Mixed Clay Research Articles

The effect of synthesis parameters on density and thermal conductivity of MMT based aerogel. Application of experimental design model

Aerogels are a class of materials largely composed of air with very low bulk densities. Due to their extremely porous nature, aerogels are very promising materials for thermal and acoustic insulation applications. While their majority described in the literature are silica-based, there are a limited number of references to clay-based aerogels. The abundance of clay and its limited toxicity make them particularly attractive. Clay aerogels formation involves mixing of clay with water, freezing of the suspension and freeze-drying of the frozen gel. This work concerns the use of montmorillonite as a raw material for the synthesis of aeroclays with low density. Clay aerogels were synthesized by mixing montmorillonite clay and water and their density was measured. Various agents were used for the reinforcement of the brittle structure of clay aerogel. A multifactorial experimental design model is applied in order to study the combined effect of synthesis parameters on the density of aeroclays. The thermal conductivity of the optimized sample was determined by means of the Heat Flow method, on a Netzsch HFM 436 lamda Heat Flow Meter. As it is concluded, aeroclays, derived from a solution of montmorillonite clay and water alone were brittle so the addition of reinforcement agent is crucial. Depending on the synthesis conditions, a density range from 0.05 to 0.4 g/cm3 and thermal conductivity in the range of 0.04 W/mK was achieved. The factors with the highest impact on the density of the final product were the content of MMT and reinforcement agent in the precursor solution. The optimized synthesis in terms of density and thermal conductivity was proved to be inflammable.

Assessment of Clay Deposits Quality from East of Erbil, Kurdistan Region, Iraq for some Ceramic Industries

For the assessment of clay deposits for brick manufacturing, seven clay samples from different locations were collected by channel sampling method from Injana, Mukdadiyah, Bai Hassan formations and Quaternary deposits in Bestana village, the study area is located east of Erbil city (NE Iraq). For ceramic manufacturing, the quality of clay should be measured according to some physical properties. The mineralogical and geochemical study revealed by using X-ray diffraction and chemical characteristics, which represented that all clay samples containing; kaolinite, smectite, illite, and chlorite with some mixed clay and non-clay mineral quartz, calcite, dolomite, and feldspar. The physical properties of clay samples including grain size analysis and Atterberg limits showed that the raw materials contain clay in high proportion, silt in medium proportion, and sand in minor proportion. Plasticity index of the studied samples showed that they are moderately plastic to plastic range. The geochemical analysis of the studied samples showed that the clay raw materials are composed mainly of silica and alumina, which act as refractory material in the ceramic industry. In addition to that, there are different proportions of calcium, iron oxides, magnesium, potassium, and sodium, which are flux oxides.

The Effects of Mineral Wool Fly Ash on Cohesive Soil Strength Behaviour

This research work represents updated results of cohesive soil strength improvement with mineral wool fly ash. In the investigations, these materials were used: Portland cement CEM I 42.5 R, fly ash obtained from a mineral wool production process, sand and clay. Mixtures were prepared as follows: dry mixing of Portland cement and fly ash; dry mixing of sand and clay; adding water into Portland cement and fly ash; adding sand and clay mixture into already prepared Portland cement and fly ash suspension. The content of fly ash replacing Portland cement varied from 0% to 40%, and the content of sand mixture varied from 20% to 60%. After 24 hours, investigated samples were taken out from cylinder forms and kept in a desiccator with a humidity of 90% and at 20 °C temperature. Uniaxial compressive strength of the samples was determined after 548 days and compared to previous research results obtained after 7, 28 and 183 days. The most predictable compressive strength is for samples, which composition is 100% cement and 0% fly ash. In these samples, the highest compressive strength was obtained, comparing them to the other investigated samples. Compressive strength change is minimal for samples with a 10–30% amount of fly ash. The most significant decrease in compressive strength was obtained for samples with a 40% fly ash after 183 days. Nonetheless, the compressive strength of these samples increased after 548 days and is almost the same as for samples with 100% Portland cement.

