Percentage Of Clay Minerals Research Articles

Clay minerals characterization of the Miduk ball mill output through spectral analysis

Porphyry copper deposits usually include typical alteration types, which are often composed of clay minerals. The mixing of clay minerals has a significant impact on their spectral absorption characteristics, and their identification and separation becomes complicated. One of the most accurate and widely used methods for identifying minerals is spectroscopy, which is a suitable alternative to traditional methods. Spectroscopy assists in identifying the mineral composition and classification. The aim of the following research is to quantitatively characterize clay minerals in mineral assemblage of ball mill output. Pure and composite samples were prepared through sampling from two alteration types and creating synthetic samples containing different percentages of clay minerals. Then they were subjected to spectral analysis in the range of 2500–350 nm and their output was subjected to necessary pre-processing. The results were used for classification by employing a hybrid algorithm. The analysis identified the following minerals in the Miduk deposit: hematite, carbonates, illite, biotite, kaolinite, chlorite and muscovite. Additionally, microscopic studies were conducted on the samples for further analysis. Finally, total and clay diffraction XRD analysis were used to validate the results.

Chemical weathering in the Himalayan system in response to the evolution of the Indian summer monsoon since 37 ka

Based on clay mineralogy, siliciclastic grain sizes and geochemical records from deep-sea sediments in the central Bay of Bengal (BoB), the evolutionary history of the Indian summer monsoon and associated weathering process in the Himalayan system since 37 ka were reconstructed. Clay minerals and ThLa elements indicate a mixture of sediments originating from the Ganges-Brahmaputra (G-B) Rivers, Indo-Burman ranges/Irrawaddy River and Godavari-Krishna (G-K) Rivers. The ThLa quantitative reconstruction revealed that sediment supply from the G-B Rivers was reduced during a series of millennial-scale cold climate events (i.e., Younger Dryas and Heinrich Events) and the Last Glacial Maximum. By removing the control of sea-level factors on the percentage of clay minerals in the sediments, we suggests that the marked decrease in the illite chemistry index and the increase in the (illite+chlorite)/smectite ratio during cold climate periods reflect enhanced physical weathering and weakened chemical weathering in the Himalayan system. Comparing the contribution from the G-B Rivers and the sedimentation rates in different regions of the BoB, it was inferred that the sediments of the G-B Rivers were mostly deposited in the upper and middle Bengal Fan. During the Holocene, the Active Channel played a crucial role in delivering sediments from the G-B Rivers to the lower Bengal Fan. The decreased chemical index of alteration (CIA) and increased K₂O/TiO₂ ratio indicated the weakening of the Indian summer monsoon. At that moment, the Himalayan system was involved in cold climatic conditions accompanied by glacial extension, which led to enhanced physical weathering and increased sediment contributions from the highlands.

Sediment mineralogy influences the rate of microbial sulfate reduction in marine sediments

Sedimentary microbial communities play a critical role in the global carbon cycle, oxidizing deposited organic carbon and thus influencing the type of carbon buried from Earth's surface. The rate of microbial metabolism within sedimentary microbial communities is often linked to the lability and amount of organic carbon deposited. Here we show that, in pure culture, for sulfate-reducing bacteria (Desulfovibrio bizertensis) the rate of microbial sulfate reduction is a function of the proportion of clay minerals present in the incubation vials. We argue that the presence of clay minerals stimulates the growth of the sulfate-reducing bacteria and the rate at which sulfate is consumed; we conclude that this is not linked to nutrients and carbon on the clay minerals but rather is a function of the high specific surface area of clay minerals. We further use a global compilation of sedimentary pore fluid data to demonstrate that these observations can be seen in marine sediments, that is pore fluid sulfate concentration gradients in marine sediments correlate with the percentage of clay minerals in the sediment. Our findings suggest that sediment mineralogy influences the rate of microbial activity in marine sediments, which has heretofore not been considered.

The Alteration of Giglio Island Granite: Relevance to the Conservation of Monumental Architecture

The research examines the alteration phenomena of Giglio island granite, a rock quarried by Romans from the 3rd century, used for columns in the Italian peninsula and later reemployed in many Christian religious buildings. The study has shown that already in the bedrock there are small percentages of clay minerals. Starting from this condition, the alteration develops by an increase in porosity, which in turn favours the establishment of a slight hydrolysis of the silicates with a decrease in Na, Ca, and K, in accordance with the sericitisation process. The alteration proceeds with a further increase in porosity, apparently not related to a real loss of cohesion, which, however, occurs shortly after, highlighting the necessity of a continuous monitoring of the state of conservation of the material in the architectural heritage.

