributions were computed. The following were found for the first time: the bias between the 3D and 2D distributions showed a clear pattern against the 2D distribution uniformity coefficient (UC); the bias became small in the UC range from 2.5–3.0, where no bias correction was likely required; and the bias became large with other values of UC, where bias correction was required. The GCO and ImpGCO were compared for the 8000 distributions, and the results showed that when UC was less than 3.5, neither method was recommended; in the UC range from 3.5–6.5, the ImpGCO showed better performance than the GCO; and when UC was greater than 6.5, both methods showed high performance, eliminating at least 80% of the bias, with the ImpGCO estimating successfully over the entire range of the wide-ranging distributions.

Geological position of the gold-sulfide-quartz deposits of the Chilean active margin

Research subject. The gold-sulphide-quartz deposits of Central Chile are typical prospecting objects, having small ore intervals (from the first tens of centimetres to 1 m), intermittent and nested ore distribution and extremely uneven gold contents.Materials and methods. The patterns of ore mineralization distribution are considered against the background of the results of modern geophysical studies of the lithosphere: the Moho surface, density and thermal regime of the upper mantle. Detailed studies were conducted on the Yapin ore field.Results. It was shown that the faults controlling gold-sulphidequartz mineralization are derivatives of shear tectonics under the conditions of a transpression regime along the Chilean active margin. At an early stage, these faults developed in a right-shift environment, which was accompanied by the introduction of diabase dikes into the northeastern faults, and gold-sulfide-quartz mineralization superimposed on the dikes was deposited during the left-shift stage. The geological structure of the deposits in the ore field Yapin was characterized. It was shown that a diverse mineralization is developed in the ore field - copper-porphyry, IOCG-type and gold-sulphide-quartz. According to geochemical data, the latter is characterized by a clear enrichment of chalcophilic elements (Au, As, Ag, Cd, Cu, Bi, Pb, Zn, Te, Co). The marked enrichment of Bi, Te and Co ores indicates the participation of magmatic fluid in ore formation and the similarity of the mineralization of the Escondida deposit with the type of gold deposits associated with granitoid intrusions. According to geochemical features, gold-sulphide-quartz mineralization in the general zoning pattern occupies a boundary position between IOCG-type objects and copper-porphyry deposits.Conclusions. The conclusion is drawn about the independence of gold-sulphide-quartz mineralization and its difference from epithermal gold deposits. It is noted that, in the volcanic belts of the North-East of Russia, the prospects for discovering unconventional gold-sulphidequartz deposits similar to those of Central Chile are rather real.

Identification of the Ore-Forming Anomaly Component by MSVD Combined with PCA from Element Concentrations in Fracture Zones of the Laochang Ore Field, Gejiu, SW China

Fault and fractures are well-developed in the Gejiu tin-polymetallic district, and they are closely related to the formation and distribution of ores. In this paper, the principal component analysis (PCA) and multifractal singular value decomposition (MSVD) methodologies were applied for identification of the ore-forming anomaly components from element concentrations of fault rocks in the Laochang ore field, Gejiu. The results show that: (1) the wall rocks and fault rocks have anomalous concentrations of ore-forming elements, indicating that these elements are mainly derived from fluid/rock interaction in the fracture zones; (2) PCA based on clr-transformed data was used to recognize significant association anomalies of ore-forming elements, which lay a foundation for further extracting ore-forming anomaly components from the element association anomalies related to Sn-Cu mineralization; (3) MSVD could effectively explore local anomaly features and decompose ore-forming element association anomalies associated with buried mineralization in more detail. The ore-forming element anomaly components can delineate ore-finding Sn-Cu polymetallic deposits more exactly than the ore-forming element association anomalies.