Formulation of an Optimal Mix of Indigenous Clay in Water Well Drilling

Formulation of an Optimal Mix of Indigenous Clay in Water Well Drilling

Strengthening of Subgrade Clayey Soil in Road Construction using Fly ash and Coir Geotextile

The best handicap for a carried-out community of road structures in growing international locations like India is the restricted monetary assets accessible to construct roads the use of traditional methods. By the usage of nearby substances inclusive of neighbourhood grounds for the constructions of the lower layers of the pavements (in precise the subgrade), the development expenses can be extensively reduced. 20% of the land in India is clayey and is expansive in nature. These lands are observed to be steeply-priced to construct and to maintain roads. The use of coir fibre substances in the discipline of civil engineering has led to new methods for stabilisation of soils in particular. A coir fibre (CF) is an herbal cloth that is broadly handy in Coastal India. A certain find out about was carried out in this paper about enhancing the stability, energy and sturdiness of soil clay mixed up with fly ash and coir fibre mat. The sample of the soil used was from the excessive clay region in Andhra Pradesh. The stabilisation was performed with classification C fly ash and grade H2M9 coir mat. The plasticity of clay fly ash mixes is decreased as fly ash content material is increased. Adding fly ash consequently lessens increasing soils and will increase their working-ability via a colloidal response and adjustments in grain size. The supplementation of fly ash led to full-size increase in soil CBR. The consequences exhibit large enhancement in compaction and CBR of composite containing clay, fly ash and coir mat. The CBR value for virgin Andhra Pradesh clayey soil was 6% which improved to 12% for optimal fly ash (15%) –clayey mix. The CBR value was determined through placing coir mat at more than a few depths in ideal fly ash clay mix. The most CBR value acquired was 44% for coir mat positioned at mixture of h/4th and h/2th depth from pinnacle in standard fly ash - clay mix.

Ergonomic Hazards Associated with Brick Making in a Tropical Wetland: The Case of Sironga Wetland, Kenya

Brick production processes involve a lot of manual handling which may lead to several ergonomic hazards. This is due to the nature of the work forcing them to bend or carry loads including frequency, time and weight of the load carried at a time. This study was done with the aim of identifying the ergonomic hazards in the brick making industry and the results compared with the local and international standards on load carrying. Different roles were played in brick production by both men and women. Females were mostly involved in carrying bricks on the head while males were involved in mixing and moulding of clay. However, both male and female workers required exerting force. Results revealed that workers were carrying loads more than 25kg against NOISH (National Institute of Occupational Safety and Health) and (International Labour Organization) ILO which stipulates the maximum weight to be lifted, carried on head or shoulders, pulled or pushed is 25 kg for men and 20 kg for women. Heavy load carrying exposes them to several ergonomic hazards such as musculoskeletal discomfort (MSD) and disability. The study recommends ergonomic intervention

Superior dyes removal by a recyclable magnetic silicate@Fe3O4 adsorbent synthesized from abundant natural mixed clay

Magnetic recyclable polymetallic silicate@Fe3O4 composites with porous structure and superior adsorption capability towards methylene blue (MB) and Cationic yellow (CY) were prepared successfully by a facile one-pot hydrothermal reaction route in the presence of non-toxic Mg(II) and SiO32− ions, using natural clay@Fe3O4 as the main starting materials. We define this reaction process as “all-into-one” conversion reaction, by which the natural clay composed of safe elements (e.g., Si, Al, Mg, Ca) can be converted to new polymetallic silicate. The silicate derived from conversion of natural clay may combine with the magnetic nanoparticles to form a stable magnetic silicate@Fe3O4 composite with the specific surface area of 252.5 m2/g (only 91.9 m2/g for magnetic clay@Fe3O4). The magnetic composite shows the adsorption capacities of 116.1mg/g and 169.5mg/g for MB and CY dyes, respectively, which are higher than that of natural clay (66.0mg/g for MB and 102.5mg/g for CY, respectively). The composite has a specific saturation magnetization of 20.6emu/g, so that it can be quickly separated and recovered from a solution by magnetic field. The structure characterization results of the dye-adsorbed silicate adsorbent indicate that the cooperative action of electrostatic interaction, pore adsorption and chemical association of the SiO groups with the dyes is mainly responsible for improving adsorption capability. The adsorption process obeys the Langmuir isotherm model (R2 > 0.996) and the pseudo-second-order adsorption kinetic model (R2 > 0.998), demonstrating a typical monolayer adsorption and chemical adsorption characteristics.