A review on soil stabilization using rice husk ash and lime sludge

Building pavements and other civil engineering projects on available land containing some percentage of clay minerals is highly dangerous, due to its low strength properties. It is not always possible to avoid using that piece of land due to financial constraints. This necessitates soil treatment in order to improve soil engineering properties. In practice, admixtures like fly ash, lime, and cement are widely used to stabilize and strengthen soils. This study reviewed two waste materials: Rice Husk Ash (RHA) and lime sludge for stabilization because they are locally available nearby, the quantity of trash that must be disposed of and therefore reducing pollution. These two react to generate complexes that fill in the gaps in the structure of the soil, reducing shrink or swell characteristics and plasticity, and therefore enhancing the strength of the soil. RHA and lime sludge are waste products that can be found in large quantities, making construction more cost-effective. The present study aims at review of literatures pertaining to the stabilization of clay using RHA and lime sludge, separately and combined as well. It was observed that increasing the amount of RHA and lime sludge in the soil improves its strength. Additionally, to determine the best ratio of the two additives in order to maximize soil strength. The study on compaction characteristics, Liquid Limit (LL), Unconfined Compression Strength (UCS) and California Bearing Ratio (CBR) was focused from the literatures. Experiment results in the literatures with RHA and lime sludge from different studies are compared to determine the optimum quantity of RHA and lime sludge required to stabilize a weak soil, as well as inferences regarding the effect on soil attributes. By comparing the results, the suitable recommendations are provided. 10% RHA and 15% Lime sludge was found to be an optimum mix for the effective stabilization of clay.

Grain-size effect on dynamic behavior of sandstone based on high-speed 3D-DIC technique

The grain size effect on the dynamic behavior of sandstone was investigated through the compression tests on coarse-grained (CG), medium-grained (MG) and fine-grained (FG) sandstones by split Hopkinson pressure bar (SHPB) tests under the strain rates of 69–83 s–1 based on the thin section and electron scanning microscopic (SEM) images analysis, the CG, MG and FG sandstone were mainly composed by quartz with the average grain size of 200–500, 90–500 and 55–120 µm, respectively. With the increasing grain size, the percentage of clay mineral was decreased correspondingly from 8% to 1%. During the dynamic compression, two high-speed cameras were applied to capture the deformation of sandstone at frame rate of 2×105 s–1 and resolution of 256×256. The real-time strain fields of rock were obtained by high-speed three-dimensional digital image correlation (3D-DIC) technique, the dynamic deformative properties, particularly the lateral strain of the specimen, were extracted by averaging the lateral strain field by pixels. The fracturing behavior of three sandstones was analyzed through the strain localization evolution within the strain fields. Results show that the critical strain rate for reversible release of elastic strain energy increases with the decreasing grain size. The dynamic strength ascends along with the reduction of grain size, while the strain rate sensitivity to the dynamic strength has an opposite trend. Compared to the quasi-static case, the dynamic elastic modulus increases by 2–3 times for MG and FG sandstone, particularly 5 times for CG sandstone. The Poisson’s ratio under dynamic loading in FG sandstone is grown by 25%, but drops at 70% of the static one in MG sandstone. The crack primarily generates inside the specimen and propagates to the surface of the specimen afterwards. The crack development is advanced under dynamic loadings, where the normalized stress threshold for crack initiation in FG sandstone is only 10%. Based on the microscopic analysis, mineral structure and clay percentage dominate the dynamic property and fracturing behavior of sandstone, respectively.

MINERALOGICAL COMPOSITION AND FABRIC AS RELATED TO THE MECHANICAL BEHAVIOR OF THE FINE – GRAINED PLIO-PLEISTOCENE SEDIMENTS OF ACHAIA, GREECE

The fine grained sediments of the Plio-Pleistocene deposits of Achaia have been distinguished into two geotechnical units, stratigraphically successive, the Upper and the Lower one. A number of tests were performed in samples from both units in order to determine their mineralogical composition and fabric, as well as their CaCO3 content. From these it is shown that the two units present main differences in mineralogical composition, type and percentage of clay minerals, concretion ratio and calcium carbonate content, which directly affect their mechanical behavior in construction of technical works.