Numerical simulations of lowering boulder yield based on delay time and double-primer initiation

Boulders, a common problem in sublevel caving mining, usually result in a low ore production efficiency and high production cost. To achieve safety and efficient production, LS-DYNA was used to study the delayed and double-primer initiations on blast-induced ore fragmentation and damage in this study. An image processing program was developed to count mineral fragmentation through MATLAB, and a blasting fragmentation evaluation method is proposed based on numerical simulation. Delayed initiation decreased the average segment size and maximum segment size significantly by 26.67% and 32%, respectively, under specified blasting parameters, but it still has a limitation that the boulder yield of ore around the first blastholes is still high. Based on the fractal theory, the effects of one-primer and double-primer initiations on the damage distribution of ore were studied. Double-primer initiation significantly enhanced the damage of ore between the initiation primers, resulting in the most complex crack failure pattern in this region. The fractal dimension of cracks between primers increased significantly. In an actual production, the advantages of delayed initiation, double-primer initiation, and even multiprimer initiation can be fully utilized to reduce the boulder yield and guide the mine production scientifically.

Cadmium and lead distribution in pyrite ores

The pyrite ores are strategic industrial resources which generally serve as raw material for producing sulfuric acid. However, during the mining and industrial processing activities, associated toxic elements of cadmium (Cd) and lead (Pb) could be released into the surroundings, posing a significant threat to local environment and human health. In this study, the Institute for Reference Materials and Measurement (IRMM) sequential extraction scheme was used to investigate the geochemical fractionation of Cd and Pb in pyrite ores from a mining area located in Yunfu, western Guangdong, China. The results showed that most of Cd and Pb (>90%) were predominantly found in the geochemically mobile fractions, indicating that Cd and Pb were readily bioaccessible thus easily assimilated and accumulated by organisms. FESEM-EDS results showed that the studied pyrite ores were mainly composed of O, S, and Fe, while the XRD characterizations suggested that FeS2 and SiO2 were the major minerals. The high-resolution transmission electron microscope and element mapping characterization further confirmed that FeS2 was the main mineral of pyrite ores which contained relatively enriched toxic heavy metals (e.g., Pb and Cd). The findings highlight that an extremely large amount of geochemically mobile heavy metals can be released into the environmental media during the mining and utilization processes of pyrite ores based on IRMM sequential extraction protocol. Therefore, proper countermeasures against environmental risks of utilizing pyrite ores should be taken to mitigate the impacts on local ecosystem and human health.

Optimization Model and Pollution Treatment of Sintering Ore Distribution

sintering process plays an important role in iron and steel smelting process. The subsequent production of blast furnace ironmaking is directly affected by the quality of sinter. Among them, the proportion of raw materials and the advanced degree of sintering process are the two main factors affecting the quality of sinter. Because the control parameters of sintering process are too many and the physical and chemical process is too complex, it is difficult to establish and control the model accurately. Therefore, workers have long relied on experience to set temperature and other factors to engage in production, resulting in the quality of sinter is unstable, the cost is not easy to be controlled. Moreover, the flue gas produced in the sintering process will have different effects on the environment. Through the data analysis of the ore distribution scheme and the results of the physicochemical analysis of sinter in a steel plant, two aspects of the work are completed: one is to establish the optimal model of the cost of the sintering process, and the most suitable temperature for the sintering process. The second is the analysis of harmful components produced in sintering process.

Металлургические шлаки и фрагменты руд с поселения бронзового века Каменный Амбар (Южное Зауралье): ключ к определению источников медного сырья

Abstract: The paper presents the characteristics of metallurgical slags and copper ore fragments from the Kamenny Ambar settlement of the Bronze Age. According to the mineral and chemical compositions we have distinguished two types of the slags: Cr-rich spinel containing olivine slags and sulfide-containing olivine slags. The Cr-rich spinel containing olivine slags are the product of oxidized ore from the copper deposits in ultramafic rocks exploited in the early Sintashta-Petrovka period the settlement functioning. The sulfide-containing olivine slags are the result of the secondary sulfide ores from the massive-sulfide, and less likely copper porphyry deposits during the latter Srubnaya-Alakul period. A similar change in the copper ore raw material type was also recorded in other Bronze Age settlements in the Southern Urals. In the Kamenny Ambar settlement and analogs, we have defined the main indicating minerals which allow us to determine the source for the Cu raw metal in historical time: Cr-rich spinels, sulfides, and tourmalines. Keywords: metallurgical slags, Bronze Age, Kamenny Ambar, South Ural, copper ores, mineral inclusions Acknowledgements: This work was supported by the Russian Science Foundation project No. 16–18– 10332‑P: analysis of slags and ores was carried out by M. N. Ankushev, V. V. Zaykov, A. M. Yuminov; the archaeological aspect of the work was analyzed by L. N. Koryakova, I. V. Molchanov (chronostratigraphic distribution of slags), S. E. Panteleeva (chronostratigraphic distribution of ceramics and ores). The authors are grateful to I. P. Alaeva, D. A. Artemyev, E. V. Belogub, A. V. Epimakhov, V. A. Kotlyarov, G. F. Lonschakova, M. S. Svirenko, L. G. Udachina. Filippova K. A., Khvorov P. V., Churin E. I., Sharapova S. V.