The indigenous settlement of Monte Iato (western Sicily): an ethnoarchaeometric approach for outlining local Archaic ceramic productions

An ethnoarchaeometric approach has been followed to identify the textural and compositional characteristics of the ceramic pastes produced in ancient Iaitas/Ietas, an indigenous site located in western Sicily on Monte Iato, a few tens of kilometres from Palermo. This approach was primarily motivated by the lack of discovered Archaic kilns or production sites/workshops and the inability to identify reference groups. Raw clays were sampled in the territory of San Cipirello and San Giuseppe Iato (today’s municipalities both sited on the northern slopes of Monte Iato), together with representative historic tiles and bricks locally produced until fairly recently. Grain-size analysis and experimental firings were performed on the clay samples. A significant number of archaeological ceramic samples (incised and painted indigenous pottery dating back to the seventh–fifth centuries BCE) from stratigraphic excavations on Monte Iato, and hypothesized as local productions on a stylistic-morphological basis, was carefully selected for archaeometric analysis. This set of samples (90 in total, comprising raw clays, historic tiles/bricks and archaeological ceramics) underwent a combined chemical and mineralogical-petrographic analysis to identify any possible compositional matching. This approach enabled the identification of minero-petrographic and chemical markers pertinent to the indigenous Archaic pottery produced at Monte Iato, although no evidence of coeval ceramic kilns has been found so far. Local raw clay sources have been documented and some significant points of the chaîne opératoire adopted in antiquity have been noted (clay mixing and tempering practices). Attesting Monte Iato as a centre of ceramic production and defining both the microscopic fabric and the average composition of local pastes open up new perspectives in the complex issue concerning the production and regional circulation of incised and painted indigenous ceramics in Archaic Sicily.

Application of oil-containing gabbro-diabase waste sludge for ceramic products manufacturing

The paper presents research findings of the possibility of recycling and using the oil-containing sludge, generated at water-oil emulsions purification with gabbro-diabase powder, in ceramic constructional products manufacture. It is suggested to add the sludge to clay mass as a mineral and pore-forming admixture. The influence of the added sludge weight on such physical and mechanical parameters of ceramic samples as strength, compressive strength, water absorption, air shrinkage and firing shrinkage values and density was studied. The ceramic samples were prepared using natural clays from the Bessonovka (Belgorod region) and Podgornoye (Voronezh region) deposits. It has been demonstrated that adding the sludge to clay mass in amount of 2% wt. increases the compressive strength of samples by 90%, the air shrinkage by 1%, and water absorption by 1-2%. The firing shrinkage stays the same. At increasing the amount of the added sludge up to 7% all the parameters are slightly changed – water absorption and air shrinkage are increased, compressive strength, firing shrinkage and density are reduced. But further, at 7% sludge content in the clay mix the ceramic samples’ strength meets the grade not lower than 150 by GOST 530-2012.

