Sillimanite group minerals: a new promising raw material for the Russian aluminum industry

The raw-material base of the Russian aluminum industry is considered. The raw materials include common (bauxites, nepheline syenites) and uncommon (nepheline ores, synnyrites, anorthosites, power-and-heating plant ashes, kaolines) types of ores. With regard to many criteria (reserves and quality of ores, technology of their processing, etc.), the problem of alumina deficit can be solved by mining sillimanite group minerals Al₂SiO₅ (wt.%: Al₂O₃ = 62.9, SiO₂ = 37.1), namely, andalusite, sillimanite, and kyanite. Their proved reserves converted to the final product (aluminum) exceed 400 mln tons. This will be enough for more than a hundred years provided that aluminum is produced in the present-day output (4 mln tons in 2008). Almost all deposits can be explored by strip mining, with application of the gravitation, flotation, and electromagnetic separation methods for ore dressing. The alumina content in concentrates reaches 60–62 wt.%. Only high-grade bauxites and the above concentration methods can ensure such a high yield of Al₂O₃. Sillimanite group minerals can be processed together with nepheline ores by sintering or be used for the direct electrothermal production of silumin and aluminum, excluding the alumina production stage. The latter method is the most promising in Russia.     

Contamination of the cement raw material in a quarry site by seawater intrusion,Darica-Turkey

The open pit mining nearby shoreline is planned to be extended into below sea level in order to use additional reserves of the cement raw material (marl). The raw material is currently contaminated by seawater intrusion below a depth of 20 m up to the distance of 90 m from shoreline. Seawater intrusion related contamination of the material used for the cement production was investigated by means of diffusion process for the future two below sea level mining scenarios covering 43 years of period. According to the results, chloride concentrations higher than the tolerable limit of a cement raw material would be present in the material about 10–25 cm inward from each discontinuity surface, controlling groundwater flow, located between 170 and 300 m landward from the shoreline at below sea level mining depths of 0–30 m. The estimations suggest that total amounts of dilution required for the contaminated raw material to reduce its concentration level to the tolerance limit with uncontaminated raw material are about 113- to 124-fold for scenario I (13 years of below sea level mining after 30 years of above sea level mining) and about 126- to 138-fold for scenario II (43 years of simultaneous above and below sea level minings).     

关于高纯石英原料矿石地质学评价方法的探讨

高纯石英资源是一种重要的战略性资源。本文结合高纯石英成矿地质特征及其对后期选矿提纯、材料加工等的影响, 系统总结了高纯石英原料中杂质的赋存状态、形成机理以及评价方法等, 得出: (1)可以作为高纯石英原料的潜在岩石类型有花岗伟晶岩(包括不含暗色矿物的伟晶状花岗岩)、脉石英以及水晶, 岩浆演化晚期的伟晶状花岗岩-伟晶岩早期阶段的NYF型花岗伟晶岩结晶形成的石英纯度更高, 后期适当的变形变质作用更有利于高纯石英矿床的形成。高纯石英原料矿石中石英矿物呈现无色透明至半透明, 矿物构造裂隙少, 伟晶岩型矿石矿物组成通常为石英、钠长石、条纹长石、白云母等, 黑云母等暗色矿物含量极少, 基本不见锂辉石、独居石等稀有金属矿物和电气石、萤石等含挥发分矿物。(2)影响高纯石英的主要地质因素包括脉石矿物及晶界杂质、包裹体、晶格杂质等。其中包裹体类型、数量和尺寸是包裹体评价的关键指标, 天然石英矿物中的气液两相包裹体、矿物包裹体和 < 10μm包裹体应尽量少; Al和Ti是晶格杂质元素评价标志性元素, 通常要求天然石英矿物中Al < 50×10^-6和Ti < 10×10^-6。(3)建议按照手标本特征-石英矿物特征-石英中包裹体特征-晶格元素赋存状态及含量的顺序, 从宏观到微观, 综合借助光学显微镜、扫描电子显微镜(SEM)、阴极荧光光谱分析系统(SEM-CL)、激光剥蚀电感耦合等离子质谱仪(LA-ICP-MS)等开展地质学评价和研究工作。

     

