Cement Minerals Research Articles

Impact of High-Performance Expansion and Shrinkage-Reducing Agents on the Mechanical Properties and Shrinkage Compensation of High-Strength Concrete

A large number of binder ingredients such as cement and active mineral admixtures are used in the preparation of high-strength concrete, and the water:binder ratio is extremely low. This leads to a large amount of shrinkage of concrete at the early stage of curing, which poses a great threat to the safety and durability of the structure. To solve the cracking problem of high-strength concrete induced by high shrinkage, we choose to change the admixture to solve it. In this study, a high-performance expansion agent (HPEA) and shrinkage-reducing agent, which are currently studied in a small number, were selected by changing the way of admixture, and their effects on the strength and shrinkage of high-strength concrete were compared and analyzed. The results show that the addition of a HPEA is beneficial to the compressive strength of concrete and sufficient expansion can be obtained by using a high amount of HPEA, but there is an excessive and delayed expansion to produce cracks in the later stage. A shrinkage-reducing agent plays an adverse role in the development of concrete strength, but it performs better in inhibiting shrinkage. The combination of a HPEA and shrinkage reducing agent can largely avoid the formation of cracks, and the two have a certain synergy. The main reason is that a HPEA compensates for some of the negative effects of a shrinkage-reducing agent on concrete strength, and the shrinkage-reducing agent further strengthens the inhibition effect of a HPEA on concrete shrinkage, and to some extent avoids the risk of cracks caused by delayed expansion caused by admixture problems.

Influence of Grain‐Scale Properties on Localization Patterns and Slip Weakening Within Dense Granular Fault Gouges

AbstractFault zones are usually composed of a granular gouge, coming from the wear material of previous slips, which contributes to friction stability. When considering a mature enough fault zone that has already been sheared, different types of infill materials can be observed, from mineral cementation to matrix particles that can fill the remaining pore spaces between clasts and change the rheological and frictional behaviors of the gouge. We aim to understand and reproduce the influence of grain‐scale characteristics on slip mechanisms and gouge rheology (Riedel bands) by employing the discrete element method. A 2D‐direct shear model is considered with a dense assembly of small polygonal cells of matrix particles. A variation of gouge characteristics such as interparticle friction, gouge shear modulus or the number of particles within the gouge thickness leads to different Riedel shear band formation and orientation that has been identified as an indicator of a change in slip stability. Interpreting results with slip weakening theory, our simulated gouge materials with high interparticle friction or a high bulk shear modulus, increase the possible occurrence of dynamic slip instabilities (small nucleation length and high breakdown energy). They may give rise to faster earthquake ruptures.

Diagenetic Evolution and Its Impact on Reservoir Quality of Tight Sandstones: A Case Study of the Triassic Chang-7 Member, Ordos Basin, Northwest China

The Upper Triassic Chang-7 Member of the Ordos Basin contains typical tight sandstone reservoirs. Reservoir quality is affected by diagenesis, which is a critical factor in tight oil exploration. In this study, the Chang-7 Member tight sandstones were studied by a variety of experimental methods, including thin sections, scanning electron microscopy (SEM), and X-ray diffraction (XRD), to determine the reservoir characteristics and diagenesis and discuss their influences on the reservoir quality. The Chang-7 Member sandstones are mainly lithic arkose and feldspathic litharenite with an average porosity and permeability of 7.17% and 0.13 mD, respectively. The pore type is mainly primary intergranular pores, and the secondary pores are feldspar dissolved pores, which are relatively developed, with pore radii of 2–20 µm. Diagenesis of Chang-7 Member tight reservoirs mainly includes compaction, quartz cementation, carbonate cementation, clay mineral cementation, and dissolution. The diagenetic stage develops into Mesodiagenesis A. The average porosity loss from compaction and cementation of sandstone in the Chang-7 Member is 15.93% and 18.67%, respectively. With the increase in burial depth, the porosity and permeability of the reservoir gradually decrease. In mesodiagenesis, the authigenic illite and carbonate cementation compacts the reservoir. The acid fluid carried by the two stages of oil and gas filling during diagenesis dissolved feldspar and carbonate cement, which plays a certain role in transforming the tight reservoir.