Distribution peculiarities of basic ore components in Goshgarchay porphyrous copper deposit (lesser Caucasus, Azerbaijan)

Formulation of the problem. Large size and great reserves, as well as the possibility to apply rational methods of metals extraction predetermined the increasing interest to the copper-porphyry deposits. Today, they are the main raw material based on Cu, Mo, accompanying metals all over the world. The value of these deposits lie in the fact that they are in located in geologically well-studied regions. However, their ores in basic and associated components have relatively small content of Cu, Mo, Au, Ag, Bi, Re, Se, Te, spreading in large area. The purpose of the article. The main objective of the research is to study distribution peculiarities of basic ore components of Goshgarchay deposits, to detect geochemical features and behaviour of elements in the process of sedimentation by developing geochemical criteria of the search and the prognosis of hidden mineralization. Methods. The author studied the distribution problem of basic ore components of copper-porphyry mineralization, carried out field investigations (field researches), documented and tested underground mine working and core samples of over seventy well bores. When choosing the type of analysis, a special attention was paid to the sensitivity and exactness of the determination method. Analytical work was conducted according to the definition of chemical elements. The following types of analytical methods were used: chemical, atomic-absorption, spectral-chemical, etc. The analytical data were processed by the method of mathematical statistics. Results. As follows from the analysis of the above-mentioned results, the elements flaccid for hydrothermal solutions (Cr, Ni, V, Co, Mn, Ti) keep their independence in all groups of rocks. Their grouping is probably associated with the process of crystallized differentiation of magma. The elements Cu, Pb, Zn, Ag and partly Mo, don’t have specific place. Their presence is likely associated with the degree of rocks susceptibility, hydrothermal interaction being the source of these elements. In various types of ores and mineral associations the definition of elemental impurities is different. Their amount increases the amount (quantity) of clarke and coefficient of concentration a thousand times. Three different mineral associations coexist in the ore body: 1-primary sulphide-chalcopyrite and bornite-chalcopyrite ore. 2-oxidized ore and zone of secondary enrichment. 3-primary sulphide ore, significantly enriched in copper. Scientific novelty. Based on existing analytical data, the author studied distribution of basic ore and admixture components (gangue) and basic sulphide minerals. The concentration in series of elemental impurities were detailed in ore-bearing rocks of copper-porphyry deposits of Goshgarchay. The primary geochemical zonality was revealed in the distribution of basic ore-containing components in the ore body of copper-porphyry deposits of Goshgarchay ore field. Practical significance. The revealed peculiarities of the distribution of basic ore components in the ore body and host rocks (wallrock), the factors contributing to the accumulation of indicated elemental impurities can be used as geochemical criteria for the prognosis of copper-porphyry mineralization , supporting the effective directions of the research.

Ore particles segmentation using deep learning methods

The feed size distribution of AG/SAG mills has a big impact on the efficiency of the whole beneficiation process. In this situation is very useful instrument could be a system for estimate size distribution of ore. In this paper method for ore segmentation was developed based on deep learning algorithm and digital image processing. First U-net network was trained on manually labelled images. Then trained network used for extracting particles area and watershed used for obtain final segmentation.