3D geostatistical modelling and uncertainty analysis of clay minerals distribution in reservoir rocks

Drilling through shale layers is associated with many problems such as wellbore instability, hole wash out, pipe stuck, etc. Reactive shale with swelling potential can lead to such problems. Reactive shale is a shale that has high swelling clay mineral like montmorillonite although there was a little amount of this clay mineral. So determine the type of clay mineral in shale formation and obtain the distribution of swellable clay mineral can help us in the selection of stable well path and determination of well location that has least instability problem, prevention and prediction of problem associated with swelling clay mineral such as pipe stuck, hole wash out, bit balling, etc. In this paper, we used thorium and potassium from corrected gamma ray (CGR) log to obtain the type and percentage of clay mineral. Then used X-ray diffraction for more detail analysis of clay mineral constitute. Finally, geostatistical modelling is used to obtain the continuity of clay mineral in the reservoir and estimate the amount of desire clay mineral along the reservoir.

Physico-chemical, mechanical and cytotoxicity characterizations of Laponite®/alginate nanocomposite

Combining clay minerals containing silica with polymers can improve the performance of polymers in biomedical applications by the synergistic combination of physico-chemical and biological properties of both phases. In this study, Laponite® — a synthetic biocompatible and biodegradable silicate clay mineral, was combined with alginate to improve alginate mechanical and biological characteristics. The physico-chemical properties (porosity, degradation, swelling, crystalline structure, compressive strength, and injectability) and biological responses (cytotoxicity and cell morphology) of the Laponite/alginate nanocomposites were investigated in the study. The results showed that the incorporation of Laponite into alginate significantly enhanced alginate compression strength without hindering its injectability when the percentage of clay mineral was below 50%. The prepared clay polymer nanocomposites (CPN) were not toxic and the viability of cells cultured in its extract was indeed higher than alginate alone. However, these prepared CPN poorly supported cell adhesion, probably due to the high degradation rate of the materials.

A comparative study of surfactant adsorption by clay minerals

Abstract The adsorption of surfactants from aqueous solutions in porous media is essential in enhanced oil recovery (EOR) from oil reservoirs. Surfactant loss that is due to adsorption by the reservoir rocks weakens the efficiency of the chemical slurry that is injected and decreases the oil–water interfacial tension (IFT). This project investigated the effect of the mineralogical composition of adsorbents on adsorption. The experiments were conducted in batches. Adsorbents were composed of various combinations of quartz sand and clay minerals at various percentages and were exposed to nonionic and anionic surfactants. The amount of surfactant that was adsorbed was quantified by subtracting the concentration of surfactants after adsorption from the initial concentration. We observed a direct relationship between the adsorption of the nonionic surfactant and the amount of clay minerals in the adsorbents as the amount of surfactant that was adsorbed by the adsorbents increased when the percentage of clay minerals in adsorbents increased (from 5% to 20% in the mixture). The rank order of adsorption power of clay minerals for the nonionic surfactant was montmorillonite⪢illite>kaolinite. Adsorption of the anionic surfactant by all adsorbents was negligible.

Adsorption Of Nonionic Surfactants On Clay Minerals

The adsorption of surfactants from aqueous solutions in porous media is very significant in the enhanced oil recovery (EOR) of oil reservoirs. Surfactant loss due to adsorption on the reservoir rocks weakens the efficiency of the chemical solution injected to decrease the oil–water interfacial tension (IFT). This study investigated the effect of the mineralogical composition of adsorbents on adsorption. Nonionic surfactants were injected into sand packs in which different amounts of clay minerals (kaolinite and illite) were added and compacted in a sand pack holder. The amount of surfactant adsorbed was quantified by subtracting the concentration of surfactants after adsorption from the initial concentration. It was concluded that there is a relationship between the adsorption of nonionic surfactants and the amount of clay mineral in the adsorbents because the quantity of surfactant adsorbed by adsorbents increased when the percentage of clay mineral in the adsorbents increased (from 2 to 8% in the sand packs). The clay mineral illite has a stronger adsorption power for nonionic surfactants than does kaolinite. Key words: Adsorption, reservoir rock minerals, clay minerals, nonionic surfactants

Hydric Properties of Some Spanish Building Stones: A Petrophysical Interpretation

ABSTRACTThe hydric properties of three types of building stone used in certain Spanish monuments of outstanding historical-artistic value have been determined. The stones selected were dolomite, limestone and sandstone used in the cathedrals of Leon (northern Spain), Seville (southern Spain) and Salamanca (central Spain) respectively.In the work described in this paper, different rock properties related to water were measured (absorption of water and water vapour, evaporation, capillarity and permeability to water vapour). Swelling characteristics of the sandstone were also determined.The close correlation between the values of the parameters obtained for each property analyzed and the mineralogical-textural features of the rock, notably the porosity and form of the pore system, has been also demonstrated. In these stones, it has been observed that water absorption capacity is linked both to the volume of empty communicating spaces (open porosity) and to the presence and percentage of clay minerals.