Upper Paleolithic ceramic figurines and similarities to some late Pleistocene pigment and pottery materials and technologies of Eurasia

Three soft stone technologies that characterize the Upper Paleolithic period are fired ceramic figurines, pigments prepared from colored minerals that often consist of or include clay, and, lastly, pottery vessels. The earliest synthetic material of which we have a permanent artifactual record was made at 26,000 cal BP (Klima 1959b, 1963), marking the beginnings of chemical technology and pyrotechnology and is the concern of the first part of this paper. A review is presented of Upper Paleolithic ceramic figurines at the group of habitation sites in Moravia that includes Dolní Věstonice, Pavlov, Předmosti and Petřkovice. Dolní Věstonice, the only proven production site with the largest collection of ceramics, was the focus of the study because of the possibility of analyzing figurine fragments, kiln remains and raw materials that enabled reverse engineering of the technology. The size of the ceramic inventory and the presence of kilns argue for intentional production of ceramic objects and demonstrates that the relevant cultural practices over time involved repetition and both transmission and learning of a specific, patterned performance behavior of ceramic technology. The high fracture rate encountered and the resistance of the raw material to thermal shock, however, strongly suggest that what was important was not the final, durable product, but rather the process of making and firing and/or refiring of the objects, probably for ritual, ceremonial and political purposes. Similar additive fabrication methods and firing of local pluvial clay deposits was practiced at the site of Maina in Siberia at ca. 15,000 cal BP to make a singular ceramic figurine. At the southern end of the Urals is Kapovaya, a cave with images and a date similar to those at Lascaux and where a single small bowl that may be a fired ceramic was excavated.The second part discusses examples of ceramic processing technology without firing, if we understand ceramics as we define them today to include non-clay products made by processing of fine sub-10 μm, equiaxed or platy particles. Fine clay and pigment particles behave similarly when processed. Clays and pigments were processed at the cave site of Lascaux where excavation of the floor produced evidence of selected, collected and imported naturally occurring mineral and sediment blocks as well as fabricated chalk-like sticks referred to as “crayons.” These ground and fabricated blocks were used as manufacturing elements to apply red, yellow and black pigment to the cave walls at Lascaux. Stone ‘palettes’ were excavated from the floor with in-situ powders that indicate grinding and mixing of clays and pigments. This mixing also occurred on the tips of crayons.The third part is focused on a third ceramic performance technology that preserved physical health of community members: the making and using of pottery vessels for cooking and storage, and a description of some problems involved in reconstructing the processing technology.

Single Well Petrophysical Analysis: A Case Study of Belle Fourche Shaly-Sand, Hatton Gas Field, Southwest Saskatchewan

This case study shows the petrophysical evaluation of the Belle Fourche Formation, Hatton Gas Field, Southwest Saskatchewan, using conventional well log interpretation techniques. The Belle Fourche reservoir analysed is indicated as shaly-sand formation, while petrophysical parameters calculated includes gross thickness, net thickness, volume of shale, porosity, and water saturation. Cross plots, in conjunction with previous core sedimentology study was used to identify lithology as shale dominated by mixed clay. The potassium content remains relatively constant as the clay content increases. In contrast, the thorium content increases with an increase in the clay content presenting thorium potassium ratio of 12, composed of montmorillonite and mixed-layer clay. Shale content increases as the thorium and uranium content increases. Results from the petrophysical evaluation revealed a gross reservoir thickness of 6.36 m, an average net shaly-sand thickness of 2.13 m, an average volume of clay of 13 %, the porosity of 15 %, and average water saturation of 43 %. Rock petrophysics cross plot of density versus P-wave (Vp) velocity was attempted to identify hydrocarbon saturation. The calculated velocities using the Greenberg and Castagna relation indicate slight increase in Vp and a decrease in density in shaly-sand data indicating hydrocarbon saturation in the reservoir interval. This paper has presented conceptually simple petrophysical method, structured in a manner that is easy to understand for a shaly-sand formation evaluation.