Dolerite-related gibbsite genesis in Australian Banded iron formations

The Pilbara region of Western Australia represents the world’s largest supply of quality iron ores predominantly sourced from supergene and hypogene enriched Banded Iron Formations. Aluminium is a major contaminant in these iron ores and its mineralogical host impacts the efficiency and productivity of the steel-making process. The aluminium can either be hosted by gangue minerals such as kaolinite (Al2Si2O5(OH)4) or be adsorbed or substituted into the crystal lattices of iron oxides. Gibbsite (Al(OH)3) is widely considered a low abundance gangue mineral in this region, posing a minimal risk to iron ore quality. As a result, investigations into the genesis of gibbsite are scarce and its spatial distribution in Pilbara iron ores is poorly understood.This latest research is prompted by discrepancies between predicted and actual aluminum distribution in world class Pilbara iron ore deposits, and reveals that the current means of prediction does not adequately account for the highly aluminous mineral gibbsite. A micromorphological and geochemical study of iron ore samples from mining benches at various depths found that significant gibbsite forms in some iron ore deposits due to localized alumina remobilization from dolerites. The study documents for the first time the micron-scale transformation of gibbsite to kaolinite in iron ores. Structure, hydrogeology and geomorphology were found to control the formation and transformation of gibbsite and explain why gibbsite is sometimes abundant in iron ore mineralization proximal to dolerite dykes and at other times completely absent.Improved fundamental understanding allows gibbsite distribution to be derived from normative mineralogy calculations, and suggests gibbsite is locally more abundant in Australian BIF-hosted iron ores than previously thought. This finding has important metallurgical implications given that ores are selected for beneficiation based on predicted aluminium deportment and its textural associations with the iron oxides.

Spatial and temporal variations in mire surface water chemistry as a function of geology, atmospheric circulation and zonal features in the south-eastern part of Western Siberia

This study analysed the chemistry of water samples collected from mires in the south-eastern part of Western Siberia. The aim was to determine spatial and temporal patterns in the hydrochemistry of mires in relation to the environmental conditions and geological history of the region. The results show that concentrations of Fetotal, Са2+, Mg2+, Na+, and HCO3– ions are higher than those obtained in other regions of Russia and Europe, which is consistent with the geological conditions of Western Siberia. High Fetotal concentrations are associated with the distribution of sedimentary ore in the region's largest iron ore basin, the Bakchar deposit, which is represented by strata of various Cretaceous sedimentsary rock at depths of 150–200 m. The Fe-rich rocks contribute to the high Fe concentrations in deep groundwater that feeds into the fens. The increase in Са2+, Mg2+, Na+, Cl−, and HCO3– in the water resulted from a xerothermic period that occurred in the southern part of Western Siberia (4500–2500 years ago) that increased the carbonation and salinity of the rocks. A feature characteristic of the hydrochemical regime in raised bogs is the transformation of the chemical composition during the year, with a change in dominant anions from HCO3– to Cl− or SO42−. The water in transitional mires and rich fens were characterised by the predominance of HCO3– and Са2+. Studies have shown that the size and stage of development play leading roles in the formation of the water chemistry in the mires. Small bogs and transitional mires were characterised by a rich mineral nutrition; while, the chemical composition of fens was mainly determined by their geomorphologic position and proximity to large river systems. The results of this study provide a better understanding of the functions of peatland ecosystems in Western Siberia and improve water sampling strategies for future research.

Pore Size Distribution of a Tight Sandstone Reservoir and its Effect on Micro Pore‐throat Structure: A Case Study of the Chang 7 Member of the Xin'anbian Block, Ordos Basin, China