Sedimentological interpretation of the Albian Nahr Umr Formation in the United Arab Emirates

In the United Arab Emirates, the Nahr Umr Formation (Albian) comprises a series of varicoloured shales, siltstones and mudstones, with increasing carbonate content toward the northern United Arab Emirates. The percentage of clay minerals in the shale ranges from 62% to 73%, while the non-clay fraction 50 is dominated by calcite, quartz and traces of dolomite, feldspar pyrite, glauconite and phosphate. The formation ranges in thickness from 63 to 220 m (200–700 ft) and forms an excellent cap rock to the major Aptian 5030 reservoirs. Geochemical studies indicate that the shales have no oil or gas generating potential; the total organic carbon content ranges from a low of 0.20% to a high of 0.50%. These sediments were deposited in a shallow marine to distal offshore shelf setting.

Varieties of Chlorites and Illites and Porosity in Mississippian Sandstone Reservoirs in the Illinois Basin

Shallow marine, Mississippian, siliclastics in the Illinois basin, although predominantly quartz, contain other minerals that directly influence the porosity and permeability of these reservoir rocks. These sandstones contain more chlorite and kaolinite, relative to illite, than the authors have observed for shales from other Chesterian and Valmeyeran strata. Clay mineral suites in reservoirs appear to be diagenetic. The Aux Vases Sandstone contains illite, illite/smectite, and chlorite; kaolinite is absent. The Cypress Sandstone contains illite, illite/smectite, chlorite, and kaolinite. Chlorite in the Aux Vases Sandstone varies from moderately Fe-rich to Mg-rich, whereas the chlorite in the Cypress Sandstone is uniformly Fe-rich. As the percentage of clay minerals in these rocks decreases, the proportion of chlorite to other clay minerals increases. In some chlorites, the width of the 003 and 005 peaks at half-height is greater than that of the 002 and 004 peaks. This suggests an interlayering of a 7{angstrom} mineral, probably berthierine- or serpentine-like. SEM photos show chlorite coating quartz grains. In some samples there are quartz overgrowths in spite of the presence of a coating of chlorite; in others, chlorite interlayered with the 7{angstrom} phase seems to have interfered with or suppressed overgrowths. Correspondingly, there is a correlation betweenmore » the 7{angstrom} phase/chlorite and porosity. Therefore, identification of the type of chlorite in a potential reservoir may be an indicator of porosity, as well as a guide for selecting completion and stimulation treatments.« less

THE NATURE OF SMECTITES IN SOME FINE TEXTURED LACUSTRINE PARENT MATERIALS IN SOUTHERN SASKATCHEWAN

Detailed mineralogy and chemistry of the clay fraction of five glacio-lacustrine deposits and of one Cretaceous marine shale (Ashville) were studied. Fine clay separates (< 0.2 μm) of the five parent materials were predominantly smectite with an average chemical composition:[Formula: see text]X-ray diffraction, dehydration, infrared, and chemical analyses, and the Greene-Kelly test showed that the smectite was an iron rich montmorillonite. Similarities in the crystal structure of the five soil parent material clays suggest that they were likely transported from the same source. Despite the differences in percentage of clay minerals, similarities between chemical composition of the coarse and the fine clays is interpreted as an indication of close diagenetic relationships between the predominant smectite and soil mica. High silicate bound iron may have caused a distortion in the crystal lattice and a slightly favorable weathering condition of smectites. However, presence of high exchangeable and soluble magnesium in the soil complex is likely retarding the smectite alteration. Thus, weathering by elemental substitution may have been restricted to the smectite end member only. Key words: Swelling clay soils, iron montmorillonite, chemical composition of smectites, dehydration of smectites

Cenozoic Clay-Mineral Stratigraphy in South Philippine Sea, DSDP Legs 59 and 60: ABSTRACT