Effect of high temperature tempering on the phase composition and structure of steelmaking slag

Abstract Blast furnace slag and steelmaking slag, as the main accessory products of iron and steel smelting, are piled up in large quantities due to their huge output, high treatment difficulty and low comprehensive utilization rate, which has a serious impact on the land and environment. In order to improve the comprehensive utilization of steelmaking slag, low basicity blast furnace slag was added to the existing steel slag for quenching and tempering. The influence of basicity on the chemical composition and phase precipitation of mixed slag was analyzed. In the research process, the phase composition and morphology of blast furnace slag and steel slag of Baotou Steel were analyzed using FactSage7.1 thermodynamic calculation software, ZEISS high-resolution scanning electron microscope (SEM), modern fast high-resolution Bruker energy dispersive spectrometer and AMICS-Mining automatic mineral analysis software. The results show that the mineral phase composition of blast furnace slag is mainly calcium aluminum yellow feldspar and that of steelmaking slag is mainly dicalcium silicate(C2S), magnesium-iron phase solid solution, rose pyroxene and calcium iron aluminate. When the basicity of the mixed slag is 2.0, it can effectively inhibit the formation of non-cementitious mineral anorthite and promote the formation of better cementitious mineral C2S. At the same time, it is found that the melting temperature of mixed slag decreases with the increase in Al2O3 content.

Effect of CO2-Brine-Rock Interactions on the Pore Structure of the Tight Sandstone during CO2 Flooding: A Case Study of Chang 7 Member of the Triassic Yanchang Formation in the Ordos Basin, China.

CO2 flooding is an effective technique to enhance oil recovery from tight sandstone reservoirs. The CO2-rich fluid reacts with the in situ minerals and results in the corrosion and precipitation of minerals in the sandstone, affecting the connectivity and morphological features of pores. However, the diagenesis of the tight sandstone is complex, and the structural modification behavior and mechanism in different lithofacies of tight sandstone during CO2 flooding are still unclear. This study combined CO2 flooding, thin-section casting, scanning electron microscopy, nuclear magnetic resonance, X-ray diffraction, and fractal analysis methods to investigate the changes in the pore structure of tight sandstone after CO2 flooding. The results show that the cement of the tight sandstone is complex and diverse. The tight sandstone can be divided into two types of lithofacies: clay cementation (CL) and ferrocalcite cementation (CA). The mineralogical alterations occur differently in each lithofacies of tight sandstone. Alterations in the cement minerals affect the pores morphology of tight sandstone depending on their mineralogical structure and texture, and the CO2 flooding mainly changes the micromorphology and heterogeneity of large pores. Clay minerals dominate the cement in the CL lithofacies of tight sandstone. The dissolution mainly occurs in small pores because the precipitation of new minerals and exfoliation of skeleton particles partially block large pores and transform them into small pores. Thus, the number of small pores of CL lithofacies increases while the number of large pores decreases. Such a phenomenon hinders the increase in porosity and permeability. On the other side, in the CA lithofacies of tight sandstone, the cement is dominated by ferrocalcite, and the dissolution of ferrocalcite is the primary mechanism of mineralogical alteration. As the ferrocalcite dissolution expands, it creates new flow paths, improving the connectivity of pores. The petrophysical properties of CA lithofacies improve significantly after CO2 flooding. There is a crucial need to study the changes in diagenetic characteristics of tight sandstone due to CO2 flooding. Such type of study provides insights related to the improvement and evaluation of the development of tight sandstone reservoirs during CO2 flooding.