Analysis and modeling of bound water adsorption by mixed clay based on adsorption theory

Analysis and modeling of bound water adsorption by mixed clay based on adsorption theory

Mesoporous polymetallic silicate derived from naturally abundant mixed clay: A potential robust adsorbent for removal of cationic dye and antibiotic

Mesoporous polymetallic silicate adsorbents with superior adsorption capability towards methylene blue (MB) and tetracycline (TC) were synthesized by a simple one-pot reaction process. The mesoporous adsorbent was formed from the conversion of the mineral components in natural clay and the simultaneous incorporation of Cu(II) without using additional template agent. The specific surface areas of the adsorbent (348.13 m2/g) reached 5.9 times that of original clay. The optimal adsorbent can adsorb rapidly 289.46 mg/g of MB and 415.56 mg/g of TC; and can remove 99.9% of MB (adsorbent dosage, 1 g/L) and 93.9% of TC (adsorbent dosage, 3 g/L) from 200 mg/L of the original solution. The superior adsorption is resulting from the synergistic action of electrostatic and hydrogen-bonding interaction between negatively charged adsorbent and positively charged MB or TC, the chemical interaction between active -Si-O− groups and MB or TC and the complexing of MB or TC with metallic sites.

Effects of layer-charge distribution on swelling behavior of mixed-layer illite-montmorillonite clays: A molecular dynamics simulation study

One of the intriguing properties of clay minerals is swelling, which is considered an essential characteristic for various geological processes, environmental science, and engineering. Almost all previous experimental and simulation studies focused on the understanding of the swelling behavior of pure clays. The fact is that about 30 percent of all clays are a pure type, and virtually 70 percent of clays are the mixed-layer one that swelling mechanism is still elusive. In this research, molecular dynamics simulations were used to exclusively investigate the effect of layer charge distribution on the crystalline swelling and hydration behavior of the most common types of mixed clays, so-called illite-montmorillonite mixed-layer clay (I-Mt MLC) with Na+ and K+ counterions in the presence of different water concentrations. Based on the results, we found that the layer charge density and charge location of both illite and Mt significantly influenced the I-Mt clays' swelling behavior. Regardless of Mt charge density, the presence of highly charged illite led to powerful interactions of counterions with the surface sheet, resulting in less swelling behavior of the I-Mt system. Also, the various polarization power of clay surface due to the difference in charge distribution of octahedral sheets had a significant influence on water molecules and interlayer cations interaction with clay surface, which affected the swelling behavior of I-Mt clays. Overall, our findings demonstrated the new insight into I-Mt clays' swelling behavior, which is a function of charge distribution of both illite and Mt.

Intentional clay-mixing in the production of traditional and ancient ceramics and its identification in thin section

Ethnographic and historical accounts have indicated that traditional potters intentionally mix two or more sources of clay in order to prepare composite pastes for pottery production. It has long been assumed that a such practice also took place in the past, but detecting evidence for clay mixing in ancient ceramic sherds has proved challenging due to thorough blending, as well as the existence of natural heterogeneity within clay sources. Very few detailed studies on clay mixing exist within the fields of ceramic petrography and ancient pottery technology, and both diagnostic criteria and descriptive terminology are therefore poorly defined. The present paper attempts to fill this gap in our knowledge by reviewing the methods of clay mixing from ethnographic sources as well as archaeologists attempts to identify it in thin section. By studying naturally heterogeneous clay under the polarising light microscope and experimentally mixing pastes according to the various methods reported ethnographically, the study attempts to identify possible lines of evidence with which to detect intentional clay mixing in ancient ceramics. These are then applied to archaeological ceramic sherds from a range of periods and geographic regions. The study reaffirms the difficulties in identifying intentional mixing, which can result in a diverse set of compositional and microstructural phenomena that may also occur naturally, and proposes additional criteria with which to distinguish these two processes. It also highlights the overlap between clay mixing and the technological practice of adding non-plastic temper to the clay body.