AbstractPore distribution and micro pore‐throat structure characteristics are significant for tight oil reservoir evaluation, but their relationship remains unclear. This paper selects the tight sandstone reservoir of the Chang 7 member of the Xin'anbian Block in the Ordos Basin as the research object and analyzes the pore size distribution and micro pore‐throat structure using field emission scanning electron microscopy (FE‐SEM), high‐pressure mercury injection (HPMI), high‐pressure mercury injection, and nuclear magnetic resonance (NMR) analyses. The study finds that: (1) Based on the pore size distribution, the tight sandstone reservoir is characterized by three main patterns with different peak amplitudes. The former peak corresponds to the nanopore scale, and the latter peak corresponds to the micropore scale. Then, the tight sandstone reservoir is categorized into three types: type 1 reservoir contains more nanopores with a nanopore‐to‐micropore volume ratio of 82:18; type 2 reservoir has a nanopore‐to‐micropore volume ratio of 47:53; and type 3 reservoir contains more micropores with a nanopore‐to‐micropore volume ratio of 35:65. (2) Affected by the pore size distribution, the throat radius distributions of different reservoir types are notably offset. The type 1 reservoir throat radius distribution curve is weakly unimodal, with a relatively dispersed distribution and peak ranging from 0.01 μm to 0.025 μm. The type 2 reservoir's throat radius distribution curve is single‐peaked with a wide distribution range and peak from 0.1 μm to 0.25 μm. The type 3 reservoir's throat radius distribution curve is single‐peaked with a relatively narrow distribution and peak from 0.1 μm to 0.25 μm. With increasing micropore volume, pore‐throat structure characteristics gradually improve. (3) The correlation between micropore permeability and porosity exceeds that of nanopores, indicating that the development of micropores notably influences the seepage capacity. In the type 1 reservoir, only the mean radius and effective porosity have suitable correlations with the nanopore and micropore porosities. The pore‐throat structure parameters of the type 2 and 3 reservoirs have reasonable correlations with the nanopore and micropore porosities, indicating that the development of these types of reservoirs is affected by the pore size distribution. This study is of great significance for evaluating lacustrine tight sandstone reservoirs in China. The research results can provide guidance for evaluating tight sandstone reservoirs in other regions based on pore size distribution.

Lead distribution in urban street dust and the relationship with mining, gross domestic product GDP and transportation and health risk assessment

Lead (Pb) is an important pollutant and it is of significance to explore the Pb distribution, influencing factors and health risk. Pb concentration and mass load per unit area in 385 street dust samples collected from 19 cities in China were determined during 2011-2013. The results show that the Pb concentration are 68.8, 105.4, 41.7, 49.7, 75.6, 81.7, 131.9, 67.5, 109.3, 164.1, 74.8, 66.4, 99.8, 58.4, 114.0, 59.6, 103.7, 55.4 and 80.4 for Beijing, Chengdu, Daqing, Harbin, Jilin, Jinan, Kunming, Lanzhou, Luoyang, Panzhihua, Qingdao, Yinchuan, Guangzhou, Tangshan, Xi’an, Guangyuan, Nanjing, Taiyuan and Tianjin, respectively. The Pb pollution level of urban street dust varies among cities in the range of 1.72–5.56 times higher than soil background values. The allometric function can fit the change in Pb concentration with particle size well. The medium-sized (38–120 μm) particles contributed 60.2%–80.4% to the Pb load and should be highlighted when selecting street dust management techniques. Influenced by the distribution of Pb ore, the Pb concentration of urban street dust in China shows obvious regional differences, with value in the south 112% higher than that in the north. Among all kinds of mining types, metal-related mining activities discharge a large amount of Pb dust in the process of crushing and smelting, thus contributing most to the Pb load. The Pb load was also affected by transportation. The relationship between Pb load and gross domestic product (GDP) was described with the environmental Kuznets curve (EKC) model, which indicated that the Pb emissions of most cities were still increasing. Finally, the human health risk assessment model with adjusted parameters showed that the Pb risk of all cities was below the threshold. Despite all this, given the EKC law of Pb emission, long-term follow-up assessments are needed.

PERENCANAAN TEKNIS OPERASI PRODUKSI BIJIH TIMAH DI BLOK 3 TAMBANG BESAR 2.1 MITRA PT TIMAH (PERSERO) TBK

The process of tin ore mining in TB 2.1 is conducted by channeling slurry (the mixture of ore and water) from the stock pile into the washing unit by using slurry pump. Now, TB 2.1 is planning block 3 for the operation of tin ore production proceess. Thus, a good technical planning in accordance with the characteristic of tin ore in TB 2.1 and evaluation of operating system design in Block 1 are necessary. The sample of tin ore concentrate is taken as many as 250 gr from the washing unit to detect P80 of particle size distribution (PSD) of sample. The data of sucker and pressure pipe’s lenghth, store tank’s height, quantity of primary and secondary jig and tin ore monthly production are required to furthermore plan the mining design, washing plant and equipment needs in the drying unit. Based on the research findings, It is obtained the grain size distribution of tin ore is 1.001 mm, so that the amount of lifting velocity is 3.27 m/s. Slurry pump discharge with a pipe’s diameter of 10 inches is 54 m3/hour, while total head of mining design is 30.23 m. Width of launder required is 6.5 m and equipped with two Grizzlies. Washing plant requires three units of primary Jig (2 × 3 cell) and a unit of secondary jig (2 × 3 cell). Adding rotary vibrating screen, shaking table and rod mill are necessary for process optimization in the drying unit.