Predicting mechanical development of mine functional mortar: experiment and thermodynamic analysis

Shotcrete mortar is an imperative material for tunnel surface supporting. The mine environment with different temperature affects the mechanical development of mortar, resulting in a difficult to predict its compressive strength development at high temperature. In this investigation, the compressive strength, hydration heat, mineral evolution, pore content of mortar samples at 20 and 60 °C, containing partial steel slag powder, were comprehensively compared by experiment and simulation in order to provide a reliable approach for underground materials compressive strength prediction. Results show that the compressive strength development of the samples cured at 20 and 60 °C, is consisted with the corresponding cumulative hydration heat, and the correlation coefficient is higher than 0.96. The hydrates and heat of the samples are significantly affected by the cement type, mineral admixture, and temperature. Indeed, increasing temperature significantly accelerates the minerals’ hydration and heat release. Combining the composition, pore and single mineral hydration heat simulation, the mortar compressive strength development of the mortar in deep mine can be predicted by a thermodynamic model.

Importance of amorphous content, surface energy, and preferred orientation on the accurate quantification of cement minerals in clinkers

In this study, a quantitative phase analysis of nine different clinkers was performed using X-ray diffraction (XRD). Density function theory simulation was also used to support the observed phenomenon of the micro-grinding-induced variation of the preferred orientation effect on certain mineral phases. Regardless of the micro-grinding, the amount of ferrite solid solution (C4AF) phase was overestimated in the quantitative XRD (QXRD) result when amorphous content was excluded during the QXRD analysis. Meanwhile, when the amorphous content was considered, a reasonable amount of C4AF phase was obtained in the clinker with the micro-grinding. Although the phase transition of the alite (C3S) (M3) phase to the nano-crystalline phase was observed during micro-grinding, the well-refined preferred orientation was confirmed at the C3S (M3) peaks. Thus, it was revealed that these crystallographic effects induced by micro-grinding can contribute to the accurate quantification of clinker materials.

Sustainable Composites from Waste Sulfur, Terpenoids, and Pozzolan Cements

Sulfur cements have drawn significant attention as binders because sulfur is a byproduct of fossil fuel refining. Sulfur cements that can be formed by the vulcanization of elemental sulfur and plant-derived olefins such as terpenoids are particularly promising from a sustainability standpoint. A range of terpenoid–sulfur cements have shown compressional and flexural properties exceeding those of some commercial structural mineral cements. Pozzolans such as fly ash (FA), silica fume (SF), and ground granulated blast furnace slag (GGBFS) and abundant clay resources such as metakaolin (MK) are attractive fines for addition to binders. Herein, we report 10 composites prepared by a combination of sulfur, terpenoids (geraniol or citronellol), and these pozzolans. This study reveals the extent to which the addition of the pozzolan fines to the sulfur–terpenoid cements influences their mechanical properties and chemical resistance. The sulfur–terpenoid composites CitS and GerS were prepared by the reaction of 90 wt% sulfur and 10 wt% citronellol or geraniol oil, respectively. The density of the composites fell within the range of 1800–1900 kg/m3 and after 24 h submersion in water at room temperature, none of the materials absorbed more than 0.7 wt% water. The compressional strength of the as-prepared materials ranged from 9.1–23.2 MPa, and the percentage of compressional strength retained after acid challenge (submersion in 0.1 M H2SO4 for 24 h) ranged from 80–100%. Incorporating pozzolan fines into the already strong CitS (18.8 MPa) had negligible effects on its compressional strength within the statistical error of the measurement. CitS-SF and CitS-MK had slightly higher compressive strengths of 20.4 MPa and 23.2 MPa, respectively. CitS-GGBFS and CitS-FA resulted in slightly lower compressive strengths of 17.0 MPa and 15.8 MPa, respectively. In contrast, the compressional strength of initially softer GerS (11.7 MPa) benefited greatly after incorporating hard mineral fines. All GerS derivatives had higher compressive strengths than GerS, with GerS-MK having the highest compressive strength of 19.8 MPa. The compressional strengths of several of the composites compare favorably to those required by traditional mineral cements for residential building foundations (17 MPa), whereas such mineral products disintegrate upon similar acid challenge.