On DSDP Legs 59 and 60, sites were drilled in the South Philippine Sea along an east-west transect at 17°N lat. Clay minerals from Cenozoic samples at DSDP sites 447A, 449, 450, 452, 453, and 454A were analyzed by X-ray diffraction methods. A semiquantitative determination of the percentages of clay minerals was made for each sample. In addition, illite crystallinities and relative iron contents in illites and chlorites were analyzed using X-ray diffraction data. At site 447A, on the western flank of the Palau-Kyushu Ridge, the drill penetrated an undated surficial clay zone into underlying early Miocene pelagic clay. The clay is smectite-rich (averaging 95% smectite). The remaining percentage is almost evenly divided between crystalline illite, relatively low-iron chlorite, and kaolinite, all of which reflect detrital input from the Chinese mainland. Site 449, on the eastern ridge flank, yielded a thick pelagic clay sequence ranging from an undated cover down through middle Miocene to upper Oligocene clays. An increase in smectite content during the late middle Miocene resulted from ash deposition due to volcanism on the West Mariana Ridge. Below this zone, in older middle Miocene clays, the content of chlorite, illite, and kaolinite increases considerably relative to smectite. The mineralogic change is associated with radiolarian-rich deposits of the same age. This change could mark a northward shift in the equatorial counter-current associated with increased boundary-current circulation that occurred at this time. Pelagic clays from the other sites in the Parece Vela Basin, Mariana Trough, and Mariana Trench are smectite-rich owing to the ash content of the sediment. However, stratigraphic interpretation of the Mariana Trough End_Page 413------------------------------ and Trench sediment is limited because the pelagic clay units consist only of thin Quaternary veneers. End_of_Article - Last_Page 414------------

Increasing rate of movement with time between California and the Pacific Plate: From Delgada Submarine Fan source areas

Changes in the percentages of clay minerals and coarse fraction minerals with depth in Deep Sea Drilling Project cores from Delgada submarine fan suggest that the rate of motion between California and the Pacific plate has increased with time during the past 15 m.y. The major changes in mineralogy indicate changes in provenance. The times of these changes found in fan sediment and palcogeographic lithologic reconstructions of California demon- strate an increase in rate of motion from about 3.0 cm/yr 15 m.y. ago to 6.5 cmfyr at preent. During the time interval of 4-9 m.y. ago the data suggest a rate of motion of 4.5 cm/yr. Rates of motion between lithospheric plates are of major concern in determining the quan- titative nature of the dynamic earth system. Spreading centers as plate boundaries have been emphasized in the study of rates of motion. Rates of movement in these areas are usually calculated from the apparent age of basement rock, as deduced from the geomagnetic time scale of Heirtzler et al. (1968), and the dis- tance between rocks of different deduced ages. Studies of the SaN Andreas fault, a transform fault plate boundary, have considered move- ment between the Pacific and the American plates primarly in terms of a constant rate of motion with time (Dickinson and Grantz, 1968; Atwater, 1970; Hayes and Pitman, 1970). Such an extrapolation of a constant rate of motion with time was necessary because of poorly understood dynamics of a transform fault plate boundary and magnetic anomalies representing only the last 4 m.y. of history between these two plates (Anderson, 1971; Larson et al., 1968). Possibilities of variable rates of motion with time are discussed by Atwater (1970), Dickinson et al. (1972), and Hein (1973). Hu.f)- man (1972), working within the San Andreas fault zone and therefore not necessarily mea- suring total relative motion between the Pacific and the American plates, suggests a change in the rate of motion of the San Andreas fault sometime in the last 22 m.y. Larson (1972), from a study of the Gulf of California and from the results of previous studies, suggests a signifi- cant change in motion of these two plates 10 m.y. ago. Frerichs and Shive (1971) speculate about episodic movement on spreading centers with an increase in spreading rate 10 m.y. ago, although they are not concerned specifically with the American and Pacific plates. Talwani et al. (1971) provide concrete evidence, from distribution of sediment, of an increase in spreading rate at 10 m.y.B.P. in the North Atlantic. This paper concerns a method by which the history of relative movement can be determined between California and the Pacific

Abrasion pH, an Index of Chemical Weathering

AbstractIf a series of rock samples with granitic composition in various stages of chemical weathering is ground in a mortar with distilled water and the pH of the slurry produced is determined, it will be evident that the pH declines as the weathering increases. This relationship can be made useful by plotting abrasion pH against some other index of weathering such as the percentage of clay mineral or the bulk density of the weathered rock. Factors controlling abrasion pH are the cations such as K, Na, Ca, and Mg and the amount of clay mineral present.