玄武岩纤维原料特征的统计及分析研究

玄武岩纤维是以玄武岩或他种成分相近的岩石为主要原料,经熔融后拉制而成的一种高性能纤维。天然矿石的成分波动会造成拉丝困难或纤维性能不稳定,笔者等收集了54组原料岩石以及114组玄武岩纤维样品的化学成分数据,研究归纳了玄武岩纤维所需原料的岩石学特征、参数指标特征和其他特征,分析提出了可拉丝岩石相关参数指标的最佳区间。适于生产玄武岩纤维的原料矿石,其特征可总结如下：岩石学方面,以基性岩以及SiO2含量为53%~57%的中性岩为佳,岩石类型最佳为玄武岩或安山玄武岩;岩石结构最佳为间隐结构、玻基斑状结构或玻璃质结构;构造的影响是间接的,主要为气孔或杏仁构造中可能含有的一些不利矿物的影响;矿物组成方面,蛇纹石、沸石等含水矿物会在熔融过程中产生气泡,影响纤维制备连续性的同时也有利于原料的充分熔融,镁橄榄石、磁铁矿等高熔点矿物会使原料在熔融阶段难以完全熔化,导致熔体不均匀并容易析晶。参数指标方面,可拉丝岩石的酸度系数（Mk）最佳区间为4. 0~5. 5;黏度系数（Mv）为2. 0~3. 0;硅铝氧化物与其他氧化物比值为1. 5~3. 0;氧化物组成的物质的量分数分布为n(RO)=20%~30%,n(RO2)=57%~70%,n(R2O3)=10%~16%（R为阳离子）。     

玄武岩纤维原料特征的统计及分析研究

玄武岩纤维是以玄武岩或他种成分相近的岩石为主要原料,经熔融后拉制而成的一种高性能纤维。天然矿石的成分波动会造成拉丝困难或纤维性能不稳定,本文收集了54组原料岩石以及114组玄武岩纤维样品的化学成分数据,研究归纳了玄武岩纤维所需原料的岩石学特征、参数指标特征和其他特征,分析提出了可拉丝岩石相关参数指标的最佳区间。适于生产玄武岩纤维的原料矿石,其特征可总结如下：岩石学方面,以基性岩以及SiO2含量为53%~57%的中性岩为佳,岩石类型最佳为玄武岩或安山玄武岩;岩石结构最佳为间隐结构、玻基斑状结构或玻璃质结构;构造的影响是间接的,主要为气孔或杏仁构造中可能含有的一些不利矿物的影响;矿物组成方面,蛇纹石、沸石等含水矿物会在熔融过程中产生气泡,影响纤维制备连续性的同时也有利于原料的充分熔融,镁橄榄石、磁铁矿等高熔点矿物会使原料在熔融阶段难以完全熔化,导致熔体不均匀并容易析晶。参数指标方面,可拉丝岩石的酸度系数（Mk）最佳区间为4.0~5.5;黏度系数（Mv）为2.0~3.0;硅铝氧化物与其他氧化物比值为1.5~3.0;氧化物组成的物质的量分数分布为n(RO)=20%~30%,n(RO2)=57%~70%,n(R2O3)=10%~16%（R为阳离子）。     

Lithic raw material usages during the Middle Stone Age at Dakhleh Oasis,Egypt

Dakhleh Oasis, the largest of the Egyptian Western Desert, presents an opportunity for diachronic study of lithic raw material preferences during the Middle Stone Age (MSA) of the Eastern Sahara. Archaeological aggregates and raw material sources are exposed and easily mapped. Diverse and abundant lithic raw materials derive from sandstone, shale, and limestone sources and are also found in secondary geological contexts. Three main raw materials were used, and there was strong preference for one of these: Tarawan chert. Easily available only in the north‐central oasis, this material was transported substantial distances even when other materials that were known and used by MSA peoples could be found closer at hand. There is little evidence for use of raw materials exogenous to Dakhleh Oasis. This pattern of usage does not appear to change from the older MSA units to the Aterian Dakhleh Unit. © 2002 Wiley Periodicals, Inc.     