Reservoir Characterization and an Integrated Approach of Reservoir Modeling for Miano Gas Field, Middle Indus Basin

The hydrocarbon-bearing formation of Miano gas field belongs to the Early Cretaceous and it is bounded by two shale intervals, which are considered as maximum flooding surfaces (MFS). The hydrocarbon-bearing interval includes two reservoir units: a tight gas reservoir and its overlying conventional reservoir. Core samples, borehole logs, and well production performance revealed that the two reservoirs present reversed trends in reservoir quality through the gas field without obvious barriers. The average shale volume of the tight gas reservoir changes from 24.3% to 12.2% and the average permeability changes from 32.65 mD to 0.02 mD from the south to north. However, the average effective porosity of the overlaying conventional reservoir increases from 20% to 26% and the average permeability increases from 10 mD to 300 mD. The reversed trends in the two reservoirs lead to challenges in production forecast and development well proposals in the tight gas reservoir. Therefore, reservoir characterization and a predictive reservoir model are essential for further exploitation of Miano gas field. The geological genesis analysis integrating cores, borehole logs, and three-dimensional (3D) seismic data reveals that the producing interval of the tight gas reservoir is tidal-influenced shore facies deposition with intergranular pore space reduced by mineral cementation during burial diagenesis, while the overlaying conventional reservoir is fluvial-influenced deltaic deposition with abundant, well-connected intergranular macropores, which leads to a better reservoir quality. A reservoir model containing both the tight gas reservoir and the conventional reservoir is constructed considering the reservoir nature understanding, and the accuracy of the model is confirmed by reservoir surveillance activities with the simulation model. The study will be critical to the further reservoir development and hydrocarbon production in Miano gas field.

Porosity and permeability correction of laumontite-rich reservoirs in the first member of the Shaximiao Formation in the Central Sichuan Basin

The development of a large amount of laumontite cement in clastic reservoirs generate pseudo fractures at normal temperatures and pressures conditions on the ground surface, causing porosity and permeability values to be significantly higher than the actual values of buried conditions. Taking the first member of the Shaximiao Formation in the Middle Jurassic of the Central Sichuan Basin as an example, this study analyzes the material composition, reservoir porosity and permeability, diagenesis, and other characteristics of reservoirs rich in laumontite using the petrology, geochemistry, porosity and permeability characterization, and overburden pressure porosity and permeability tests and further discusses a method for correcting porosity and permeability at normal temperatures and pressures conditions on the ground surface. The reservoir rich in laumontite in the first member of the Shaximiao Formation in the Central Sichuan Basin primarily comprises lithic arkose sandstone, with porosity ranging from 2.12% to 17.48%, with an average of 10.28%, and permeability ranging from 0.004 to 120.351 mD, with an average of 2.691 mD. There are various types of diagenesis, including laumontite cementation, calcite cementation, siliceous cementation, clay mineral cementation, laumontite dissolution, feldspar dissolution, etc. Laumontite is mainly exhibited as pore filling cementation, and the extensive cementation and dissolution of laumontite are the key factors affecting porosity and permeability of reservoirs. By comparing the porosity and permeability difference between overburden pressure condition and normal temperatures and pressures condition, the influence of granular marginal pseudo fractures on the porosity and permeability of the reservoir is corrected. The corrected porosity and permeability values at normal temperatures and pressures conditions on the ground surface are linearly correlated with those before the correction. In different laumontite content intervals, the permeability of the reservoir rich in laumontite accords with the linear correction correlation. The higher the laumontite content, the smaller the correction coefficient is. Therefore, this correction guarantees accurately predict the porosity and permeability of the reservoir rich in laumontite at normal temperatures and pressures conditions on the ground surface.