ARCHAEOMETRIC ANALYSES ON PRECUCUTENI-TYPE POTTERY FROM TRANSYLVANIA (ROMANIA). CASE STUDY: ALBA IULIA-LUMEA NOUĂ

The aim of this paper is to find out - for the first time - through archaeometric analysis the provenance of the Precucuteni-type pottery from Alba Iulia-Lumea Nouă settlement and whether it has a local origin or is an imported ceramic. The presence of so-called Precucuteni-type pottery in Transylvanian sites, decorated by motifs using excision techniques, represents one of the most challenging debates related to the understanding of the material culture that belongs to Early Eneolithic human communities in the Intra-Carpathian area. A combination of non-invasive / micro-destructive analytical techniques and statistical methods were applied to provide comprehensive information about the studied fragments. In this respect, ten pottery samples were investigated to establish the elemental and molecular composition, as well as its origin. Overall, the analytical and statistical analyses show us that the local production of pottery is predominant, with a limited presence of imports. In summary, nine ceramic fragments out of all analyzed samples belong to the same group, with a strong correlation between them, confirming that they are locally made, while one sample can be considered as imported from elsewhere or obtained through mixing clay with some existing soils in the area during the pottery production stage.

Use of kaolinite clays in development of a low carbon MgO-clay binder system

Magnesium oxide based cements may provide a promising alternative to the conventional Portland cement in many applications. This study investigates the feasibility of using calcined kaolinitic clay to produce an MgO binder. The MgO-based binder were prepared using a low kaolinite content clay and metakaolin and were compared with a silica fume system. Implications of the addition of magnesium carbonate in the binder were also investigated. Isothermal calorimetry, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) were used to study the hydration characteristics of the binder system whereas compressive strength and porosity were measured to determine mechanical and durability attributes. The economic and environmental aspects of the binder system is also discussed. Hydrotalcite like phases were clearly produced on hydration in the clay mixes containing carbonate additions. The compressive strength of clay mixes was at par or better compared to systems containing silica fume, and the clay systems had significantly lower porosity levels. The presence of magnesium carbonate further enhanced the physical properties of the clay mixes.

Synergistic Effect of Combined Additions of Clay and Complex Organomineral Thinner (COMT) in Ceramic Concrete Technology (Review Article)

The exceptional efficiency of combining clay additives with introduction of thinning additives of a complex organomineral thinner (COMT) is observed. Values of 14 – 15% initial porosity of compacted high-alumina ceramic concrete with a compaction pressure of 30 MPa are achieved. Depending on mix composition and clay additive content with a comparable moisture content during static compaction material porosity with the addition of COMT is approximately equal to that of material without the additive under a compaction pressure, 3 – 6 times lower than that on material with additive.

An in vitro Method to Determine Intestinal Bioavailability of Glucosamine Salt Mixture

Glucosamine is an amino sugar commonly used to improve joint health. It is often available for consumers as specialized supplements, the matrixes of which are formulated with components that facilitate enhancing functionality of the bioactive glucosamine. The primary objective of this study was to determine the in vitro bioaccessibility and bioavailability of a commercial glucosamine sulphate supplement, formulated with a mineral clay mixture. We used a modified a 3-step in vitro digestion procedure that included oral, gastric, and gastrointestinal digestions to assess bioaccessibility. Bioavailability followed using a Caco2 cell permeability test. Glucosamine bioaccessibility was not affected by gastric digestion and only marginally affected by gastrointestinal digestion (e.g., > 90% recovery). Bioavailability was dramatically lower, averaging approximately 15%, but similar for both the glucosamine reference standard and clay mineral mix glucosamine formulated product. Our in vitro bioavailability measurement of glucosamine, corrected for bioaccessibility, agree with values from in vitro rodent models. We conclude that the in vitro 3-step digestion of glucosamine, used to mimic gastrointestinal digestion, followed by the Caco2 permeability assay represents an alternative method to assess digestibility and bioavailability of formulated glucosamine products. Keywords: Glucosamine; Clay Mineral Mix; Bioaccessibility; Bioavailability

УСТОЙЧИВОСТЬ К СУФФОЗИИ ПРЕССОВАННЫХ БЛОКОВ ИЗ МОНТМОРИЛЛОНИТОВЫХ ПОРОШКОВ

The pressed blocks made of mixes of Cambrian clay and bentonite were examined depending on montmorillonite content in those blocks. It was established that compositions with montmorillonite content in the range of 40-60 wt. % have the minimum suffusion rate