Evaluation of low-rank coals as raw material for Fe and Ca organomineral fertilizer using a new EDXRF method

A rapid and reliable method for analyzing Fe and Ca in low-rank Greek coals was developed. The presence of Fe and Ca is of importance regarding the potential use of these coals as raw material for organomineral fertilizers. Samples were collected from the main Greek lignite deposits and standards were prepared using Atomic Absorption Spectroscopy (AAS), which were also employed in the Energy Dispersive X-ray Fluorescence (EDXRF) method. The new method offers the advantages of being timesaving, non-destructive and can be easily incorporated in a fertilizer production line. Analysis of low-rank Greek coals demonstrated a significant Fe and Ca content ranging from 0.15 to 1.97 wt.% for Fe and from 0.04 to 2.51 wt.% for Ca. When both EDXRF and AAS techniques were applied, the Fe and Ca concentration values differed less than 5%, demonstrating that both techniques are reliable for low-rank coals in the above concentration range. These EDXRF results may be used as a preliminary test regarding the application of Greek coals in organomineral fertilizer production, given that in these coals iron and calcium are the most abundant metals.     

Petrographical,structural, and mechanical analysis of armorican phtanites: A key raw material for the Mesolithic in Western France

Over the last ninety years or so, archaeological field work on outcrops of raw materials in western France has allowed researchers to identify the use of a large number of deformed rock types in lithic industries. These materials include Armorican phtanites, which are cherts that were widely exploited during the Mesolithic, principally during its final phase (5500–5000 yrs cal. B.C.). Because of variations in the mineralogical composition and physical properties of phtanites, different mechanical properties are exhibited by samples from the four main geological formations containing this rock type in the Armorican Massif of western France. These geological and mechanical parameters influenced the quantity of rock used and the knapping methods employed. They also influenced the tool types produced and their transfer, as recorded in archaeological sequences. The types of raw materials used are also controlled by the distance to sources of coastal flint pebbles or other autochthonous siliceous rocks. Therefore, the role of raw material properties in the creation and persistence of techno‐cultural or economic characteristics is different for each type of phtanite and yields fundamental information on the interaction of society with the geological environment. © 2010 Wiley Periodicals, Inc.     

巫山玉米洞遗址石制品原料利用策略分析

玉米洞遗址因石灰岩石器而备受关注,文章拟在"资源域"概念指导下对玉米洞遗址石制品原料利用策略和石器工业面貌成因进行考察分析,进而探讨该遗址古人类的行为模式及文化传统。从原料资源条件和古人类利用策略的关联性来看,石灰岩能够成为玉米洞遗址石制品原料的首选,是古人类在充分认知和权衡遗址周边资源分布的一种被动选择,石制品技术和工业面貌受制于石灰岩原料特殊的质量和形态,原料决定论在该遗址有着非常契合的表现。在原料资源不利的情况下,古人类采取扬长避短、灵活务实的策略主动适应现有的资源条件和原料特性。同时,原料开发利用的策略和方式也在一定程度上反映了偶遇式和嵌入式的原料获取方式以及流动性较低的迁徙组织形式。     

Ground calcium carbonate (GCC) from the Barre de Ghomrassene in Southeast Tunisia: a suitable raw material for paint industry

The main scope of the present work is to investigate the potential of using ground calcium carbonate (GCC) from the Barre de Ghomrassene (BDG) in Southeast Tunisia in paint industry. In order to evaluate the performance of the material and the formulated paint films, representative raw specimens of main deposits of naturel GCCs in the Mediterranean basin and Middle East countries such as extra-white limestone from the Abiod Formation (Feriana region in West-Central Tunisia), A??gedi?i Formation (Ni?de Group, South Central Turkey), and Samalut Formation (Elminea, South Cairo, Egypt) were considered. Samples were ground to specific surface of about 3000 cm²/g and were subjected to detailed characterization including chemical and mineral composition, physical, and chromaticity characteristics. Results show that the GCC from the lower part of the Barre de Ghomrassene is, in most, dark and grainstone in texture, which limit its use in paint and coating application. Elsewhere, it is marked by high purity degree (generally more than 97% calcite); high lightness (more than 86.5, 95.2 in average) with relatively low chromaticity (a*?<?3.3, b*?<?9.1); low oil intake (17.4 g/100 GCC); very low electrolyte levels; good pH buffering (close to 9); accepted ranges of density and abrasion (2.65–2.7 and 10–18, respectively); good grindability; low levels of harmful components such as MgO, SiO₂, Fe₂O₃, and acid insoluble residue (less than 0.1% each); and improved rheological properties. The BDG seems to be a suitable filler for paint when mixed with water, styrene acrylic, and common additives. The formulated paint films meet all standard requirements, in that they have very good opacity, matt visual dualgloss 20/60°, high luminescence (L*?=?96.4), suitable hardness (145 s), good adhesion (B5), and sufficient impact resistance (1.5 kg m). The performances of these films are analogous to those based on Abiod and Samalut formations (natural carbonate), but they are slightly less lighter than those based on A??gedi?i Formation (metamorphic carbonate). Hence, the studied GCC can be used to substitute them in particular for local GCCs from the Abiod Formation, which are limited and over exploited.     