Determining Factors of Energy Intensity in the Manufacturing Industry of Provinces in Indonesia

Energy is vital to Indonesia's economic activities in various sectors. Energy plays an important role in the sustainability of the economic structure, which includes is the manufacturing industry. However, limited natural resources are one of the challenges for policymakers. Although energy conservation policies have been implemented in Indonesia since 1982, their enforcement in the manufacturing industry sector has not been solutive in supporting the development of the manufacturing industry in all regions. This study aims to determine the relationship between the development of energy intensity and economic growth in 26 provinces of Indonesia, using the growth and share analysis method from the data the authors have obtained. The results showed that the paper and printed goods, cement, and non-metallic minerals industries are the sub-sectors with high energy consumption. Then, Riau, DKI Jakarta, and West Java provinces are in the dominant quadrant for economic growth, but their energy intensity is in the low/slow quadrant. This indicates that industries in these three provinces have efficient use of energy.

Sedimentology and Diagenetic Evolution of Maastrichtian Fugar Sandstone, Western Flanks of Anambra Basin, Nigeria

Diagenetic studies unravel the different diagenetic processes a rock has been subjected to and this plays an important role in the formation of sedimentary rocks, therefore the detailed study of the sedimentology and diagenetic evolution of the Fugar Sandstone depicts the diagenetic history and the paragenetic sequence of the cements present. The Fugar sandstone is an extension of the Upper Cretaceous Ajali Sandstone unit of the Anambra Basin in South western Nigeria and this study was aimed at understanding the sedimentological and petrographical characteristics of the sandstone with a view to model the sandstone diagenesis. The field study and granulometric analysis results reveals that the sandstones are unconsolidated, friable, fine to medium-coarse grained, poorly sorted, planar and herringbone cross-bedded and exhibits a repeated succession of fining upward cycles with the inferred depositional environment of fluvial to marginal-marine. The samples were analyzed using a range of techniques: X-ray diffraction, X-ray fluorescence and Optical microscope which shows that the sandstone is quartz arenite with an average of 95% quartz consisting of subangular to subrounded grains and this implies that the sandstone is mineralogically matured but texturally immature. Detailed diagenetic study using thin section petrography reveals that the rocks have undergone different diagenetic processes; compaction, cementation, dissolution, alteration and replacement, and the paragenetic order of the cementing minerals were from authigenic quartz which occurs as quartz overgrowth, clay and then Iron oxides which serves as the predominant mineral cements in the rocks.

Chemical recycling of poly(ethylene terephthalate)viasequential glycolysis, oleoyl chloride esterification and vulcanization to yield durable composites

Glycolyzed PET was esterified then vulcanized to produce composites with strength exceeding that of mineral cement. The process may allow replacing environmentally-damaging materials while recycling plastic waste.

Lithology, Pore‐Filling Media, and Pore Closure Depth Beneath InSight on Mars Inferred From Shear Wave Velocities

AbstractWe quantify the volume and distribution of water, cement, sediments, and fractured rocks within the Martian crust beneath NASA's InSight (Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport mission) lander by using rock physics models to interpret shear wave velocities (Vs) measured from InSight data. The models assume that Mars' crust comprises sediments and fractured rocks whose pores and fractures host variable combinations of gas, liquid water, and mineral cements. Measured Vs in the upper crust (0–8 km) can be explained by layers of minimally (<2%) cemented sediments and gas‐filled fractured basalts. Measured Vs in the deeper crust (8–20 km) can be explained by fractured basalts or more felsic igneous rocks (modeled here as 100% plagioclase feldspar) that is unfractured or has up to 23% porosity. Open pores in the deeper crust could host gas, liquid water, and up to 2% cement. Modeled Vs are too low for a seismically detectable ice‐saturated cryosphere in the upper crust and temperatures are too high to freeze liquid water in the deeper crust. Notably, with Vs alone, we are unable to distinguish between liquid water and gas within the pores.