The Role of Black-Shale Strata in the Formation of the Natalka and Pavlik Gold Deposits (Yana–Kolyma Orogenic Belt)

Abstract —Data on geochemistry, distribution of ore and rare-earth elements and precious metals, and micromineralogy are presented. The objects of study are late Permian sedimentary and volcanosedimentary deposits of the Tikhonya Brook (Atkan (P3at) and Omchak (P3om) formations) and hydrothermally metamorphosed rocks of the Natalka and Pavlik gold deposits of the Omchak ore–placer cluster. Analysis of the deposit ores showed enrichment in chalcophile trace elements Au, Ag, As, W, and Sb relative to their average contents in the upper crust and the host Permian rocks. The high contents of W and Bi in the ores suggest the participation of a magmatic fluid. The absence of abnormal contents of Ni, Co, Sb, Mo, Cr, and Se indicates the redeposition of these elements from ore-bearing rocks, without their input by ore-forming fluids, which is confirmed by the isotopic composition of sulfide sulfur and the characteristics of carbonaceous ore material. The formation of deposits proceeded with a change in REE contents. All objects show similar trace-element patterns: The rocks are enriched in LREE and lack a Ce anomaly. The identical REE patterns of ores reflect their inheritance from unaltered late Permian deposits. It has been established that the ores formed under different redox conditions, mainly with the participation of a relatively oxidized fluid enriched in LREE of the hydrothermal system NaCl–H2O, with domination of Cl over F. The studies have shown that the host carbonaceous sedimentary complexes, which served as additional sources of precious and associated metals, played a crucial role in the formation of the Natalka and Pavlik gold deposits. Some of the ore elements in the unaltered deposits form their own minerals.

Arkhangelsky Andrei Dmitrievich (to the 140th anniversary of birth)

The material in the article contains biographical information from the life and scientific activity of the doctor of geological and mineralogical sciences, professor, academician Academy of Sciences of the USSR A.D. Arkhangelsky. A wide range of the scientist is shown and a description of the main directions of research in the field of regional geology, fauna and stratigraphy of the Paleogene and Upper Cretaceous deposits of the Volga and Central Asia, lithology and paleography, issues of tectonics and the relationship of gravitational and magnetic anomalies with the geological structure of the territory of the USSR is given. The main attention is paid to his work in the study of the geology of oceans and seas. The main contribution of the scientist to the study of Mesozoic bauxites, their structure and mineral composition is described. On this basis, the scientist developed and substantiated a new sedimentary theory of their formation. This theory opened the possibility for geologists to approach the study of bauxite as sedimentary rocks; this played an important role in the search for new deposits of this valuable mineral. The complex of geological and geophysical work carried out by him on expeditions along the East European Plain provided an answer to important questions about the distribution of oil, coal and iron ores on the territory of the Russian Platform. Much attention was paid to the study of the geology of the Black Sea. Processing materials collected by a hydrographic expedition and a comparative study of the columns of the Black Sea silt and oil-bearing sediments of the Crimean-Caucasian region led the scientist to important conclusions about the conditions of accumulation of oil-producing suites. Long-year research A.D. Arkhangelsk sediments of the Black Sea, their lithology, geochemistry, structure, subsequent changes and deformations were summarized in a number of works, among which are “Conditions for the formation of oil in the North Caucasus” (1927), “Geological history of the Black Sea” (1932), “Geological structure and the history of the development of the Black Sea“ (1938), written together with N.M. Strakhov. In 1926—1928 Arkhangelsky lead the field geological survey work on the Kerch Peninsula for the study of oil fields.