Evaluation of Greek low-rank coals as potential raw material for the production of soil amendments and organic fertilizers

This study evaluates Greek peat and coal samples for applications in the agricultural/horticultural sector and assesses the suitability of a certain peat/coal either as soil conditioner or as raw material for manufacturing organic fertilizers.Twenty-six samples of different rank ranging from peat to subbituminous coal obtained from several Greek peat/coal deposits, were studied. The laboratory tests included: a) pH and electrical conductivity (EC) determinations, as well as proximate, ultimate and maceral analyses, in order to characterize the samples, b) major and trace element analyses of both the total and the easily exchangeable fractions (EEF), in order to assess the phytotoxicity effect, c) cation exchange capacity (CEC) determination in mixtures of the samples (5 wt.%) with a certain soil (95 wt.%), in order to evaluate the peat/coal impact, and d) the determination of the contents of humic substances (HS), as well as of carboxylic and phenolic groups.The majority of the samples reveal moderate to high ash yields (16–80 wt.%), a slightly acidic to neutral character and electrical conductivity ranging from 100–2500 μS/cm. Concerning the environmental impact of the sensitive trace elements, which might be leached, As, Mn, Ni and Sr show relatively strong mobilization in some samples, although severe impacts are not expected. The soil's CEC is generally improved, although it remains at moderate levels. The most interesting aspect is the humic acids content, which ranges between 9.6 and 52.2 wt.% on a dry basis, exceeding 25 wt.% for most of the samples. The obtained results enable an initial correlation among the different parameters and a rating of the samples according to their suitability for soil-amelioration agents.     

Indications of a major Neolithic trade route? An archaeometric geochemical and Sr,Pb isotope study on amphibolitic raw material from present day Europe

In order to interpret pre-historic cultural interactions, the provenance of amphibolitic raw material used for flat-axes and adzes in lower to middle Neolithic cultures throughout present day Germany were investigated by elemental and Sr, Pb isotopic methods. Within all settlements studied, a homogeneous actinolite-hornblende schist rock type (AHS) was found to be massively dominating, with a distinct petrography of needle-shaped actinolite interwoven with single larger grains of hornblende along with calcic plagioclase and large amounts of ilmenite. Geochemically, the AHS group is very homogeneous and has a signature of an enriched basaltic precursor with high concentrations of particularly the LIL-elements. The geochemical signature is relatively rare and can not be matched in nearby geological outcrops, wherefore the conclusion of “imported material” is quickly reached. Strontium and Pb isotopic analyses of the AHS were compared to the isotopic composition of amphibolitic rocks with similar petrography and trace elemental signatures within possible archaeological trade regions. The isotopic data of the archaeological material point roughly to a Proterozoic age of the stone used; an age which can be reasonable matched to a single outcrop situated at Jistebsko within the Czech Republic. This area further shows archaeological traces of prehistoric mining. Based on petrographic, geochemical and isotopic evidence, this area is here presented as the provenance area of the stone raw material, which later spread throughout prehistoric Europe – establishing contact and trade routes between Neolithic cultures.     

Failure phenomena and environmental control of the relatively unstable hammana area,Lebanon

Engineering geological investigations of the Hammana area showed slope failure phenomena to consist of large masses involving toppling, translational and rotational slides; also of single blocks involving wedge separation; and composite types. The causes of mass wasting were environmental, i.e. geomorphologic and climatic, internal causes inherent in the geology and engineering properties of the materials, and external causes having to do with natural and/or man-induced vibrations. Environmental control using all field and laboratory information resulted in production of a stability map indicating areas of potential hazard, that is to say, immediate within the coming few years, near-future hazard within tens of years, and of long-term hazard. The map is vital for land evaluation prior to development and construction.     