Stabilization of Dredged Materials Using Cement and a Pozzolanic Binder Mineral Additive

In this study, it was aimed to stabilize the dredged materials with low bearing capacity, brought from Edirne, by using cement and pozzolanic binder mineral additives. In the first stage of the study, the geotechnical properties of the dredging materials were determined. Then, the optimum water contents and maximum dry unit weight values of the soil samples without additives and with different additive ratios were found by compaction tests. Pure and additive unconfined compressive samples were prepared with the optimum water contents obtained in the compaction tests. Samples were prepared by adding 8%, 10% and 12% cement and 2% pozzolanic binder additive by weight to the dredged materials. Unconfined compressive tests were performed on the samples at the end of instant, 1-day, 7-day and 28-day curing periods. In addition, soaked CBR, permeability and flexural tests were performed on 12% cement+pozzolanic added samples. As a result of the experiments, with the addition of cement and pozzolanic binder additives in different ratio to the dredged materials, permeability decreased, unconfined compressive strength, soaked CBR values and flexural strength increased significantly.

Evaluation and Technical Requirements of the Initial Anti-Wear Performance of an Emulsified Asphalt Cold Recycled Mixture: A Case Study in Northern China

Considering the initial strength evaluation method of a cold recycled asphalt emulsified mixture, the abrasion test was selected as the evaluation method. The comparison test was designed to determine the key parameters of the test, including the molding method, the curing temperature, the curing relative humidity, and the curing time. The influence of different emulsifiers, the emulsifier dosage, the asphalt dosage, the cement dosage, and the mineral aggregate gradation on the initial anti-wear performance of the mixture was analyzed. The technical requirements for the emulsified asphalt cold recycled mixture were put forward. We analyzed the significance of different influencing factors using analysis of variance. The results shows that the abrasion test is simple and reliable. It can be used to evaluate the initial abrasion resistance of the emulsified asphalt cold recycled mixture. The curing conditions had a great impact on the abrasion loss. With the increase in temperature or the extension of the curing time, the abrasion loss gradually decreased. With the increase in relative humidity, the abrasion loss gradually increased. The testing protocols, namely 25 °C with a relative humidity of 70%, the curing time was 4 h, followed an active Chinese standard (JTG/T 5521). The results indicate that the factors that affect the initial performance of the cold reclaimed mixture of emulsified asphalt are in the following order: cement dosage, cement strength grade, emulsifier type, mineral aggregate gradation, emulsified asphalt dosage, mixture moisture content, and emulsifier dosage. The cement dosage, emulsifier type, and mineral aggregate gradation had significant effects on the initial strength of the cold recycled mixture. An abrasion loss of less than 3.5% was selected as the basis for optimizing the design of the emulsified asphalt cold recycled mixture.

Analysis of Mineral Pigments from the Gnishikadzor Area, Southeastern Armenia

The territory of the Republic of Armenia is very rich with ores and different types of deposits, including resources of natural mineral pigments. They differ by large variation of colours and are represented by painted ores, clays, and earths, among which the most significant is the group of paints with yellow, red and brown shades (ochre). Vayots Dzor Province in South-Eastern Armenia is among the rich areas where painted earths are widely spread. Presence of red and brown ochre are very well visible in the south-western part of the province, in the gorge of the Gnishik River, which is also known as the Noravank Gorge, due to the monastic complex of Noravank located here. Red colour rocks in the area of the Noravank Gorge (Gnishikazdor) represented by the sedimentary strata of the Upper Devonian and are determined by the Famennian Stage (375-359 million years). The samples analysed were taken from the foothills of the Noravank Monastery and analysed by different techniques: Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS); FT-IR spectroscopy; XRD diffraction analysis, which allow to indicate the presence of different elements trough contrast variations (atomic number contrast), to determine spectral ranges where absorption peaks were detected, as well as to perform phase identifications. The results show that the concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. It is composed of a carbonate mineral such as calcite; an amorphous or microcrystalline form of silica such as chert, flint, jasper or an iron oxide or hydroxide such as goethite and hematite. Implementation of such kind of study is valuable for the future comparison of similar finds from the nearby prehistoric archaeological contexts, where inhabitants exploited red ochre as a pig.