鄂东南付家山脉石英矿杂质特征及其用作高纯石英原料的潜力

作为战略性矿产资源之一,高纯石英已广泛应用于集成电路、半导体芯片、太阳能等高新技术产业中,但是能够生产高纯石英的原料矿床极为稀缺,我国尤为紧缺高纯石英原料矿。鄂东南地区是湖北省脉石英矿床的主要分布区。本文针对鄂东南付家山脉石英矿床,通过光学显微镜、扫描电子显微镜观察了脉石英的脉石矿物类型和包裹体特征,采用电感耦合等离子发射光谱法(ICP-OES)对原矿进行了微量元素分析,旨在获得付家山脉石英矿床的杂质元素特征,进而评价矿床用作高纯石英原料的潜力。结果表明,付家山脉石英矿石SiO₂含量大于99.95%,杂质元素主要为Al、K、Fe、Ti、Ca等,脉石矿物主要有白云母、钾长石、铁氧化物等,流体包裹体较为发育。杂质元素分析结果表明,付家山脉石英原矿质量达到低端高纯石英标准,经传统工艺提纯后,可能具有生产中高端高纯石英的潜力。     

Gravel washing wastes from Jarama river deposits (Spain): an undervalued natural raw material

This work presents the main characteristics of 97 quarry wastes, collected in 23 gravel pits, from the Jarama river area, Madrid province, Spain. In this area, more than 2.5 × 10⁶ ton of silty-clay waste are generated every year, and no applications have as yet been defined for them. This work is the first systematic study of the fine fractions generated from the Jarama river quaternary deposits, playing part in the comprehension of this complex terrace systems. Quartz, potassium feldspar, plagioclase, calcite, and complex mixtures of phyllosilicates, such as smectite, illite, kaolinite, chlorite and illite/smectite mixed layer, have been detected. Two sets of waste which are recognized according to the calcite content, have been directly related with the terrace level beneficed in the Jarama river, and the position along the valley. Calcite concentrates in the wastes produced in the lower course, where Henares and Tajuña tributaries promote an extensive change in the geochemistry of underground water, and locally, in the petrology of quarried conglomerates. This clear distinction by location between calcite-bearing and calcite-free wastes is essential for potential applications, such as soil conditioning, raw materials for brick or tiles, etc. The wastes studied can be considered as a potential source of industrial raw materials because of their uniformity and large volume. This suggestion is now being carried out, with an attempt at assessing the possibilities of using these mining wastes as ceramic raw materials.     

The source of raw materials for Roman pottery from Leptiminus,Tunisia

Leptiminus, a Roman port city on the west coast of Tunisia, North Africa, exported olive oil and a garum fish paste to Rome. Excavations have uncovered many facilities including kilns and a potter's workshop, indicating an extensive ceramic industry. The vessels, manufactured at Leptiminus, included African red‐slip fineware, coarseware, and amphorae. A petrographic study of pottery sherds showed them to contain very similar temper, rounded aeolian sand grains and limestone, but varying in proportions to produce different textures. An investigation of the source of raw materials for the pottery found three distinct types of clay within a 50 km radius of Leptiminus: grey Miocene, brown Pliocene, and green Late Pliocene clay. Statistical analysis of trace element compositions, using induced neutron activation, of clays and sherds showed that the Pliocene brown clay was used to create all types of pottery. The specific clay horizon, used in Roman times, has apparently been removed by quarrying. However, a lateral continuation of this bed was found 7 m beneath the Leptiminus site 290. © 2002 Wiley Periodicals, Inc.     

Flood control failures in a Third World City: Benin City,Nigeria — some environmental factors and policy issues

GeoJournal - Inspite of step-up efforts at controlling flood hazards in Third World cities, the frequency and magnitude of the flood problem have more than doubled in recent years. A survey of the...     

Green's functions for a fully coupled thermoporoelastic material

The Green's functions for a set of fully coupled linear equations governing thermal consolidation of a homogeneous isotropic material are presented. The Green's functions are evaluated for one, two and three spatial dimensions, and in the Laplace and real-time domains. The Green's functions are employed in a boundary integral analysis of a simple problem to demonstrate the influence of full coupling on the field quantities.