Fabrication of bulk hydrophobic cement-based materials with ultra-high impermeability

The internal hydrophobic modification of cement-based material will undoubtedly significantly improve its durability, which is of great significance for prolonging its service life in harsh environments such as the ocean. In this study, a bulk hydrophobic cement-based materials were fabricated mainly based on polydimethylsiloxane (PDMS) and nano-silica (SiO2) as the main components of the composite emulsion. The research results demonstrate that waterborne emulsion of PDMS@SiO2 can be uniformly dispersed and effectively used in cement-based materials. The hydroxyl groups of hydrophobic emulsions can combine with the hydroxyl groups from the hydration surfaces of cement minerals to form hydrogen bonds, which result in mortars with bulk hydrophobicity. In developed cement-based materials, water contact angle can reach an overhydrophobic state with 132°. For developed compositions, the water repellent properties and corrosion resistance have been significantly improved.

Illitization in the Mt. Simon Sandstone, Illinois Basin, USA: Implications for carbon dioxide storage

Clay mineral cementation is one of the most important controls on sandstone reservoir properties. In this paper, the diagenetic history of the Mt. Simon reservoir complex is studied to reveal the origin, timing, and controls of illitization. Samples of sandstone and shale from Mt. Simon reservoir complex were acquired from the Illinois Basin–Decatur Project (IBDP), a CO2 storage demonstration project in the central Illinois Basin. Petrographic, SEM, TEM, XRD analyses and K/Ar age dating were completed to identify the major detrital and diagenetic components of the samples and reveal illite to be the major clay component in all samples. Illitic clay coatings in the lower Mt. Simon reservoir are identified as a major control on reservoir properties by inhibiting major precipitation of authigenic quartz during illitization, resulting in highly permeable sandstone, essential for CO2 storage. The coating box-work morphology and mineralogy are indicative of a detrital smectite origin with subsequent illite growth associated with feldspar dissolution and kaolinite alteration. The mineralogy of bulk material and separate grain size fractions (2–0.6 μm; 0.6–0.2 μm; < 0.2 μm) with illite polytypes 2M1, 1M, and 1Md were quantified and age dated via 40K-40Ar methods. The shales or reservoir seals contain the highest proportions of detrital illite with illite in the lower Mt. Simon Sandstone reservoir identified as solely diagenetic. Two major events of illitization are identified throughout the Mt. Simon with more porous reservoir rock exhibiting the older event from approximately 360 to 315 Ma and tighter sandstone units with reservoir properties too low to be considered reservoir exhibiting illite dates from 250 to 220 Ma. This partitioning of illitization is attributed to varied mineralogy controlled by depositional changes and evolution of the greater basin.

Experimental Investigation of Mineral Particle Deposition in the Cement Production Process.

This study aims to improve the understanding of the formation and prevention of deposits caused by the introduction of alternative fuels in the cement industry. Experiments were conducted with cement mineral materials in a laboratory-scale entrained flow reactor. To simulate the temperature conditions in a cement calciner, two different deposit probe systems were used: a high probe surface temperature (HPST) deposit system with a probe surface temperature range of 700–1200 °C and a low probe surface temperature (LPST) deposit system with a probe surface temperature range of 500–700 °C. The effects of fed materials (raw meal, hot meal, bypass dust), flue gas temperature (700–1200 °C), deposit probe surface temperature (550–1200 °C), gas velocity (0.9–2.7 m/s), and experimental duration (5–60 min) on the deposit formation rate were investigated. The results revealed that the concentration of KCl in the fed materials has a large influence on deposit formation. In HPST experiments with furnace temperatures ranging from 700 to 1100 °C, the bypass dust has a higher deposition rate than hot and raw meals, due to a large amount of K and Cl (>10 wt %) in the bypass dust, which forms melts and increases the stickiness between impacting particles and deposits. In LPST experiments, the presence of KCl facilitated the deposit formation rate by providing a sticky layer on the deposit probe via condensation, resulting in a higher deposition rate of bypass dust than the raw meal. An increase in gas velocity showed a negative effect on the deposit formation rate due to an increase in rebound. The present study suggests that keeping the calciner wall temperature at 900–1100 °C and a low level of KCl content would effectively reduce the deposit formation, thereby increasing the equipment life and reducing the operating cost during cement production.